Synthesis of 1,4-Bis(Chloromethyl)-2-Methoxy-5-Phenoxy Benzene

Much attention has been paid to Poly(p-Phenylene Vinylene) (PPV) because they are associated with good electro-optical characterization, especially electro-luminescence which first discovered by Burroughes in 1990^[1]. 1,4-bis(chloromethyl) benzene is an important tool to synthesize PPV by dehydrochlorination. So the chloromethylation of substituted benzene becomes active. We once synthesized a series of dialkoxyl bischloromethyl benzene^[2]. Unfortunately, short chain alkoxyl-substituted PPV has poor solubility, which limits its utility. There are little reports on aryloxy PPV up to now, while aryloxy-substituted PPV may has good mechanical properties.     

全氟或多氟烷基氯代烷在保险粉引发下与芳香烃 的反应

全氟或多氟烷基氯代烷在保险粉引发下在DMSO溶剂中可以与富电子芳香烃反应,方便地得到氟烷基化的产物。氟烷基化产物的结构和产率主要取决于取代基的供电子能力和位置。     

多孔玻璃载体自转晶B-Al-MFI型沸石膜的原位合成

在乙胺和水的混合蒸汽相中,首次通过载体自转晶,在多孔玻璃表面原位合成了B-Al-MFI型沸石膜。X射线衍射和扫描电镜观察证明,膜中沸石晶体的取向是随机的。晶体尺寸约为15～25μm,单层晶体厚的膜约为10～20μm。在焙作去有机模板剂后的沸石膜上,O~2和N~2的透过性分别为0.095×10^-^8和0.15×10^-^8mol/(m^2·s·Pa)。计算的O~2/N~2的理想选择值(0.63)明显低于诺森扩散的理想选择性值(0.94)和透过原载体的理想选择性值(0.91)。     

量子力学中的密度矩阵与具有相同密度矩阵的系综的可区分性

讨论了密度矩阵的不同定义。建议使用完全密度矩阵、压缩密度矩阵和约化密度矩阵分别描写一个封闭量子体系的、一个系综中平均分子的和一个复合体系中的一个子系统的密度矩阵。强调这与现在人们认为的具有相同压缩密度矩阵的系综是完全等价的结论完全不同,具有相同压缩密度矩阵但是成分不同的系综可以通过系综整体测量来区别。作为一个应用,现在认为现有的核磁共振量子计算中没有纠缠的结论是没有根据的。Density matrix is one important tool in quantum mechanics, and it has very broad applications. However there are different definitions about the density matrix, and they describe quite different systems. There has been some misunderstanding about the density matrix in the community, and these misunderstandings hinder the right application of the density matrix. In this article, we discuss the different definitions of density matrix. We suggest to use the full density matrix, compressed density matrix and the reduced density matrix to describe the state of a complete quantum system, the state of an averaged particle in an ensemble and the state of part of a composite system. We stress that contrary to the wide accepted understanding that ensembles with the same compressed density matrix are physically indistinguishable, they are distinguishable through the so-called ensemble measurement. As an application, we suggest that the present conclusion that the present-day nuclear magnetic resonance quantum computation does not have quantum entanglement is groundless.     

High Spin States and Shape Coexistence in 134Ce

high spin states in ¹³⁴Ce nucleus have been studied by using the heavy–ion induced reaction ¹²²Sn(¹⁶O,4n) carried out at china institute of atomic energy. the early level scheme has been extended with spin up to 22. however,our result is different from that in a recent publication,and the magnetic rotation bands reported there have not been confirmed. our observed level structures may be interpreted as shape coexistence. the 10+ state at the backbending with h_11/2 quasineutron configuration has an oblate deformation with an asymmetry parameter γ≈–60°(lund convention),and the 10+ isomer is a yrast trap of prolate deformation with γ≈–120°,whereas the other signature partner bands with h_11/2 and g_7/2 proton configuration probably have a prolate deformation with γ≈0°.     

对称四甲基六元瓜环与2-氨基甲基吡啶相互作用的研究

分别用核磁共振、紫外可见吸收和X射线单晶衍射方法研究对称四甲基六元瓜环与2-氨基甲基吡啶的相互作用及其结构特征. ¹H NMR谱图和紫外可见吸收光谱图清晰表明, 2-氨基甲基吡啶与对称四甲基六元瓜环有明显的相互作用, 客体2-氨基甲基吡啶的吡啶环部分进入了瓜环空腔, ¹H NMR谱图相关质子峰的积分强度以及客体吸光度随主体瓜环浓度变化明确表示它们之间形成了1∶1的包结配合物, 此包结比并不随瓜环的浓度增加而改变. X射线单晶衍射法对包结配合物晶体的测定进一步证实了核磁共振、紫外可见吸收方法所得结论.     

托卡马克等离子体内部输运垒触发机制的数值模拟和并行效率

对托卡马克等离子体内部输运垒触发机制的动力学特征进行了数值模拟,通过区域分解法实现了数值模拟程序并行化,并行效率随计算机规模的增加而提高,结果与理论分析相吻合.并行模拟程序也适合MHD非线性撕裂模的数值求解.     

亚硫酸根离子荧光化学传感器的研制

亚硫酸根离子对固定于聚氯乙烯(PVC)膜中的5,10,15,20四苯基卟啉(TPP)/t(2,6二氧异丁基)β环糊精(DOBβCD)有可逆荧光熄灭作用。据此研制成测定亚硫酸根离子浓度的荧光化学传感器,该传感器敏感膜最佳组成质量分数为PVC308%,BOS615%,TPP150%,DOBβCD620%。在pH=65的KOHKH2PO4缓冲溶液底液中测定亚硫酸根离子,其线性响应范围为622×10-6～311×10-4mol/L,检测限为780×10-7mol/L,其响应时间小于40s。其它常见阴离子和阳离子不干扰测定。可用于实际样品中亚硫酸根离子含量的测定。     

Isospin and Mixed Symmetry Excitations in 60—66Zn Isotopes

The level structure of ^60—66Zn isotopes is studied within the framework of interacting boson model-3 (IBM-3). The mixed symmetry states are investigated in these nuclei by analyzing the wave functions. The isospin excitation states are identified for ⁶⁰Zn (N=Z) nucleus. The calculated energy levels and transition probabilities are compared with available experimental data. The results obtained and the values of parameters used in this calculation indicated that the Zn isotopes are in the transition from vibrational to γ-unstable nuclei.     

束流强度探测变压器

兰州重离子加速器冷却储存环工程 (HIRFL CSR)主环和实验环上带电粒子束流强度的测量和监视拟由环型束流变压器实现 .通过对各种磁芯性能的分析和比较 ,束流变压器磁芯材料最终采用环形高磁导率超微晶合金 ,可测量束流脉冲的频率范围为 0 .2 - 2MHz .选择低噪声放大器将感应信号适当放大 ,可以实现对最小流强为 1μA束流的测量. The intensity of a pulsed beam of charged particles in the Cooling Storage Ring Project of Heavy Ion Research Facility in Lanzhou (HIRFL-CSR) will be measured with a toroidal current transformer. By comparing and analyzing the properties of kinds of magnetic cores, a strip wound toroidal core is adopted, which is made of a high-permeability alloy and can measure a pulsed beam with frequency range of 0.2 to 2 MHz. The permeability of Fe-based nanocrystalline alloy varying with frequency is measured...