维普中文期刊产品整合服务
635篇 您的检索式:作者名="Xinghua"
    题名 作者 年代 出处 被引量
1cMyc-mediated activation of serine biosynthesis pathway is critical for cancer progression under nutrient deprivation conditions显示文摘癌症房间被知道经历新陈代谢的 reprogramming 然而,支撑幸存和快速的增长 oncogenic 损害怎么在各种各样的强调条件下面协调新陈代谢的开关,尚待充分被阐明。这里,我们显示出葡萄糖或夫酸安的那剥夺,为癌症房间的二主要营养来源,被伴随由的戏剧性地激活的丝氨酸生合成小径(SSP ) 提高了 cMyc 表示。我们进一步鉴别那 cMyc 刺激了 SSP 激活由 transcriptionally 多重 SSP 酶的 upregulating 表示。而且,我们证明 cMyc 便于的 SSP 激活导致了提高的谷胱甘肽(GSH ) 生产,房间周期前进和 nucleic 酸合成,它在剥夺营养素的条件下面特别为房间幸存和增长是必要的。我们进一步揭开了那 phosphoserine 磷酸酶( PSPH ), SSP 小径的最后的限制率的酶,在 vitro 并且在 vivo 为 驾驶cMyc 的癌症前进是批评的,并且重要地, PSPH 的异常表示高度在 hepatocellular 与死亡被相关癌( HCC )病人,一般来说建议在这 调整cMyc 的酶,或 SSP 激活之间的一种潜在的原因的关系,并且癌症开发。一起拿,我们的结果表明 cMyc 的那异常表情导致提高的 SSP 激活,新陈代谢的开关的必要部分,在剥夺营养素的条件下面便于癌症前进。Linchong Sun Libing Song Qianfen Wan Gongwei Wu Xinghua Li Yinghui Wang Jin Wang Zhaoji Liu Xiuying Zhong Xiaoping He Shengqi Shen Xin Pan Ailing Li Yulan Wang Ping Gao Huiru Tang Huafeng Zhang 2015Cell Research2015,25,4:33
2G-CSF is a key modulator of MDSC and could be a potential therapeutic target in colitis-associated colorectal cancers显示文摘Granulocyte 刺激殖民地的因素(G-CSF ) 是嗜中性的 trafficking 的一个必要管理者并且高度在多重肿瘤被表示。Myeloid 导出 suppressor 房间(MDSC ) 由有免疫力的抑制通过多重机制支持肿瘤的前进。尽管有在结肠癌前进的 G-CSF 功能的调查结果, MDSC 规定上的 G-CSF 和它肿瘤生长上的封锁效果的精确机制仍然是调查的一个相称的区域。在这研究,我们在一只老鼠观察了 G-CSF 的 overexpression 联系大肠炎的癌症(CAC ) 当模特儿,它与在老鼠结肠纸巾的 MDSC 的累积一致。进一步,在 vitro,研究证明 G-CSF 能通过信号变换器和表明小径的抄写 3 的使活跃之物(STAT3 ) 支持 MDSC 幸存和激活。而且与适应于不同地区生活的动物控制相比, anti-G-CSF mAb 治疗表明了减少的 MDSC 累积,它在鼠标在瘤尺寸和数字导致了显著减少。我们的结果显示 G-CSF 是在迁居,增长和 MDSC 的功能维护的一个批评调整分子,它能是为联系大肠炎的癌症的一个潜在的治疗学的目标。Wenbin Li Xinghua Zhang Yongkang Chen Yibin Xie Jiancheng Liu Qiang Feng Yi Wang Wei Yuan Jie Ma 2016Protein & Cell2016,7,2:29
3Genetic diversity of rice cultivars (Oryza sativa L.) in China and the temporal trends in recent fifty years显示文摘To understand geographical distribution of the genetic diversity of rice cultivars {Oryza sativa L.) and its trends in recent fifty years in China, 453 ’ accessions were analyzed by 36 microsatellites loci and 42 phenotypic traits. Results revealed that the genetic diversity by SSRs is highly consistent with that by phenotypic traits and the genetic diversity of indica cultivars was higher than that of japonica cultivars; the genetic diversity of cultivars declined from 1950s to 1980s and then increased greatly; among the six rice ecological zones (REZs), genetic diversity of REZTl was the highest and those of REZV and REZVT were the lowest at both DNA and phenotypic level. Jiangsu and Jiangxi provinces in the middle and lower reaches of Yangtze River and Sichuan province in southwest of China were the areas with the highest genetic diversity. Breeders in REZV which is an important japonica rice area but with very low genetic diversity should explore more gene resources to widen the genetic backgrounds of cultivars.QI Yonawen ZHANG Dongling ZHANG Hongliang WANG Meixing SUN Junli WEI Xinghua QIU Zongen TANG Shengxiang CAO Yongsheng WANG Xiangkun LI Zichao 2006Chinese Science Bulletin2006,51,6:27
4Variation of head and facial morphological characteristics with increased age of Han in Southern China显示文摘We investigated 13940 (6735 male, 7250 female) adult head and facial physical attributes from 19 different Han ethnic groups in 10 southern-China provinces, and calculated 12 head and facial indexes. Indexes were used to analyze the variation of head and facial morphological characteristics with increased age. Results showed that as age increases: (1) Head breadth, minimum frontal breadth, face breadth, interocular breadth, external biocular breadth, lip height, lip thickness, head circumference, auricular height, length-breadth head index, length-height head index, and lip-index values decline significantly in a linear fashion. (2) Nose breadth, mouth breadth, morphological facial height, upper-lip height, physiognomic ear length, physiognomic ear breadth, visor skin-fold, and vertical head-facial index values significantly increase in a linear fashion.LI YongLan ZHENG LianBin YU KeLi LU ShunHua ZHANG XingHua LI YuLing WANG Yang XUE Hong DENG Wei 2013Chinese Science Bulletin2013,58,4:20
5Temporal changes in SSR allelic diversity of major rice cultivars in China显示文摘Forty simple sequence repeats (SSRs) were used to assess the changes of diversity in 310 major Chinese rice cultivars grown during the 1950s-1990s. Of the 40 SSR loci, 39 were polymorphic. A total of 221 alleles were detected with an average of 5.7 alleles per locus (Na). The Nei’s genetic diversity index (He) varied drastically among the loci (0.207 to 0.874, mean 0.625). Comparing the temporal changes in Na and He, the cultivars from the 1950s had more alleles and higher He scores than the cultivars from the other four decades Analysis of molecular variance (AMOVA) indicated that the genetic differentiation among the five decades was not significant in the whole set, but significant within indica and japonica. More changes among the decades were revealed in indica cultivars than in japonica cultivars. Some alleles had been lost in current rice cultivars in the 1990s, occurring more frequently in indica. These results suggest that more elite alien genetic resources should be explored to widen the genetic backgrounds of rice cultivars currently grown in China.Xinghua Wei Xiaoping Yuan Hanyong Yu Yiping Wang Qun Xu Shengxiang Tang 2009Journal of Genetics and Genomics2009,36,6:16
6The herbal compound geniposide rescues formaldehyde-induced apoptosis in N2a neuroblastoma cells显示文摘The herbal medicine Tong Luo Jiu Nao(TLJN)contains geniposide(GP)and ginsenoside Rg1 at a molar ratio of 10:1.Rg1 is the major component of another herbal medicine,panax notoginseng saponin(PNS).TLJN has been shown to strengthen brain function in humans,and in animals it improves learning and memory.We have previously shown that TLJN reduces amyloidogenic processing in Alzheimer’s disease(AD)mouse models.Together this suggests TLJN may be a potential treatment for patients with dementia.Because chronic damage of the central nervous system by formaldehyde(FA)has been presented as a risk factor for age-associated cognitive dysfunction,in the present study we investigated the protective effect of both TLJN and GP in neuron-like cells exposed to FA.FA-exposed murine N2a neuroblastoma cells were incubated with TLJN,its main ingredient GP,as well as PNS,to measure cell viability and morphology,the rate of apoptosis and expression of genes encoding Akt,FOXO3,Bcl2 and p53.The CCK-8 assay,cytoskeletal staining and flow cytometry were used to test cell viability,morphology and apoptosis,respectively.Fluorescent quantitative real-time PCR(qRT-PCR)was used to monitor changes in gene expression,and HPLC to determine the rate of FA clearance.Treatment of N2a cells with 0.09 mmol L?1 FA for 24 h significantly reduced cell viability,changed cell morphology and promoted apoptosis.Both TLJN and GP conferred neuroprotection to FA-treated N2a cells,whereas PNS,which had to be used at lower concentrations because of its toxicity,did not.Our data demonstrate that TLJN can rescue neuronal damage caused by FA and that its main ingredient,GP,has a major role in this efficacy.This presents purified GP as a drug or lead compound for the treatment of AD.CHEN JinYan SUN MengRu WANG XingHua LU Jing WEI Yan TAN Yan LIU Ying GTZ Jürgen HE RongQiao HUA Qian 2014Science China(Life Sciences)2014,57,4:15
7A 3D hybrid grid generation technique and a multigrid/parallel algorithm based on anisotropic agglomeration approach显示文摘A hybrid grid generation technique and a multigrid/parallel algorithm are presented in this paper for turbulence flow simulations over three-dimensional (3D) complex geometries. The hybrid grid generation technique is based on an agglomeration method of anisotropic tetrahedrons. Firstly, the complex computational domain is covered by pure tetrahedral grids, in which anisotropic tetrahedrons are adopted to discrete the boundary layer and isotropic tetrahedrons in the outer field. Then, the anisotropic tetrahedrons in the boundary layer are agglomerated to generate prismatic grids. The agglomeration method can improve the grid quality in boundary layer and reduce the grid quantity to enhance the numerical accuracy and efficiency. In order to accelerate the convergence history, a multigrid/parallel algorithm is developed also based on anisotropic agglomeration approach. The numerical results demonstrate the excellent accelerating capability of this multigrid method.Zhang Laiping Zhao Zhong Chang Xinghua He Xin 2013Chinese Journal of Aeronautics2013,26,1:14
8Petrogenesis of mafic enclaves from the north Taihang Yanshanian intermediate to felsic plutons: Evidence from petrological, geochemical, and zircon Hf-O isotopic data显示文摘We report the zircon Hf-O isotopic data for mafic enclaves from the Taihang Yanshanian intermediate to felsic plutons, and use them, along with the petrological, whole-rock chemical and Nd-Sr isotopic data, to reveal the petrogenesis of mafic enclaves. Mafic enclaves show magmatic textures and are finer-grained than host rocks. In places they are highly elongated due to stretching within the partially crystallized, convective felsic magma, but show no solid-state deformation. These data suggest that mafic enclaves and host rocks were co-existing, but compositionally distinct magmas. The mafic enclaves contain abundant hydrous minerals such as hornblende and biotite, with pyroxene relict being surrounded by hornblende reaction rim. Plagioclase xenocrysts from mafic enclaves show a complicated compositional and textural disequilibrium. Comparison between mafic enclaves and the immediate host rocks suggests that the two rock units are compositionally correlated. The εNd values of mafic enclaves are generally higher than the host rocks, though the Sr isotopic ratios of the two rock units are indistinguishable. Zircons from a single enclave sample show a significant variation in Hf isotopic compositions, with εHf = -10―-22, suggesting an origin through magma mixing between mafic and felsic magmas. This is supported by the relatively large variation of zircon O isotopic ratios (δ 18O = 5.5‰- 7.8‰) of the mafic enclaves. The petrogenesis of mafic enclaves could be described as below. Evolved basaltic magma (via fractionation of olivine and pyroxene) first mixed with crustally derived granitic melts in depths, forming a hybrid magma; then the hybrid magma broke up into discrete lumps upon entering the above felsic magma. Subsequently, the enclave-forming magma experienced a double mechanical transfer of plagioclase, and inward chemical transfer of fluid and Na, P, Y, Nb and Pb at the contacts with host felsic magmas.CHEN Bin HE JingBo MA XingHua 2009Science China Earth Sciences2009,52,9:12
9Gait Planning for a Quadruped Robot with One Faulty Actuator显示文摘Fault tolerance is essential for quadruped robots when they work in remote areas or hazardous environments. Many fault-tolerant gaits planning method proposed in the past decade constrained more degrees of freedom(DOFs) of a robot than necessary. Thus a novel method to realize the fault-tolerant walking is proposed. The mobility of the robot is analyzed first by using the screw theory. The result shows that the translation of the center of body(Co B) can be kept with one faulty actuator if the rotations of the body are controlled. Thus the DOFs of the robot body are divided into two parts: the translation of the Co B and the rotation of the body. The kinematic model of the whole robot is built, the algorithm is developed to actively control the body orientations at the velocity level so that the planned Co B trajectory can be realized in spite of the constraint of the faulty actuator. This gait has a similar generation sequence with the normal gait and can be applied to the robot at any position. Simulations and experiments of the fault-tolerant gait with one faulty actuator are carried out. The Co B errors and the body rotation angles are measured. Comparing to the traditional fault-tolerant gait they can be reduced by at least 50%. A fault-tolerant gait planning algorithm is presented, which not only realizes the walking of a quadruped robot with a faulty actuator, but also efficiently improves the walking performances by taking full advantage of the remaining operational actuators according to the results of the simulations and experiments.CHEN Xianbao GAO Feng QI Chenkun TIAN Xinghua 2015Chinese Journal of Mechanical Engineering2015,28,1:12
10Near-surface sand-dust horizontal flux in Tazhong-the hinterland of the Taklimakan Desert显示文摘Tazhong is the hinterland and a sandstorm high-frequency area of the Taklimakan Desert. However, little is known about the detailed time-series of aeolian sand transport in this area. An experiment to study the sand-dust horizontal flux of near-surface was carried out in Tazhong from January to December 2009. By measuring the sand-dust horizontal flux throughout sixteen sand-dust weather processes with a 200-cm tall Big Spring Number Eight (BSNE) sampler tower, we quantitatively analyzed the vertical variation of the sand-dust horizontal flux. And the total sand-dust horizontal flux of different time-series that passed through a section of 100 cm in width and 200 cm in height was estimated combining the data of saltation movement continuously recorded by piezoelectric saltation sensors (Sensit). The results indicated that, in the surface layer ranging from 0-200 cm, the intensity of sand-dust horizontal flux decreased with the increase of the height, and the physical quantities obeyed power function well. The total sand-dust horizontal flux of the sixteen sand-dust weather processes that passed through a section of 100 cm in width and 200 cm in height was about 2,144.9 kg, the maximum of one sand-dust weather event was about 396.3 kg, and the annual total sand-dust horizontal flux was about 3,903.2 kg. The high levels of aeolian sand transport occurred during daytime, especially from 13:00 to 16:00 in the afternoon. We try to develop a new method for estimation of the detailed time-series of aeolian sand transport.XingHua YANG Qing HE Mamtimin ALI Wen HUO XinChun LIU 2013Journal of Arid Land2013,5,2:11
11Assimilating Doppler radar observations with an ensemble Kalman filter for convection-permitting prediction of convective development in a heavy rainfall event during the pre-summer rainy season of South China显示文摘This study examines the effectiveness of an ensemble Kalman filter based on the weather research and forecasting model to assimilate Doppler-radar radial-velocity observations for convection-permitting prediction of convection evolution in a high-impact heavy-rainfall event over coastal areas of South China during the pre-summer rainy season. An ensemble of 40 deterministic forecast experiments(40 DADF) with data assimilation(DA) is conducted, in which the DA starts at the same time but lasts for different time spans(up to 2 h) and with different time intervals of 6, 12, 24, and 30 min. The reference experiment is conducted without DA(NODA).To show more clearly the impact of radar DA on mesoscale convective system(MCS)forecasts, two sets of 60-member ensemble experiments(NODA EF and exp37 EF) are performed using the same 60-member perturbed-ensemble initial fields but with the radar DA being conducted every 6 min in the exp37 EF experiments from 0200 to0400 BST. It is found that the DA experiments generally improve the convection prediction. The 40 DADF experiments can forecast a heavy-rain-producing MCS over land and an MCS over the ocean with high probability, despite slight displacement errors. The exp37 EF improves the probability forecast of inland and offshore MCSs more than does NODA EF. Compared with the experiments using the longer DA time intervals, assimilating the radial-velocity observations at 6-min intervals tends to produce better forecasts. The experiment with the longest DA time span and shortest time interval shows the best performance.However, a shorter DA time interval(e.g., 12 min) or a longer DA time span does not always help. The experiment with the shortest DA time interval and maximum DA window shows the best performance, as it corrects errors in the simulated convection evolution over both the inland and offshore areas. An improved representation of the initial state leads to dynamic and thermodynamic conditions that are more conducive to earlier initiation of the inland MCS and longer maintenance of the offshore MCS.BAO XingHua LUO YaLi SUN JiaXiang MENG ZhiYong YUE Jian 2017Science China Earth Sciences2017,60,10:11
12Local and global behavior for algorithms of solving equations显示文摘The theory of 'point estimate' and the concept of 'general convergence', which were put forward by Smale in order to investigate the complexity of algorithms for solving equations, have been producing a deep impact on the research about the local behavior, the semi-local behavior and the global behavior of iteration methods. The criterion of point estimate introduced by him not only provides a tool for quantitative analysis of the local behavior but also motivates the establishing of the unified determination for the semi-local behavior. Studying the global behavior in the view of discrete dynamical system will lead to many profound research subjects and open up a rich and colorful prospect. In this review, we will make a summarization about the research progress and some applications in nonsmooth optimizations.WANG Xinghua & LI ChongDepartment of Mathematics, Zhejiang University, Hangzhou 310028, China Academy of Mathematics and System Sciences, Chinese Academy of Sciences, Beijing 100080, China Department of Applied Mathematics, Southeast University, Nanjing 210096, China 2001Chinese Science Bulletin2001,46,6:10
13Characterization of interspecific hybrids and backcross progenies from a cross between Oryza minuta and Oryza sativa显示文摘Oryza minuta, a tetraploid wild relative of cultivated rice, is an important source for the genetic improvement. Interspecific hybrids were obtained from the cross of O. sativa L. (IR24) and O. minuta (Acc. No. 101133) with 5.58% crossability, which ranged from 0.11% to 1.62% in the backcross generations. The chromosome numbers of the backcross progenies were 24 to 48. Seven yield-related traits of the parents, hybrid F1, and backcross progenies were evaluated. Simple sequence repeat markers analysis showed that the polymorphism ratio of SSR bands between IR24 and Acc. No. 101133 was 93.2%. The average donor segment number, length, donor genome size, and percentage of donor genome of 92 BC3F1 plants (2n=24) were 24.1, 17.8 cM, 438.4 cM and 26.2%, respectively. They were complex variation and uneven among the chromosomes. These introgression lines could be used to identify the favorable genes of O. minuta and provide a new platform for the genetic improvement of cultivated rice.GUO SiBin, QIN FaLan, ZHANG DuanPin & LIN XingHua· National Key Laboratory of Crop Genetic Improvement, National Center of Crop Molecular Breeding, Huazhong Agricultural University, Wuhan 430070, China 2009Science China(Life Sciences)2009,52,12:9
14Constant Speed Control for Complex Cross-section Welding Using Robot Based on Angle Self-Test显示文摘Expandable profile liner(EPL) is a promising new oil well casing cementing technique, and welding is a major EPLs connection technology. Connection of EPL is still in the stage of manual welding so far, automatic welding technology is a hotspot of EPL which is one of the key technologies to be solved. A robot for automatic welding of '8' type EPL is studied. Four quadrants of mathematical equations of the 8-shaped cross-section track of EPL, consisting of multiple arcs, are established. Mechanism program for complex cross-section welding of EPL based on angle detection is proposed according to characteristics of small size, small valleys, and large forming errors, etc. A welding velocity vector control model is established by linkage control of a welding vehicle, a small driven actuator, and a height tracking mechanism. A constant speed control model based on an angle and symmetrical analysis model of rectangular coordinate system for EPL is built. Constraint conditions of constant speed control between each section are analyzed with 4 sections in first quadrant as an example, and cooperation work mechanism of the welding vehicle and the small tracking actuator is established based on pressure detection. The constant speed control model using angle self-test can be used to avoid the need for a precise mathematical model for tracking control and to adapt manufacture and installation deviation of EPL workpiece. The model is able to solve constant speed and trajectory tracking problems of EPL cross-section welding. EPL seams welded by the studied robot are good in appearance, and non-destructive testing(NDT) shows the seams are good in quality with no welding defects. Bulge tests show that the maximum pressure of welded EPL is 35 MPa, which can fulfill expansion performance requirements.XUE Long ZOU Yong HUANG Jiqiang HUANG Junfen TAO Xinghua HU Yanfeng 2014Chinese Journal of Mechanical Engineering2014,27,2:8
15A preliminary study of the failure mechanisms of cascading landslide dams显示文摘Landslide dams commonly form when mass earth or rock movements reach a river channel and cause a complete or partial blockage of the channel.Intense rainfalls can induce upstream flows along a sloping channel that significantly affect downstream landslide dams.If a series of landslide dams are collapsed by incoming mountain torrents(induced by intense rainfall),large debris flows can form in a very short period.Furthermore,the failure of these dams can amplify the magnitude and scale of debris flows in the flow direction.The catastrophic debris flows that occurred in Zhouqu County,China on 8 August 2010 were caused by intense rainfall and the upstream cascading failure of landslide dams along the gullies.Incorporating the role of outburst floods associated with the complete or partial failure of landslide dams is an interesting problem usually beyond the scope of analysis because of the inherent modeling complexity.To understand the cascading failure modes of a series of landslide dams,and the dynamic effect these failures have on the enlargement of debris flow scales,experimental tests are conducted in sloping channels mimicking field conditions,with the modeled landslide dams distributed along a sloping channel and crushed by different upstream flows.The failure modes of three different cascades of landslide dams fully or partially blocking a channel river are parametrically studied.This study illustrates that upstream flows can induce a cascading failure of the landslide dams along a channel.Overtopping is the primary failure mechanism,while piping and erosion can also induce failures for different constructed landslide dams.A cascading failure of landslide dams causes a gradually increasing flow velocity and discharge of the front flow,resulting in an increase in both diameter and percentage of the entrained coarse particles.Furthermore,large landslide blockages can act to enhance the efficiency of river incision,or conversely to induce aggradation of fluvial sediments,depending on the blockage factor of the landslide dams and upstream discharge.Gordon G.D Peng Cui Xinghua Zhu Jinbo Tang Huayong Chen Qicheng Sun 2015International Journal of Sediment Research2015,30,3:8
16Impact factors of soil wind erosion in the center of Taklimakan Desert显示文摘The development and progress of soil wind erosion are influenced by the factors of climate,terrain,soil and vegetation,etc. This paper,taking Tazhong region,a town in the centre of the Taklimakan Desert,as an example and using comparative and quantitative methods,discussed the effects of climate,surface roughness(including vegetation cover) and surface soil properties on soil wind erosion. The results showed that the climate factor index C of annual wind erosion is 28.3,while the maximum of C is 13.9 in summer and it is only 0.7 in winter. The value of C has a very good exponential relationship with the wind speed. In Tazhong region,the surface roughness height is relatively small with a mean of 6.32 × 10-5 m,which is in favor of soil wind erosion. The wind erosion is further enhanced by its sandy soil types,soil particle size,lacking of vegetation and low soil moisture content. The present situation of soil wind erosion is the result of concurrent effects of climate,vegetation and surface soil properties.Qing HE XingHua YANG Ali Mamtimin ShiHao TANG 2011Journal of Arid Land2011,3,1:8
17Long-distance ranging with high precision using a soliton microcomb显示文摘Laser-based light detection and ranging(lidar)plays a significant role in both scientific and industrial areas.However,it is difficult for existing lidars to achieve high speed,high precision,and long distance simultaneously.Here,we demonstrate a high-performance lidar based on a chip-scaled soliton microcomb(SMC)that can realize all three specialties simultaneously.Aided by the excellent properties of ultrahigh repetition rate and the smooth envelope of the SMC,traditional optical frequency comb(OFC)-based dispersive interferometry is heavily improved and the measuring dead zone induced by the mismatch between the repetition rate of the OFC and resolution of the optical spectrum analyzer is totally eliminated.Combined with an auxiliary dual-frequency phase-modulated laser range finder,the none-dead-zone measurable range ambiguity is extended up to 1500 m.The proposed SMC lidar is experimentally implemented in both indoor and outdoor environment.In the outdoor baseline field,real-time,high-speed(up to 35 k Hz)measurement of a long distance of^1179 m is achieved with a minimum Allan deviation of 5.6μm at an average time of 0.2 ms(27 nm at an average time of 1.8 s after high-pass filtering).The present SMC lidar approaches a compact,fast,high-precision,and none-dead zone long-distance ranging system,aimed at emerging applications of frontier basic scientific research and advances in industrial manufacturing.JINDONG WANG ZHIZHOU LU WEIQIANG WANG FUMIN ZHANG JIAWEI CHEN YANG WANG JIHUI ZHENG SAI T.CHU WEI ZHAO BRENT E.LITTLE XINGHUA QU WENFU ZHANG 2020Photonics Research2020,8,12:8
18Nested-loop Mechanism Based Modular Multilevel Converter Topology and Optimal Design显示文摘普通模块化多电平换流器(modular multilevelconverter,MMC)拓扑中,因子模块数量较多,系统需采集和处理的信息量大,导致控制系统硬件构成复杂。提出一种基于循环嵌套机理的MMC拓扑,其电平输出能力得到显著提升。通过上下两组子模块的协调投切,相对于普通MMC拓扑,新型拓扑输出相同电平数所需的子模块及控制设备数量大幅减少。阐述该新型拓扑的构成方式及基本参数选取原则;针对循环嵌套结构,设计相应的模块协调控制策略;分别以模块用量最小化和换流器运行损耗最小化为目标,优化设计拓扑构成方案。在RTDS中搭建换流器模型,仿真结果表明,新型拓扑具备更强的电平输出能力,并达到大幅减少子模块数量、简化控制系统硬件构成的目标。LIU Xinghua ZHAO Chengyong PENG Maolan GUO Chunyi ZHANG Baoshun 2013中国电机工程学报2013,33,9:7
19Diurnal dynamics of soil respiration and the influencing factors for three land-cover types in the hinterland of the Taklimakan Desert,China显示文摘Knowledge of soil respiration and the influencing factors in desert ecosystems is essential to understanding carbon dynamics and responses of biotic and abiotic processes in soils to climate change. In this study, soil respiration rate(R_s) for three land-cover types(shifting sandy land, sandy land with straw checkerboard barriers, and shelter forest land) in the hinterland of the Taklimakan Desert was measured in May 2015 using an automated soil CO_2 flux system. The effects of soil temperature(T_s) and soil water content(W_s) on R_s were also analyzed. The results showed that R_s values in shifting sandy land, sandy land with straw checkerboard barriers, and shelter forest land were all low and exhibited obvious diurnal fluctuations. The establishment of straw checkerboard barriers in sandy land had no significant effect on R_s, while the establishment of shelterbelts significantly increased R_s. Shifting sandy land and sandy land with straw checkerboard barriers were carbon sinks at night and early morning and were carbon sources in the daytime, while shelter forest land always acted as a carbon source during the whole day. The synergistic effect of T_s and W_s could better explain the diurnal dynamics in R_s than single factor. In shifting sandy land and sandy land with straw checkerboard barriers, W_s was identified as a limiting factor influencing the diurnal dynamics of R_s. Furthermore, a relatively strong hysteresis loop existed between R_s and T_s. In contrast, in shelter forest land, R_s was significantly influenced by T_s, and a relatively weaker hysteresis loop existed between R_s and W_s.YANG Fan ALI Mamtimin ZHENG Xinqian HE Qing YANG Xinghua HUO Wen LIANG Fengchao WANG Shaoming 2017Journal of Arid Land2017,9,4:7
20Seed bank and regeneration dynamics of Emmenopterys henryi population on the western side of Wuyi Mountain,South China显示文摘Emmenopterys henryi Oliv.(Rubiaceae) is an endangered tree species that is native to China.The wild populations of E.henryi have declined rapidly because of its poor natural regeneration,but the actual regeneration processes are not yet understood.In field tracking surveys and experiments in the Wuyishan Nature Reserve in Southeast China to determine the most important stage that affects the regeneration process,seed bank characteristics,seed germination,and seedling growth dynamics were studied in the typical habitats of E.henryi,Phyllostachys pubescens and broad-leaved forests.Results showed that in both P.pubescens and broad-leaved forests,more than 70% of the E.henryi seeds were distributed in moss and litter layers,and few were found in the soil beneath them.However,seed germination in the soil layer was significantly higher than in the moss and litter layers.Seed density,overall seed quality,and germination rate in the broad-leaved forest were significantly higher than in P.pubescens forest.Seed germination was highest in the microsites around the edge of the crown projection area of E.henryi mother trees.The order of survival rate of the seedlings on different ground surfaces was soil> moss>litter.In both habitats,the average seed density was 24.9 seeds m^(-2),and the total germination rate was less than 3.5%.However,seedlings developed from only 1% of the germinated seeds,indicating that the seed germination is the most important stage in the natural regeneration of E.henryi.Lianjin Guo Pingping Xue Mei Li Xinghua Shao 2017Journal of Forestry Research2017,28,5:7
返回顶部 每页显示:
共32页 首页 上一页 第1页 下一页 末页 /32 跳转

网站首页 | 关于我们 | 联系我们 | 产品服务 | 客服中心 | 广告服务 | 版权声明 | 网站联盟 | 友情链接 | 售卡网点

版权所有© 渝B2-20050021-1 渝公网安备 50019002500403号 违法和不良信息举报中心

互联网出版许可证 新出网证(渝)字10号 全国400电话 - 免长途话费