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Search Results: 1 - 10 of 532835 matches for " <br>王龙远 "
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Cytology of Two Species in the Genus Caltha (Ranunculaceae) from China
国产毛茛科驴蹄草属两种植物的细胞学研究

WANG Long-yuan,REN Chen,YANG Qin-er,<br>,任琛,杨亲二
热带亚热带植物学报 , 2013,
Abstract: Three populations in Caltha palustris and five in C. scaposa from China, two closely related species in the small genus Caltha of the Ranunculaceae, have been cytologically investigated. Of the populations checked in C. palustris, the Nayong population from Guizhou has the chromosome number of 2n=32 (tetraploid), and the two Zhongdian populations from Yunnan have the number of 2n=64 (octoploid). Among those checked in C. scaposa, the Hongyuan, Kangding, and Serxu populations from Sichuan all have the tetraploid number of 2n=32, and the Nyingchi population from Xizang and the Deqen population from Yunnan both have the octoploid number of 2n=64. We have performed a karyotypic analysis on most of these populations. The present results, together with those reported previously, show that both C. palustris and C. scaposa from China may have undergone strong differentiation among populations in ploidy level and karyotypic constitution. Caltha palustris from China includes at least three cytotypes with different ploidy levels, namely, the tetraploid cytotype with 2n=32, the hexaploid cytotype with 2n=48, and the octoploid cytotype with 2n=64. The tetraploid cytotype is the commonest and the most widespread, and currently only in northwestern Yunnan all the three cytotypes have been found to co-occur. Caltha scaposa from China includes two cytotypes, the tetraploid cytotype with 2n=32 and the octoploid cytotype with 2n=64, with the former occurring in the northeastern part of the geographical range of the species while the latter in the southwestern part. Although the 32 or 64 chromosomes in both C. palustris and C. scaposa can be roughly arranged into eight groups of four or eight homologues, in some of the groups there often exists obvious heteromorphy among the presumably homologous chromosomes, and thus different populations are more or less distinct in karyotypic constitution. Although C. palustris and C. scaposa are the two most closely related species in the genus, they are revealed to be rather well differentiated chromosomally, particularly in chromosome size. The chromosomes in C. scaposa are smaller than those in C. palustris, which may represent a derived condition.
Preparation of Novel Chiral Stationary Phases for Ligand Exchange Chromatography and Their Applications
新型手性配体交换色谱固定相的制备及应用

WANG Qun-biao,LONG Yuan-de,HUANG Tian-bao,<br>群标,,黄天宝
色谱 , 2000,
Abstract: Two novel chiral stationary phases for ligand exchange chromatography were prepared by synthesizing 2-(2-hydroxyl-3-octoxy)propyl-(S)-1,2,3,4-tetrahydro-3-isoquinolinecarboxylic acid (C_8-(S)-THIQCA) and 2-(2-hydroxyl-3-dodecoxy)propyl-(S)-1,2,3,4-tetrahydro-3-isoquinolinecarboxylic acid (C_12-(S)-THIQCA) as chiral selectors, and coating them on ODS bonded stationary phase. Chromatographic resolutions of some DL-amino acids were achieved on the chiral stationary phases by using 1 mmol/L NH_4Cl with 0.2 mmol/L Cu(Ac)_2solution as mobile phase and detection at 254 nm. Ability of chiral resolution of the DL-amino acids through the stationary phases was compared and the effect of cupric ion on resolutions of the DL-amino acids was examined. The elution order of D-isomer before L-isomer was observed for all the DL-amino acids resolved, except DL-Val For DL-Pro, DL-Val and DL-Leu the elution order through the chiral phases was different from that through the chiral ligand exchange phases prepared from L-Pro or L-hydroxyl proline with five membered ring structure.
Characteristics of Precipitation and Temperature Changes in Beijing City During 1951-2010
1951年至2010年北京市降水和气温的变化特征

ZHU Longteng,CHEN Yuansheng,YAN Ranran,SHEN Tian,JIANG Lei,WANG Ying,<br>朱,,燕然然,沈恬,蒋蕾,
资源科学 , 2012,
Abstract: 根据北京市1951年-2010年的降水和气温数据资料, 综合运用滑动平均法、Mann-Kendall检验、Hurst指数法、GM(1, 1)模型等方法, 从不同时间尺度和层面上分析北京市降水和气温变化的规律以及未来的趋势特征。结果表明:北京市降水的72.5%集中在夏季, 7月份的降水最多, 12月份最少;极端降水指标中的1日最大降水量、极端强降水日数、极端强降水比率、最长连续无降水天数呈不同程度的递减趋势, 零降水日数以2d/10a的速率递增;北京市历年的降水量以44.3mm/10a的速率递减, 1994年为降水的突变年份, 未来的降水整体上呈增加趋势, 北京市下一次旱灾大致指向2028年-2029年左右;北京市历年的平均气温、平均最高气温和平均最低气温呈不同程度的增加趋势, 平均最低气温的增加趋势最为显著, 平均气温和平均最低气温的突变年份都是1989年, 而平均最高气温的突变年份为1993年-1994年和1996年, 三者未来整体上都呈增加趋势, 而平均最低气温的增加趋势最为显著。
环糊精色谱固定相及其在手性化合物分离中的应用
黄天宝,,
色谱 , 1993,
Abstract: 随着生命科学,尤其是生命化学和药物化学的发展,已经认识到并开始重视手性药物异构体在生物体内代谢和药理作用的差别,识别对映异构体、分离和分析手性化合物的研究在生命科学的基础研究中无疑具有重要的学术意义和实际意义。
自动武器广义模块化快速设计研究与系统开发
永娟,赵军,
兵工学报 , 2008,
Abstract: ?为了提高自动武器产品设计质量和效率,缩短开发周期,推动自动武器向通用化、模块化、系列化方向发展,结合自动武器结构特点,采用广义模块化设计理论,研究并提出了产品模块、接口划分方法及模块信息编码方案。分析自动武器广义模块化实施过程,给出了自动武器快速设计模块总体框架。用MicrosoftVC++6.0、Oracle和Pro/TOOLKIT二次开发工具,建立了自动武器专用模板库、实例库及参数化图库。开发了在Pro/E环境下专用的自动武器快速设计模块,并通过实例验证了其可行性。
EFFECT OF PHONON CONFINEMENT AND STRAIN ON RAMAN SPECTRA FROM LIGHT-EMITTING POROUS SILICON
空间限制与应变对发光多孔硅喇曼光谱的影响

YANG MIN,HUANG DA-MING,HAO PING-HAI,ZHANG FU-LONG,HOU XIAO-YUAN,WANG XUN,<br>杨敏,黄大鸣,郝平海,张甫,侯晓,
物理学报 , 1994,
Abstract: 发光多孔硅的喇曼光谱在520cm-1附近呈现一锐峰,峰位的红移随多孔度的增大而增大采用微晶模型拟合喇曼谱的线形,发现除了光学声子的空间限制效应,硅单晶的应变对峰位的移动也有显著贡献。通过谱形的拟合估算了硅微粒的应变,与已报道的X射线衍射结果相一致。在多孔硅的喇曼光诸中没有观察到起源于非晶硅的光散射信号。
IMPROVEMENT OF THE STABILITY OF POROUS SILICON BY CHEMICAL METHOD
多孔硅发光稳定性的改进

ZHANG FU-LONG,HOU XIAO-YUAN,YANG MIN,HUANG DA-MING,WANG XUN,<br>张甫,侯晓,杨敏,黄大鸣,
物理学报 , 1994,
Abstract: Porous silicon of low porosity was oxidized in boiling HNO3 solution. Photo-luminescence, microluminescence and SEM studies show that the stability and the uniformity of the sample were greatly improved by such a treatment. This is a new method much easier to control than rapid thermal oxidation.
Desertification Evolution Prediction for Lake Area of Minqin Oasis Based on Integration of GIS and Cellular Automata
基于元胞自动机民勤绿洲湖区荒漠化演化预测

SONG Dong-mei,WU Yuan-long,ZHANG Zhi-cheng,WANG Jian,LI Xia-oyu,<br>宋冬梅,,张志诚,,李小玉
中国沙漠 , 2009,
Abstract: 民勤湖区是民勤绿洲中生态环境最为恶劣的地区,土地荒漠化问题十分突出。以民勤绿洲湖区为例,解译1992年、1998年、2002年和2006年TM卫星影像,分析其荒漠化动态变化情况,利用ArcObjects模块结合地理元胞自动机理论构造荒漠化动态模拟模型,通过对比2006年的预测数据与实际数据,对模型进行参数调整和预测检验。预测结果表明,模型预测的准确性达到90%。最后对2012年该区土地利用状况做出预测,进而对荒漠化的发展趋势进行预测分析。
Growth and Properties of High Quality InAs Single Crystals
高质量InAs单晶材料的制备及其性质

Zhao Youwen,Sun Wenrong,Duan Manlong,Dong Zhiyuan,Yang Zixiang,Wang Yingli,<br>赵有文,孙文荣,段满,董志,杨子祥,吕旭如,应利
半导体学报 , 2006,
Abstract: 利用液封直拉法(LEC)生长了直径50mm〈100〉和〈111〉晶向的InAs单晶.分析研究了n型杂质Sn,S和p型杂质Zn,Mn的分凝特性、晶格硬化作用、掺杂效率等.利用X射线双晶衍射分析了晶体的完整性.对InAs晶片的抛光、化学腐蚀和清洗进行了分析,在此基础上实现了抛光晶片的开盒即用(EPI-READY).
Effect of Electric Field on Cell Growth, Permeability and Extracellular Enzymatic Reactions of Phanerochaete chrysosporium
电场对黄孢原毛平革菌生长、细胞通透性及其胞外酶反应的影响

WANG Fu-yuan,MIAO Chang-chun,HAN Hui-long,JIN Wen-biao,LIU Zheng,<br>,苗长春,韩慧,金文标,刘铮
过程工程学报 , 2007,
Abstract: The effect of electric field on the cell growth and permeability ofPhanerochaete chrysosporium, and extracellular enzymatic activity of laccase, lignin peroxidase and manganese peroxidase, squeezed extracellularly out of Phanerochaete chrysosporium, was experimentally investigated, respectively. The application of 50 Hz alternating current of 50 mA enhanced the growth of Phanerochaete chrysosporium, giving a 1.72 fold increase in cell dry weight after 10 d culture. The cell permeability was also increased when exposed to either DC or AC. The enzymatic activity of laccase, lignin peroxidase and manganese peroxidase was firstly increased and then reduced when exposed to DC, and the suitable operation time was 10 h for DC of 10 mA.
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