Unusual Boron-Carbon Compounds Containing Planar Tetracoordinate and Pentacoordinate Carbons

采用密度泛函理论(dfT),在b3lyP/6-311+g**水平上,研究了三类包含平面四配位碳原子(PTC)和平面五配位碳原子(PPC)的硼碳化合物.这三类新型化合物是由C3b2H4(包含PTC)、Cb4H2(包含PTC)和Cb5H2(包含PPC)三种稳定结构和—CHCH—单元连接起来而得到的.在理论上探讨了这些新型的硼碳化合物的成键特征,光谱性质以及芳香性.研究结果表明:包含PTC和PPC原子的能量最低的结构,在不受对称面限制的条件下,具有C2V对称性的顺式立体构型比具有反式平面构型的化合物稳定.计算的核独立化学位移(nICS)显示,这些新型化合物的三元环中心有强的芳香性.计算最稳定硼碳化合物的PTC和PPC原子的WIbErg键指数(WbIS)表明PTC和PPC的成键遵循八隅规则.Unusual boron-carbon compounds containing planar tetracoordinate carbon (ptC) and planar pentacoordinate carbon (ppC) were investigated using density functional theory (DFT) at B3LYP/6-311+G** level.These novel compounds are generally assembled with three types of stable structural units C3B2H4 with ptC, CB4H2 with ptC, and CB5H2 with ppC as well as linking elements—CHCH—.On the basis of calculation results the bonding features, spectroscopic properties, and the aromaticities of these novel boron-carbon compounds were discussed.Results show that as for the lowest-energy compounds contained ptC and ppC without being limited by symmetrical planes, stereo cis-structures of C2v symmetry are more stable than the corresponding planar trans-structures.Calculated nucleus-independent chemical shift (NICS) values show that the aromaticity of the center of the three-membered rings is the strongest.The total Wiberg bond indices (WBIs) of the ptC and ppC atoms of the most stable structures of the boron-carbon compounds indicate that the ptC and ppC obey the octal rule.supportedbytheExcellentSciencePre-researchProjectofShaanxiNormalUniversity(China)in2008---

Unusual Boron-Carbon Compounds Containing Planar Tetracoordinate and Pentacoordinate Carbons

Unusual boron-carbon compounds containing planar tetracoordinate carbon (ptC) and planar pentacoordinate carbon (ppC) were investigated using density functional theory (DFT) at B3LYP/6-311+G * * level. These novel compounds are generally assembled with three types of stable structural units C3B2H4 with ptC, CB4H2 with ptC, and CB5H2 with ppC as well as linking elements -CHCH-. On the basis of calculation results the bonding features, spectroscopic properties, and the aromaticities of these novel boron-carbon compounds were discussed. Results show that as for the lowest-energy compounds contained ptC and ppC without being limited by symmetrical planes, stereo cis-structures of C-2v symmetry are more stable than the corresponding planar trans-structures. Calculated nucleus-independent chemical shift (NICS) values show that the aromaticity of the center of the three-membered rings is the strongest. The total Wiberg bond indices (WBIs) of the ptC and ppC atoms of the most stable structures of the boron-carbon compounds indicate that the ptC and ppC obey the octal rule.Excellent Science Pre-research Project of Shaanxi Normal University (China

高效液相色谱-串联质谱法分析姜黄中微量的姜黄素类化合物

建立了同时检测中药姜黄中3种微量的姜黄素类化合物的高效液相色谱-电喷雾串联质谱分析方法。姜黄根茎经乙醇超声提取后,无需其他处理可直接进样分析。以Microsorb C18色谱柱（250mm×4.6mm,5μm）分离,乙腈和0.1%甲酸水梯度洗脱,在多反应监测模式（MRM）下对目标成分进行定性分析。利用质谱碎裂规律,分别对每个目标成分同时监测8个母离子/特征子离子对的反应过程,首次从姜黄中发现了3个微量的姜黄素类化合物成分。一次性完成了目标成分的同时定性,方法的检出限为0.2μg/L。结果表明,该方法具有简便、快速、准确、灵敏度高的优点,适用于中药复杂体系中姜黄素类化合物的分析检测

天麻指纹图谱模式识别研究

天麻为兰科植物天麻Gastrodia elata Bl．的干燥块茎。多年来其质量主要以指标成分天麻素等酚性成分的含量测定来加以控制，因此很难全面评定药材的真正质量。中药指纹图谱及化学模式识别技术是解决中药质量评价和分类鉴别的有效手段，继前文对天麻指纹图谱的建立及相似度评价进行报道之后，本研究主要讨论指纹图谱的模式识别工作。常用的模式识别方法有聚类分析、判别分析等拉,近年来广泛应用于中药指纹谱的数据处理工作。作者应用聚类分析和判别分析对不同产地及不同质量等级的20个天麻药材进行了模式识别研究，以期更全面评价天麻药材质量

Allocation of water cellar in Malus pumila Mill orchard on

针对如何合理配置水窖以解决黄土高原梯田种植苹果存在的水资源短缺问题,利用WEPP模型,在对0～200 cm土壤储水量动态变化模拟验证的基础上,以满足梯田苹果在不同典型代表年的生育期需水为目标,对水窖进行优化配置。结果表明:在更新土壤及作物管理数据库后,WEPP模型可实现对梯田苹果园0～200 cm土壤储水量的动态模拟;利用土壤水分动态变化选择典型年来进行水窖优化配置,更能满足苹果的需水要求;黄土丘陵沟壑区适宜的水窖配置干旱年为1 150 m3/hm2,平水年为180 m3/hm2,湿润年为50 m3/hm2。该研究为高效利用该区有限水资源提供了一种基于土壤水分动态变化来满足苹果生长需水的水窖优化配置方法。</span

ANALYSIS of DAILY VARIATION PROCESS of TEMPERATURE AND SALINITY IN THE CENTRAL AND NORTHERN TAIWAN STRAIT IN FEBRUARY-MARCH 1998

本文分别对位于台湾海峡中部和北部两个连续观测站1998年2~3月的CTd资料进行分析，认为北部测站在观测期间经历了低温、低盐水入侵的过程，但此过程只显著影响到30M层，温盐垂直结构有时出现单跃层，有时出现阶梯结构；而中部测站盐度垂直均匀，温度垂直梯度也较小，已不受闽浙沿岸水的影响。Through an analysis on the CTD data from two time series anchored stations in the central and northern Taiwan Strait during February - March 1998, it is concluded that: the vertical structure of temperature and salinity at the northern station and the central station can be classified into 2 types, respectively; the northern station undergoes an invasion process of low temperature and low salinity water during the period of investigation, but the remarkable effect can only be seen at 0-30m depth; and the central station can not be affected by the Minzhe Coastal Water.国家自然科学基金重点项目资助!4963622

毛细管区带电泳法测定四物汤及其配伍组方中川芎嗪和阿魏酸的含量

建立了毛细管区带电泳测定中药复方四物汤及其配伍组方中有效成分——川芎嗪和阿魏酸含量的分析方法，并对配伍规律进行了初步的探索。采用50mmol／L硼酸钠溶液(pH9．00)为缓冲溶液，在电压20kV、检测波长212nm和内标为对羟基苯甲酸(p-HBA)的条件下，四物汤及其配伍组方中川芎嗪和阿魏酸在24min内获得良好的分离。定量分析表明，川芎嗪和阿魏酸的相对峰面积Y(即待测组分与内标的峰面积之比Ai／As)和各自的质量浓度X(mg／L)之间呈良好的线性关系，相关系数分别为0．9997和0．9967。上述两种组分的平均回收率依次为98．2％和100．1％。此外，还讨论了缓冲溶液的浓度、pH值、电压对有效成分迁移的影响。方法简单、灵敏、快速

An analysis on temperature and salinity at the surface water of Fujian coast in late August of 2006

通过对福建沿海2006年8月20~24日表层温、盐度的调查资料进行分析,得出以下结果:(1)受九龙江、晋江以及闽江冲淡水的影响,福建沿海存在较强的河口锋.(2)在东山、平潭附近海域存在上升流迹象.(3)在沿岸区,潮汐对海水表层温、盐分布的影响显著.Several phenomena are analyzed according to the temperature and salinity measurements at surface water along the Fujian coast in late August of 2006.The results show that:(1)As affected by the diluted water from the Jiulongjiang River,Jinjiang River and Minjiang River,there exist strong salinity fronts in the estuaries.(2)Upwelling are evident near both Dongshan and Pingtan.(3)Tide has shown effects on the sea surface temperature and salinity along Fujian coast.国家自然科学基金资助项目(40576015、40521003、40331004