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Method for determining number of coherent signals in the presence of colored noise
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作者 Jiaqi Zhen, Xicai Si, and Lutao Liu College of Information & Communication Engineering, Harbin Engineering University, Harbin 150001, P. R. China 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2010年第1期27-30,共4页
The approach of estimating the number of signals based on information theoretic criteria has good performance in the assumption of white noise, but it always leads to false estimation of the coherent sources in colore... The approach of estimating the number of signals based on information theoretic criteria has good performance in the assumption of white noise, but it always leads to false estimation of the coherent sources in colored noise. An approach combining the combined information theoretic criteria and eigen- value correction, is presented to determine number of signals. The method uses maximum likelihood (ML) and information theoretic criteria to estimate coherent signals alternately, then eliminate the inequality of the eigenvalues caused by colored noise by correcting the noise eigenvalues. The computer simulation results prove the effective performance of the method. 展开更多
关键词 determining the number of signals coherent signals colored noise information theoretic criteria.
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Genetic polymorphism of CYP2A6 is one of the potential factors determining tobacco-related cancer risk
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作者 S TSUDA I SATO +2 位作者 N SAITO K OAMI JIN YH 《中国药理学与毒理学杂志》 CAS CSCD 北大核心 2006年第3期163-163,共1页
While we studied pharmacokinetics of SM-12502 which was under development as an anti-PAF agent, we found three subjects showing a slow metabolic phenotype in its pharmacokinetics. Analyzing the genes for CYP2A6 from t... While we studied pharmacokinetics of SM-12502 which was under development as an anti-PAF agent, we found three subjects showing a slow metabolic phenotype in its pharmacokinetics. Analyzing the genes for CYP2A6 from the three subjects, we discovered that the three subjects possessed the whole CYP2A6 gene deletion (CYP2A6*4C), a novel genetic polymorphism of the CYP2A6 gene. Genetically engineered Salmonella YG7108 cells expressing human CYP2A6 or CYP2E1 together with the NADPH-CYP reductase were established in our laboratory to compare the mutagen-producing capacity of these enzymes for various N-nitrosamines. We found that CYP2E1 was responsible for the metabolic activation of N-nitrosamines with relatively short alkyl chains, whereas CYP2A6 was involved in the metabolic activation of N-nitrosamines possessing relatively bulky alkyl chains such as a tobacco-specific nitrosamine, NNK, which has been known to cause lung tumor in rodents. Thus, to examine a hypothesis that individuals possessing the CYP2A6*4C have the reduced risk of lung cancer due to the lack of the capacity of the metabolic activation of certain carcinogens in tobacco smoke, a case-control study was performed. 展开更多
关键词 CYP Genetic polymorphism of CYP2A6 is one of the potential factors determining tobacco-related cancer risk
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Determining Geometric Accuracy in Turning
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作者 Kwong Chi Kit A Geddam 《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 2002年第S1期97-,共1页
Mechanical components machined to high levels of ac cu racy are vital to achieve various functional requirements in engineering product s. In particular, the geometric accuracy of turned components play an important r... Mechanical components machined to high levels of ac cu racy are vital to achieve various functional requirements in engineering product s. In particular, the geometric accuracy of turned components play an important role in determining the form, fit and function of mechanical assembly requiremen ts. The geometric accuracy requirements of turned components are usually specifi ed in terms of roundness, straightness, cylindricity and concentricity. In pract ice, the accuracy specifications achievable are influenced by many factors such as component materials, production equipment, environmental factors, and machini ng process variables. While the sources of geometric errors due to materials, ma chinery and environment can be predicted to a large extent, the geometric accura cy due to the machining practice is unpredictable and difficult to determine. Since the fundamental geometric tolerances of work-pieces machined by tur ning a re sensitive to the cutting conditions, optimizing the cutting parameters such a s cutting speed, feed rate, and depth of cut is important for achieving the requ ired accuracy levels. Optimization studies of process variables in turning have not been well documented in the literature. Some experimental studies show the e ffect of process variables like cutting speed, feed rate and depth of cut on sur face roughness, production rate, production cost, etc. However, there have been no in-depth studies of the influence of the process variables on mechanical acc uracy related to the geometrical tolerances. In practice, a mechanical part usually consists of several geometrical features. For many mechanical parts, the geometric tolerances determine their functional characteristics. For example, diameter of a shaft and diameter of a hole decide the clearance of a cylindrical fit. The features of the cylindrical fit depend o n the dimensional tolerances of the size as well as several other geometrical to lerances like, roundness, cylindricity, and concentricity. In the study reported here, the dimensional and geometric tolerances achieved using turning experimen ts over a wide selection of cutting conditions will be used to analyze their inf luence on satisfying the functional requirements. The study will also show a met hodology of optimizing the process variables to achieve dimensional and geom etric tolerances to meet the requirements of specific functional features. 展开更多
关键词 determining Geometric Accuracy in Turning
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Determining winner in multi-attribute procurement auction:a method based on technical and business experts' evaluation information
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作者 Guangxin Gao Zhiping Fan Yang Liu 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2015年第6期1244-1253,共10页
A method for solving the winner determination problem (WDP) in multi-attribute procurement auctions is proposed, based on technical and business experts' evaluation information. Firstly, on the background of procur... A method for solving the winner determination problem (WDP) in multi-attribute procurement auctions is proposed, based on technical and business experts' evaluation information. Firstly, on the background of procurements in China, a multi-attribute pro- curement auction mechanism is presented, where technical and business experts participate in the bid evaluation. Then, the concept of TOPSIS is used to determine the positive and negative ideal points of the WDP according to bid prices, the technical and business experts' evaluation information. Further, the closeness coefficient of each bidder (candidate supplier) is obtained by calculating the distances to the positive and negative ideal points. Thus, the winning supplier can be determined according to the closeness coefficients. Finally, a numerical example is used to illustrate the use of the proposed method. 展开更多
关键词 multi-attribute auction winner determination technical and business experts bid evaluation.
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Relative orbit determination algorithm of space targets with passive observation
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作者 DAI Chenchao QIANG Hongfu +2 位作者 ZHANG Degang HU Shaolei GONG Baichun 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第3期793-804,共12页
Angles-only relative orbit determination for space non-cooperative targets based on passive sensor is subject to weakly observable problem of the relative state between two spacecraft. Previously, the evidence for ang... Angles-only relative orbit determination for space non-cooperative targets based on passive sensor is subject to weakly observable problem of the relative state between two spacecraft. Previously, the evidence for angles-only observability was found by using cylindrical dynamics, however, the solution of orbit determination is still not provided. This study develops a relative orbit determination algorithm with the cylindrical dynamics based on differential evolution. Firstly, the relative motion dynamics and line-of-sight measurement model for nearcircular orbit are established in cylindrical coordinate system.Secondly, the observability is qualitatively analyzed by using the dynamics and measurement model where the unobservable geometry is found. Then, the angles-only relative orbit determination problem is modeled into an optimal searching frame and an improved differential evolution algorithm is introduced to solve the problem. Finally, the proposed algorithm is verified and tested by a set of numerical simulations in the context of highEarth and low-Earth cases. The results show that initial relative orbit determination(IROD) solution with an appropriate accuracy in a relative short span is achieved, which can be used to initialize the navigation filter. 展开更多
关键词 angles-only measurement relative orbit determination cylindrical coordinate differential evolution
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Study on multi-wavelength thin film thickness determination method
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作者 SHI Ce XIE Mao-Bin +3 位作者 ZHENG Wei-Bo JI Ruo-Nan WANG Shao-Wei LU Wei 《红外与毫米波学报》 CSCD 北大核心 2024年第6期813-819,共7页
This work introduces a novel method for measuring thin film thickness,employing a multi-wavelength method that significantly reduces the need for broad-spectrum data.Unlike traditional techniques that require sev⁃eral... This work introduces a novel method for measuring thin film thickness,employing a multi-wavelength method that significantly reduces the need for broad-spectrum data.Unlike traditional techniques that require sev⁃eral hundred spectral data points,the multi-wavelength method achieves precise thickness measurements with data from only 10 wavelengths.This innovation not only simplifies the process of spectral measurement analysis but also enables accurate real-time thickness measurement on industrial coating production lines.The method effectively reconstructs and fits the visible spectrum(400-800 nm)using a minimal amount of data,while maintaining measurement error within 7.1%.This advancement lays the foundation for more practical and efficient thin film thickness determination techniques in various industrial applications. 展开更多
关键词 film thickness determination transmittance and reflectance spectra FITTING spectral reconstruction
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液相色谱-质谱联用对复杂食品基质中407种多农药残留量的测定 被引量:12
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作者 薄涛 詹顺安 +3 位作者 胡培斌 王颖 张之旭 李平 《分析测试学报》 CAS CSCD 北大核心 2008年第S1期190-192,共3页
A new method was developed for determination of 407 pesticide residues in complex matrix by using LC-MS with triple quadrupole(QQQ).Comparing with regular method,the method has high sensitivity and repeativity,and was... A new method was developed for determination of 407 pesticide residues in complex matrix by using LC-MS with triple quadrupole(QQQ).Comparing with regular method,the method has high sensitivity and repeativity,and was applied for the determination of peticide in real sample with satisfactory results. 展开更多
关键词 LC-MS PESTICIDES RESIDUES DETERMINATION
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高分辨电感耦合等离子体质谱法测定煤质样品中49种痕量元素 被引量:4
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作者 张彦辉 武朝晖 +1 位作者 郭虹 薛丽丽 《质谱学报》 EI CAS CSCD 2005年第z1期33-34,共2页
Various trace elements, especially potential toxic trace elements such as As, Cd, Cr, Cu, Hg, Pb, Ni, Se, Tl, Zn, would be concentrated in processing of coal. Determination of these elements in coal is very important ... Various trace elements, especially potential toxic trace elements such as As, Cd, Cr, Cu, Hg, Pb, Ni, Se, Tl, Zn, would be concentrated in processing of coal. Determination of these elements in coal is very important for identification of coal quality. A method is developed for determination of 49 trace elements in coal by high resolution inductively coupled plasma mass spectrometry (HR-ICPMS). Microwave acid digestion and low-temperature airproof acid digestion for sample preparation were investigated. It is shown that the low-temperature airproof acid digestion method is of lower blank, and more suitalbe for the coal sample preparation. The on-line internal standard (Rh) sample introduction is applied to compensate matrix effects in measurement by ICPMS. The method gives low detection limits (0.002-1.60 μg/g) and better relative standard deviations (0.60%-4.78%) for the determined 49 elements in coal. 展开更多
关键词 TRACE ELEMENTS COAL HR-ICPMS determination
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气相色谱-质谱联用对浓缩苹果汁中多种拟除虫菊酯类农药的快速测定 被引量:2
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作者 汤桦 陈大舟 +3 位作者 王覃 吴雪 徐锐锋 钟石林 《分析测试学报》 CAS CSCD 北大核心 2008年第S1期219-220,共2页
A GC-MS method was established for determination of 10 pyrethroids in apple juice concentrate.The sample was extracted by acetone and hexane,and the 10 pyrethroids were separated on a capillary column(DB-5,30 m×2... A GC-MS method was established for determination of 10 pyrethroids in apple juice concentrate.The sample was extracted by acetone and hexane,and the 10 pyrethroids were separated on a capillary column(DB-5,30 m×250 μm×0.25 μm) and determined by GC-MSD.The recoveries of pyrethroids were range of 84%-96% with the detection limits of 3-46 μg/kg.The relative standard deviations were range of 0.68%-5.11%. 展开更多
关键词 determination apple JUICE CONCENTRATE PYRETHROIDS GC-MS
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电喷雾解吸电离质谱法直接测定蔬菜表面的莠去津残留 被引量:4
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作者 张新忠 马晓东 +1 位作者 韩昊 李重九 《分析测试学报》 CAS CSCD 北大核心 2007年第z1期222-224,共3页
A direct determination method for the atrazine residue on the vegetable was developed by using desorption electrospray ionization mass spectrometry (DESI MS) without any sample pretreatment.Acetonitrile-water (1:1,v/v... A direct determination method for the atrazine residue on the vegetable was developed by using desorption electrospray ionization mass spectrometry (DESI MS) without any sample pretreatment.Acetonitrile-water (1:1,v/v),which contained 0.1% formic acid,was used as the spray solvent.The working conditions,such as ESI gas inlet pressure,ESI flow rate,ESI spray voltage,spray-to-sample distance,spray-to-cone-hole distance and the collision induced dissociation (CID) voltage for MS/MS,were optimized for both DESI and esquires 6 000 mass spectrometer.The linear range of atrazine on cabbage leaves was 25.25-2 525 pg/mm2,the R2 was 0.991 6,and the relative standard deviations were between 3.37% and 26.17%.The LOD of atrazine calculated by S/N=3 was 2.50 pg/mm2. 展开更多
关键词 Desorption electrospray ionization mass spectrometry (DESI MS) ATRAZINE VEGETABLE Real time determination
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高效液相色谱-电感耦合等离子体质谱法测量三甲基铅 被引量:2
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作者 逯海 韦超 +3 位作者 王军 巢静波 周涛 陈大周 《质谱学报》 EI CAS CSCD 2005年第z1期103-104,96,共3页
A high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICPMS) was combined, and the chromatography conditions were optimized. The stability and homogeneity of a trimethyllead refer... A high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICPMS) was combined, and the chromatography conditions were optimized. The stability and homogeneity of a trimethyllead reference material were determined using this method. 展开更多
关键词 HPLC-ICPMS trimethyllead REFERENCE MATERIAL DETERMINATION
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葡萄糖醛酸吗啡的LC-MS/MS检验方法研究 被引量:3
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作者 王俊伟 郭亚飞 +1 位作者 罗敬峰 王绘军 《分析测试学报》 CAS CSCD 北大核心 2007年第z1期130-131,134,共3页
In human subjects,morphine is extensively metabolized to form(M3G)and morphine-6-glucuronide(M6G).This article established a sensitive LC-MS/MS method that allows the quantification of morphine and its glucuronide met... In human subjects,morphine is extensively metabolized to form(M3G)and morphine-6-glucuronide(M6G).This article established a sensitive LC-MS/MS method that allows the quantification of morphine and its glucuronide metabolites. 展开更多
关键词 Morphine-glucuronide HPLC-MS/MS Determination method
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比色法测定茶叶GABA含量的可行性研究 被引量:8
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作者 魏珍珍 赵明 +2 位作者 李双容 杨四润 周红杰 《江西农业学报》 CAS 2010年第8期56-58,66,共4页
应用比色法、HPLC和氨基酸自动分析仪法同时测定了六大茶类共45个样品的GABA含量,结果表明,HPLC与氨基酸分析仪测定结果基本一致,比色法和HPLC法测定的普洱茶、红茶、白茶、黄茶的结果差异极显著(P<0.01),应用比色法测得的普洱茶和... 应用比色法、HPLC和氨基酸自动分析仪法同时测定了六大茶类共45个样品的GABA含量,结果表明,HPLC与氨基酸分析仪测定结果基本一致,比色法和HPLC法测定的普洱茶、红茶、白茶、黄茶的结果差异极显著(P<0.01),应用比色法测得的普洱茶和黑茶中GABA含量比HPLC测定结果高,而其他茶类测定结果低,推测茶叶中含有化学物质(色素、氨基酸等)干扰比色法测定。目前比色法不能应用于茶叶GABA测定,需要进一步改进方法以排除如氨基酸、茶色素等的干扰。 展开更多
关键词 比色法测定 茶叶 GABA 含量比 可行性研究 COLORIMETRIC Method Tea Determination of 测定结果 氨基酸自动分析仪 HPLC法测 普洱茶 氨基酸分析仪 同时测定 茶色素 结果差异 化学物质 干扰 改进方法 茶类
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高温高压下NaCl-H_2O体系的Raman光谱分析:一种新的流体包裹体盐度测定方法 被引量:2
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作者 杨玉萍 郑海飞 +2 位作者 张立飞 刘曦 邓松涛 《岩石学报》 SCIE EI CAS CSCD 北大核心 2009年第8期2023-2028,共6页
利用水热金刚石压腔研究了高温高压下0.0%、5.0%、10.0%和20.0%的NaCl-H_2O体系的Raman光谱,研究结果发现:对于盐度一定的NaCl-H_2O体系,当压力不变时,水的Raman伸缩谱峰的波数变化量△v_((O-H))随温度的升高而不断增加;当压力不同时,△... 利用水热金刚石压腔研究了高温高压下0.0%、5.0%、10.0%和20.0%的NaCl-H_2O体系的Raman光谱,研究结果发现:对于盐度一定的NaCl-H_2O体系,当压力不变时,水的Raman伸缩谱峰的波数变化量△v_((O-H))随温度的升高而不断增加;当压力不同时,△v_((O-H))随温度的变化关系(偏移斜率S)不受压力的影响,而只与盐度相关。利用该性质可以用来确定流体包襄体的盐度(W),其计算公式如下:W=123.25S^2-128.11S+32.40,误差为0.46%。 展开更多
关键词 高温高压 体系 RAMAN光谱 分析 流体包裹体 盐度 测定方法 HIGH temperature HIGH pressure spectroscopic analysis fluid inclusion SALINITY method of STRETCHING vibration different determination of frequency shift 压力 relationship application
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HPLC-ESI MS/MS对动物组织中痕量四环素类抗生素的同时测定
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作者 王覃 陈大舟 +3 位作者 汤桦 张经华 周晓晶 赵新颖 《分析测试学报》 CAS CSCD 北大核心 2008年第S1期215-218,共4页
A method for simultaneous determination of oxytetracycline,tetracycline,chlortetracycline in animal tissue was successfully established by HPLC-ESI MS/MS.The tetracycline antibiotics in animal tissue were extracted by... A method for simultaneous determination of oxytetracycline,tetracycline,chlortetracycline in animal tissue was successfully established by HPLC-ESI MS/MS.The tetracycline antibiotics in animal tissue were extracted by liquid-solid extraction and cleaned up by SPE.The mass spectrometer was operated in the positive-ion mode using selected reaction monitoring(SRM).The results showed that three tetracycline antibiotics were well separated under the optimal conditions.The detection limits of oxytetracycline,tetracycline and chlortetracycline were 0.16 ng/g,0.1 ng/g and 0.1 ng/g,respectively.The spiked recoveries were range of 84%-94% and the relative standard deviations were 2.4%-2.9%. 展开更多
关键词 TETRACYCLINE ANTIBIOTICS HPLC-ESI MS/MS ANIMAL TISSUE determination
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Programmable extracellular matrix mimics for regenerative medicine
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作者 Yong Wang 《医用生物力学》 EI CAS CSCD 北大核心 2013年第S1期72-74,共3页
The extracellular matrix(ECM)plays an important role of determining the functionalities of cells and tissues.Thus,biomaterials that can recapitulate the biological and mechanical functionalities of the ECM are promisi... The extracellular matrix(ECM)plays an important role of determining the functionalities of cells and tissues.Thus,biomaterials that can recapitulate the biological and mechanical functionalities of the ECM are promising in the treatment of numerous complicated human diseases.Great efforts have been made to develop a variety of smart ECM mimics that can alter their functionalities dynamically in response to physical stimulation(e.g.,temperature variation).However,it remains challenging to develop a biomimetic ECM that can undergo functional changes regulated at the biomolecular level in the way natural ECMs are regulated. 展开更多
关键词 REGENERATIVE hydrogel challenging dynamically stimulation NUMEROUS ALTER determining biomaterial MIMIC
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Acoustic Measurement
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《计量学报》 CSCD 1991年第S1期92-94,共3页
09001 The Calibration of a Reference SoundSource in Semianechoic Room. Yu Bo. Zhong Meie,Cheng Jianlin:1(3). 1980.pp.213--218.This paper describes the calibration method of areference Sound source.A set of calibration... 09001 The Calibration of a Reference SoundSource in Semianechoic Room. Yu Bo. Zhong Meie,Cheng Jianlin:1(3). 1980.pp.213--218.This paper describes the calibration method of areference Sound source.A set of calibration data for areference sound source type 4204 of A--power leveland sound power level in third octave band frequenciesin semianechoic room are given.The factors 展开更多
关键词 CALIBRATION AFFECTING instead ROOM determining ANALOG valent UNDERWATER analysed deser
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Measurement of Geometrical Quantities
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《计量学报》 CSCD 1991年第S1期37-47,共11页
01001 Two--coordinates Measuring Machine withLaser Interferometer. Yang Ziben:1 (2), 1980. pp.81--92.A precision instrument called two -- coordinatesmeasuring machine has been developed. which is basedon determining l... 01001 Two--coordinates Measuring Machine withLaser Interferometer. Yang Ziben:1 (2), 1980. pp.81--92.A precision instrument called two -- coordinatesmeasuring machine has been developed. which is basedon determining length by means of laser interferencetechnique. In this article. the main construction of themachine and the four interference systems including 展开更多
关键词 COORDINATES determining instrument rotation length distr ILLUMINATION align CRITERION GRATING
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英文大事记 1992年9月16日~30日
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作者 古真 《国际展望》 北大核心 1992年第19期32-32,共1页
On September 20, France voted on a referendum determining whether Western Europe strides toward or steps back from closer political and economic union. The final official result in France’s referendum showed 51.05 pe... On September 20, France voted on a referendum determining whether Western Europe strides toward or steps back from closer political and economic union. The final official result in France’s referendum showed 51.05 per cent of voters approved the Maastricht Treaty. Of 38333696 registered voters, 13172710 voted "yes" to European political, economic and monetary union and 12632816 voted "no." The turnout was 69.68 per cent. 展开更多
关键词 registered UNION CLOSER steps POLITICAL determining MAASTRICHT OFFICIAL approved MONETARY
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Sex Identification of Red-crowned Crane by the Polymerase Chain Reaction
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作者 LIJian-hong LIShu-ling +1 位作者 BAOJun BAIXiu-juan 《Journal of Northeast Agricultural University(English Edition)》 CAS 2004年第2期151-155,共5页
Sex determining gene primers of Oriental White Stork were used to amplify sex-linked gene of the Red-crowned Crane′s W chromosome-specific by PCR for sex identification. The sexes of 7 couples of grown Red-crowned Cr... Sex determining gene primers of Oriental White Stork were used to amplify sex-linked gene of the Red-crowned Crane′s W chromosome-specific by PCR for sex identification. The sexes of 7 couples of grown Red-crowned Cranes and 15 youngs were identified. Through DNA sequence analysis, the identity is 94.77% between Red-crowned Crane and Oriental White Stork. The results of this study suggest that the application of the polymerase chain reaction technique is practicable for determining sex in the Red-crowned Crane. 展开更多
关键词 Red-crowned Crane sex determining gene sex identification
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