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LD-pumped Ho,Tm:YLF microchip laser

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Journal of Marine Science and Application 2003年第1期2卷 71-75页

作者： SUN Jing-hua, ZHANG Xin-lu College of Science, Harbin Engineering University, Harbin 150001,China College of Science Harbin Engineering University Harbin 150001China

A simple rate equation model for 2μm Tm,Ho:YLF laser is given to study laser dynamics. Under low pump power, the explicit formulae for the threshold pump power and the relation between output power and incident power are obtained. The present model provides a straightforward procedure to design the laser resonator and the optical coupling system for optimization. At the same time, the experimental results are reported. At room temperature the slope efficiency is 22.4% and the typical lasing threshold is about 328mW. The theory is in good agreement with experiment.

关键词： Tm,Ho:YLF room temperature laser diode rate equation.

Scrutinizing the facile growth of β-Ag_(2)Se fine films

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Chinese Chemical Letters 2023年第11期34卷 307-310页

作者： Yongkang Ge Yan Lei Xu Li Ruijuan Qi Xiaoming Ma Zhi Zheng School of Materials Science and Engineering Zhengzhou UniversityZhengzhou 450001China College of Advanced Materials and Energy Key Laboratory of Micro-Nano Energy Storage and Conversion Materials of Henan ProvinceInstitute of Surface Micro and Nano MaterialsXuchang UniversityXuchang 461000China School of Physics and Electronic Science Key Laboratory of Polar Materials and DevicesMinistry of EducationDepartment of Electronic ScienceEast China Normal UniversityShanghai 200241China School of Chemistry and Chemical Engineering Key Laboratory of Green Chemical Media and ReactionMinistry of EducationCollaborative Innovation Center of Henan Province for Fine Chemicals Green ManufacturingHenan Normal UniversityXinxiang 453007China

Silver selenide thin film is one of the best candidates for thermoelectric *** the previous report,we demonstrated that high-performanced[201]orientedβ-Ag_(2)Se thin films can be prepared by direct metal surface element reaction(DMSER)solution selenization in a really short time at room ***,the underlying mechanism of the fast reaction process were not discussed in ***,based on hard soft acid base(HASB)theory and strong oxidation,we further explored the possible reaction mechanism of the in-situ growth ofβ-Ag_(2)Se thin films as the function of the reaction *** time-dependent experimental results showed that the formation of theβ-Ag_(2)Se on elemental Ag precursor(∼690nm thick)in Se/Na_(2)S precursor solution is in a growth driven mode with no obvious orientation or growth rate selections to the elemental Ag *** investigations provide a prerequisite for the further preparation of thermoelectric materials with excellent properties.

关键词： β-Ag_(2)Se Fine film room temperature In-situ transformation Thermoelectric

AlInAs/GaInAs SUPERLATTICED NEGATIVEDIFFERENTIAL-RESISTANCE SWITCH（SNDRS） PREPARED BY MOCVD

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AlInAs/GaInAs SUPERLATTICED NEGATIVEDIFFERENTIAL-RESISTANCE ...

1998 International Conference on Microwave and Millimeter Wave Technology

作者： Wen-Chau Liu Shiou-Ying Cheng Wen-Lung Chang Hsi-Jen Pan Yung-Hsin Shie Department of Electrical Engineering National Cheng-Kung University

ISBN: (纸本)0780343085

＜正＞A new AlInAs/GaInAs superlatticed negative-differential-resistance switch（SNDRS） is fabricated successfully and demonstrated.A 5-period AlInAs/GalnAs superlattice is used to serve the resonant tunneling route and the confinement barrier for minority ***,an interesting threeterminal -controlled N-shaped multiple negative-differential-resistance（MNDR） phenomenon and transistor action are obtained for the studied SNDRS device in the saturation and forward active mode at room temperature,*** is believed that the N-shaped MNDR is resulted mainly from resonant tunneling within the 5-period AlInAs/GaInAs superlattice.

关键词： aluminium compounds indium compounds gallium arsenide III-V semiconductors semiconductor superlattices negative resistance devices semiconductor switches minority carriers resonant tunnelling vapour phase epitaxial growth superlatticed NDR switch negative-differential-resistance switch MOCVD preparation 5-period superlattice resonant tunneling confinement barrier minority carriers three-terminal-controlled NDR N-shaped multiple NDR phenomenon transistor action saturation mode forward active mode room temperature AlInAs-GaInAs

Effect of Traps and Self Heating on the Microwave Performance of SiC MESFETs

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Effect of Traps and Self Heating on the Microwave Performanc...

2006 8th International Conference on Solid-State and Integrated Circuit Technology

作者： Shabna Asmi Ibrahim M.Abdel-Motaleb Department of Electrical Engineering Northern Illinois UniversityDeKalbIL 60115 USA

ISBN: (纸本)1424401607

The impact of traps and self-heating on the performance of SiC MESFETs,operating in the microwave range has been investigated.A non-quasi-static model that includes these effects has been *** model’s simulation results were found to be in full agreement with the measured data,The results show that an increase of the trap concentration from 10 cm to 10 cm reduces the cutoff frequency by about 40%,and an increase in the temperature by about only 50K above the room temperature reduces the cutoff frequencies by about 45%.

关键词： Cutoff frequency traps MESFETs microwave range Self heating SILICON CARBIDE room temperature Fever

Solvent-free D-proline Catalyzed Synthesis of N,O-Acetal Compounds

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Solvent-free D-proline Catalyzed Synthesis of N,O-Acetal Com...

中国化学会·第十六届全国有机合成化学学术研讨会

作者：兰金 Leihan Fu Zhanggao Le Zongbo Xie 东华理工大学 Department of Applied Chemistry East China University of Technology

N,O-acetal compound is present in many biologically active natural products,and N,O-acetal compound also can be used as a synthetic material for some reaction, In this paper,a convenient method for synthesizing N,O-acetal compounds was developed,using aromatic aldehyde,urea and alcohol as materials,and D-proline as catalyst.A series of N,O-acetal compounds were synthesized with good yields after reaction for 30 h at room temperature.

关键词： D-proline N,O-acetal compounds green chemistry solvent-free room temperature

GeMn-substituted barium hexaferrite

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GeMn-substituted barium hexaferrite

2002 3rd International Conference on Microwave and Millimeter Wave Technology

作者： Quanyuan Feng School of Computer and Comm.Eng. Southwest Jiaotong University

ISBN: (纸本)078037486X

The microwave properties have been studied on Polycrystalline hexaferrite BaZn(GeMn)*** X-ray diffrection has shown that the W-type hexaferrites BaZn(GeMn)xFeO can not be formed at x≥*** anisotropy field of hexaferrite BaZn(GeMn)FeO measured at room temperature is 7.90×10A/*** exchange interaction constants and the contributions to magnetocrystalline anisotropy for various sublattices in BaZn(GeMn)FeO have been calculated based on the molecular field theory and ***’s single ion anisotropy *** results show that the sublattices 12k and 2d have stronger contribution to anisotropy.

关键词： barium compounds zinc compounds ferrites microwave materials crystal structure magnetic anisotropy exchange interactions (electron) crystal field interactions GeMn-substituted barium hexaferrite BaZn/sub 2/(GeMn)/sub 0.2/Fe/sub 15.6/O/sub 27/ BaZn/sub 2/(GeMn)/sub x/Fe/sub 16-2x/O/sub 27/ microwave properties polycrystalline hexaferrite X-ray diffraction W-type hexaferrites anisotropy field room temperature exchange interaction magnetocrystalline anisotropy sublattices molecular field theory single ion anisotropy model 20 C

Novel Synthesis of Quinoline-7,8-diol Derivative

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有机化学 2004年第Z1期24卷 361-页

作者： HE,Juan WANG,Xue-Bin WAN,Zheng-Kai Department of Chemistry and Chemical Engineering Henan University of Technology Zhengzhou 450052 Department of Chemistry and Chemical Engineering Henan University of Technology Zhengzhou 450052 Department of Chemistry and Chemical Engineering Henan University of Technology Zhengzhou 450052

　　Quinoline 7,8-diol derivatives can be expected to form metal complexes, and are the moiety of marine alkaloid,which exhibits strong cytotoxic activity against several human tumor. Our synthesis of 6 commences from L-dopa (1)(Scheme 1). Esterification of 2 with methanol and treatment of the resulting ester 3 with trichloroethoxycarbonyl (Troc)chloride yielded the N-protected amino acid ester 4. Treatment of 4 with acrolein in 1.3 mol/L methanolic HCl for 4 d at room temperature yielded the quinoline derivative 5, which was dissolved in 25% aq. HBr and the resulting solution was heated at reflux for 6 h to afford compound 6.……

关键词： quinoline derivative cytotoxic activity room temperature metal complexes amino acid

A Convenient Method of Synthesis of Ferrocenylethynyl Ketones

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有机化学 2004年第Z1期24卷 140-页

作者： WANG,Xiao-Jun YIN,Ju-Xing LIANG,Yong-Min WU,Xiao-Li CHEN,Bao-Hua MA,Yong-Xiang State Key Laboratory of Applied Organic Chemisty Lanzhou University Lanzhou 730000

It is well known that molecules possessing extensive conjugated π-electron systems exhibit large non-linear optical properties,[1,2] but the compounds of ferrocenylethynyl ketones have not been reported so far. We now reported preparation of some ferrocenylethyl ketones. These new ethynylketones containing ferrocenyl were prepared conveniently via coupling reaction catalyzed by PdCl2(PPh3)2/PdBzCl(PPh3)2-CuI from ferrocenylethyne and acyl chlorides. This coupling reaction proceeded smoothly in argon and free-water atmosphere at room temperature and gave coupling products in satisfactory yields. All products were characterized by 1H NMR, MS, IR and UV spectra.……

关键词： coupling reaction optical properties room temperature acyl chlorides UV spectra

A New Esterification Reaction in Synthesis of Gibberellins

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有机化学 2003年第Z1期23卷 346-346页

作者： ZHAO Yuan-Hong ZHANG Hong-Bin School of Pharmacy Yunnan University Kunming 650091 School of Pharmacy Yunnan University Kunming 650091

　　Esterification is an important reaction in organic synthesis. In the synthesis of gibberellin derivative, a new es terification reaction was found. Ent-16-oxo-20-norgibberella-9-ene-7, 19-dioic acid 7-(methyl ester) (Ⅰ) is a key material in synthesis of GA73. [1] Ⅰ is dissolved in acetone, and treated with ICl and anhydrous K2CO3 at room temperature for 2 h to produce a new ester, ent-16-oxo-20-norgibberella-9-ene-7, 19-dioic acid 7-(methyl ester), 19-(oxopropyl ester ) (Ⅱ). The yield is above 90%. The structure of Ⅱ is confirmed by NMR and MS.……

关键词： organic synthesis room temperature