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Ecological-breaking zone originates and its ecosystems reconstruction in arid area

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Journal of Environmental Sciences 1996年第2期8卷 203-211页

作者： Huang Peiyou Lu Zili(Biology department of xinjiang university,urumqi 830046,china) Biology department Xinjiang University Urumqi 830046 China

In the process of arid land exploitation, the landscape of desert is divided into three types. Oasis is rising,the area of uneffected area keeps its original state,the serious degenerated area where is only limited between oasis and desert, but not overall. Its relationship with the neighbor region, the zone of ecological-breaking region or ecological rift valley is not successive. . Its ecological effect endangered the arid land overall. Rehabilitating vegetation is the basic measure for abatement. The authors proposed a new tactics that based on the properties of vegetation. Depending on the local water sources and partly regulating the composition of environmental factor to satisfy the requirement of desert community, the rehabilitate vegetation should be realized.

关键词： arid area ecological-breaking zone ecosystems reconstruction.

Solvothermal synthesis of nanocrystalline FeS_2

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Science china(physics,Mechanics & Astronomy) 2005年第2期48卷 188-200页

作者： CHEN Yanhua1, ZHENG Yufeng1, ZHANG Xiaogang2, SUN Yanfei1 & DONG Youzhong11. physics department of xinjiang university, urumqi 830046, china 2. Institute of Applied Chemistry of xinjiang university, urumqi 830046, china physics department of xinjiang university Urumqi China Institute of Applied Chemistry of xinjiang university Urumqi China

This paper reports on the synthesis of the nanocrystalline FeS2 via a solvent-thermal process. Using FeSO4 and NH2CSNH2 as precursors and polyvinyl- pyrrolidone (PVP) as a protective agent (dispersant), we have successfully synthesized nanocrystalline FeS2 both under acidic conditions (pH = 5) and under alkali conditions (pH = 10) at various temperatures and for different time in alcohol-water solution. X-ray diffraction (XRD), Transmission electron microscopy (TEM) and Ultraviolet Visible (UV-VIS) spectroscopy were used to characterize the morphology, structure, particle size and optical characterization of sample synthesized under acidic condition, and the XRD pattern was refined by Rietveld method. The experimental result shows that nanocrystalline FeS2 with uniform size, highly crystallized quality and excellent dispersivity has been synthesized at 200℃for 36 h.

关键词： FeS2 (Pyrite), solvothermal, PVP, the Rietveld method.

Formation of bulk ferromagnetic nanostructured Fe_(40)Ni_(40)P_(14)B_6 alloys by metastable liquid spinodal decomposition

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Science china(Technological Sciences) 2009年第7期52卷 1919-1922页

作者： LI Qiang1,2 1 School of physics Science and Technology, xinjiang university, urumqi 830046, china 2 department of physics, The Chinese university of HongKong, Shatin N.T., HongKong, china School of physics Science and Technology Xinjiang University department of physics The Chinese University of HongKong Shatin N.T.

Nanostructured Fe40Ni40P14B6 alloy ingots of 3―5 mm in diameter could be synthesized by a metastable liquid state spinodal decomposition method. For undercooling T> 260 K, the microstructure of the undercooled specimen had exhibited liquid state spinodal decomposition in the undercooled liquid state. The microstructure could be described as two intertwining networks with small grains dispersed in them. For undercooling T>290 K, the overall microstructure of the specimen changed into a granular morphology. The average grain sizes of the small and large grains are 30 nm and 80 nm, respectively. These prepared samples are soft magnets with saturation magnetization Bs 0.744 T.

关键词： nanomaterials magnetic materials solidification bulk nanostructured alloy Fe40Ni40P14B6 metastable liquid spinodal decomposition

THE NEAR-CRITICAL AND SUPER-CRITICAL ASYMPTOTIC BEHAVIOR IN THE THERMODYNAMIC LIMIT OF REVERSIBLE RANDOM POLYMERIZATION PROCESSES

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Acta Mathematica Scientia 2000年第3期20卷 380-389页

作者：韩东 department of Mathematics University of Xinjiang Urumqi 830046 China

In this paper, the near-critical and super-critical asymptotic behavior of a reversible Markov process as a chemical model for polymerization was studied. The results of the present paper, together with an analysis of the sub-critical stage, establish the existence of three distinct stages (sub-critical, near-critical and super-critical stages) of polymerization (in the thermodynamic limit as N --> +infinity,),depending on the value of strength of the fragmentation reaction. These three stages correspond to the size of the largest length of polymers of size N to be itself of order log N, Nm/m+1 (m greater than or equal to 2, m not equal 4n, n greater than or equal to 1) and N, respectively.

关键词： polymerization Markov process limit behavior stationary distribution

New Hardy Spaces Associated with Herz Spaces and Beurling Algebras on Homogeneous Groups

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Acta Mathematica Sinica,English Series 2002年第4期18卷 661-670页

作者： Yin Sheng JIANG department of Mathematics. xinjiang university, urumqi, 830046, P. R. china department of Mathematics Xinjiang University Urumqi P. R. China

The author introduces the Hardy spaces associated with the Herz spaces and the Beurling algebras on homogeneous groups and establishes their atomic decomposition characterizations. As the applications of this decomposition, the duals of these Hardy spaces and the boundedness of the central δ-Calderon-Zygmund operators on these Hardy spaces are studied.

关键词： Homogeneous group Hardy spaces Herz spaces Beurling algebras Central atoms

FeS_(2) (pyrite) electrodeposition thin films and study of growth mechanism

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Science china(Technological Sciences) 2005年第6期48卷 601-611页

作者： DONG Youzhong1, ZHENG Yufeng1, ZHANG Xiaogang2, DUAN He1, SUN Yanfei1 & CHEN Yanhua1 1. department of physics, xinjiang university, urumqi 830046, china 2. Institute of Applied Chemistry, xinjiang university, urumqi 830046, china department of physics Xinjiang University Urumqi 830046 China

Ferrous sulfide (FeS) thin films were initially electrodeposited on indium-tin oxide (ITO) substrates in the aqueous solution containing iron, sulfur elements and then annealed in the sulfur atmosphere. Thereby, we successfully obtained the single-phased iron pyrite (FeS2) thin films with good quality. The experimental parameters for electrodeposition and the post-growth thermal-dynamical conditions have been calculated so that more details about the effect of thermal-dynamical conditions on the micromechanism concerned with the iron pyrite crystal growth as well as the properties of the samples have been discussed.

关键词： electrodeposition, FeS2 (pyrite), thin films, growth dynamics.

Biomimetic soft robotic wrist with 3-DOF motion and stiffness tunability based on ring-reinforced pneumatic actuators and a particle jamming joint

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Science china(Technological Sciences) 2024年第3期67卷 774-790页

作者： HU TeTe LU xinjiang YI Jian WANG YuHui XU Du State Key Laboratory of Precision Manufacturing for Extreme Service Performance School of Mechanical and Electrical EngineeringCentral South UniversityChangsha 410083China

The human wrist, a complex articulation of skeletal muscles and two-carpal rows, substantially contributes to improvements in maneuverability by agilely performing three-degree-of-freedom(3-DOF) orienting tasks and regulating stiffness according to variations in interaction forces. However, few soft robotic wrists simultaneously demonstrate dexterous 3-DOF motion and variable stiffness;in addition, they do not fully consider a soft-rigid hybrid structure of integrated muscles and two carpal *** this study, we developed a soft-rigid hybrid structure to design a biomimetic soft robotic wrist(BSRW) that is capable of rotating in the x and y directions, twisting around the z-axis, and possessing stiffness-tunable capacity. To actuate the BSRW, a lightweight soft-ring-reinforced bellows-type pneumatic actuator(SRBPA) with large axial, linear deformation(η_(lcmax)=70.6%,η_(lemax)=54.3%) and small radial expansion(η_(demax)=3.7%) is designed to mimic the motion of skeletal muscles. To represent the function of two-carpal rows, a compact particle-jamming joint(PJJ) that combines particles with a membrane-covered ballsocket mechanism is developed to achieve various 3-DOF motions and high axial load-carrying capacity(>60 N). By varying the jamming pressure, the stiffness of the PJJ can be adjusted. Finally, a centrally positioned PJJ and six independently actuated SRBPAs, which are in an inclined and antagonistic arrangement, are sandwiched between two rigid plates to form a flexible,stable, and compact BSRW. Such a structure enables the BSRW to have a dexterous 3-DOF motion, high load-carrying ability,and stiffness tunability. Experimental analysis verify 3-DOF motion of BSRW, producing force of 29.6 N and 36 N and torque of2.2 Nm in corresponding rotations. Moreover, the range of rotational angle and stiffness-tuning properties of BSRW are studied by applying jamming pressure to the PJJ. Finally, a system combining a BSRW and a soft enclosing gripper is proposed to demo

关键词： pneumatic soft actuators particle jamming robotic wrist soft robotics stiffness-tunable

Synthesis Characterization Non-isothermal Kinetics of the Thermal Decomposition and Redox Properties Derived from Copper(Ⅱ) Binuclear Coordination Compound of 1,4-Bis-(1'-Phenyl-3'-Methyl-5'-Pyrazolone-4')-1,4-Butanedione

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Chinese Chemical Letters 1997年第5期8卷 455-458页

作者： Cun SHAN Dian Zen JIA Xi XIA(department of Chemistry,, xinjiang university, urumqi,830046). department of Chemistry Xinjiang University Urumqi 830046 China

The paper reports the synthetic procedure and character of Copper(II) binuclearcoordination compound of 1,4-bis-(1'-phenyl-3'-methyl-5'-pyrazolone Thenon-isothermal kinetics of thermal decomposition of the complex has been stUdied from the TG-DTGcurves by means of the Achar et al. and Coats-Redfern methods,the most probab1e kinetic equation canbe expressed as dofdtrAe -E / RT * l /(2Q).The corresponding kinetic compensation effect expressions arefound to be lnuA=0. 1794E+0. *** non-isothermal thermal decomposition process of the complex isone-dimensional *** electrochemical studies of the complex(Cu2L'2)from cyclic voltamrnetriccurves by means of powder microelectrodes technique'',shows one two-electron irreversible process.

关键词： Methyl-5 Phenyl-3 Pyrazolone-4 Synthesis Characterization Non-isothermal Kinetics of the Thermal Decomposition and Redox Properties Derived from Copper Binuclear Coordination Compound of 1,4-Bis

A NOTE ON THE PAPER “UNIFORM PERSISTENCE IN DISCRETE SEMIDYNAMICAL SYSTEM AND ITS APPLICATION”

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Systems Science and Mathematical Sciences 1999年第2期12卷 145-148页

作者： TENG Zhidong(department of Mathematics, xinjiang university, urumqi 830046, china) 新疆大学数学系新疆乌鲁木齐

In this paper, we study the uniform persistence of a class of two dimensional periodic Kolmogorov ecosystems. As an improvement on a main result in [1] we obtain a new criterion of the uniform persistence for solutions.

关键词： Kolmogorov system periodic uniform persistence unbounded ultimate bound.