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123篇 您的检索式:作者名="Xuhua"
    题名 作者 年代 出处 被引量
1High-altitude salt lake elevation changes and glacial ablation in Central Tibet, 2000-2010显示文摘This research quantifies lake level variations in the Siling Co, Co'e and Bangor Co salt lakes in Central Tibet from 1976 to 2010, and most notably for the 2000-2010 periods. In particular, the effects of different water replenishment modes on the lakes have been analyzed. Here we have provided new evidences for climate warming and accelerated glacial ablation on the Central Tibetan Plateau from 2000 to 2010. Based on fieldwork involving Differential Global Positioning System (DGPS) surveying and Remote Sensing (RS) interpretations of the lake area, we have drawn the following conclusions. (1) From 1976 to 2010, the process of lake level variation in Siling Co can be divided into two stages. From 1976 to 2000, the lake level rose 4.3 m in a steady fashion (from 4530 to 4534.3 m); the rise rate was 0.18 m/a. From 2000 to 2010, the lake level rapidly rose 8.2 m (from 4534.3 to 4542.5 m), with a dramatically higher rise rate of 0.82 m/a. Compared with the rapidly increasing lake level of Siling Co from 2000 to 2010, the fluctuations observed at Co'e and Bangor Co were smooth and inconspicuous. (2) From 1976 to 2009, the lake area of Siling Co experienced a steady-rapid-steady expansion pattern. The lake area of Siling Co increased 656.64 km2 in the 34 years to 2010, a proportional growth of 39.4%. This was particularly significant in the 2000-2010 period, when the lake area of Siling Co increased by 549.77 km2, a proportional growth of 30.6%. (3) According to correlation analysis, the rise in regional temperatures, which has led to the ablation of glaciers, is the main reason for the rapid rise in Siling Co lake levels in the 10 years to 2010. During this period, Siling Co rose approximately 8 m as the direct result of glacial melting. An increase in precipitation in the Siling Co catchment area is the secondary factor. This contrasts with Bangor Co, where the dominant factor in lake level change is the long-term increase in precipitation; here, the increasing temperature is the secondary factor.MENG Kai SHI XuHua WANG Erchie LIU Feng 2012Chinese Science Bulletin2012,57,5:17
2Low-frequency wide-band hybrid energy harvester based on piezoelectric and triboelectric mechanism显示文摘Recently,hybrid energy harvester has been considered as an attractive potential approach to response the worldwide energy crisis due to the combination of advantages from different harvesting mechanism.In this paper,a novel low-frequency wide-band hybrid energy harvester based on piezoelectric and triboelectric mechanism is presented and systematically studied including structural design,fabrication process,working principle simulation and measurement.With a vibrational excitation,the polyvinylidene fluoride(PVDF) cantilevers will vibrate and impact the polydimethylsiloxane(PDMS) film on the substrate,producing a piezoelectric output as well as a triboelectric output.The structural parameters of each cantilever are optimized using finite element simulation,and the well-designed PVDF cantilevers with controllable PDMS mass not only reduce the device working frequency but also enlarge the bandwidth.Under a sweep-frequency test,three voltage peaks induced by the piezoelectric part are observed at 15,32.5 and 47.5 Hz,with the value of 320,288 and 264 mV,respectively.With the combined triboelectric part,a 20 V peak-peak voltage is generated at 15 Hz.The electrical driving ability of this hybrid energy harvester also has been demonstrated by lighting up a commercial light emitting diode(LED).HAN MengDi ZHANG XiaoSheng LIU Wen SUN XuMing PENG XuHua ZHANG HaiXia 2013Science China(Technological Sciences)2013,56,8:17
3Estimation of the inter-frequency clock bias for the satellites of PRN25 and PRN01显示文摘We present two efficient approaches,namely the epoch-differenced(ED) and satellite-and epoch-differenced(SDED) approaches,for the estimation of IFCBs of the two Block IIF satellites.For the analysis,data from 18 stations from the IGS network spanning 96 d is processed.Results show that the IFCBs of PRN25 and PRN01 exhibit periodical signal of one orbit revolution with a magnitude up to 18 cm.The periodical variation of the IFCBs is modeled by a sinusoidal function of the included angle between the sun,earth and the satellite.The presented model enables a consistent use of L1/L2 clock products in L1/L5-based positioning.The algorithm is incorporated into the MGPSS software at SHAO(Shanghai Astronomical Observatory,Chinese Academy of Sciences) and is used to monitor the IFCB variation in near real-time.LI HaoJun ZHOU XuHua WU Bin WANG JieXian 2012Science China(Physics,Mechanics & Astronomy)2012,55,11:9
4Precise orbit determination of Haiyang-2 using satellite laser ranging显示文摘With the successful launch and official commissioning of China's first dynamic ocean environment satellite Haiyang-2(HY-2),China's capabilities for oceanic environment monitoring and oceanic resource detecting have been further improved and enhanced.Precise tracking and orbit determination are not only key technical concerns in the ocean dynamic environment satellite project but also necessary conditions for carrying out related oceanic science research using observational data obtained using spaceborne instruments including radar altimeter.In this study,the current available status of international satellite laser ranging(SLR) monitoring on HY-2 was introduced.Six-months of SLR data from HY-2 were processed to obtain precise satellite orbit information using the dynamic orbit determination method.We carried out a detailed assessment of the SLR orbit accuracy by internal evaluation,comparisons with the orbit derived by the French Doppler orbitography and radio-positioning integrated by satellite(DORIS) system,and station-satellite distance validation.These assessments indicate that the three-dimensional orbital accuracy of HY-2 is about 12.5 cm,and the radial accuracy is better than 3 cm.It provides a good example of the application of international SLR monitoring and precise orbit determination in China's earth observation satellite project.ZHAO Gang ZHOU XuHua WU Bin 2013Chinese Science Bulletin2013,58,6:8
5How complex is the 2016 Mw 7.8 Kaikoura earthquake, South Island, New Zealand?显示文摘A powerful earthquake of moment magnitude(Mw)7.8occurred in the Kaikoura region,South Island,New Zealand,at00:02:56 AM(local time),14 November 2016.According to the Institute of Geological and Nuclear Sciences(GNS)in New Zealand,Xuhua Shi Yu Wang Jing Liu-Zeng Ray Weldon Shengji Wei Teng Wang Kerry Sieh 2017Science Bulletin2017,62,5:6
6An improved form of smoothed particle hydrodynamics method for crack propagation simulation applied in rock mechanics显示文摘The simulation of crack propagation processes in rock engineering has been not only a research hot spot among scholars but also a challenge.Based on this background,a new numerical method named improved kernel of smoothed particle hydrodynamics(IKSPH)has been put forward.By improving the kernel function in the traditional smoothed particle hydrodynamics(SPH)method,the brittle fracture characteristics of the base particles are realized.The particle domain searching method(PDSM)has also been put forward to generate the arbitrary complex fissure networks.Three numerical examples are analyzed to validate the efficiency of IKSPH and PDSM,which can correctly reveal the morphology of wing crack and the laws of crack coalescence compared with previous experimental and numerical studies.Finally,a rock slope model with complex joints is numerically simulated and the progressive failure processes are exhibited,which indicates that the IKSPH method can be well applied to rock mechanics engineering.The research results showed that IKSPH method reduces the programming difficulties and avoids the traditional grid distortion,which can provide some references for the application of IKSPH to rock mechanics engineering and the understanding of rock fracture mechanisms.Shuyang Yu Xuhua Ren Jixun Zhang Haijun Wang Zhaohua Sun 2021International Journal of Mining Science and Technology2021,31,3:6
7The expression profile of genes in rice roots under low phosphorus stress显示文摘Phosphorus (P) is one of the most essential macronutrients required for plant growth. Although it is abundant in soil, P is often the limiting nutrient for crop yield potential because of the low concentration of soluble P that plants can absorb directly. The gene expression profile was investigated in rice roots at 6, 24 and 72 h under low P stress and compared with a control (normal P) profile, using a DNA chip of 60000 oligos (70 mer) that represented all putative genes of the rice genome. A total of 795 differentially expressed genes were identified in response to phosphate (Pi) starvation in at least one of the treatments. Based on the analysis, we found that: (i) The genes coding for the Pi transporter, acid phosphatase and RNase were up-regulated in rice roots; (ii) the genes involved in glycolysis were first up-regulated and then down-regulated; (iii) several genes involved in N metabolism and lipid metabolism changed their expression patterns; (iv) some genes involved in cell senescence and DNA or protein degradation were up-regulated; and (v) some transmembrane transporter genes were up-regulated. The results may provide useful information in the molecular process associated with Pi deficiency and thus facilitate research in improving Pi utilization in crop species.LI LiHua, QIU XuHua, LI XiangHua, WANG ShiPing & LIAN XingMing National Key Laboratory of Crop Genetic Improvement, National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China 2009Science China(Life Sciences)2009,52,11:5
8Generation dispatch method based on maximum entropy principle for power systems with high penetration of wind power显示文摘This paper proposes a generation dispatch model based on the maximum entropy principle. The objective is to find an optimal generation dispatch strategy that minimizes the generation cost and satisfies the security constraints of power systems, while taking into account the uncertainty of wind power. Since in many situations, only partial information of the probabilistic variables can be obtained, the maximum entropy principle is introduced to find the most likely realized probability distributions of the power flow, thus providing an accurate probabilistic circumstance to solve the generation dispatch model. The proposed method is tested on the IEEE 39-bus system, and is compared with the methodologies based on Monte Carlo simulation and Gram-Charlier expansions.Qiaoyan BIAN Yutao QIU Wenlian WU Huanhai XIN Xuhua FU 2018Journal of Modern Power Systems and Clean Energy2018,6,6:5
9Reconciliation of research on forest carbon sequestration and water conservation显示文摘Carbon sequestration and water conservation are two of the key ecosystem services that forests provide for societal need to address environmental issues.Optimization of the dual services is the ultimate goal in forest management for mitigating global climate change and safeguarding terrestrial water balance.However,there are some tradeoff s between gain in forest productivity and ecosystem water balance.We conducted literature review based on published articles for learned knowledge on forest carbon fi xation and hydrological regulations.Some knowledge gaps and research needs are identifi ed by examining the inter-connections between forest carbon sequestration and water conservation.Past researches have helped gain basic understanding of the mechanisms and controls of forest carbon fi xation and hydrological regulations as two separate issues.Tools and approaches are well established for quantifying and monitoring forest carbon and hydrological issues,operating at diff erent spatial and temporal scales.There are knowledge gaps on how to design aff orestation schemes facilitating enhanced ecosystem services in forest carbon sequestration and water conservation.For the top-down planning of aff orestation in regions where water availability is anticipated to be problematic,the questions of how much and where to plant for given land availability,known environmental implications,and sustained regional development and livelihood need to be addressed.For local management considerations,the questions of what and how to plant prevail.Eff orts are needed in joint studies of forest carbon sequestration and water conservation functionalities,specifi cally in relation to establishment and management of planted forests aiming for delivering regulatory ecosystem services in carbon sequestration,water conservation and other social values.We propose an integrated framework with dual consideration of carbon sequestration and water conservation in forest management for future research pursue.Tanzeel Javaid Aini Farooqi Xuhua Li Zhen Yu Shirong Liu Osbert Jianxin Sun 2021Journal of Forestry Research2021,32,1:4
10Study on embedded length of piles for slope reinforced with one row of piles显示文摘The embedded length of anti-slide piles for slope is analyzed by three-dimensional elastoplastic shear strength reduction method. The effect of embedded pile length on the factor of safety and pile behavior is analyzed. Furthermore, the effects of pile spacing, pile head conditions, pile bending stiffness and soil properties on length and behavior of pile are also analyzed. The results show that the pile spacing and the pile head conditions have significant influences on the critical embedded length of pile. It is found that the critical embedded length of pile, beyond which the factor of safety does not increase, increases with the decrease in pile spacing. The smaller the pile spacing is, the larger the integrity of the reinforced slope will be. A theoretical analysis of the slip surface is also conducted, and the slip surface determined by the pressure on piles, considering the influences of both soil and piles for slope, is in agreement with the ones in previous studies.Shikou Yang, Xuhua Ren, Jixun Zhang College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing, 210098, China 2011Journal of Rock Mechanics and Geotechnical Engineering2011,3,2:4
11Fracture of two three-dimensional parallel internal cracks in brittle solid under ultrasonic fracturing显示文摘Similar to hydraulic fracturing(HF), the coalescence and fracture of cracks are induced within a rock under the action of an ultrasonic field, known as ultrasonic fracturing(UF). Investigating UF is important in both hard rock drilling and oil and gas recovery. A three-dimensional internal laser-engraved crack(3D-ILC) method was introduced to prefabricate two parallel internal cracks within the samples without any damage to the surface. The samples were subjected to UF. The mechanism of UF was elucidated by analyzing the characteristics of fracture surfaces. The crack propagation path under different ultrasonic parameters was obtained by numerical simulation based on the Paris fatigue model and compared to the experimental results of UF. The results show that the 3D-ILC method is a powerful tool for UF research.Under the action of an ultrasonic field, the fracture surface shows the characteristics of beach marks and contains powder locally, indicating that the UF mechanism includes high-cycle fatigue fracture, shear and friction, and temperature load. The two internal cracks become close under UF. The numerical result obtained by the Paris fatigue model also shows the attraction of the two cracks, consistent with the test results. The 3D-ILC method provides a new tool for the experimental study of UF. Compared to the conventional numerical methods based on the analysis of stress-strain and plastic zone, numerical simulation can be a good alternative method to obtain the crack path under UF.Haijun Wang Hanzhang Li Lei Tang Xuhua Ren Qingxiang Meng Chun Zhu 2022Journal of Rock Mechanics and Geotechnical Engineering2022,14,3:4
12GNSS clock corrections densification at SHAO:from 5 min to 30 s显示文摘High frequency multi-GNSS zero-difference applications like Precise Orbit Determination(POD)for Low Earth Orbiters(LEO)and high frequency kinematic positioning require corresponding high-rate GNSS clock corrections.The determination of the GNSS clocks in the orbit determination process is time consuming,especially in the combined GPS/GLONASS processing.At present,a large number of IGS Analysis Centers(AC)provide clock corrections in 5-min sampling and only a few ACs provide clocks in 30-s sampling for both GPS and GLONASS.In this paper,an efficient epoch-difference GNSS clock determination algorithm is adopted based on the algorithm used by the Center for Orbit Determination in Europe(CODE).The clock determination procedure of the GNSS Analysis Center at Shanghai Astronomical Observatory(SHAO)and the algorithm is described in detail.It is shown that the approach greatly speeds up the processing,and the densified 30-s clocks have the same quality as the 5-min clocks estimated based on a zero-difference solution.Comparing the densified 30-s GNSS clocks provided by SHAO with that of IGS and its ACs,results show that our 30-s GNSS clocks are of the same quality as that of IGS.Allan deviation also gives the same conclusion.Further validation of the SHAO 30-s clock product is performed in kinematic PPP and LEO POD.Results indicate that the positions have the same accuracy when using SHAO 30-s GNSS clocks or IGS(and its AC)finals.The robustness of the algorithm and processing approach ensure its extension to provide clocks in 5-s or even higher frequencies.The implementation of the new approach is simple and it could be delivered as a black-box to the current scientific software packages.CHEN JunPing ZHANG YiZe ZHOU XuHua PEI Xiao WANG JieXian WU Bin 2014Science China(Physics,Mechanics & Astronomy)2014,57,1:4
13Analyses of factors forming offshore SST anomaly (O-SSTA) in China seas显示文摘Based on the observations, the location and the strength of warm(cold) anomaly of SST in surnmer are conrolled mainly by the subtropical highs of atmosphere (typhoon track) on the off shore of the China seas. It may be considered for the physical causes that the factors forming O-SSTA include the dynamic respome of upper layer ocean on tbe strong atmospheric forcing and the shallow sea effects. The former consists of the entrainment, the detrainment, the Ekman pumping and the convergence of surface warm watet; the later the tidal mixing and higher absorptivity. The parameterized expressions and the significance estimations of each factor are shown. The differences of both forming mechanisms and forming time-scales between the warm anomaly and the cold one are also indicated with different forcing systems.Wang Sizhen, Li Xuhua, Qi Jianhua and Su Yusong (Ocean University of Qingdao, Qingdao 266003, China) 1998Acta Oceanologica Sinica1998,17,4:4
14Basal internode elongation of rice as affected by light intensity and leaf area显示文摘Short basal internodes are important for lodging resistance of rice(Oryza sativa L.).Several canopy indices affect the elongation of basal internodes,but uncertainty as to the key factors determining elongation of basal internodes persists.The objectives of this study were(1)to identify key factors affecting the elongation of basal internodes and(2)to establish a quantitative relationship between basal internode length and canopy indices.An inbred rice cultivar,Yinjingruanzhan,was grown in two split-plot field experiments with three N rates(0,75,and 150 kg N ha−1 in early season and 0,90,and 180 kg N ha−1 in late season)as main plots,three seedling densities(16.7,75.0,and 187.5 seedlings m−2)as subplots,and three replications in the 2015 early and late seasons in Guangzhou,China.Light intensity at base of canopy(Lb),light quality as determined from red/far-red light ratio(R/FR),light transmission ratio(LTR),leaf area index(LAI),leaf N concentration(NLV)and final length of second internode(counted from soil surface upward)(FIL)were recorded.Higher N rate and seedling density resulted in significantly longer FIL.FIL was negatively correlated with Lb,LTR,and R/FR(P<0.01)and positively correlated with LAI(P<0.01),but not correlated with NLV(P>0.05).Stepwise linear regression analysis showed that FIL was strongly associated with Lb and LAI(R2=0.82).Heavy N application to pot-grown rice at the beginning of first internode elongation did not change FIL.We conclude that FIL is determined mainly by Lb and LAI at jointing stage.NLV has no direct effect on the elongation of basal internodes.N application indirectly affects FIL by changing LAI and light conditions in the rice canopy.Reducing LAI and improving canopy light transmission at jointing stage can shorten the basal internodes and increase the lodging resistance of rice.Xuhua Zhong Kaiming Liang Bilin Peng Ka Tian Xiaojuan Li Nongrong Huang Yanzhuo Liu Junfeng Pan 2020The Crop Journal2020,8,1:3
15Structural basis for the neutralization of hepatitis E virus by a cross-genotype antibody显示文摘肝炎 E 病毒(HEV ) ,一个非包的、积极感觉的、搁浅单人赛的 RNA 病毒,是伤寒肝炎的一个主要原因。分类进家庭 Hepeviridae, HEV 包括四遗传型(遗传型 1-4 ) ,它属于单个 serotype。我们描述 monoclonal 抗体(mAb ) ,有 ~ 2.53-3.45 nM 的 8G12,同等地认出 HEV 的所有四遗传型,有约束力的亲密关系。mAb 8G12 有一保护,抵销能力,它能显著地在主人房间堵住病毒感染。动物与 1, 3 和 4 证实了跨遗传型的抵销的遗传型学习 8G12 和它肝炎 E 疾病的有效预防的能力。有丰富的遗传型的 HEV E2s 领域(病毒衣壳的最耸出的区域) 的 8G12 的复杂水晶结构 1 和 4 在 4.0 和 2.3 Å 被决定;分辨率分别地。这些结构表明 8G12 在 E2s dimerization 区域通过 epitopes 认出两遗传型。有像病毒的粒子的基于结构的 mutagenesis 和房间模型试金识别了为 8G12 中立化是必要的几保存残余(Glu549, Lys554 和 Gly591 ) 。而且, 8G12 的 epitope 作为涉及病毒主人相互作用的关键 epitope 被识别。这些调查结果将帮助为 HEV 感染的最丰富的形式的预防开发普通策略。Ying Gu Xuhua Tang Xiao Zhang Cuiling Song Minghua Zheng Kaihang Wang Jun Zhang Mun-Hon Ng Choy-Leong Hew Shaowei Li Ningshao Xia J. Sivaraman 2015Cell Research2015,25,5:3
16Recent Progress on Smart Fiber and Textile Based Wearable Strain Sensors:Materials,Fabrications and Applications显示文摘With the rapid development of smart products,fexible and stretchable smart wearable electronic devices gradually play an important role,and they are considered as the pioneers of the new generation of fexible electronic devices.Among these intelligent devices,fexible and stretchable strain sensors have been widely studied for their good fexibility,high sensitivity,high repeatability and huge potential for application in personal healthcare and motion detection.Moreover,unlike traditional rigid bulky sensors,the high-performance fexible strain sensors are lightweight portable devices with excellent mechanical and electrical performance,which can meet personalized needs and become more popular.Herein,the research progress of fexible strain sensors in recent years are reviewed,which mainly introducing the sensing principles and key parameters of strain sensors,commonly used conductive materials and fexible substrates and common preparation methods,and fnally proposes the future application and prospects of strain sensors.Xuhua Liu Jinlei Miao Qiang Fan Wenxiao Zhang Xingwei Zuo Mingwei Tian Shifeng Zhu Xueji Zhang Lijun Qu 2022Advanced Fiber Materials2022,4,3:3
17Effect of different inter-satellite range on measurement precision of Earth’s gravitational field from GRACE显示文摘The precision of Earth's gravitational field from GRACE up to degree and order 120 was studied for different inter-satellite ranges using the improved energy conservation principle.Our simulated result shows that:For long wavelength(L≤20)at degree 20,the cumulative geoid-height error gradually decreased with increasing range,from 0.052 cm for 110 km to 1.156 times and 1.209 times as large for 220 km and 330 km,respectively.For medium-wavelength(100≤L≤120)at degree 120,the cumulative geoid-height error decreased from 13.052 cm for 110 km,to 1.327 times and 1.970 times as large for the ranges of 220 km and 330 km,respectively;By adopting an optimal range of 220±50 km,we can suppress considerably the loss of precision in the measurement of the Earth's long-wavelength and medium-wavelength gravitational field.Zheng Wei Hsu Houtse Zhong Min Yun Meijuan Zhou Xuhua 2012Geodesy and Geodynamics2012,3,1:3
18A New Cultivation-Evolution Technology of Accident Immune Function for a Petrochemical Enterprise显示文摘为在一家石油化学的企业在生产事故上开发一个有免疫力的函数的目的,预防机制的一条新耕作进化途径被分析关于有免疫力的缺乏症候群的各种各样的因素建议,由指免疫,基因算法和相关概念在药science.Accident免疫系统申请了高度危险的石油化学的企业,它由它的生产系统的安全 Organand 安全组织组成,典型地是为有免疫力的功能的进化耕作进步,新 Bimmune 房间在几层的家以后被产生屏蔽,克隆膨胀, receptored iting ,在石油化学的企业在工作事故的免疫系统组织。有有高本能的一个 B 有免疫力的房间,一个功利性的函数作为解决方案作为目标函数和有免疫力的抗体在工业为 accident-immunity.Taking 锁住事故的抗原,作者 scarried 外面为在抗原和抗体之间的本能的预言的一张计算图。Yang Zhenhong Zhang Xuhua Wang Xiangyao Wang Zhihu Liu Yank Zhang Xuan 2007China Petroleum Processing & Petrochemical Technology2007,9,1:3
19显示文摘WUJuan-xia XUHua ZHANGJin(吴娟霞 徐华 张锦) 2014化学学报2014,3,:2
20Strategies for overcoming low agronomic nitrogen use efficiency in irrigated rice systems in China显示文摘Shaobing Peng Roland J. Buresh Jianliang Huang Jianchang Yang Yingbin Zou Xuhua Zhong Guanghuo Wang Fusuo Zhang 2005Field Crops Research2005,,1:2
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