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| 1 | Terrestrial vegetation carbon sinks in China,1981―2000显示文摘Using China's ground observations, e.g., forest inventory, grassland resource, agricultural statistics, climate, and satellite data, we estimate terrestrial vegetation carbon sinks for China's major biomes between 1981 and 2000. The main results are in the following: (1) Forest area and forest biomass car- bon (C) stock increased from 116.5×106 ha and 4.3 Pg C (1 Pg C = 1015 g C) in the early 1980s to 142.8×106 ha and 5.9 Pg C in the early 2000s, respectively. Forest biomass carbon density increased form 36.9 Mg C/ha (1 Mg C = 106 g C) to 41.0 Mg C/ha, with an annual carbon sequestration rate of 0.075 Pg C/a. Grassland, shrub, and crop biomass sequestrate carbon at annual rates of 0.007 Pg C/a, 0.014― 0.024 Pg C/a, and 0.0125―0.0143 Pg C/a, respectively. (2) The total terrestrial vegetation C sink in China is in a range of 0.096―0.106 Pg C/a between 1981 and 2000, accounting for 14.6%―16.1% of carbon dioxide (CO2) emitted by China's industry in the same period. In addition, soil carbon sink is estimated at 0.04―0.07 Pg C/a. Accordingly, carbon sequestration by China's terrestrial ecosystems (vegetation and soil) offsets 20.8%―26.8% of its industrial CO2 emission for the study period. (3) Considerable uncertainties exist in the present study, especially in the estimation of soil carbon sinks, and need further intensive investigation in the future. | FANG JingYun GUO ZhaoDi PIAO ShiLong CHEN AnPing | 2007 | Science China Earth Sciences2007,50,9: | 188 |
| 2 | Increasing terrestrial vegetation activity in China, 1982—1999显示文摘Variations in vegetation activity during the past 18 years in China were investigated using the normalized difference vegetation index (NDVI) derived from the 3rd generation time series dataset of NOAA-AVHRR from 1982 to 1999. In order to eliminate the effects of non-vegetation factors, we characterized areas with NDVI < 0.1 as sparsely vegetated areas and areas with NDVI ≥ 0.1 as vegetated areas. The results showed that increasing NDVI trends were evident, to varying extents, in almost all regions in China in the 18 years, indicating that vegetation activity has been rising in recent years in these regions. Compared to the early 1980s, the vegetated area increased by 3.5% by the late 1990s, while the sparsely vegetated area declined by 18.1% in the same period. The national total mean annual NDVI increased by 7.4% during the study period. Extended growing seasons and increased plant growth rates ac-counted for the bulk of these increases, while increases in temperature and summer rainfall, and strengthening agricultural activity were also likely important factors. NDVI changes in China ex-hibited relatively large spatial heterogeneity; the eastern coastal regions experienced declining or indiscernibly rising trends, while agricultural regions and western China experienced marked increases. Such a pattern was due primarily to urbanization, agricultural activity, regional climate characteristics, and different vegetation responses to regional climate changes. | FANG Jingyun PIAO Shilong HE Jinsheng MA Wenhong | 2004 | Science China(Life Sciences)2004,47,3: | 109 |
| 3 | Biomass carbon stocks in China's forests between 2000 and 2050:A prediction based on forest biomass-age relationships显示文摘China's forests are characterized by young forest age,low carbon density and a large area of planted forests,and thus have high potential to act as carbon sinks in the future.Using China's national forest inventory data during 1994-1998 and 1999-2003,and direct field measurements,we investigated the relationships between forest biomass density and forest age for 36 major forest types.Statistical approaches and the predicted future forest area from the national forestry development plan were applied to estimate the potential of forest biomass carbon storage in China during 2000-2050.Under an assumption of continuous natural forest growth,China's existing forest biomass carbon(C) stock would increase from 5.86 Pg C(1 Pg=1015 g) in 1999-2003 to 10.23 Pg C in 2050,resulting in a total increase of 4.37 Pg C.Newly planted forests through afforestation and reforestation will sequestrate an additional 2.86 Pg C in biomass.Overall,China's forests will potentially act as a carbon sink for 7.23 Pg C during the period 2000-2050,with an average carbon sink of 0.14 Pg C yr-1.This suggests that China's forests will be a significant carbon sink in the next 50 years. | XU Bing,GUO ZhaoDi,PIAO ShiLong & FANG JingYun* Department of Ecology,College of Urban and Environmental Sciences,and Key Laboratory for Earth Surface Processes of the Ministry of Education,Peking University,Beijing 100871,China | 2010 | Science China(Life Sciences)2010,53,7: | 61 |
| 4 | Multispherical interactions and their effects on the Tibetan Plateau's earth system: a review of the recent researches显示文摘The Tibetan Plateau(TP) is a regional Earth system showing very strong interactions among its lithosphere, hydrosphere, cryosphere, biosphere, atmosphere, and anthrosphere. hese interactions manifest TP's impact on surrounding regions and relect TP's response to the global change. Quantifying the multispherical interactions is critically important to understand the TP environment. Our recent years researches including the ongoing program entitled ‘Tibetan Multi-Spheres Interactions and heir Resource-Environment Signiicance(TIMI)', the completed program entitled. ‘Paleo-Altitudes of Tibetan Plateau and Environment(PATE)', as well as the other relating projects have focused on multidisciplinary research approaches and emphasized on three major pathways: Eurasia-Indian plates collision on deep-Earth dynamics, uplit impact on Earth's mantle–crust dynamics, and contemporary interface on land surface and atmospheric dynamics. Our researches have taken in situ measurement as priority and developed several platforms of data acquisition and analysis, including the platforms of water-phase transformations, and ecosystem observations. Our ield investigations have been conducted to obtain data about stratum, paleontology, paleoenvironment, genetic diferentiation of animals and plants. We have developed conceptual and mathematical models for crust uplit formation, paleoclimate, glacial melt,water–air interface lux, vegetation climate, and soil erosion. We have also assessed the anthropogenic impacts on environment. Our researches have achieved new and reliable redating of the mantle–crust interaction and initial formation of the TP, found the interaction between tectonics and uplit of the TP and resultant paleoaltitude acting as a spreading source; discovered the interaction between the westerlies and Indian monsoon acting as a control chain that dominates the TP's contemporary environment. he scientiic results can play fundamental roles in supporting the TP's resource exploration and societal sustainable development. | Tandong Yao Fuyuan Wu Lin Ding Jimin Sun Liping Zhu Shilong Piao Tao Deng Xijun Ni Hongbo Zheng Hua Ouyang | 2015 | National Science Review2015,2,4: | 35 |
| 5 | Estimation of China’s terrestrial ecosystem carbon sink:Methods,progress and prospects显示文摘China announced its national goal to reach the peak of carbon emission by 2030 and achieve carbon neutrality by 2060,during the General Assembly of the United Nations in September 2020.In this context,the potential of the carbon sink in China’s terrestrial ecosystems to mitigate anthropogenic carbon emissions has attracted unprecedented attention from scientific communities,policy makers and the public.Here,we reviewed the assessments on China’s terrestrial ecosystem carbon sink,with focus on the principles,frameworks and methods of terrestrial ecosystem carbon sink estimates,as well as the recent progress and existing problems.Looking forward,we identified critical issues for improving the accuracy and precision of China’s terrestrial ecosystem carbon sink,in order to serve the more realistic policy making in pathways to achieve carbon neutrality for China. | Shilong PIAO Yue HE Xuhui WANG Fahu CHEN | 2022 | Science China Earth Sciences2022,65,4: | 30 |
| 6 | Future biomass carbon sequestration capacity of Chinese forests显示文摘Chinese forests, characterized by relatively young stand age, represent a significant biomass carbon(C)sink over the past several decades. Nevertheless, it is unclear how forest biomass C sequestration capacity in China will evolve as forest age, climate and atmospheric CO_2 concentration change continuously. Here,we present a semi-empirical model that incorporates forest age and climatic factors for each forest type to estimate the effects of forest age and climate change on total forest biomass, under three different scenarios based on the fifth phase of the Coupled Model Intercomparison Project(CMIP5). We estimate that age-related forest biomass C sequestration to be 6.69 Pg C(~0.17 Pg C a^(-1)) from the 2000s to the 2040s.Climate change induces a rather weak increase in total forest biomass C sequestration(0.52–0.60 Pg C by the 2040s). We show that rising CO_2 concentrations could further increase the total forest biomass C sequestration by 1.68–3.12 Pg C in the 2040s across all three scenarios. Overall, the total forest biomass in China would increase by 8.89–10.37 Pg C by the end of 2040s. Our findings highlight the benefits of Chinese afforestation programs, continued climate change and increasing CO_2 concentration in sustaining the forest biomass C sink in the near future, and could therefore be useful for designing more realistic climate change mitigation policies such as continuous forestation programs and careful choice of tree species. | Yitong Yao Shilong Piao Tao Wang | 2018 | Science Bulletin2018,63,17: | 25 |
| 7 | Altered trends in carbon uptake in China’s terrestrial ecosystems under the enhanced summer monsoon and warming hiatus显示文摘The carbon budgets in terrestrial ecosystems in China are strongly coupled with climate changes.Over the past decade,China has experienced dramatic climate changes characterized by enhanced summer monsoon and decelerated warming.However,the changes in the trends of terrestrial net ecosystem production(NEP)in China under climate changes are not well documented.Here,we used three ecosystem models to simulate the spatiotemporal variations in China's NEP during 1982–2010 and quantify the contribution of the strengthened summer monsoon and warming hiatus to the NEP variations in four distinct climatic regions of the country.Our results revealed a decadal-scale shift in NEP from a downtrend of–5.95 Tg C/yr^2(reduced sink)during 1982–2000 to an uptrend of 14.22 Tg C/yr^2(enhanced sink)during 2000–10.This shift was essentially induced by the strengthened summer monsoon,which stimulated carbon uptake,and the warming hiatus,which lessened the decrease in the NEP trend.Compared to the contribution of 56.3%by the climate effect,atmospheric CO2 concentration and nitrogen deposition had relatively small contributions(8.6 and 11.3%,respectively)to the shift.In conclusion,within the context of the global-warming hiatus,the strengthening of the summer monsoon is a critical climate factor that enhances carbon uptake in China due to the asymmetric response of photosynthesis and respiration.Our study not only revealed the shift in ecosystem carbon sequestration in China in recent decades,but also provides some insight for understanding ecosystem carbon dynamics in other monsoonal areas. | Honglin He Shaoqiang Wang Li Zhang Junbang Wang Xiaoli Ren Lei Zhou Shilong Piao Hao Yan Weimin Ju Fengxue Gu Shiyong Yu Yuanhe Yang Miaomiao Wang Zhongen Niu Rcmg Ge Huimin Yan Mei Huang Guoyi Zhou Yongfei Bai Zongqiang Xie Zhiyao Tang Bingfang Wu Leiming Zhang Nianpeng He Qiufeng Wang Guirui Yu | 2019 | National Science Review2019,6,3: | 24 |
| 8 | Regional differences in the timing of recent air warming during the past four decades in China显示文摘Global surface temperature has dramatically increased in the past decades.It is critical to evaluate such a change using appropriate approaches.The previous studies for assessment of the change usually used overall trends of temperature series(i.e.slopes of simple linear regression of temperature versus year based on a least-square analysis) for entire study period.Temperature trends,however,differ among different periods,i.e.there are often breakpoints in the temperature series.Therefore,the overall linear trend of a temperature series may conceal some of the temporal characteristics of the temperature change.To precisely characterize the temporal and spatial patterns of air temperature change in China,we analyze the annual mean temperature series between the year of 1961?2004 for 536 meteorological stations across China,using piecewise linear regression approach.We found remarkable breakpoints in the annual mean temperature during the study period across the country.The annual mean temperature started to increase in 1984 at a rate of 0.058°C/a at the country level.The year when warming started appeared to be gradually later from the north to the south:temperature increased since the 1970s in the north(north of 40°N),and did not rise until the 1980s in most areas of the south(south of 40°N),with warming starting in 1983 in the Tibetan Plateau.The trends in annual mean temperatures showed a large spatial heterogeneity across China:a relatively small rising with a rate of 0.025-0.05°C/a in the Sichuan Basin,Central China and South China;the greatest increase in some parts of northwest China(i.e.Xinjiang) with up to a rate of 0.1°C/a;and rising at a rate of >0.05°C/a for most regions of the country.The feedbacks of cold waves and snow may be responsible for such regional differences in the timing and rates of warming in China. | WANG ShaoPeng WANG ZhiHeng PIAO ShiLong FANG JingYun | 2010 | Chinese Science Bulletin2010,55,19: | 18 |
| 9 | The impacts of climate extremes on the terrestrial carbon cycle:A review显示文摘The increased frequency of climate extremes in recent years has profoundly affected terrestrial ecosystem functions and the welfare of human society. The carbon cycle is a key process of terrestrial ecosystem changes. Therefore, a better understanding and assessment of the impacts of climate extremes on the terrestrial carbon cycle could provide an important scientific basis to facilitate the mitigation and adaption of our society to climate change. In this paper, we systematically review the impacts of climate extremes(e.g. drought, extreme precipitation, extreme hot and extreme cold) on terrestrial ecosystems and their mechanisms. Existing studies have suggested that drought is one of the most important stressors on the terrestrial carbon sink, and that it can inhibit both ecosystem productivity and respiration. Because ecosystem productivity is usually more sensitive to drought than respiration, drought can significantly reduce the strength of terrestrial ecosystem carbon sinks and even turn them into carbon sources. Large inter-model variations have been found in the simulations of drought-induced changes in the carbon cycle, suggesting the existence of a large gap in current understanding of the mechanisms behind the responses of ecosystem carbon balance to drought, especially for tropical vegetation. The effects of extreme precipitation on the carbon cycle vary across different regions. In general, extreme precipitation enhances carbon accumulation in arid ecosystems, but restrains carbon sequestration in moist ecosystems. However, current knowledge on the indirect effects of extreme precipitation on the carbon cycle through regulating processes such as soil carbon lateral transportation and nutrient loss is still limited. This knowledge gap has caused large uncertainties in assessing the total carbon cycle impact of extreme precipitation. Extreme hot and extreme cold can affect the terrestrial carbon cycle through various ecosystem processes. Note that the severity of such climate extremes depends greatly on their timing, which needs to be investigated thoroughly in future studies. In light of current knowledge and gaps in the understanding of how extreme climates affect the terrestrial carbon cycle, we strongly recommend that future studies should place more attention on the long-term impacts and on the driving mechanisms at different time scales.Studies based on multi-source data, methods and across multiple spatial-temporal scales, are also necessary to better characterize the response of terrestrial ecosystems to climate extremes. | Shilong PIAO Xinping ZHANG Anping CHEN Qiang LIU Xu LIAN Xuhui WANG Shushi PENG Xiuchen WU | 2019 | Science China Earth Sciences2019,62,10: | 16 |
| 10 | The effects of simulated nitrogen deposition on extracellular enzyme activities of litter and soil among different-aged stands of larch显示文摘Aims Nitrogen(N)addition could affect the rate of forest litter and soil organic matter decomposition by regulating extracellular enzyme activity(EEa).The impact of N addition on EEa may differ across different age stands with different organic matter quality.We were interested in whether the impact of N addition on EEa in litter and mineral soil during the growing season was dependent on stand age of a larch plantation in North China.Methods We added three levels of N(0,20 and 50 kg N ha^(−1) year^(−1))in three age stands(11,20 and 45 years old)of Larix principis-rupprech-tii plantation in North China.We measured potential activities of β-1,4-glucosidase(b),cellobiohydrolase(Cb),β-1,4-N-acetyl-glucosaminidase(Nag)and phenol oxidase(Po)in litter(organic horizon)and mineral soil(0-10 cm)during the second growing sea-son after N amendment.We also measured C and N concentrations,microbial biomass C and N,and KCl-extractable ammonium and nitrate in both litter and mineral soil.Important Findings We observed unimodal patterns of EEa during the growing season in all three stands,consistent with the seasonal variations of soil temperature.stand age had a strong effect on EEa in both litter and mineral soil,and this effect differed between litter and mineral soil as well as between different enzymes.N addition did not significantly affect the activities of b or Cb but significantly suppressed the activity of Nag in litter.We also found stand age-specific responses of Po activity to N addition in both litter and mineral soil.N addition suppressed Po activity of the high C:N ratio litters in 20-and 45-year-old stands but had no significant effect on Po activity of the low C:N ratio litter in 11-year-old stand.moreover,N addition inhibited Po activity of the high C:N ratio soil in 20-year-old stand but had no significant impact on Po activity of the low C:N ratio soils in 11-and 45-year-old stands.overall,stand age had a greater effect on EEa in litter and mineral soil compared to 2 years of N addition.moreover,the effect of N addition on Po activity is stand age dependent,which may affect the long-term soil carbon storage in this forest. | Yuecun Ma Biao Zhu Zhenzhong Sun Chuang Zhao Yan Yang Shilong Piao | 2014 | Journal of Plant Ecology2014,7,3: | 14 |
| 11 | Role and effect of vein-transplanted human umbilical cord mesenchymal stem cells in the repair of diabetic foot ulcers in rats显示文摘Diabetic foot ulcer(DFU)is one of diabetic complications,which is frequently present and tormented in diabetes mellitus.Most multipotent mesenchymal stromal cells(MSCs)are capable of immune evasion,providing an allogeneic,ready-to-use,cell product option for therapeutic applications.The beneficial effect of MSCs for the treatment of a variety of traumatic injuries,such as open wounds,has been extensively explored.In this study,a rat DFU model was used to simulate the pathophysiology of clinical patients and to investigate the localization of human umbilical cord mesenchymal stem cells(hUC-MSCs)after intravenous transplantation and its role in DFU healing,so as to evaluate the potential of hUC-MSCs in the treatment of DFU.The diabetic rat model was established by streptozotocin injection,which was used to create full-thickness foot dorsal skin wounds to mimic DFU by a 6-mm skin biopsy punch and a Westcott scissor.The hUC-MSCs were transplanted through femoral vein,and the ulcer cicatrization situation and the fate of hUC-MSCs were evaluated.Our data suggest that intravenously transplantated hUC-MSCs have the ability to migrate and locate to the wound tissue and are helpful to wound healing in DFU rats,partly by regulating inflammation,trans-differentiation and providing growth factors that promote angiogenesis,cell proliferation and collagen deposition.Herein,we demonstrate that hUC-MSC transplantation is able to accelerate DFU healing in rats and transplantation of exogenous stem cells may be a potential strategy for clinical application in DFUs. | Rongfeng Shi Weishuai Lian Yinpeng Jin Chuanwu Cao Shilong Han Xiaohu Yang Suming Zhao Maoquan Li Hui Zhao | 2020 | Acta Biochimica et Biophysica Sinica2020,52,6: | 13 |
| 12 | Plant phenological responses to climate change on the Tibetan Plateau: research status and challenges显示文摘Phenology studies the cycle of events in nature that are initiated and driven by an annually recurring environment. Plant phenology is expected to be one of the most sensitive and easily observable natural indicators of climate change. On the Tibetan Plateau(TP), an accelerated warming since the mid-1980 s has resulted in signiicant environmental changes. hese new conditions are accompanied by phenological changes that are characterized by considerable spatiotemporal heterogeneity. Satellite remote sensing observed widespread advance in the start of the plant growing season across the plateau during the 1980 s and 1990 s but substantial delay over 2000–2011 in the southwest although it continued to advance in the northeast regions of the TP. Both observational studies and controlled experiments have revealed, to some extent, the positive role of higher preseason temperature and even more precipitation in advancing the leaf onset and irst lowering date of the TP. However, a number of rarely visited research issues that are essential for understanding the role of phenology in ecosystem responses and feedback processes to climate change remain to be solved. Our review recommends that addressing the following questions should be a high priority. How did other phenological events change, such as lowering and fruiting phenology? What are the inluences from environmental changes other than temperature and precipitation, including human activities such as grazing? What are the genetic and physiological bases of plants phenological responses?How does phenological change inluence ecosystem structure and function at diferent scales and feedback to the climate system? Investigating these research questions requires, irst of all, new data of the associated environmental variables, and consistent and reliable phenological observation using diferent methodologies(i.e. in situ observations and remote sensing). | Miaogen Shen Shilong Piao Tsechoe Dorji Qiang Liu Nan Cong Xiaoqiu Chen Shuai An Shiping Wang Tao Wang Gengxin Zhang | 2015 | National Science Review2015,2,4: | 13 |
| 13 | Upper Devonian and Lower Carboniferous Sequence Stratigraphy of South China显示文摘In South China four depositional sequences are recognized in the upper part of Upper Devonian and Tournaisian. They are named SQ0 SQ1, SQ2 and SQ3 in ascending order. SQ0 is Strunian (uppermost Devonian), and the other three Tournaisian in age. These four depositional sequences appear to correlate fairly well with the four sequence recognized in Europe, North America and other areas. This may suggest that these sequences are synchronous depos- its resulted from the eustatic changes. The present study on sequence stratigraphy, biostratigraphy and event stratigraphy indicates that in neritic facies areas of South China, the Devonian-Carboniferous boundary, matching the boundary between Siphonodella praesulcata zone and S. sulcata zone in pelagic facies areas, is not only higher than the top of the Cystophrentis zone, but also higher than the top of the Devonian-Carboniferous boundary event bed. In neritic facies areas, the Devonian-Carbonifrerous boundary is marked by the most distinct transgressive surface within the Cystophrentiseudouralina interval zone, i. e. at the base of the TST of the SQ1. This boundary coincides with the top surface of the event bed resulted from the eustatic fall, and approximately corresponds to the basal part of Rseudouralina assemblage zone. | Wang Xunlian Li Shilong (Department of Geology and Mineral Resources, China University of Geosciences, Beijing 100083) Wang Yue (Mineral Office of Dushan County, Dushan 558200) | 1996 | Journal of Earth Science1996,15,1: | 12 |
| 14 | Acupuncture preconditioning protects hippocampal neurons from transient ischemia/reperfusion injury显示文摘The present study established a model of brain ischemia in aged rats using four-vessel occlusion.We observed hippocampal CA1 neuronal apoptosis and apoptosis-mediated protease caspase-3 expression following preconditioning of electroacupuncture at Baihui(GV 20).Our results showed that the number of hippocampal CA1 normal neurons was decreased,and degenerated neurons were increased 12 hours to 3 days following cerebral ischemia/reperfusion.The number of hippocampal CA1 apoptotic neurons and caspase-3-positive neurons in rats with cerebral ischemia/reperfusion injury was significantly decreased following acupuncture preconditioning.Acupuncture preconditioning protects aged rats against ischemia/reperfusion injury by regulating caspase-3 protein expression. | Mingshan Wang Haipeng Zhou Fei Shi Shilong Ma Yanlin Bi Yuqiu Liu Hong Liu Haiou Li | 2011 | Neural Regeneration Research2011,6,15: | 12 |
| 15 | Development of a supercritical and an ultra-supercritical circulating fluidized bed boiler显示文摘The supercritical circulating fluidized bed(CFB)boiler,which combines the advantages of CFB combustion with low cost emission control and supercritical steam cycle with high efficiency of coal energy,is believed to be the future of CFB combustion technology.It is also of greatest importance for low rank coal utilization in China.Different from the supercritical pulverized coal boiler that has been developed more than 50 years,the supercritical CFB boiler is still a new one which requires further investigation.Without any precedentor engineering reference,Chinese researchers have con ducted fundamental research,development,design of the supercritical CFB boilers independently.The design theory and key technology for supercritical CFB boiler were proposed.Key components and novel structures were invented.The first 600 MWe supercritical CFB boiler and its auxiliaries were successfully developed and demonstrated in Baima Power Plant,Shenhua Group as well as the simulator,control technology,installation technology,commissioning technology,system integration and operation technology.Compared with the 460 MWe supercritical CFB in Poland,developed in the same period and the only other supercritical one of commercial running in the word beside Baima,the 600 MWe one in Baima has a better performance.Besides,supercritical CFB boilers of 350 MWe have been developed and widely commercialized in China.In this paper,the updated progress of 660 MWe ultra-supercritical CFB boilers under development is introduced. | Junfu LYU Hairui YANG Wen LING Li NIE Guangxi YUE Ruixin LI Ying CHEN Shilong WANG | 2019 | Frontiers in Energy2019,13,1: | 11 |
| 16 | Complexity of software trustworthiness and its dynamical statistical analysis methods显示文摘Developing trusted softwares has become an important trend and a natural choice in the development of software technology and applications. At present,the method of measurement and assessment of software trustworthiness cannot guarantee safe and reliable operations of software systems completely and effectively. Based on the dynamical system study,this paper interprets the characteristics of behaviors of software systems and the basic scientific problems of software trustworthiness complexity,analyzes the characteristics of complexity of software trustworthiness,and proposes to study the software trustworthiness measurement in terms of the complexity of software trustworthiness. Using the dynamical statistical analysis methods,the paper advances an invariant-measure based assessment method of software trustworthiness by statistical indices,and hereby provides a dynamical criterion for the untrustworthiness of software systems. By an example,the feasibility of the proposed dynamical statistical analysis method in software trustworthiness measurement is demonstrated using numerical simulations and theoretical analysis. | ZHENG ZhiMing MA ShiLong LI Wei JIANG Xin WEI Wei MA LiLi TANG ShaoTing | 2009 | Science in China(Series F)2009,52,9: | 11 |
| 17 | Rational optimization of reprogramming culture conditions for the generation of induced pluripotent stem cells with ultra-high efficiency and fast kinetics显示文摘几个抄写因素的宫外的表示能恢复胚胎的房间命运到有教养的体的房间并且产生导致的 pluripotent 干细胞(iPSCs ) ,揭示到 pluripotency 的一条以前未知的小径。然而,这种技术被低效率,慢动力学和多因素的要求当前限制。这里,我们证明 reprogramming 能被优化文化条件改进并且戏剧性地加速了。首先,我们开发了优化定义媒介, iCD1,它允许 Oct4/Sox2/Klf4 (OSK ) 完成的调停的 reprogramming 超离频效率(~10% 在白天 8 点) 。我们也发现这个优化条件使 Sox2 和 Klf4 变为非必需,尽管这二个因素的消除导致更低的效率和更慢的动力学。我们的研究定义一条弄短的线路,两个在预定和因素要求,向 pluripotency。这个新范例不仅提供一个基本原理进一步改进 iPSC 产生而且由定义因素简化 reprogramming 的概念的理解。 | Jiekai Chen Jing Liu You Chen Jiaqi Yang Jing Chen He Liu Xiangjie Zhao Kunlun Mo Hong Song Lin Guo Shilong Chu Deping Wang Ke Ding Duanqing Pei | 2011 | Cell Research2011,21,6: | 9 |
| 18 | Photonics-based radar with balanced I/Q de-chirping for interference-suppressed high-resolution detection and imaging显示文摘Photonics-based radar with a photonic de-chirp receiver has the advantages of broadband operation and real-time signal processing, but it suffers from interference from image frequencies and other undesired frequency-mixing components, due to single-channel real-valued photonic frequency mixing. In this paper, we propose a photonicsbased radar with a photonic frequency-doubling transmitter and a balanced in-phase and quadrature(I/Q)de-chirp receiver. This radar transmits broadband linearly frequency-modulated signals generated by photonic frequency doubling and performs I/Q de-chirping of the radar echoes based on a balanced photonic I/Q frequency mixer, which is realized by applying a 90° optical hybrid followed by balanced photodetectors. The proposed radar has a high range resolution because of the large operation bandwidth and achieves interference-free detection by suppressing the image frequencies and other undesired frequency-mixing components. In the experiment, a photonics-based K-band radar with a bandwidth of 8 GHz is demonstrated. The balanced I/Q de-chirping receiver achieves an image-rejection ratio of over 30 dB and successfully eliminates the interference due to the baseband envelope and the frequency mixing between radar echoes of different targets. In addition, the desired dechirped signal power is also enhanced with balanced detection. Based on the established photonics-based radar,inverse synthetic aperture radar imaging is also implemented, through which the advantages of the proposed radar are verified. | XINGWEI YE FANGZHENG ZHANG YUE YANG SHILONG PAN | 2019 | Photonics Research2019,7,3: | 9 |
| 19 | Design and Modeling on Stranded Wires Helical Springs显示文摘A stranded wires helical spring is formed of a multilayer and coaxial strand of several wires twisted together with the same direction of spiral. Compared with the conventional single wire spring, the stranded wires helical spring has the notable predominance in strength, damping and vibration reduction, which is usually used in aircraft engines, automatic weapons, etc. However, due to its complicated structure, the precise computation of its strength and rigidity need be a correct mathematical model, which then will be imported to finite element analysis software for solutions. Equations on solving geometric parameters, such as external diameters of strands and screw pitches of wires, are put forward in the paper. It also proposes a novel methodology on solving geometric parameters and establishing entity models of the stranded wires helical spring, which provides foundation of computing mechanical parameters by FEA. Then mathematical models on the centre line of the strand and the surface curve of each wire, after closing two ends in a spring, are proposed. Finally, geometric parameters are solved in a case study, and a 3D entity model of a spring with 3 layers and 16 wires is established, which has validated the accuracy of the proposed methodology and the 3D entity mathematical model. The method provides a new way to design stranded wire helical spring. | ZHOU Jie WANG Shilong KANG Ling CHEN Tianyi | 2011 | Chinese Journal of Mechanical Engineering2011,24,4: | 8 |
| 20 | Dynamical characteristics of software trustworthiness and their evolutionary complexity显示文摘Developing trusted softwares has become an important trend and a natural choice in the development of software technology and applications, and software trustworthiness modeling has become a prerequisite and necessary means. To discuss and explain the basic scientific problems in software trustworthiness and to establish theoretical foundations for software trustworthiness measurement, combining the ideas of dynamical system study, this paper studies evolutionary laws of software trustworthiness and the dynamical mechanism under the effect of various internal and external factors, and proposes dynamical models for software trustworthiness, thus, software trustworthiness can be considered as the statistical characteristics of behaviors of software systems in the dynamical and open environment. By analyzing two simple examples, the paper explains the relationship between the limit evolutionary behaviors of software trustworthiness attributes and dynamical system characteristics, and interprets the dynamical characteristics of software trustworthiness and their evolutionary complexity. | ZHENG ZhiMing MA ShiLong LI Wei WEI Wei JIANG Xin ZHANG ZhanLi GUO BingHui | 2009 | Science in China(Series F)2009,52,8: | 8 |