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A Simple Birefringent Terahertz Waveguide Based on Polymer Elliptical Tube

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Chinese Physics Letters 2011年第1期28卷 112-114页

作者： WANG Jing-li YAO Jian-Quan CHEN He-Ming li zhong-yang Institute of Laser and Optoelectronics Key Laboratory of Optoelectronic Information Science and Technology (Ministry of Education) College of Precision Instrument and Optoelectronic Engineering Tianjin University Tianjin 300072 College of Optoelectronic Engineering Institute of Optical Communications Nanjing University of Posts and Telecommunications Nanjing 210003

We propose a simple birefringent terahertz （THz） waveguide which is a polymer elliptical tube with a cross section of elliptical ring structure. It can be achieved by stretching a normal circular-tube in one direction. Simulations based on the full-vector finite element method （FEM） show that this kind of waveguides exhibits high birefringenee on a level of 10- 2 over a wide THz frequency range. Moreover, as a majority of modal power is trapped in the air core inside the polymer elliptical tube, the THz waveguide guiding loss caused by material absorption can be reduced effectively.

关键词： Computational physics Electronics and devices

ZrCl_4/Hantzsch 1,4-dihydropyridine as a new and efficient reagent combination for the direct reductive amination of aldehydes and ketones with weakly basic amines

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Chinese Chemical Letters 2007年第4期18卷 458-460页

作者： Zhen Gang liu Nan li li yang zhong li liu Wei Yu State Key Laboratory of Applied Organic Chemistry Lanzhou University Lanzhou 730000 China

ZrCl4/Hantzsch 1,4-dihydropyridine is a mild and highly efficient reagent combination for the direct reductive amination. Weakly basic amines such as anilines substituted by electron-withdrawing group and heteroaromatic amines can be reductively alkylated with electron rich aldehydes and ketones under mild conditions to form the secondary amines in excellent yields.

关键词： Zirconium tetractfloride Hantzsch 1,4-dihydropyfidine Reductive amination

CaY-zeolite Catalyzed Etherification and Alkylation of Substituted Benzyl Alcohols

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Chinese Chemical Letters 2006年第1期17卷 15-18页

作者： Wei YU Miao WEN Guang Yu ZHAO li yang zhong li liU National Laboratory of Applied Organic Chemistry Lanzhou University Lanzhou 730000

The reaction of p- and/ α-subtituted benzyl alcohols in CaY-zeolite produced the corresponding dibenzyl ethers and/or benzyl toluenes as the principal products.

关键词： Benzyl alcohols CaY-zeolite etherification alkylation.

Effects of reclaimed water irrigation and nitrogen fertilization on the chemical properties and microbial community of soil

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Journal of Integrative Agriculture 2017年第3期16卷 679-690页

作者： GUO Wei Mathias N Andersen QI Xue-bin li Ping li zhong-yang FAN Xiang-yang ZHOU Yuan Farmland Irrigation Research Institute Chinese Academy of Agricultural Sciences (CAA S) Xinxiang 453003 P.R. China Graduate School of Chinese Academy of Agricultural Sciences Beijing 100081 P.R. China Department of Agroecology Faculty of Science and Technology Aarhus University Tjele 8830 Denmark Key Laboratory of High-efficient and Safe Utilization of Agriculture Water Resources of CAAS Xinxiang 453003 P.R. China

The ecological effect of reclaimed water irrigation and fertilizer application on the soil environment is receiving more *** microbial activity and nitrogen（N）levels are important indicators of the effect of reclaimed water irrigation on *** study evaluated soil physicochemical properties and microbial community structure in soils irrigated with reclaimed water and receiving varied amounts of N *** results indicated that the reclaimed water irrigation increased soil electrical conductivity（EC）and soil water content（SWC）.The N treatment has highly significant effect on the ACE,Chao,Shannon（H）and Coverage *** on a 16S ribosomal RNA（16S rRNA）sequence analysis,the Proteobacteria,Gemmatimonadetes and Bacteroidetes were more abundant in soil irrigated with reclaimed water than in soil irrigated with clean *** clustering of microbial communities using either clean or reclaimed water for irrigation indicated that the type of irrigation water may have a greater influence on the structure of soil microbial community than N fertilizer *** on a canonical correspondence analysis（CCA）between the species of soil microbes and the chemical properties of the soil,which indicated that nitrate N（NO3-–-N）and total phosphorus（TP）had significant impact on abundance of Verrucomicrobia and Gemmatimonadetes,meanwhile the p H and organic matter（OM）had impact on abundance of Firmicutes and Actinobacteria *** was beneficial to the improvement of soil bacterial activity and fertility under 120 mg kg^-1 N with reclaimed water irrigation.

关键词： reclaimed water nitrogen soil chemical properties 16S rRNA sequence soil microbe community

Pd/C-catalyzed selective reduction of aromatic azides with Hantzsch 1,4-dihydropyridine

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Chinese Chemical Letters 2008年第8期19卷 885-888页

作者： Zhen Gang liu Xiu Qin Niu Wei Yu li yang zhong li liu State Key Laboratory of Applied Organic Chemistry Lanzhou University Lanzhou 730000 China

The reagent combination of Hantzsch 1,4-dihydropyridine and Pd/C was found to be an efficient reducing system for the selective reduction of aromatic azides.

关键词： Reduction Hantzsch 1,4-dihydropyridine Pd/C Aromatic azides

Output Enhancement of a THz Wave Based on a Surface-Emitted THz-Wave Parametric Oscillator

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Chinese Physics Letters 2011年第11期28卷 103-105页

作者： li zhong-yang YAO Jian-Quan XU De-Gang BING Pi-Bin zhong Kai North China University of Water Resources and Electric Power Zhengzhou 450011 College of Precision Instrument and Opto-electronics Engineering Institute of Laser and Opto-electronicsTianjin UniversityTianjin 300072

High-power nanosecond pulsed THz-wave radiation is achieved via a surface-emitted THz-wave parametric *** MgO:liNbO3 crystal with large volume is used as the gain ***-wave radiation from 1.084 THz to 2.654 THz is *** maximum THz-wave average power is 5.8W at 1.93 THz when the pump energy is 84 mJ,corresponding to a energy conversion efficiency of 6.9×10^(−6).The polarization characteristics of THz wave are *** the experiments the radiations of the first-order and the second-order Stokes wave are observed.

关键词： polarization pump wave

Threshold Analysis of a THz-Wave Parametric Oscillator

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Chinese Physics Letters 2010年第6期27卷 100-103页

作者： li zhong-yang YAO Jian-Quan ZHU Neng-Nian WANG Yu-Ye XU De-Gang College of Precision Instrument and Opto-electronics Engineering Institute of Laser and Opto-electronics Tianjin University Tianjin 300072 Key Laboratory of Opto-eleetronics Information Science and Technology (Ministry of Education) Tianjin University Tianjin 300072

The parametric gain of a terahertz wave parametric oscillator （TPO） is analyzed. Meanwhile the expression of TPO threshold pump intensity is derived and theoretically analyzed with different factors. The effective interaction length between the pump wave and Stokes wave is calculated, and particular attention is paid to the coupling efficiency of the pump wave and Stokes wave. Such an analysis is useful for the experiments of TPO.

关键词： TERAHERTZ technology PARAMETRIC oscillators STOKES flow WAVE mechanics OPTICAL pumping

THz-Wave Difference Frequency Generation by Phase-Matching in GaAs/Al_(x)Ga_(1-x)As Asymmetric Quantum Well

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Chinese Physics Letters 2012年第6期29卷 133-136页

作者： CAO Xiao-Long WANG Yu-Ye XU De-Gang zhong Kai li Jing-Hui li zhong-yang ZHU Neng-Nian YAO Jian-Quan College of Precision Instrument and Opto-electronics Engineering Institute of Laser and Opto-electronicsTianjin UniversityTianjin 300072 Key Laboratory of Opto-electronics Information Technology(Ministry of Education) Tianjin UniversityTianjin 300072 Department of Computer Science and Technology Renai CollegeTianjin UniversityTianjin 301636

An asymmetric quantum well (AQW) is designed to emit a terahertz (THz) wave by using difference frequency generation (DFG) with the structure of GaAs/Al_(0.2)Ga_(0.8)As/Al_(0.5) Ga_(0.5)As under a doubly resonant *** is found that the second-order nonlinear susceptibility χ^((2)) varies with the two pump wavelengths,and it can reach the peak value of 1.61 μm/V when the wavelengths are given as λ_(p1) =9.756 μm and λ_(p2) =10.96 μm,*** numerical results show that the refractive index of one pump wave in the AQW is concerned with not only its own wavelength but also the other ***-matching inside the AQW can be obtained through the tuning of the two pump wavelengths.

关键词： pump tuning Phase

High-Power Terahertz Radiation Based on a Compact Eudipleural THz-Wave Parametric Oscillator

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Chinese Physics Letters 2011年第6期28卷 145-148页

作者： li zhong-yang YAO Jian-Quan LÜDa XU De-Gang WANG Jing-li BING Pi-Bin College of Precision Instrument and Opto-electronics Engineering Institute of Laser and Opto-electronicsTianjin UniversityTianjin 300072 Institute of Electric Power North China University of Water Resources and Electric PowerZhengzhou 450011 Key Laboratory of Opto-electronics Information Science and Technology(Ministry of Education) Tianjin UniversityTianjin 300072

Tunable high-power THz-wave radiation is achieved via a compact eudipleural THz-wave parametric *** maximum THz-wave output is 1.164 V at 1.755 THz when the pump energy is 90 *** the experiments we find that the maximum output of THz-wave moves to the high frequency band as the pump energy increases and this phenomenon is reasonably *** polarization characteristics of the THz-wave are analyzed.

关键词： pump polarization wave