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Acoustic impedance characteristics of linear compressors

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Journal of Zhejiang University-Science A(Applied physics & Engineering) 2013年第7期14卷 494-503页

作者： Zhi-hua GAN Long-yi WANG Sheng-ying ZHAO Yu-jing SONG Wei-wei WANG Yi-nong WU institute of Cryogenics and Refrigeration Zhejiang University School of Information and Electrical Engineering Zhejiang University City College Shanghai institute of Technical physics Chinese Academy of Sciences

The acoustic field of a linear compressor serves to deliver the compression work to the load, such as the connected cold head of a cryocooler; it plays an equivalently important role as the electrical and mechanical parts, especially in the impedance match issue. This paper studies the acoustic impedance characteristics of a linear compressor. The parameters including the current, the piston displacement, the pressure amplitude, the electrical power dissipation, the power factor, the pressure-volumetric (PV) power delivered, and the efficiency are theoretically and experimentally investigated. Different from previous theoretical studies, optimization for the operations away from the resonance is also included. More general optimization results imply relevance between thermoacoustic engines and linear compressors. The predicted results are validated by the experiments performed on a linear compressor with an adjustable resistive-capacitive (RC) acoustic load. The comparisons between the calculations and the measurements are presented and analyzed. The results provide deeper insight into the mechanism of the linear compressor and the impedance match in a cryocooler system.

关键词： Linear compressor Acoustic impedance Resistive-capacitive (RC) load

Confirmation of a natural hybrid species in Petrocosmea(Gesneriaceae) based on molecular and morphological evidence

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Journal of Systematics and Evolution 2011年第5期49卷 449-463页

作者： 1,3~Zhi-Jing QIU 2.Zu-Li YUAN 1~Zhen-Yu LI 1~Yin-Zheng WANG 1(State Key Laboratory of Systematic and Evolutionary Botany,institute of Botany,Chinese Academy of Sciences,beijing 100093,{2.) 2.Henan Agricultural University,Zhengzhou 45002.{2.) 3(Graduate School of the Chinese Academy of Sciences,beijing 100049,{2.) StateKeyLaboratoryofSystematicandEvolutionaryBotany InstituteofBotanyChineseAcademyofSciencesBeijing100093China HenanAgriculturalUniversity Zhengzhou450002 GraduateSchooloftheChineseAcademyofSciences Beijing100049

A natural hybrid species in Petrocosmea named Longianthera in Yanshan County,Yunnan Province is confirmed for the first time based on molecular and morphological *** character count procedure of the variable characters show that Longianthera populations are characteristic of the intermediate morphological traits between its putative parents Yanshan and Petrocosmea *** nuclear ribosomal internal transcribed spacer region and three chloroplast regions of matK,trnL-F,and trnT-L are sequenced in the putative hybrid and the related *** alignment of DNA sequences and the phylogenetic trees could exclude all the other species in Petrocosmea as the parental species except for Yanshan and *** haplotypes in the 31 internal transcribed spacer sequences and six haplotypes in 42.cpDNA sequences were found from 14 individuals of Longianthera *** analyses of DNA sequences,haplotypes,and phylogenetic trees indicate that Longianthera is likely a hybrid species between its putative parents Yanshan and ***,in which Yanshan might be the most possible maternal *** factors may contribute to the natural hybridization between these two parental species in Petrocosmea,such as the overlapped geographic distribution,habitats,flowering periods,and shared ***,the new species of Yanshan and the natural hybrid species of Longianthera are described.

关键词： chloroplast DNA Gesneriaceae ITS morphology natural hybridization Petrocosmea.

Effects of Soil Matric Potential on Tomato Growth Under Drip Irrigation of Soda Alkali-saline Soils

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Effects of Soil Matric Potential on Tomato Growth Under Drip...

EFFECT OF VANADIUM DOPING ON SUPERCONDUCTIVITY AND GLASS FORMING ABILITY OF Bi BASED SUPERCONDUCTORS

亚洲精细农业与计算机农业应用联合大会

作者： LIU Shuhui 1 2.KANG Yaohu 1 WAN Shuqin 1 1. Key Laboratory of Water Cycle and Related Land Surface Processes institute of Geographic Science and Natural Resources Research Chinese Academy of Sciences beijing 100101 {2. 2. Graduate School of Chinese Academy of Sciences beijing 100049 {2.

The effects of irrigation frequency and soil matric potential on to mato growth under drip irrigation in No rth china were studied. Results suggested that drip irrigation frequency and soil matric potential significantly influence the distribution of soil water. By presetting threshold of soil matric potential（-5 kPa, S1;-10 kPa, S2.-15 kPa, S3;-2. kPa, S4;-2. kPa,S5） to control the timing of the irrigation cycle with vacuum tensiometers buried at 0.2. depth immediately under drip emitter. Field experiments were carried out to investigate the effect of soil matric potential on tomato growth, y ield and irrigation water use efficiency under mulch drip irrigation in Soda Alkali -saline So ils in Jilin Province in china in the year of 2.08. The results showed that the plant height, stem circu mference, LAI, Ch lorophyll content of tomato all increased with the increasing of soil matric potential. The higher the soil matric potential was, the higher the yields and the better the characteristics were. The highest yields were achieved with the soil matric potential of -5 kPa and the irrigation water use efficiency with the soil matric potential fro m -10 kPa to -15 kPa were h igher than that of other treatments.

关键词： Soda Alkali-Saline So ils Drip Irrigation So il Matric Potential Irrigation Frequency Tomato Growth

来源： cnki会议评论

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cnki会议

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Acta Metallurgica Sinica(English Letters) 1999年第4期12卷 485-487页

作者： Y. Zhuo1) , M. Gao1 ,2.and J.Y. Chen1,3) 1) Department of physics,Shenyang Normal College,Shenyang 110031 ,china2. {2. of Metal Research , The Chinese Academy ofsciences,Shenyang 110015 ,china 3) International Centerfor Materials physics,CAS,Sheny

BiVxSrCaCu2.Oysystem glasses were prepared by using doubleroller quenching method. Thedifferentialthermal analysis was employed to investigate the effect of V doping on glass forming ability( GFA). Theresultsshowedthatthe GFAof Bisystem increases withthein creasing ofthe amountof Vdoping. Thebestatomic ratiofor having both superconductivityandthegreatest GFAwas BiV0 18 CaCu2.Oy .

关键词： analysis Bisystem glass Bi based high TCsuperconductors differentialthermal

Einstein-Maxwell-dilaton引力模型中的5维宇宙膜解

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物理学报 2004年第9期53卷 2843-2845页

作者：颜骏陶必友西南交通大学物理研究所成都610031 成都77信箱工学院成都610066

获得了Einstein_Maxwell_dilaton引力模型中的一种新型的 5维宇宙膜解。

关键词： Einstein-Maxwell-dilaton引力模型 5维时空宇宙膜解宇宙学黑洞解

A NEW METHOD OF DECONVOLUTION IN THE FREQUENCY DOMAIN

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Journal of Electronics(china) 1997年第2期14卷 112-116页

作者： Wang Yanfei(institute of Electronics, Academia Sinica, beijing 100080)

A new deconvolution method has been presented in this paper. Like conventional Discrete Fourier Transform(DFT) method, it is also a frequency domain method. Since there are only DFT, IDFT and multiplication calculations in the new method, the singular problem appeared in the conventional DFT method can be avoid, and the deconvolution problem can always be solved with the new method. The relationship between the presented method and conventional DFT method is discussed. A numerical example is also presented to illustrate the new method.

关键词： Signal processing Deconvolution Signal restoration

Effect of docosahexaenoic acid on interleukin-2.receptor signaling pathway in lipid rafts

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Science china(Life Sciences) 2006年第1期49卷 63-72页

作者： LI Qiurong1, MA Jian1, TAN Li1, WANG Chang2. LI Ning1, LI Yousheng1, XU Guowang2.& LI Jieshou1 1. institute of General Surgery, General Hospital of Nanjing Command, Nanjing 2.0002. china 2. National Chromatographic R. & A. Center, institute of Chemical physics, Chinese Academy of Sciences, Dalian 116011, china institute of General Surgery General Hospital of Nanjing Command Nanjing 210002 China National Chromatographic R. & A. Center Institute of Chemical Physics Chinese Academy of Sciences Dalian 116011 China

Recent studies have shown that polyunsaturated fatty acids (PUFA) regulated the func-tions of membrane receptors in T cells and suppressed T cell -mediated immune responses. But the molecular mechanisms of immune regulation are not yet elucidated. Lipid rafts are plasma membrane microdomains, in which many receptors localized. The purpose of this study was to investigate the effect of DHA on IL-2. signaling pathway in lipid rafts. We isolated lipid rafts by discontinuous sucrose density gradient ultracentrifugation, and found that DHA could change the composition of lipid rafts and alter the distribution of key molecules of IL-2. signaling pathway, which transferred from lipid rafts to detergent-soluble membrane fractions. These results revealed that DHA treatment increased the proportion of polyunsaturated fatty acids especially n?3 polyunsaturated fatty acids in lipid rafts and changed the lipid environment of membrane microdomains in T cells. Compared with controls, DHA changed the localization of IL-2., STAT5a and STAT5b in lipid rafts and suppressed the expression of JAK1, JAK3 and tyrosine phosphotyrosine in soluble membrane fractions. Summarily, this study con-cluded the effects of DHA on IL-2. signaling pathway in lipid rafts and explained the regulation of PUFAs in T cell-mediated immune responses.

关键词： polyunsaurated fatty acids, docosahexaenoic acid, IL-2 receptor signaling pathway, lipid raft.

急倾斜煤层开采非连续变形的相似模型实验研究

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湘潭矿业学院学报 2000年第3期15卷 1-6页

作者：戴华阳王金庄张俊英郑志刚中国矿业大学北京校区北京100080 煤炭科学研究总院唐山分院河北唐山100035

与缓倾斜煤层开采相比 ,急倾斜煤系地层常隐含软弱夹层 ,其露头容易出现台阶和裂缝 ;与切割岩层的结构面比较 ,层间软弱面并不对移动盆地起全局控制作用 ,而只产生局部影响通过综合考虑急倾斜地层与层间弱面两个因素 ,阐明了急倾斜煤... 详细信息

与缓倾斜煤层开采相比 ,急倾斜煤系地层常隐含软弱夹层 ,其露头容易出现台阶和裂缝 ;与切割岩层的结构面比较 ,层间软弱面并不对移动盆地起全局控制作用 ,而只产生局部影响通过综合考虑急倾斜地层与层间弱面两个因素 ,阐明了急倾斜煤层开采地表非连续变形的发生条件 ;采用相似材料模型实验 ,研究了岩层垮落、弯曲、离层的方式和形态 ;提出了急倾斜煤层开采岩层的层梁移动模式 ;揭示了地表非连续变形的形态特征和变形机理 ,为进一步研究地表非连续变形的计算提供了依据图 7,表 2.,参

关键词：急倾斜煤层非连续变形相似模型实验开采

Performance Study of Copper-Bearing High Strength Ship-Hull Steel

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Journal of Iron and Steel Research International 2011年第S1期18卷 422-426页

作者： LUO Xiao-bing,YANG Cai-fu,SU Hang,CHAI Feng (Central Iron and Steel Research institute,institute for Structural Materials,{2. 100081,china) Cent Iron & Steel Res Inst Inst Struct Mat Beijing 100081 Peoples R China

The variation in microstructures and the mechanical properties of a Copper-bearing high strength ship-hull steel at different aging temperature was *** peak strength was obtained at the aging temperature of 450 ℃,which was attribute to the plentiful Cu precipitates and a bit of Nb(C,N).In the over-aged condition,both the partial recovery of matrix and the coarsening of Cu particles (10-60 nm) caused the loss of the yield strength (YS) and the improvement of *** increase of the ultimate tensile strength (UTS) at aging temperature above 660℃ due to the formation of alloy-rich island structure transformed from the austenite phase upon cooling,and complied with the mixture *** copper-bearing ship steel can exhibit an excellent combination of high strength and toughness while aging at 660 ℃ for 2.hours (UTS-818 MPa,YS-745 MPa,Akv-161 J at-40℃).

关键词： copper-bearing aging HSLA ship-hull steel