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International Journal of Agricultural and Biological Engineering 2024年第2期17卷 47-58页

作者： Song mei Jinpeng Wang zhiyu Song Dunbing Tang Cheng Shen College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China Nanjing Research Institute for Agricultural Mechanization Ministry of Agriculture and Rural AffairsNanjing 210014China Nanjing Forestry University Nanjing 210037China

In order to realize the efficient and high-quality mechanical picking for Chinese wolfberry,firstly,the forced reciprocating vibration picking principle of the Chinese wolfberry branch was studied,and the mechanical model of vibration picking was established based on the simplified cantilever model,and the response analysis and solution of all positions for the branch were carried *** the same time,the critical mechanical model of fruit detachment under the condition of fruit hanging on branches was established,and the theoretical values of inertia force for each component of the branch were ***,through actual measurement and finite element modeling,the natural frequency and forced vibration response simulation for each component of the branch of Chinese wolfberry terminal branch model were both studied,and the relationship between single-point periodic excitation force and high-quality fruit shedding parameters was ***,according to the conclusion of the picking model,a test bench with many groups of adjustable parameters was ***,the last branch of fruit-hanging Chinese wolf berry for Ningqi No.1 was taken as the experimental object,a four-level orthogonal experiment was designed with three factors:frequency,amplitude and entrance ***,the net picking rate,damage rate and false picking rate were taken as the evaluating indicators,referring to the comprehensive scores of the three *** was concluded that the primary and secondary relations of factors affecting the picking effect are frequency,amplitude and entrance angle,and the best operation parameters are frequency of 20 Hz,amplitude of 15 mm,and entrance angle of 45°,then,a hand-held vibration picker with setting parameters was trial-produced,and the optimal parameter combination was verified in the Chinese wolfberry planting base of the National Chinese wolfberry Engineering and Technology Research *** results showed that the net picking rate of rip

关键词： Chinese wolfberry branches reciprocating vibration inertial force orthogonal experiment

不同饲料类型和放养密度对乌鳢生长特性及营养品质的影响

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大连海洋大学学报 2017年第5期32卷 534-543页

作者：原居林郭建林刘梅顾志敏浙江省淡水水产研究所农业部淡水渔业健康养殖重点实验室浙江湖州313001

为了解不同饲料类型和放养密度对体质量(136.62±5.34)g的乌鳢Channa argus生长及营养品质的影响,采用围隔养殖试验法,研究了3种放养密度(15 000、30 000、45 000 ind./hm2)和2种饲料类型(冰鲜鱼和配合饲料)对乌鳢生长性能、生物学性状... 详细信息

为了解不同饲料类型和放养密度对体质量(136.62±5.34)g的乌鳢Channa argus生长及营养品质的影响,采用围隔养殖试验法,研究了3种放养密度(15 000、30 000、45 000 ind./hm2)和2种饲料类型(冰鲜鱼和配合饲料)对乌鳢生长性能、生物学性状和肌肉营养成分的影响。结果表明:冰鲜鱼投喂组乌鳢的增重率、特定生长率显著高于配合饲料投喂组(P0.05),放养密度对乌鳢增重率、特定生长率、饵料系数和成活率均无显著性影响(P>0.05);饲料投喂组乌鳢的肥满度、肝体指数和脏体指数显著高于冰鲜鱼投喂组(P0.05),但饵料类型与放养密度二者的交互作用对脏体指数影响显著(P0.05);饲料类型、放养密度对乌鳢肌肉的水分、灰分、粗蛋白质和粗脂肪无显著性影响(P>0.05);各试验组乌鳢肌肉中的18种氨基酸含量除脯氨酸外无显著性差异(P>0.05);氨基酸评价表明,投喂配合饲料的乌鳢肌肉蛋白质品质优于投喂冰鲜鱼的乌鳢,且以低密度养殖时最佳;脂肪酸分析表明,投喂配合饲料的乌鳢饱和脂肪酸(SFA)含量显著高于投喂冰鲜鱼(P0.05);3种放养密度对乌鳢生长性能和营养成分无显著性影响(P>0.05)。研究表明,配制饲料时可参考冰鲜鱼的营养成分,降低碳水化合物含量,增加不饱和脂肪酸添加量,以提升养殖乌鳢营养品质。

关键词：乌鳢饲料类型放养密度生长特性营养品质

液态搅拌铸造SiC_P及SiO_(2(P))增强Al-4wt%Mg基复合材料的界面反应研究

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复合材料学报 1998年第4期15卷 43-47页

作者：梅志崔昆顾明元吴人洁华中理工大学材料系上海交通大学

利用分析透射电镜研究了液态搅拌铸造原始态与氧化态ＳｉＣＰ以及ＳｉＯ２（Ｐ）增强Ａｌ－４ｗｔ％Ｍｇ基复合材料的界面反应情况。结果在原始态和氧化态碳化硅颗粒表面观察到细小的ＭｇＯ，石英粒子在高温下与基体中的镁反应生成Ｍｇ... 详细信息

利用分析透射电镜研究了液态搅拌铸造原始态与氧化态ＳｉＣＰ以及ＳｉＯ２（Ｐ）增强Ａｌ－４ｗｔ％Ｍｇ基复合材料的界面反应情况。结果在原始态和氧化态碳化硅颗粒表面观察到细小的ＭｇＯ，石英粒子在高温下与基体中的镁反应生成ＭｇＡｌ２Ｏ４，并运用扩散理论分别解释了其反应机制。

关键词：液态搅拌铸造界面反应铝镁基复合材料

First total synthesis of paecilodepsipeptide A

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Chinese Chemical Letters 2009年第5期20卷 527-530页

作者： Ming Jun Yang Jing Wu Zhong Duo Yang Ying mei Zhang School of Life Sciences Lanzhou University Lanzhou 730000 China School of Life Science and Engineering Lanzhou University of Technology Lanzhou 730050 China

The first total synthesis of paecilodepsipeptide A is reported. A convergent, flexible strategy employing peptide chemistry and culminating in macrolactamisation is described. The previously reported structure of comp... 详细信息

关键词： Paecilodepsipeptide A Macrolactamisation Total synthesis

Synthesis,Characterization and Biological Activity of (Z)-1-[2-(Triphenylstannyl]Cyclopentanol and Their Phenylhalostannyl Derivativies

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Chemical Research in Chinese Universities 1999年第1期15卷 31-36页

作者： YUE Su-mei LI Xiao-li SUN Zhen-gang LIU Jing-fu Department of Chemistry Northeast Normal UniveristryChangchun130024

The synthesis and characterization, by elementary analysis, IR and 1H NMR of ( Z ) 1 [2 (triphenylstannyl)vinyl] 1 cyclopentanol, CH 2(CH) 3C(OH)CHCHSnPh 3 are described together with its halodemetallation by I 2, Br 2 and ICl to yield derivatives of the types CH 2(CH 2) 3C(OH)CHCHSnPh 3- n X n (n =1, 2; X=I, Br, Cl). The solid state structures of the dibromide were determined by X ray diffraction analysis. In the crystal of CH 2(CH 2) 3C(OH)· CHCHSnBr 2 , the Sn atom has a destorted trigonal bipyramidal geometry, in which Sn—O interaction is noted[0 244 6(8) nm]. The biological activity of the title complexes was also investigated.

关键词： Crystal structure Cyclopentanol Biological activity

Changes of 5＇ Terminal Nucleotides of PCR Primers Causing Variable T-A Cloning Efficiency

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Journal of Integrative Plant Biology 2007年第3期49卷 382-385页

作者： mei-Qin Liu Xin Shen Wei-Lun Yin Cun-Fu Lu College of Biological Sciences and Biotechnology Beijing Forestry University Beijing 100083 China

T-A cloning takes advantage of the unpaired adenosyl residue added to the 3＇ terminus of amplified DNAs by Taq and other thermostable DNA polymerase and uses a Ilnearlzed plasmld vector with a protruding 3＇ thymldylate residue at each of Its 3＇ termini to clone polymerase chain reaction （PCR）-derived DNA fragments. It Is a simple, reliable, and efficient Ilgatlon-dependent cloning method for PCR products, but the drawback of variable cloning efficiency occurs during application. In the present work, the relationship between variable T-A cloning efficiency and the different 5＇ end nucleotlde base of primers used In PCR amplification was studied. The results showed that different cloning efficiency was obtained with different primer pairs containing A, T, C and G at the 5＇ terminus respectively. The data shows that when the 5＇ end base of primer pair was adenosyl, more white colonies could be obtained In cloning the corresponding PCR product In comparison with other bases. And the least white colonies were formed when using the primer pair with 5＇ cytldylate end. The gluanylate end primers resulted In almost the same cloning efficiency In the white colonies amount as the thymldylate end primer did, and this efficiency was much lower than that of adenosyl end primers. This presumably is a consequence of variability In 3＇dA addition to PCR products mediated by Taq polymerase. Our results offer instructions for primer design for researchers who choose T-A cloning to clone PCR products.

关键词： efficiency polymerase chain reaction primer T-A cloning terminal nucleotide

Generalized analysis model for fractional frequency reuse

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The Journal of China Universities of Posts and Telecommunications 2010年第5期17卷 1-5页

作者： XI Wei YIN Chang-chuan YUE Guang-xin SUN Hong-mei Laboratory of Wireless Cornmtmication Systems and Networks Beijing University of Posts and Telecommunications Beijing 100876 China Communication Technology Laboratory Intel China Research Center Beijing 100190 China

Fractional frequency reuse （FFR） is an effective technique to mitigate co-channel interference in orthogonal frequency division multiple access （OFDMA）-based broadband cellular *** this paper,we present a generalized model for FFR under which all existing FFR schemes can be considered as its special ***,quality factor has been proposed to indicate the quality of the *** interesting conclusion can be drawn that,as the power ratio in FFR is adjusted continuously,the corresponding quality factor varies ***,simulation is conducted based on worldwide interoperability for microwave access （WiMAX）,and the result agrees well with our theoretical ***,an effective range for power ratio is presented,which is very instructive to practical system design.

关键词： co-channel interference FFR power ratio

Analysis of Chemical Components of Longjing Teas Prepared Using Various Tea Varieties

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茶叶 2013年第4期39卷 264-266页

作者： mei-Juan Wu Qiang Miao Jian-Hua Chen Guo-Fang Yang zhi-Cheng Xu Fuyang Gaoqiao Agricultural Service Center Fuyang Agriculture Bureau Fuyang Xindeng Agriculture Office

Longjing tea is a famous tea in China and it is major green tea products produced in Zhejiang *** are 3 kinds of Longjing tea(Xihu Longjing,Qiantang Longjing and Yuezhou Longjing) according to their producing *** Longjing tea in Fuyang City is usually produced using materials picked from tea varieties Longjing-43,Jiukeng and *** composition is important indicator for identifying quality and *** tea samples were collected from tea gardens of tea varieties Longjing-43,Jiukeng and Wuniuzao were *** showed that chemical composition of tea samples prepared using the three varieties were quite ***,level of gallic acid decreased with picking time except for Wuniuzao,and caffeine and total catechins increased with increase in altitude.

关键词：化学成分分析茶树品种龙井茶茶叶化学组合物西湖龙井采摘时间茶产品

一株拮抗细菌HJ5高产抗菌物质发酵条件优化

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河北农业大学学报 2012年第4期35卷 70-74页

作者：辛媛媛侯美玲郝志敏董金皋河北农业大学生命科学学院河北保定071000

从黄顶菊茎中分离得到的内生细菌HJ5,是一株具有拮抗玉米大斑病菌活性的枯草芽孢杆菌。研究发现,HJ5菌株通过产生并分泌某种胞外物质发挥拮抗活性。为了增强HJ5菌株发酵产拮抗物质的能力,对HJ5菌株发酵条件进行单因子试验以及正交试验,... 详细信息

从黄顶菊茎中分离得到的内生细菌HJ5,是一株具有拮抗玉米大斑病菌活性的枯草芽孢杆菌。研究发现,HJ5菌株通过产生并分泌某种胞外物质发挥拮抗活性。为了增强HJ5菌株发酵产拮抗物质的能力,对HJ5菌株发酵条件进行单因子试验以及正交试验,从而确定了HJ5菌株发酵产抗菌活性物质的最佳培养基配方为1%葡萄糖作为碳源、1%大豆蛋白胨作为氮源、0.01%MnCl2作为添加无机盐,初始pH为8。对HJ5菌株发酵工艺参数优化结果为:50/250mL的装液量、2%的接种量、28℃180r/min振荡培养66h。经发酵条件优化后较基础培养基,HJ5菌株拮抗活性增强了近1倍。

关键词：玉米大斑病菌内生细菌拮抗发酵条件