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Rational design of continuous and short-range lithium ion pathways based on polydopamine-anchored metal-organic frameworks for all-solid-state electrolytes
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作者 Kun Shi Changsong Yu +2 位作者 Dawei Zheng Zeheng Yang Weixin Zhang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第12期712-724,共13页
The immerging three dimensional(3D) metal-organic framework(MOF)-reinforced composite solid-state electrolytes have attracted great interest because of the enhanced ionic conductivity and mechanical properties. Howeve... The immerging three dimensional(3D) metal-organic framework(MOF)-reinforced composite solid-state electrolytes have attracted great interest because of the enhanced ionic conductivity and mechanical properties. However, the defective spatial arrangement of MOFs restricted by fabrication methodology leads to insufficient lithium ion transport in electrolytes. Herein, a 3D interconnected MOF framework tailored for all-solid-state electrolytes is rationally designed by a universal polydopamine(PDA)-engineered "double-sided tape" strategy. The PDA serves as a double-sided tape, firmly adhering on the special single-layer Nylon grid as well as offering uniform nucleation sites to anchor the metal nodes to ensure continuous growth of well-ordered MOFs. Benefiting from the Lewis acid feature of MOFs and its cage effect toward TFSI^(-), a fast and homogeneous lithium ion transport can be achieved through the internal channels within neighboring MOFs and the continuous MOFs/polymer interfaces both along the short-range circumferential boundary of Nylon fiber. The resultant composite electrolytes exhibit high lithium ion conductivity and prominent mechanical properties, rendering excellent cyclic stability whether used in coin or pouch cells. This work demonstrates a widely applicable "double-sided tape"strategy for controllable spatial arrangement of MOF nanoparticles on optional substrates, which provides a scalable approach to rationally construct desired lithium ion pathways within composite electrolytes. 展开更多
关键词 All-solid-state electrolytes “Double-sided tape”strategy Continuous lithium ion pathways short-range pathways Mechanical properties
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Comparison of Microwave Imaging Algorithms for Short-Range Scenarios
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作者 Zhengyue Dong Ning Xu Kuiwen Xu 《Journal of Beijing Institute of Technology》 EI CAS 2024年第3期227-236,共10页
Three dimensional(3-D)imaging algorithms with irregular planar multiple-input-multiple-output(MIMO)arrays are discussed and compared with each other.Based on the same MIMO array,a modified back projection algorithm(MB... Three dimensional(3-D)imaging algorithms with irregular planar multiple-input-multiple-output(MIMO)arrays are discussed and compared with each other.Based on the same MIMO array,a modified back projection algorithm(MBPA)is accordingly proposed and four imaging algorithms are used for comparison,back-projection method(BP),back-projection one in time domain(BP-TD),modified back-projection one and fast Fourier transform(FFT)-based MIMO range migration algorithm(FFT-based MIMO RMA).All of the algorithms have been implemented in practical application scenarios by use of the proposed imaging system.Back to the practical applications,MIMO array-based imaging system with wide-bandwidth properties provides an efficient tool to detect objects hidden behind a wall.An MIMO imaging radar system,composed of a vector network analyzer(VNA),a set of switches,and an array of Vivaldi antennas,have been designed,fabricated,and tested.Then,these algorithms have been applied to measured data collected in different scenarios constituted by five metallic spheres in the absence and in the presence of a wall between the antennas and the targets in simulation and pliers in free space for experimental test.Finally,the focusing properties and time consumption of the above algorithms are compared. 展开更多
关键词 multiple-input-multiple-output(MIMO) short-range imaging back projection modi-fied back propagation range migration algorithm(RMA) through-wall imaging
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Methodology for local correction of the heights of global geoid models to improve the accuracy of GNSS leveling
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作者 Stepan Savchuk Alina Fedorchuk 《Geodesy and Geodynamics》 EI CSCD 2024年第1期42-49,共8页
At present,one of the methods used to determine the height of points on the Earth’s surface is Global Navigation Satellite System(GNSS)leveling.It is possible to determine the orthometric or normal height by this met... At present,one of the methods used to determine the height of points on the Earth’s surface is Global Navigation Satellite System(GNSS)leveling.It is possible to determine the orthometric or normal height by this method only if there is a geoid or quasi-geoid height model available.This paper proposes the methodology for local correction of the heights of high-order global geoid models such as EGM08,EIGEN-6C4,GECO,and XGM2019e_2159.This methodology was tested in different areas of the research field,covering various relief forms.The dependence of the change in corrected height accuracy on the input data was analyzed,and the correction was also conducted for model heights in three tidal systems:"tide free","mean tide",and"zero tide".The results show that the heights of EIGEN-6C4 model can be corrected with an accuracy of up to 1 cm for flat and foothill terrains with the dimensionality of 1°×1°,2°×2°,and 3°×3°.The EGM08 model presents an almost identical result.The EIGEN-6C4 model is best suited for mountainous relief and provides an accuracy of 1.5 cm on the 1°×1°area.The height correction accuracy of GECO and XGM2019e_2159 models is slightly poor,which has fuzziness in terms of numerical fluctuation. 展开更多
关键词 GNSS leveling Global geoid model Gravity anomaly Weight data Correcting data
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Production and Detection of Ultracold Ground State 85Rb133Cs Molecules in the Lowest Vibrational Level by Short-Range Photoassociation
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作者 赵延霆 元晋鹏 +3 位作者 李中豪 姬中华 肖连团 贾锁堂 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第11期35-38,共4页
We investigate the production of ultracold ground state x^1∑7+(u = 0) RbCs molecules in the lowest vibrational level via short-range photoassociation followed by spontaneous emission. The starting point is the las... We investigate the production of ultracold ground state x^1∑7+(u = 0) RbCs molecules in the lowest vibrational level via short-range photoassociation followed by spontaneous emission. The starting point is the laser cooled 85Rb and laa cs atoms in a dual species, forced dark magneto-optical trap. The special intermediate level (5)O+ (u = 10) correlated to the (2)311 electric state is achieved by the photoassociation process. The formed ground state X1∑+ (u = 0) molecule is resonantly excited to the 2111 intermediate state by a 651 nm pulse laser and is ionized by a 532nm pulse laser and then detected by the time-of-flight mass spectrum. Saturation of the photoionization spectroscopy at large ionization laser energy is observed and the ionization efficiency is obtained from the fitting. The production of ultracold ground state 85Rblaacs molecules is facilitative for the further research about the manipulation of ultracold molecules in the rovibrational ground state. 展开更多
关键词 Cs Molecules in the Lowest Vibrational level by short-range Photoassociation Production and Detection of Ultracold Ground State Rb
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Coseismic vertical deformation of the M_S8.0 Wenchuan earthquake from repeated levelings and its constraint on listric fault geometry 被引量:24
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作者 Qingliang Wang Duxin Cui +4 位作者 Xi Zhang Wenping Wang Jinwen Liu Kang Tian Zhaoshan Song 《Earthquake Science》 CSCD 2009年第6期595-602,共8页
The devastating Ms8.0 Wenchuan earthquake ruptured two large parallel thrust faults along the middle segment of the Longmenshan thrust belt. Preseismic and postseismic leveling data indicated the hanging wall of the Y... The devastating Ms8.0 Wenchuan earthquake ruptured two large parallel thrust faults along the middle segment of the Longmenshan thrust belt. Preseismic and postseismic leveling data indicated the hanging wall of the Yingxiu-Beichuan-Nanba thrust fault mainly presented coseismic uplift with respect to the reference point at Pingwu county town, and the observed maximum uplift of 4.7 m is located at Beichuan county (Qushan town) which is about 100 m west of the fault scarp. The foot wall of the Yingxiu-Beichuan-Nanba thrust fault mainly showed subsidence with maximum subsidence of 0.6 m near the rupture. By employing a listric dislocation model, we found that the fault geometry model of exponential dip angle δ=88°×[1-exp(-9/h)] with depth of 18 km and uniform thrust-slip of 5.6 m could fit the observed coseismic vertical deformation very well, which verifies the listric thrust model of the Longmenshan orogenic zone. 展开更多
关键词 Wenchuan earthquake leveling vertical deformation listric faulting
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结合GPS/Leveling和正高改正确定GPS常年观测站正高 被引量:1
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作者 尹弘植 黄鹤 李东河 《测绘通报》 CSCD 北大核心 2008年第3期25-27,共3页
利用精密几何水准测量结合GPS/Leveling方法计算韩国行政自治部管辖内30所GPS常年观测站天线基准点的正高。并联合进行对水准点和GPS常年观测站偏心点的重力测量,使用正高改正方法计算出其改正量,提高正高的精确度。
关键词 GPS常年观测站 几何水准测量 GPS/leveling 重力测量 正高改正 正高
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Numerical Simulation of Continuous Tension Leveling Process of Thin Strip Steel and Its Application 被引量:12
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作者 LI Sheng-zhi YIN Yuan-de +2 位作者 XU Jie HOU Jun-ming Jaehong YOON 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2007年第6期8-13,共6页
Cold-rolled thin strip steel of high flatness quality undergoes multistage deformation during tension leveling. Thus, the parameters of set-up and manipulating are more difficult. With the aid of FE code MSC. MARC, th... Cold-rolled thin strip steel of high flatness quality undergoes multistage deformation during tension leveling. Thus, the parameters of set-up and manipulating are more difficult. With the aid of FE code MSC. MARC, the tension leveling process of thin strip steel was numerically simulated. Concentrating on the influence of the roll intermeshes in 2# anti-cambering on the distribution and magnitude of residual stresses in leveled strip steel, several experiments were clone with the tension leveler based on the results from the simulation. It was found from the simulation that the magnitude of longitudinal residual stresses in the cross-section of the leveled strip steel regularly presents obvious interdependence with the roll intermeshes in 2# anti-cambering. In addition, there is a steady zone as the longitudinal residual stresses of the surface layers in leveled strip steel vary with the roll intermeshes of 2# anticambering, which is of importance in the manipulation of tension levelers. It was also found that the distribution of strains and stresses across the width of strip steel is uneven during leveling or after removing the tension loaded upon the strip, from which it was found that 3D simulation could not be replaced by 2D analysis because 2D analysis in this case cannot represent the physical behavior of strip steel deformation during tension leveling. 展开更多
关键词 cold-rolled strip steel FLATNESS tension leveling numerical simulation shell element residual stress
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Model for the Whole Roller Leveling Process of Plates with Random Curvature Distribution Based on the Curvature Integration Method 被引量:4
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作者 Ben Guan Chao Zhang +1 位作者 Yong Zang Yuan Wang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2019年第3期145-155,共11页
A model based on the curvature integration method has been applied in an online plate leveling system. However, there are some shortcomings in the current leveling models. On the one hand, the models cannot deal with ... A model based on the curvature integration method has been applied in an online plate leveling system. However, there are some shortcomings in the current leveling models. On the one hand, the models cannot deal with the leveling process of plates with a random curvature distribution. On the other hand, the current models are suitable only for stable leveling processes and ignore the biting in and tailing out stages. This study presents a new plate-leveling model based on the curvature integration method, which can describe the leveling process of plates with random curvature distribution. Further, the model is solved in two cases in order to take the biting in and tailing out stages into consideration. The proposed model is evaluated by comparing with a plate leveling experiment. Finally, the leveling process of a plate with a wave bent is studied using the proposed model. It is found that the contact angles vary greatly during the biting in and tailing out stages. However, they are relatively steady during the 5 roller leveling stage. In addition, the contact angle of roller No. 2 is the smallest, which is close to 0. Roller leveling can effectively eliminate bending in the plate, but there are regions in the head and tail of the plate, where roller leveling is not effective. The non-leveling region length is about 2 times that of the roller space. This study proposes a quasi-static plate-leveling model, which makes it possible to analyze the dynamic straightening process using a curvature integration method. It also makes it possible to analyze the straightening process of a plate with random curvature distribution. 展开更多
关键词 leveling CURVATURE integration method CURVATURE Contact ANGLE DEFLECTION
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Fuzzy Sliding Mode Control for the Vehicle Height and Leveling Adjustment System of an Electronic Air Suspension 被引量:8
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作者 Xiao-Qiang Sun Ying-Feng Cai +2 位作者 Chao-Chun Yuan Shao-Hua Wang Long Chen 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2018年第2期238-250,共13页
The accurate control for the vehicle height and leveling adjustment system of an electronic air suspension(EAS) still is a challenging problem that has not been effectively solved in prior researches. This paper propo... The accurate control for the vehicle height and leveling adjustment system of an electronic air suspension(EAS) still is a challenging problem that has not been effectively solved in prior researches. This paper proposes a new adaptive controller to control the vehicle height and to adjust the roll and pitch angles of the vehicle body(leveling control) during the vehicle height adjustment procedures by an EAS system. A nonlinear mechanism model of the full?car vehicle height adjustment system is established to reflect the system dynamic behaviors and to derive the system optimal control law. To deal with the nonlinear characters in the vehicle height and leveling adjustment processes, the nonlinear system model is globally linearized through the state feedback method. On this basis, a fuzzy sliding mode controller(FSMC) is designed to improve the control accuracy of the vehicle height adjustment and to reduce the peak values of the roll and pitch angles of the vehicle body. To verify the effectiveness of the proposed control method more accurately, the full?car EAS system model programmed using AMESim is also given. Then, the co?simulation study of the FSMC performance can be conducted. Finally, actual vehicle tests are performed with a city bus, and the test results illustrate that the vehicle height adjustment performance is effectively guaranteed by the FSMC, and the peak values of the roll and pitch angles of the vehicle body during the vehicle height adjustment procedures are also reduced significantly. This research proposes an effective control methodology for the vehicle height and leveling adjustment system of an EAS, which provides a favorable control performance for the system. 展开更多
关键词 Electronic air suspension Height adjustment leveling control Fuzzy sliding mode control Vehicle tests
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Present-day 3D deformation field of Northeast China,observed by GPS and leveling 被引量:6
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作者 Ji Lingyun Wang Qingliang Wang Shuangxu 《Geodesy and Geodynamics》 2014年第3期34-40,共7页
A broad view of present-day 3D deformation field around the Northeast China region was derived from GPS and leveling observations. We draw the following conclusions: First, the Northeast China region moved towards no... A broad view of present-day 3D deformation field around the Northeast China region was derived from GPS and leveling observations. We draw the following conclusions: First, the Northeast China region moved towards northwest with an average velocity of 5 ram/a, with respect to South China. The entire Northeast China region was in a low strain state from the strain rate field. Second, we processed two periods of first- order leveling data in 1970s and 1990s, showing the vertical deformation of the Northeast China region is "uplift in western part and subsidence in eastern part' 展开更多
关键词 3D deformation fields Northeast China region GPS leveling
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Research on Precise Trigonometric Leveling in Place of First Order Leveling 被引量:7
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作者 ZHANG Zhenglu ZHANG Kun +1 位作者 DENG Yong LUO Changlin 《Geo-Spatial Information Science》 2005年第4期235-239,共5页
Through the analysis of the principle, error sources and precision of trigonometric leveling, this paper points out the key problems about first order leveling replaced by trigonometric leveling; and for the first tim... Through the analysis of the principle, error sources and precision of trigonometric leveling, this paper points out the key problems about first order leveling replaced by trigonometric leveling; and for the first time puts forward that, in some given conditions, it is not only feasible but also valuable to replace first order leveling by precise trigonometric leveling, and proves it by experimentation as well. The content and conclusion of this paper have consulting significance and practicable value for our setting down relational criterion and production practice. 展开更多
关键词 electronic distance measurements trigonometric leveling first order leveling surveying for deformation monitoring
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Boundary determination of leveling capacity for plate roller leveler based on curvature integration method 被引量:2
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作者 刘志芳 罗远新 +1 位作者 严兴春 王勇勤 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第12期4608-4615,共8页
Leveler is widely used to improve the quality of defective mild steel plates.Its typical ranges of the leveling capacity are constrained by three criteria,namely the maximum stroke of rollers,allowable total leveling ... Leveler is widely used to improve the quality of defective mild steel plates.Its typical ranges of the leveling capacity are constrained by three criteria,namely the maximum stroke of rollers,allowable total leveling force and motor power.In this work,an optimization model with equality and inequality constraints was built for the maximum yield stress search of each thickness of plates.The corresponding search procedure with three loops was given.The approximate range by the simplification model could be used as the initial value for the actual range search of the leveling capacity.Therefore,the search speed could be accelerated compared with a global search.The consistency of the analytical results and field data demonstrates the reliability of the proposed model and procedure.The typical ranges of the leveling capacity are expressed by several boundary curves which are helpful to judge whether the incoming plate can be leveled quickly or not.Also,these curves can be used to find the maximum yield stress for a specific thickness or the maximum thickness for a yield stress for plates. 展开更多
关键词 plastic ratio leveling capacity curvature integration PLATE
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APPLICATION EXPERIMENT OF ASSIMILATING RADAR-RETRIEVED WATER VAPOR IN SHORT-RANGE FORECAST OF RAINFALL IN THE ANNUALLY FIRST RAINY SEASON OVER SOUTH CHINA 被引量:2
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作者 张诚忠 陈子通 +4 位作者 万齐林 林振敏 黄燕燕 戴光丰 丁伟钰 《Journal of Tropical Meteorology》 SCIE 2016年第4期578-588,共11页
A scheme of assimilating radar-retrieved water vapor is adopted to improve the quality of NWP initial field for improvement of the accuracy of short-range precipitation prediction. To reveal the impact of the assimila... A scheme of assimilating radar-retrieved water vapor is adopted to improve the quality of NWP initial field for improvement of the accuracy of short-range precipitation prediction. To reveal the impact of the assimilation of radar-retrieved water vapor on short-term precipitation forecast, three parallel experiments, cold start, hot start and hot start plus the assimilation of radar-retrieved water vapor, are designed to simulate the 31 days of May, 2013 with a fine numerical model for South China. Furthermore, a case of heavy rain that occurred from 8-9 May 2013 over the region from the southwest of Guangdong province to Pearl River Delta is analyzed in detail. Results show that the cold start experiment is not conducive to precipitation 12 hours ahead; the hot start experiment is able to reproduce well the first6 hours of precipitation, but badly for subsequent prediction; the experiment of assimilating radar-retrieved water vapor is not only able to simulate well the precipitation 6 hours ahead, but also able to correctly predict the evolution of rain bands from 6 to 12 hours in advance. 展开更多
关键词 radar-retrieved water vapor RAINFALL in annually FIRST RAINY season short-range FORECAST data assimilation
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Effects of short-range attraction on Jamming transition 被引量:1
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作者 Zhenhuan Xu Rui Wang +2 位作者 Jiamei Cui Yanjun Liu Wen Zheng 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第6期409-413,共5页
Enormous progresses to understand the jamming transition have been driven via simulating purely repulsive particles which were somehow idealized in the past two decades. While the attractive systems are both theoretic... Enormous progresses to understand the jamming transition have been driven via simulating purely repulsive particles which were somehow idealized in the past two decades. While the attractive systems are both theoretical and practical compared with repulsive systems. By studying the statistics of rigid clusters, we find that the critical packing fraction φ_(c) varies linearly with attraction μ for different system sizes when the range of attraction is short. While for systems with long-range attractions, however, the slope of φ_(c) appears significantly different, which means that there are two distinct jamming scenarios. In this paper, we focus our main attention on short-range attractions scenario and define a new quantity named "short-range attraction susceptibility" χ_(p), which describes the degree of response of the probability of finding jammed states pjto short-range attraction strength μ. Our central results are that χ_(p) diverges in the thermodynamic limit as χ_(p) ∝|φ-φ_(c)^(∞)|^(-γ_(p)), where φ_(c)^(∞) is the packing fraction at the jamming transition for the infinite system in the absence of attraction. χ_(p) obeys scaling collapse with a scaling function in both two and three dimensions, illuminating that the jamming transition can be considered as a phase transition as proposed in previous work. 展开更多
关键词 short-range attraction Jamming transition short-range attraction susceptibility
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Comparative study on vertical deformation based on GPS and leveling data 被引量:1
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作者 Shanlan Qin Wenping Wang Shangwu Song 《Geodesy and Geodynamics》 2018年第2期115-120,共6页
The development of GPS(Global Positioning System) technology has led to increasingly widely and successful applications of GPS surveys for monitoring crustal movements. However, multi-period GPS survey solutions have ... The development of GPS(Global Positioning System) technology has led to increasingly widely and successful applications of GPS surveys for monitoring crustal movements. However, multi-period GPS survey solutions have not been applied in monitoring vertical crustal movements with normal backgrounds. In this paper, we carried out a comparative study on the vertical deformation of the comprehensive profile of the cross-fault zone in Shanyin, Shanxi province, China, based on GPS and precise leveling observation data for multiple time periods. The vertical deformation rates observed with repeating GPS survey are obviously different(over 20 mm/y at some sites) from those with repeating leveling survey within a relatively short period. However, the deviations in the vertical displacement between GPS and leveling in a long-term survey(over three years) showed good consistency at 3-4 mm/y at most sites, on GPS forced offset surveying and fixed survey instruments in a long-term survey(over three years). Therefore, GPS vertical displacement results can be applied to the study of vertical crustal movements. 展开更多
关键词 Vertical deformation GPS Precise leveling DEVIATIONS
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Layering Precision Land Leveling and Furrow Irrigated Raised Bed Planting: Productivity and Input Use Efficiency of Irrigated Bread Wheat in Indo-Gangetic Plains 被引量:6
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作者 M. L. Jat Raj Gupta +1 位作者 Y. S. Saharawat Raj Khosla 《American Journal of Plant Sciences》 2011年第4期578-588,共11页
Stagnating yield and declining input use efficiency in irrigated wheat of the Indo-Gangetic Plain (IGP) coupled with diminishing availability of water for agriculture is a major concern of food security in South Asia.... Stagnating yield and declining input use efficiency in irrigated wheat of the Indo-Gangetic Plain (IGP) coupled with diminishing availability of water for agriculture is a major concern of food security in South Asia. The objective of our study was to establish an understanding of how wheat yield and input use efficiency can be improved and how land leveling and crop establishment practices can be modified to be more efficient in water use through layering of precision-conservation crop management techniques. The “precision land leveling with raised bed” planting can be used to improve crop yield, water and nutrient use efficiency over the existing “traditional land leveling with flat” planting practices. We conducted a field experiment during 2002-2004 at Modipuram, India to quantify the benefits of alternate land leveling (precision land leveling) and crop establishment (furrow irrigated raised bed planting) techniques alone or in combination (layering precision-conservation) in terms of crop yield, water savings, and nutrient use efficiency of wheat production in IGP. The wheat yield was about 16.6% higher with nearly 50% less irrigation water with layering precision land leveling and raised bed planting compared to traditional practices (traditional land leveling with flat planting). The agronomic (AE) and uptake efficiency (UE) of N, P and K were significantly improved under precision land leveling with raised bed planting technique compared to other practices. 展开更多
关键词 Precision Land leveling FURROW IRRIGATED Raised BED PLANTING Input Use EFFICIENCY IRRIGATED Bread Wheat Water PRODUCTIVITY Uptake EFFICIENCY Agronomic EFFICIENCY
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Bias-Corrected Short-Range Ensemble Forecasts for Near-Surface Variables during the Summer Season of 2010 in Northern China 被引量:2
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作者 ZHU Jiang-Shan KONG Fan-You LEI Heng-Chi 《Atmospheric and Oceanic Science Letters》 CSCD 2014年第4期334-339,共6页
A running mean bias (RMB) correction ap- proach was applied to the forecasts of near-surface variables in a seasonal short-range ensemble forecasting experiment with 57 consecutive cases during summer 2010 in the no... A running mean bias (RMB) correction ap- proach was applied to the forecasts of near-surface variables in a seasonal short-range ensemble forecasting experiment with 57 consecutive cases during summer 2010 in the northern China region. To determine a proper training window length for calculating RMB, window lengths from 2 to 20 days were evaluated, and 16 days was taken as an optimal window length, since it receives most of the benefit from extending the window length. The raw and 16-day RMB corrected ensembles were then evaluated for their ensemble mean forecast skills. The results show that the raw ensemble has obvious bias in all near-surface variables. The RMB correction can remove the bias reasonably well, and generate an unbiased ensemble. The bias correction not only reduces the ensemble mean forecast error, but also results in a better spreaderror relationship. Moreover, two methods for computing calibrated probabilistic forecast (PF) were also evaluated through the 57 case dates: 1) using the relative frequency from the RMB-eorrected ensemble; 2) computing the forecasting probabilities based on a historical rank histogram. The first method outperforms the second one, as it can improve both the reliability and the resolution of the PFs, while the second method only has a small effect on the reliability, indicating the necessity and importance of removing the systematic errors from the ensemble. 展开更多
关键词 short-range ensemble forecast bias-corrected ensemble forecast running mean bias correction near-surface variable forecast
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Temporal-spatial Distribution and Short-range Prediction Indicators of Hail Weather in East Central Haixi Prefecture of Qinghai Province 被引量:2
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作者 Xiuping Cheng Chengtao Shan +1 位作者 Gasang Pei Na Wang 《Meteorological and Environmental Research》 CAS 2013年第4期21-25,共5页
[ Objective] The study aimed to discuss the temporal-spatial distribution and short-range prediction indicators of hail weather in east central Haixi Prefecture of Qinghai Province. [Method] Using hail data of six sta... [ Objective] The study aimed to discuss the temporal-spatial distribution and short-range prediction indicators of hail weather in east central Haixi Prefecture of Qinghai Province. [Method] Using hail data of six stations in east central Haixi Prefecture from 1960 to 2010, the temporal and spatial distribution of hail weather was analyzed firstly. Afterwards, based on the high-altitude factual data of 30 case studies of hail during 2006 -2010, its high-altitude and ground weather situation and physical quantity field were studied to summarize short-term circulation pattern and shod- range prediction characteristics of hail weather. [ Result] In east central Haixi, hail appeared from April to September, and it was most frequently from May to August. Meanwhile, hail was frequent from 14:00 to 20:00. Among the six stations, hail was most frequent in Tianjun but least frequent in Wulan. Moreover, hail disaster mainly occurred in Wulan and Tianjun. In addition, there were three typos of circulation pattern of hail weather at 500 hPa. Hail mainly occurred under the effect of northwest airflow, and it had shortwave trough, cold center or trough, jet stream core or one of the three. Hail appeared frequently under the situation of upper-level divergence and low-level convergence, and abundant water vapor and water vapor flux convergence at low levels were important conditions for hailing. [ Conclusion] The research could provide scientific references for improving the accuracy of hail forecast. 展开更多
关键词 East central Haixi Prefecture HAIL Temporal-spatial distribution Physical quantity field short-range prediction indicators China
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Effects of wind guide plates on wind velocity acceleration and dune leveling: a case study in Ulan Buh Desert, China 被引量:3
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作者 HAN Yanlong GAO Yong +4 位作者 MENG Zhongju DANG Xiaohong JIA Xu DING Yanlong LI Peng 《Journal of Arid Land》 SCIE CSCD 2017年第5期743-752,共10页
The areas used to be covered by shifting sand dunes have been reclaimed rapidly in recent years. However, it is a challenge to reclaim high sand dunes because it is rather costly to level the high dunes to gentle arab... The areas used to be covered by shifting sand dunes have been reclaimed rapidly in recent years. However, it is a challenge to reclaim high sand dunes because it is rather costly to level the high dunes to gentle arable lands. In this study, a wind guide plate was used to change the characteristics of natural wind to level the sand dunes. The use of wind energy could significantly increase the efficiency of dune leveling and decrease the cost. Low wind velocity is a typical characteristic in Ulan Buh Desert of China where the average wind speed is much lower than the threshold velocity for sand movement. The experiment of this study was conducted to accelerate the wind velocity by a wind guide plate to level a sand dune. Results show that the threshold velocity for sand movement is 3.32 m/s at 10 cm above the sand surface in Ulan Buh Desert. A wind guide plate set at an angle less than 50° could significantly increase the wind velocity. The wind velocity could be accelerated up to the threshold velocity for sand movement behind a plate when the plate is at the angles of 20°, 25°, 35° and 40°. The most significant acceleration of wind velocity appears at 1.5 and 3.0 m behind the plate with an angle of 25°. An obvious wind velocity acceleration zone exists behind the wind guide plate when the angles are at 25°, 35°, 40° and 45°, with the most obvious zone under the angle of 45°. The results also show that the total amount of sand transferred over the experimental period increased by 6.1% under the effects of wind guide plates compared to the sand moved without wind guide plates. The results of the study will provide theoretical and practical supports for desert management in sand dune areas. 展开更多
关键词 wind guide plate sand dune dune leveling wind velocity sandy desert Ulan Buh Desert
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Short-range clutter suppression method combining oblique projection and interpolation in airborne CFA radar 被引量:1
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作者 HU Yili ZHAO Yongbo +1 位作者 PANG Xiaojiao CHEN Sheng 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2021年第1期92-102,共11页
The airborne conformal array(CFA)radar's clutter ridges are range-modulated,which result in a bias in the estimation of the clutter covariance matrix(CCM)of the cell under test(CUT),further,reducing the clutter su... The airborne conformal array(CFA)radar's clutter ridges are range-modulated,which result in a bias in the estimation of the clutter covariance matrix(CCM)of the cell under test(CUT),further,reducing the clutter suppression performance of the airborne CFA radar.The clutter ridges can be effectively compensated by the space-time separation interpolation(STSINT)method,which costs less computation than the space-time interpolation(STINT)method,but the performance of interpolation algorithms is seriously affected by the short-range clutter,especially near the platform height.Location distributions of CFA are free,which yields serious impact that range spaces of steering vector matrices are non-orthogonal complement and even no longer disjoint.Further,a new method is proposed that the shortrange clutter is pre-processed by oblique projection with the intersected range spaces(OPIRS),and then clutter data after being pre-processed are compensated to the desired range bin through the STSINT method.The OPIRS also has good compatibility and can be used in combination with many existing methods.At the same time,oblique projectors of OPIRS can be obtained in advance,so the proposed method has almost the same computational load as the traditional compensation method.In addition,the proposed method can perform well when the channel error exists.Computer simulation results verify the effectiveness of the proposed method. 展开更多
关键词 airborne conformal arrays(CFA)radar oblique projection intersected range space short-range clutter suppression
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