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1Strontium and boron isotopic constraint on the marine origin of the Khammuane potash deposits in southeastern Laos显示文摘Since 2006,we have conducted a geological exploration of the Khammuane area in southeastern Laos.Several thick sequences of potash deposits containing sylvite and carnallite were discovered from drilling Paleocene strata of the Thangon Formation(E1tg).To constrain the origin of the brine that formed thick sequences of salt mineral deposits,we measured the strontium and boron isotope composition of some salt minerals in the potash deposit.Boron isotope composition of halite-and potash-associated minerals in the Khammuane potash deposit varied from 19.91%to 31.01‰,which differs significantly from continental evaporates(-6.83‰--5.79‰)but is very close to that of salts precipitated from evapo-concentrated seawater(10‰-36‰).The 87Sr/86Sr ratios(0.707542 to 0.709461)of salts were also close to the values of Paleocene seawater(0.70772 to 0.707830).The content of Br-(0.01%-0.25%)and Br×103/Cl ratios(0.10-0.52)of halite were>10 times higher than that of common continental salts.These characteristics indicate clearly that the Laos potash deposits were deposited from seawater.The small variation in boron and strontium isotopes in all salt sedimentary sequences(gypsum-halite-potash-halite)also suggests that the recharge source should be stable and the effects of other continental water mixing are negligible.Large-scale potash deposits are commonly precipitated from seawater.Hence,the results of recent regional drilling work and geochemical research suggest extensive potash resources could occur in the Thangon Formation of southeastern Laos.TAN HongBing MA HaiZhou LI BinKai ZHANG XiYing XIAO YingKai 2010Chinese Science Bulletin2010,55,27:37
2China's Energy Strategy Adjustment under Energy Conservation and Carbon Emission Constraints显示文摘经济发展和能源需求的阶段性特征、节能减排的基本国策以及气候变暖和温室气体减排的制约,都要求中国能源战略,尤其是能源结构战略,进行相应调整。以往中国的能源战略规划主要是从能源储备和能源生产,即能源供给侧来考虑满足能源需求问题。为了应对气候变化,中国能源结构战略亟待调整:一是要从供给和需求双侧管理来考虑满足能源需求问题,二是要将二氧化碳排放作为满足能源需求的一个约束。建立优化模型,得到反映节能和排放约束下的最优能源结构,进而通过可计算一般均衡模型,评估能源结构变化导致的能源成本增加对宏观经济的影响,结果表明:政府的可再生能源规划对二氧化碳减排具有重要的正面影响,但二氧化碳排放约束改变能源结构导致的能源成本增加,对宏观经济具有一定的负面影响。因为中国许多重要行业对煤炭和火电的依赖程度依然很高,所以,现阶段通过改变能源结构减排的空间不大,应该重视其他方面的节能减排努力。Lin Boqiang Yao Xin Liu Xiying 2010Social Sciences in China2010,31,2:11
3Typical Geochemical Elements in Loess Deposit in the Northeastern Tibetan Plateau and Its Paleoclimatic Implication显示文摘Widespread and thick loess deposit in the northeastern Tibetan Plateau records paleoclimatic changes over the Quaternary period. In this study, we investigate a loess section located in a high terrace of the Huangshui River in the Xining Basin, and collect samples at 20-cm intervals by digging a well of 16-m depth (including paleosol S1 and S0 and several loess interlayers over the last glacial-interglacial cycle and the Holocene). Concentration of some active elements (Sr and Ca) and inert elements (Rb, Zr, Ti) in these loess samples are measured. The results show that ratios of those elements (oxide), such as Rb/Sr, Ti/Sr, and Zr/CaO ratios, would indicate sensitively paleoclimatic changes, especially the history of precipitation over the last glacial-interglacial and the Holocene. Moreover, the curves of Rb/Sr, Ti/Sr, and Zr/CaO ratios had almost the same variable trends from the bottom to the top and also closely correlated with values of magnetic susceptibility and the global marine δ18O record. But compared with the curves of magnetic susceptibility, the changes of ratios of these elements (oxide) are clearer and easy to understand. Therefore, the ratios of these typical chemical elements in the loess deposit may be used as an excellent index to investigate the history of paleoclimate, particularly precipitation changes in the northeastern Tibetan Plateau.TAN Hongbing MA Haizhou ZHANG Xiying LU Huayu WANG Jianguo 2006Acta Geologica Sinica(English Edition)2006,80,1:10
4滇池流域农田不同土地利用方式对土壤磷素积累及其吸附的影响显示文摘【目的】研究滇池周边不同土地利用方式下土壤基本理化性质和土壤总磷(TP)、有效磷(Olsen-P)、水溶性磷(Water-P)含量在不同土层(0~20,20~40,40~60,60~80,80~100cm)变化状况及其磷吸附特性,旨在阐明农田土地利用方式对滇池流域土壤磷流失的潜在影响。【方法】2009年,在滇池流域选择常规水稻-蚕豆轮作、露地蔬菜、3~5年和10年以上塑料大棚4种土地利用方式下的农田作为研究对象,采集0~100cm土层的土样,测定土壤基本理化性质和不同形态磷含量,用Langmuir方程拟合不同土地利用方式下土壤的磷吸附特性,并对土壤基本理化性质及不同形态磷含量与土壤磷素吸附特征参数土壤磷最大吸附量(Smax)和土壤磷吸附能常数(k)相关性进行分析。【结果】不同土地利用方式对不同土层土壤基本理化性质有明显影响。4种土地利用方式下,农田土壤TP、Ols-en-P和Water-P主要积累于土壤表层(0~20cm)。与常规水稻-蚕豆轮作地相比,露地蔬菜地、10年以上塑料大棚和3~5年塑料大棚表层(0~20cm)土壤的Olsen-P含量分别高达89.86,74.93,45.07mg/kg,均超过土壤磷向周围水体流失的'突变点'。4种土地利用方式农田的Smax和k分别为747~1 533mg/kg和0.08~0.75L/mg,其中露地蔬菜地、3~5年和10年以上塑料大棚表层(0~20cm)土壤的Smax较水稻-蚕豆轮作地显著降低,k值则随土层深度的增加及塑料大棚种植时间的延长而增大;Smax和k与不同土地利用方式下土壤全氮、NH4+-N、NO3--N含量及C/N呈显著相关关系,Olsen-P和Water-P含量与k呈显著负相关关系(r分别为-0.49和-0.52,P<0.05)。【结论】农田土地利用方式由水稻-蚕豆轮作向集约化蔬菜、花卉生产转变,将会引起土壤特性改变、磷素积累及降低土壤对磷吸附,使农田土壤磷向周边水体流失从而增加水体富营养化的环境风险。杨广容 Hao Xiying 李春莉 王自林 李永梅 2012西北农林科技大学学报(自然科学版)2012,40,7:8
5集约化生产对农田土壤碳氮含量及δ^(13)C和δ^(15)N同位素丰度的影响显示文摘集约化生产下农田土壤碳、氮含量变化是衡量土壤肥力持久性的重要指标.对常规水稻-蚕豆轮作地、露地蔬菜地、3年塑料大棚地和10年以上塑料大棚地的土壤pH、电导率(EC)、土壤有机碳(SOC)和总氮(TN)含量及δ13C和δ15N同位素丰度进行测定,研究了集约化生产程度对土壤特性的影响.结果表明:与水稻-蚕豆轮作地相比,露地蔬菜地、3年塑料大棚地和10年以上塑料大棚地0~20 cm耕层土壤pH分别降低1.1、0.8和0.7,而土壤EC分别是水稻-蚕豆轮作地的4.2、4.9和5.2倍;土壤碳、氮含量随塑料大棚地生产年限的增加总体上呈先增大后减小的趋势.与水稻-蚕豆轮作地相比,10年以上塑料大棚地0~20、20~40、40~60、60~80、80~100 cm土层的土壤SOC含量分别下降了54%、46%、60%、63%和59%,土壤TN含量分别下降了53%、53%、71%、82%和85%.农田集约化生产程度显著影响土壤SOC、TN含量和δ13C、δ15N丰度,土壤δ13C丰度与SOC含量呈显著负相关.土壤δ13C丰度可作为评价农田土壤碳循环受人为干扰强度的指标.杨广容 HAO Xiying 李春莉 王自林 李永梅 2012应用生态学报2012,23,3:7
6Soil Quality in Relation to Agricultural Production in the North China Plain显示文摘Sustainable agricultural production is of vital importance to food supply security. This study aimed to investigate crop yield response to spatial variability of soil quality at a county scale in the North China Plain(NCP) and subsequently derive key soil quality indicators. Soil samples were geo-referenced and taken in 2008 from both surface(0–20 cm) and subsurface(20–40 cm) layers in132 fields throughout the Fengqiu County, located in the centre of the NCP, for subsequent soil properties' analyses. Annual crop yields were obtained from the same fields where soil samples were collected. Soil quality was evaluated based on a fuzzy set with 13 soil properties, and its spatial distributions were investigated by integrating geostatistical analysis and geographic information system(GIS) techniques. Soil quality indices were classified into five grades, and their spatial distributions were mapped within the county.The surface soil qualities were about one to two grades higher than the subsurface soil. The quality indices for surface and subsurface soils were positively associated with the annual crop yields, suggesting the importance of both. Soil organic matter, total nitrogen,available P, and available K contributed 50% of the combined weight to the soil quality index and were identified as key indicators of soil quality status in the area in terms of sustainability.XIA Min ZHAO Bingzi Xiying HAO ZHANG Jiabao 2015Pedosphere2015,25,4:6
7Invariant tori for asymptotically linear impact oscillators显示文摘The existence of invariant tori and quasi-periodic solutions for asymptotically linear impact oscillators is proved by using the successor map and some generalized versions of the Moser's twist theorem.QIAN Dingbian & SUN Xiying School of Mathematical Sciences, Suzhou University, Suzhou 215006, China Laboratory of Mathematics for Nonlinear Sciences, Fudan University, Shanghai 200433, China 2006Science China Mathematics2006,49,5:5
8Enhanced transdermal delivery of meloxicam by nanocrystals: Preparation, in vitro and in vivo evaluation显示文摘Meloxicam(MLX) is efficient in relieving pain and inflammatory symptoms, which, however, is limited by the poor solubility and gastrointestinal side effects. The objective of this study is to develop a nanocrystal formulation to enhance transdermal delivery of MLX. MLX nanocrystals were successfully prepared by the nanoprecipitation technique based on acidbase neutralization. With poloxamer 407 and Tween 80(80/20, w/w) as mixed stabilizers,MLX nanocrystals with particle size of 175 nm were obtained. The crystalline structure of MLX nanocrystals was confirmed by both differential scanning calorimetry and X-ray powder diffractometry. However, the nanoprecipitation process reduced the crystallinity of MLX.Nanocrystals increased both in vitro and in vivo transdermal permeation of MLX compared with the solution and suspension counterparts. Due to the enhanced apparent solubility and dissolution as well as the facilitated hair follicular penetration, nanocrystals present a high and prolonged plasma MLX concentration. And 2.58-and 4.4-fold increase in AUC0 →2 4 h was achieved by nanocrystals comparing with solution and suspension, respectively. In conclusion, nanocrystal is advantageous for transdermal delivery of MLX.Qina Yu Xiying Wu Quangang Zhu Wei Wu Zhongjian Chen Ye Li Yi Lu 2018Asian Journal of Pharmaceutical Sciences2018,13,6:4
9Improving water use ef fi ciency in grain production of winter wheat and summer maize in the North China Plain: a review显示文摘Reducing irrigation water use by improving water use ef ficiency(WUE) in grain production is critical for the development of sustainable agriculture in the North China Plain(NCP). This article summarizes the research progresses in WUE improvement carried out at the Luancheng station located in the Northern part of NCP for the past three decades. Progresses in four aspects of yield and WUE improvement are presented, including yield and WUE improvement associated with cultivar selection, irrigation management for improving yield and WUE under limited water supply, managing root system for ef ficient soil water use and reducing soil evaporation by straw mulch. The results showed that annual average increase of 0.014 kg$m^(–3)for winter wheat and 0.02 kg$m^(–3)in WUE were observed for the past three decades, and this increase was largely associated with the improvement in harvest index related to cultivar renewal and an increase in chemical fertilizer use and soil fertility. The results also indicated that de ficit irrigation for winter wheat could signi ficantly reduce the irrigation water use, whereas the seasonal yield showed a smaller reduction rate and WUE was signi ficantly improved. Straw mulching of summer maize using the straw from winter wheat could reduce seasonal soil evaporation by 30–40 mm. With new cultivars and improved management practices it was possible to further increase grain production without much increase in water use. Future strategies to further improve WUE are also discussed.Xiying ZHANG Wenli QIN Juanna XIE 2016Frontiers of Agricultural Science and Engineering2016,3,1:4
10Biases of the Arctic climate in a regional ocean-sea iceatmosphere coupled model: an annual validation显示文摘The Coupling of three model components, WRF/PCE(polar climate extension version of weather research and forecasting model(WRF)), ROMS(regional ocean modeling system), and CICE(community ice code), has been implemented, and the regional atmosphere-ocean-sea ice coupled model named WRF/PCEROMS-CICE has been validated against ERA-interim reanalysis data sets for 1989. To better understand the reasons that generate model biases, the WRF/PCE-ROMS-CICE results were compared with those of its components, the WRF/PCE and the ROMS-CICE. There are cold biases in surface air temperature(SAT) over the Arctic Ocean, which contribute to the sea ice concentration(SIC) and sea surface temperature(SST) biases in the results of the WRF/PCE-ROMS-CICE. The cold SAT biases also appear in results of the atmospheric component with a mild temperature in winter and similar temperature in summer. Compared to results from the WRF/PCE, due to influences of different distributions of the SIC and the SST and inclusion of interactions of air-sea-sea ice in the WRF/PCE-ROMS-CICE, the simulated SAT has new features. These influences also lead to apparent differences at higher levels of the atmosphere, which can be thought as responses to biases in the SST and sea ice extent. There are similar atmospheric responses in feature of distribution to sea ice biases at 700 and 500 hPa, and the strength of responses weakens when the pressure decreases in January. The atmospheric responses in July reach up to 200 hPa. There are surplus sea ice extents in the Greenland Sea, the Barents Sea, the Davis Strait and the Chukchi Sea in winter and in the Beaufort Sea, the Chukchi Sea, the East Siberian Sea and the Laptev Sea in summer in the ROMS-CICE. These differences in the SIC distribution can all be explained by those in the SST distributions. These features in the simulated SST and SIC from ROMS-CICE also appear in the WRF/PCE-ROMS-CICE. It is shown that the performance of the WRF/PCE-ROMS-CICE is determined to a large extent by its components, the WRF/PCE and the ROMS-CICE.LIU Xiying 2014Acta Oceanologica Sinica2014,33,9:4
11Deleting Vertices and Interlacing Laplacian Eigenvalues显示文摘The authors obtain an interlacing relation between the Laplacian spectra of a graph G and its subgraph G-U,which is obtained from G by deleting all the vertices in the vertex subset U together with their incident edges.Also,some applications of this interlacing property are explored and this interlacing property is extended to the edge weighted graphs.Baofeng WU Jiayu SHAO Xiying YUAN 2010Chinese Annals of Mathematics,Series B2010,31,2:3
12A Multi–fluid Constrain for the Forming of Potash Deposits in the Savannakhet Basin: Geochemical Evidence from Halite显示文摘The Khorat Plateau on the Indochina Terrane is known to have formed during the closure of the Tethys Ocean, although the origin of its potash mineral deposits is a topic of current debate. Data from a borehole on Savannakhet Basin is used in this study to re-define the evaporation processes of the study area. Geochemical analyses of halite from various borehole-derived evaporite strata have elucidated the fluid sources from which these ores formed. Measured δ11 B indicated that ore deposits formed primarily due to evaporation of seawater, although non-marine fluids affected the later stages of the evaporation process. Fluctuations in B and Br concentrations in carnallite-and sylvite-rich strata indicate the influence of fresh water. Boron concentration in carnallite unit indicated the influence of hydrothermal fluids. From the relative timings of these various fluid influxes, the evolution of these evaporates can be divided into four stages:(1) an initial marine evaporation at the beginning of the deposit's formation, where seawater(and minor fresh water) trapped on the uplifted Khorat Plateau produced sediments and salts with Br contents lower than those of normal marine-derived evaporites;(2) a transgression stage, where seawater recharged the basin;(3) a hydrothermal infiltration stage, which was coeval with the late Yanshan movement; and(4) a stage of fresh water supply, as recorded by fluctuations in B and Br contents, inferring intermittent fresh water influx into the basin. Thus, although evaporites on the Savannakhet Basin primarily formed via marine evaporation, they were also influenced to a significant degree by the addition of non–marine fresh water and hydrothermal fluids.REN Qianhui DU Yongsheng GAO Donglin LI Binkai ZHANG Xiying LIU Xiuting YUAN Xiaolong 2018Acta Geologica Sinica(English Edition)2018,92,2:3
13Thermal Evaporation Deposition of Few-layer MoS_2 Films显示文摘We present a study of the fabrication of monolayer MoS_2 on n-Si(111) substrates by modified thermal evaporation deposition and the optoelectrical properties of the resulting film. The as-grown MoS_2 ultrathin film is about 10 nm thick, or about a few atomic layers of MoS_2. The film has a large optical absorption range of 300-700 nm and strong luminescence emission at 682 nm. The optical absorption range covered almost the entire ultraviolet to visible light range, which is very useful for making high-efficiency solar cells. Moreover, the MoS_2/Si heterojunction exhibited good rectification characteristics and excellent photovoltaic effects. The power conversion efficiency of the heterojunction device is about 1.79% under white light illumination of 10 m W/cm^2. The results show that the monolayer MoS_2 film will find many applications in high-efficiency optoelectronic devices.Xiying Ma Miaoyuan Shi 2013Nano-Micro Letters2013,5,2:3
14Ordering uniform supertrees by their spectral radii显示文摘Xiying YUAN Xuelian SI Li ZHANG 2017Frontiers of Mathematics in China2017,12,6:3
15Family-level diversity of extracellular proteases of sedimentary bacteria from the South China Sea显示文摘Protease-producing bacteria and their extracellular proteases are key players in degrading organic nitrogen to drive marine nitrogen cycling and yet knowledge on both of them is still very limited. This study screened protease-producing bacteria from the South China Sea sediments and analyzed the diversity of their extracellular proteases at the family level through N-terminal amino acid sequencing. Results of the 16 S rRNA gene sequence analysis showed that all screened protease-producing bacteria belonged to the class Gammaproteobacteria and most of them were affiliated with different genera within the orders Alteromonadales and Vibrionales. The Nterminal amino acid sequence analysis for fourteen extracellular proteases from fourteen screened bacterial strains revealed that all these proteases belonged to the M4 family of metalloproteases or the S8 family of serine proteases. This study presents new details on taxa of marine sedimentary protease-producing bacteria and types of their extracellular proteases, which will help to comprehensively understand the process and mechanism of the microbial enzymatic degradation of marine sedimentary organic nitrogen.Jinyu Yang Yangyang Feng Xiulan Chen Binbin Xie Yuzhong Zhang Mei Shi Xiying Zhang 2019Acta Oceanologica Sinica2019,38,12:3
16Evidence of multistage late Quaternary strong earthquakes on typical segments of Longmenshan Active Fault Zone in Sichuan, China显示文摘Investigation of offset landforms and trench excavation are important means to acquire the evidence of multistage activities of active faults. Here we present the result of fault trough investigation in Beichuan County and the Pingtong Town of Pingwu County along the Longmenshan Central Fault Belt, as well as the result from trench excavation at the platform foreslope in Hanwang Town of Mianzhu County on the Longmenshan Front Range Fault Belt. These results show that at least three fault activity events, including the Wenchuan earthquake, occurred in the Beichuan fault trough, at least two, including the Wenchuan earthquake, at Pingtong fault trough, and 2-3 paleoearthquakes in the Hanwang trench. Among these three localities, the times of the last strong earthquake prior to Wenchuan earthquake at Beichuan fault trough and Hanwang trench are close, approximately 6000 years ago, i.e., greater than 5.8 ka and smaller than 6.63 ka ago. This provides the evidence of synchronous activity of the Central Fault Belt and the Front Range Fault Belt of the Longmenshan Active Fault Zone during the previous strong earthquake activities prior to Wenchuan earthquake.JIANG WaLi XIE XinSheng ZHANG JinFa SUN ChangBin HUANG Wei SHENG Qiang FENG XiYing 2009Science China Earth Sciences2009,52,9:3
17GLOBAL WEAK SOLUTION TO COMPRESSIBLE NAVIER-STOKES EQUATIONS WITH DENSITY-DEPENDENT VISCOSITY,VACUUM AND GRAVITATIONAL FORCE显示文摘Recently,the global existence of weak solutions to the compressible Navier-Stokes equations with vacuum has attracted much attention.In this paper,we study the one-dimension isentropic Navier-Stokes equations with gravitational force and fixed boundary condition when the density connects with vacuum discontinuously.We prove the global existence and the uniqueness of weak solution,requiring less regularity of the initial data.Sun Yuejuan (Dept.of Math.,Shangqiu Normal University,Shangqiu 476000,Henan) Zheng Xiying (Dept.of Math.and Physics,Yellow River Technical College,Zhengzhou 450052) 2008Annals of Differential Equations2008,24,1:3
18Mechanics analysis of axisymmetric thin-walled part in warm sheet hydroforming显示文摘To obtain the influence of fluid pressure and temperature on warm hydroforming of5A06-O aluminum alloy sheet, the unified mechanics equilibrium equations, which take throughthickness normal stress and friction into account, were established in spherical coordinate system.The distribution of through-thickness normal stress in the thickness direction was determined. The relation between through-thickness normal stress and fluid pressure was also analyzed in different regions of cylindrical cup. Based on the method of subtracting one increasing function from another, the constitutive equation of 5A06-O applied to warm hydroforming was established and in a good agreement with uniaxial tensile data. Based on whether the thickness variation was taken into account, two mechanic models were established to do the comparative study. The results for the studied case show that the calculated stress values are pretty close according to the two models and consistent with results of finite element analysis; the thickness distribution in flange computed by the second model conforms to the experimental data. Finally, the influences of fluid pressure on the flange thickness and radial stress were analyzed.Yang Xiying Lang Lihui Liu Kangning Liu Baosheng 2015Chinese Journal of Aeronautics2015,28,5:2
19EFFECT OF CATHODIC PROTECTION ON FRACTURE BEHAVIOUR OF LOWALLOY STEELS IN SEAWATER显示文摘Fracture behaviour of low-alloy steels AIST4340,HY100,Welten60,AISIA537 and A131 inartificial seawater under static,cyclic loading and at cathodic protection potential has beeninvestigated by using the techniques of fracture mechanics, electrochemistry andelectronfractography.The results reveal that at hydrogen evolution potentials(cathodic pro-tection potential)the critical yield strength required for the occurrance of SCC decreasesfrom 985 at corrosion potential(Ec)to 872 MPa.The effect of cathodic protection on crackpropagation of corrosion fatigue(CF)is not simple,it is closely related to the yield strengthof steels and their SCC behaviour.For the steels with high yield strength,cathodic protectionpromotes(da/dN) evidently,and reduces △Kth value.The(da/dN)-△K curves dis-play a plateau at the third stage of CF for steels with medium or low yield strength.It is men-tioned that the cathodic protection potential for oceaneering constructures should be control-led at top level of the protective range.It seems reasonable that the strength of steel foroceaneeing use might be increased by 200 or 300 MPa.ZHENG Wenlong ZHU Xiying SU Limin Shanghai Research Institute of Materials,Shanghai,China ZHENG Wenlong,Senior Research Engineer,Shanghai Research Institute of Materials,99 Handan Road,Shanghai,China 1989Acta Metallurgica Sinica(English Letters)1989,2,1:2
20Cloning and characterization of a novel CBL-interacting protein kinase from maize显示文摘Jinfeng Zhao Zhenfei Sun Jun Zheng Xiying Guo Zhigang Dong Junling Huai Mingyue Gou Junguang He Yongsheng Jin Jianhua Wang Guoying Wang 2009Plant Molecular Biology2009,,6:2
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