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Physiological Responses of Three Contrasting Plant Species to groundwater Level Changes in an Arid Environment

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Journal of Integrative Plant Biology 2006年第5期48卷 520-526页

作者： li Zhuang ya-Ning Chen Xinjiang Institute of Ecology and geography the Chinese Academy of Sciences Urumqi 830011 China

Plants growing on both sides of the Tarim River in western China serve as a natural barrier containing the deserts and protecting the oasis, and their growth is greatly affected by water conditions In their local habitat. We studied the physiological responses of three different types plants （i.e. Populus euphratlca Oliver, Tamarix ramosissima L., and Apocynum venetumas linn） to changing groundwater levels by analyzing changes in chlorophyll, soluble sugar, proline （Pro）, malondialdehyde （MDA）, superoxlde dlsmutase （SOD）, peroxidase （POD）, indoleacetic acid （IAA）, giberellic acid, abscisic acid （ABA） and cytokinin （CK）. Relationships between these physiological characteristics and groundwater levels were analyzed in order to assess the drought tolerance of the three plant species based on the values of average membership function. We found that MDA, SOD and ABA were more susceptible to changes in groundwater level, followed by POD, IAA and CK. Among the three plant species, Populus euphratica responded physiologically less to changing groundwater level than T. ramosissima and A. venetumas.

关键词： Apocynum venetumas groundwater level membership function method Populus euphratica Tamarix ramosissima Tarim River.

Structures of sodium vanadate solution under different conditions

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Rare Metals 2018年第1期37卷 59-65页

作者： ya-li Zhang li-Qun yang Xian-Jin Yu School of Chemical Engineering Shandong University of Technology

Combined with Fourier transform infrared spectroscopy（FTIR） analysis of sodium vanadate solution,the relationship between conductivity and structure was investigated by measuring the electric conductivity of the solution under different alkali concentrations and molar ratios of NaOH to V2O5. Results suggest that the polymerization vanadium acid radical ions gradually transform into monomer with the solution diluting. When the solution is diluted to a certain extent,only the vanadium acid radical ion with V-OH chemical bond exists in the solution. At NaOH concentration of below 105.21 g·L^（-1）,the vanadate anions mainly exist in the form of vanadium acid radical ion with V-OH chemical bond and the ion transference number is approximately from 0.58 to 0.82. In the medium NaOH concentration range of 105.21-117.03 g·L^（-1）, the vanadate anions mostly exist in the form of vanadium acid radical ion with V-OH and V-O-V chemical bonds and the ion transference number is approximately 3.29. At NaOH concentration of above 117.03 g·L^（-1）, vanadate anions exist in the form of vanadium acid radical ion with V-OH and V-O-V chemical bonds.

关键词： Sodium vanadate solution Electric conductivity Migration number Infrared spectroscopy

Improved space-time processing for X channel using precoders

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The Journal of China Universities of Posts and Telecommunications 2014年第5期21卷 31-36页

作者： TIAN Xin-ji li ya School of Computer Science and Technology Henan Polytechnic University

The article investigates how to send perfect space-time codes with low feedback amount and symbol-by-symbol decoding for X channel using precoders. It is assumed that two users are introduced with two antennas and two receivers. Each user employs a rate-2 space-time block code and follows certain rule when sending codewords. The multi-user interference is eliminated by pre-coding at the transmitter and linear processing at the receiver. Compared with the existing scheme for the same scene, the proposed scheme greatly reduces feedback amount and improves the transmission efficiency, while keeping the same decoding complexity. Simulations demonstrate the validity of the proposed scheme.

关键词： X channel space-time code pre-coding multi-user interference feedback amount transmission efficiency

Boron separation from Si–Sn alloy by slag treatment

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International Journal of Minerals,Metallurgy and Materials 2018年第12期25卷 1439-1446页

作者： Rowaid Al-khazraji ya-qiong li li-feng Zhang School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing Key Laboratory of green Recycling and Extraction of Metal University of Science &Technology Beijing

This study investigates a purification process for metallurgical-grade silicon(Mg-Si) in which Si is alloyed with tin(Sn) and Ca O–Si O_2–Ca Cl_2 slag is used to remove boron(B) impurity. Acid leaching was performed to remove the Sn phase after slag refining to recover high-purity Si from the Si–Sn alloy. The effect of refining time was investigated, and acceptable refining results were realized within 15 min. The effects of slag composition and Sn content on the removal of B were also studied. The results indicate that increasing Sn content favors B removal. With the increase of Sn to 50% of the alloy, the final B content decreased to 1.1 × 10^(-4) wt%, 93.9% removal efficiency.

关键词： boron removal metallurgical grade silicon Si–Sn alloy slag refining

Improvement of location methods based on RFID

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The Journal of China Universities of Posts and Telecommunications 2013年第6期20卷 36-41页

作者： WU ling HUANg li-ya Institute of Electronic Science and Engineering Nanjing University of Posts and Telecommunications

The most common location algorithms based on received signal strength （RSS） are location identification based on dynamic active radio frequency identification （LANDMARC） and virtual reference elimination （VIRE）. However, both the original algorithms suffer from some drawbacks. In this paper, several aspects of the two original algorithms have been modified to reduce the positioning errors. Firstly, Lagrange interpolation has been used instead of linear interpolation. Secondly, adaptive threshold has been introduced in the new algorithm. Thirdly, insert virtual reference tags to improve the location accuracy of the boundary of the sensing area. Finally, combine LANDMARC with VIRE to absorb both advantages. Compared with the original algorithms, on average, simulated results show that the modified algorithms can improve the location performance efficiently and achieve the goal of accurate positioning in indoor environment.

关键词： LANDMARC VIRE received signal strength indicator (RSSI) Lagrange adaptive threshold

Paths of algebraic hyperbolic curves

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第6期9卷 816-821页

作者： ya-juan li li-zheng LU guo-zhao WANg School of Science Hangzhou Dianzi University Hangzhou 310018 China Department of Mathematics Zhejiang University Hangzhou 310027 China

Cubic algebraic hyperbolic （AH） Bezier curves and AH spline curves are defined with a positive parameter a in the space spanned by {1, t, sinht, cosht}. Modifying the value of a yields a family ofAH Bezier or spline curves with the family parameter α. For a fixed point on the original curve, it will move on a defined curve called ＂path of AH curve＂（AH Bezier and AH spline curves） when a changes. We describe the geometric effects of the paths and give a method to specify a curve passing through a given point.

关键词： Algebraic hyperbolic (AH) Bezier curve AH spline curve Path Shape modification

Reductive leaching of manganese from low-grade pyrolusite ore in sulfuric acid using pyrolysis-pretreated sawdust as a reductant

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International Journal of Minerals,Metallurgy and Materials 2016年第3期23卷 241-246页

作者： ya-li Feng Shi-yuan Zhang Hao-ran li School of Civil and Environmental Engineering University of Science and Technology Beijing National Key Laboratory of Biochemical Engineering Institute of Process Engineering Chinese Academy of Sciences

Manganese （Mn） leaching and recovery from low-grade pyrolusite ore were studied using sulfiaric acid （H2SO4） as a leachant and pyrolysis-pretreated sawdust as a reductant. The effects of the dosage of pyrolysis-pretreated sawdust to pyrolusite ore, the concentration of sulfuric acid, the liquid/solid ratio, the leaching temperature, and the leaching time on manganese and iron leaching efficiencies were inves- tigated. Analysis of manganese and iron leaching efficiencies revealed that a high manganese leaching efficiency was achieved with low iron extraction. The optimal leaching efficiency was determined to be 20wt% pyrolysis-pretreated sawdust and 3.0 mol/L H2SO4 using a liq- uid/solid ratio of 6.0 mL/g for 90min at 90℃. Other low-grade pyrolusite ores were tested, and the results showed that they responded well with manganese leaching efficiencies greater than 98%.

关键词： manganese ore treatment pyrolusite sawdust pyrolysis leaching manganese

Study of parachute inflation process using fluid–structure interaction method

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Chinese Journal of Aeronautics 2014年第2期27卷 272-279页

作者： Yu li Cheng Han Zhan ya'nan li Shaoteng College of Aerospace Engineering Nanjing University of Aeronautics and Astronautics

A direct numerical modeling method for parachute is proposed firstly, and a model for the star-shaped folded parachute with detailed structures is established. The simplified arbitrary Lagrangian-Eulerian fluid structure interaction （SALE/FSI） method is used to simulate the infla- tion process of a folded parachute, and the flow field calculation is mainly based on operator split- ting technique. By using this method, the dynamic variations of related parameters such as flow field and structure are obtained, and the load jump appearing at the end of initial inflation stage is cap- tured. Numerical results including opening load, drag characteristics, swinging angle, etc. are well consistent with wind tunnel tests. In addition, this coupled method can get more space-time detailed information such as geometry shape, structure, motion, and flow field. Compared with previous inflation time method, this method is a completely theoretical analysis approach without relying on empirical coefficients, which can provide a reference for material selection, performance optimi- zation during parachute design.

关键词： Empirical formula Fluid-structure interaction Inflation process Opening shockiParachute Wind tunnel test

Temperature stability of magnetic field for periodic permanent-magnet focusing system

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Rare Metals 2014年第2期33卷 180-184页

作者： li li Jian-ya Chen Yun-Jie liu Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications

In this study, finite element analysis based on an Ansoft Maxwell software was used to reveal the temperature stability of a magnet ring and the equivalent structural periodic permanent-magnet（PPM） focusing system. It is found that with the temperature increasing, the decrease rate of magnetic induction peak（Bz）maxof single magnet ring is greater than that of remanence Brof magnet in the range from room temperature to 200 °C, however,the PPM focusing system do have the same temperature characteristics of permanent-magnet materials. It indicates that the magnetic temperature properties of the PPM system can be effectively controlled by adjusting the temperature properties of the magnets. Moreover, the higher permeability of the magnets indicates the less Hcb, giving rise to lower magnetic induction peak （Bz）′max： Finally, it should be noted that the magnetic orientation deviation angle θ（／15°） of permanent magnets has little effect on the focusing magnetic field of the PPM system at different temperatures and the temperature stability. The obtained results are beneficial to the design and selection of permanent magnets for PPM focusing system.

关键词： Periodic permanent-magnets focusing system Rare earth permanent magnets Finite element simulation Temperature stability Wireless underground sensor network