双位置

The more the number of hydroxyl substitution in phenyl ring, the better the ability of scavenging DPPH free radical. That is, trihydroxy is better than dihydroxy, and dihydroxy is better than monohydroxy. Moreover, when the polyhydroxy exists in phenyl ring and it is ortho-position or para-position, the ability of scavenging DPPH free radical is better too.

当苯甲醯基的苯环上羟基取代数量越多，其清除DPPH自由基的能力越好，三羟基效果优於双羟基、单羟基，双羟基效果优於单羟基；而苯甲醯基苯环上若为多羟基且羟基的位置为邻位或对位的关系时，其在清除DPPH自由基的能力较佳。

The electron impact mass spectra of the chemical products modified by 2-amino-2-methylpropanol of the fatty acids in sunflower oil were analyzed; the allocation rule for the carbon double bonds in olefinic acids was discussed and the location of the carbon double bonds of the fatty acids in sunflower oil was confirmed.

解析了葵子油脂肪酸2-氨基－2-甲基－丙醇化学修饰产物的EI质谱图，讨论了烯酸中碳碳双键的定位规则，确定了葵子油脂肪酸中碳碳双键的位置鉴定出葵子油6种脂肪酸，不饱和脂肪酸相对含量为89.41%，其中人体必需脂肪酸9，12-十八碳二烯酸含量占65.30%。

We have designed and synthesized 9,9'-spirobifluorene-based materials and introduced different functional group at 2,2' and 2,2',7,7' positions of 9,9'-spirobifluorene. All of these obtained materials adopted a bichromophoric system configured orthogonally via a chiral spiro center.

中文摘要以旋环双芴为核心结构，分别在2，2'与2，2'，7，7'位置引入不同基团，设计合成出ㄧ系列具双共轭的材料，两相正交相互独立的共轭链，使分子具光学异构物，可避免分子堆叠，提高热稳定性。

We have designed and synthesized 9,9'-spirobifluorene-based materials and introduced different functional group at 2,2' and 2,2',7,7' positions of 9,9'-spirobifluorene. All of these obtained materials adopted a bichromophoric system configured orthogonally via a chiral spiro center.

以旋环双芴为核心结构，分别在2，2'与2，2'，7，7'位置引入不同基团，设计合成出ㄧ系列具双共轭的材料，两相正交相互独立的共轭链，使分子具光学异构物，可避免分子堆叠，提高热稳定性。

Genus and 40 species of Jurassic Pteriomorphia and Isofilibranchia from Northern Tibet were described in present paper. The data of genus and species of Jurassic Pteriomorphia and Isofilibranchia from Northern Tibet, Southern Tibet, and India were studied with cluster analysis respectively. The Jurassic palaeobiogeographic and palaeogeographic relations of these three regions were also discussed on the basis of the result of cluster analysis and analysis of the controlling factors of bivalve distribution.

本文记述了藏北侏罗纪双壳类Pteriomorphia和lsofilibranchia化石22属40种，对藏北、藏南及印度侏罗纪Pteriomorphia和Isofilibranchia的属和种分别进行了统计和聚类分析，以此探讨这三个地区之间的古生物地理关系，并进一步分析了控制侏罗纪双壳类分布的因素及讨论了藏北、藏南与印度这三大地块的古地理位置。

The possible reason is that doped Zr〓 ion enters the interstitial sites for its small ionic radius and no dipole complexes were formed. Monovalent ion F〓 has been reported to improve the scintillating performance greatly. Our results show that Agrand diagrams of F〓: PWO crystals obey an modified Cole-Cole equation. The crystals present similar dielectric relaxation phenomena to but have much higher activation energy than that of RE〓: PWO crystals, which originate from the 〓 dipole complexes. The co-doping of trivalent Y〓 and pentavalent ion Nb〓 does not always show a better scintillation performance than that of solely doped samples, which could be attributed to the existence of the 〓 dipole complexes, which counteract the solely doping effect.

而Zr〓由于离子半径太小，可能进入间隙位置，不形成类似的偶极缺陷；一价负离子F〓的掺入提高了晶体闪烁性能，阻抗谱测试结果表明F〓：PWO晶体Argand图符合修正的Cole—Cole方程，晶体同样表现出介电弛豫现象，并具有比RE〓：PWO晶体中高得多的弛豫激活能，可能起源于形成的〓偶极缺陷；Y〓和Nb〓双掺的PWO晶体并没有显示出两种离子单掺优点的叠加，阻抗谱测量结果表明，在双掺晶体中可能形成〓偶极缺陷，使两者掺杂作用相互抵消。

Haversion system was clearly observed and matured bone tissues filled the ceramic pores and interconnected with each other. All the result suggested that, taking advantage of"living organic culturing medium"in vivo, culturing composite that consisted of autogenous periostea and biomaterials should be an effective approach to obtain satisfactory bioactive bone substitutes which have the potential to repair load-bearing bone defects clinically.

上述研究表明，1、双相多孔TCP/HA陶瓷是一种优良的骨组织工程支架材料，进一步优化其骨诱导作用后，有可能直接用于再生和重建负重骨干的缺损；2、在目前情况下，以双相多孔TCP/HA陶瓷为支架，通过体内非骨位置培养骨组织细胞形成活体骨修复器件，有可能用于负重骨干缺损的再生和重建。

Combined with additional sequences of 20 bivalves and 6 gastropods downloaded from NCBI (National Center of Biological Institution), molecular phylogenetic trees were constructed using 4 Polyplacophora species as outgroup. The result resolved by maximum-parsimony, maximum-likelihood and Bayes-induce methods were in congruent with each other, which indicated that all bivalves formed a monophyletic group clustering with its sister-group, Gastropod.

结果显示：所有双壳纲的种类构成了单系发生的进化枝，与其姐妹群腹足纲聚在一起；双壳纲可以分为异齿亚纲和翼形亚纲两大类群，异齿亚纲是单系发生，翼形亚纲的系统发生关系则随方法的不同有所区别，牡蛎科的位置是造成此差异的主要因素。

The results showed that the MS2 fragmentation pathways of DASSSB were affected by the character and position of substitutes on salicylidene phenyl. The C=N cleaving to form fragmentation ion [M+H-283](superscript +) was dominant for DASSSB compounds with electron-donating group on the C4 of the salicylidene phenyl; while fragmentation ion [M+H-254] (superscript +) forming by C-C cleavage of the β-position of C=N was dominant for DASSSB compounds with electron-withdrawing group on the C5 of the salicylidene phenyl.

结果显示，这些化合物的ESI-MS/MS裂解方式与它们分子中水杨醛苯环上取代基的性质和位置有关：当水杨醛苯环上4位连接供电子取代基时，分子以CN双键断裂为主，生成[M+H-283]碎片离子；当水杨醛苯环上5位连接吸电子取代基时，分子以CN双键β位的C-C键发生断裂为主，生成[M+H-254]碎片离子。

The results showed that: at metaphase I, the homoeologous chromosome pairing among different F1 hybrids ranged from 2.0 to 11.4 bi-valents formed by homoeologous chromosomes per pollen mother cell, and very few multivalents, and even very few bivalents were formed by two chromosomes within one genome rather than homoeologous chromosomes in some PMCs; at anaphase I, all biva-lents were disjoined and most univalents were divided.

结果表明在中期I阶段，这些杂种一代的近缘染色体联会变化很大，每个花粉母细胞中二价体形成的数目从平均2个到11.4个不等，甚至在某些花粉母细胞中，还发现极少的多价体和非部分同源染色体所形成的单基因组内二价体；在后期I时，所有的二价体分离，同时多数单价体也分离，分离的二价体和分离的单价体都移向两极，从而形成两组染色体；因为这时完整花粉母细胞中分离的二价体在两组染色体中总是对应出现，从而根据半二价体上染色体重组的位置可以分析在二价体的四分体时期发生在非姊妹染色体之间的多种染色体交换类型，如单交换、三线双交换、四线双交换、四线三交换和四线多交换。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。