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排序方式: 共有345条查询结果,搜索用时 343 毫秒
71.
对社会转型期国民心态的思考 总被引:5,自引:0,他引:5
改革开放使中国社会产生了巨大变迁,也使国民心态发生了巨大的变化。社会转型时期国民心态呈现出跺动倾向、粗俗化倾向、虚假化倾向、冷漠化倾向。这些病态心理倾向形成原因既有历史方面的因素,也有社会结构变迁、化变迁及民主和法制建设滞后的负面影响的因素。调适和纠正这些倾向,需要通过构建符合现代社会特点的价值体系、道德化体系、社会控制机制及公民化素质自我完善能力的提高才能实现。 相似文献
72.
本文研究了以5-Br-pADAP作显色剂,利用三阶导数光谱法,在碱性介质中同时测定铜和锌。该法测得铜、锌的表观三阶导数摩尔吸光系数分别为1.0×10 ̄5和3.0×10 ̄5,同时解决了谱带相互重叠干扰的问题。对石油化工厂污水进行测定,得到满意结果。 相似文献
73.
Intramolecular stacking interaction in mixed-ligand complexes containing ATP4- and aromatic N-heterocyclic ligands 总被引:1,自引:0,他引:1
The stability constants of the binary ML2+ and ternary M(ATP)L2- complexes,where L=Iq (isoquinoline) or BIm (benzimidazole) and M=Zn2+ or Cd2+,have been determined by poten-tiometric pH titration in aqueous solution at I=0.1 mol/L (NaClO4),T=25℃.The stability of the ternary complexes characterized by corresponding to the equilibrium M(ATP)2-+ML2+=M(ATP)L2-+M2+ is higher than what would be expected on statistical grounds.The increase may be related to the stacking interaction between the aromatic ring of the ligands L and the purine moiety of ATP4- 1H NMR studies of Zn2+/ATP4-/L confirm the presence of stacking in the ternary complexes.It is concluded that the strength of the intramolecular stacking interaction is dependent on the structure of the aromatic ring of the ligand L and the formation of a metal ion bridge.Possible implications are discussed briefly. 相似文献
74.
75.
MgO改性的γ-Al2O3负载CuCl2-KCl催化剂上乙烷氧氯化制氯乙烯 总被引:1,自引:0,他引:1
采用浸渍法制备了不同含量MgO改性的γ-Al2O3,采用X射线衍射、N2物理吸附、NH3的程序升温脱附和程序升温还原等手段表征了催化剂的结构、表面酸性和氧化还原性质,并对CuCl2-KCl/MgO-Al2O3催化剂催化乙烷氧氯化制氯乙烯反应进行了活性评价.XRD结果表明,通过使用Mg(NO3)2溶液浸渍γ-Al2O3载体在表面上形成了表层镁铝尖晶石结构.TPR结果说明,表层MgAl2O4的生成加强了活性物种Cu与载体的作用,促进了CuⅡ→CuⅠ的还原.CuCl2-KCl/MgO-Al2O3催化剂对乙烷氧氯化反应的催化性能表明,随着MgO-Al2O3载体中MgO含量的增加,乙烷转化率和氯乙烯选择性逐渐升高,当MgO含量增加至10%时,氯乙烯的选择性最高(49.1%).NH3-TPD结果表明,表层MgAl2O4中和了γ-Al2O3表面的强酸中心,增加了弱酸中心的数量是氯乙烯选择性提高的主要原因. 相似文献
76.
YE Bao-Hui ZENG Tian-Xian JI Liang-NianChemistry Department Zhongshan University Guangzhou Guangdong China 《中国化学》1995,13(3):207-215
The complexes [Pd(phen)(aa)]Cl.3H2O, where phen is 1,10-phenanthroline and aa is the anion of glycine (gly), .DL-alanine (ala), DL-serine (ser) or DL-asparagine (asn), were synthesized and characterized by spectroscopies. The NMR signals were assigned completely on the basis of the double irradiation, 1H-1H COSY and 1H-13C COSY techniques. In the 1H NMR spectra of phen in the complexes, the signals of 2-H and 9-H show upfield shifts 0.8-1 ppm, while the signals of 4-H and 3-H show downfield shifts or almost no shift, as compared to the free phen ligand, and the signal of 4-H appears in the lowest field. The signals of ring B which is trans to the carboxyl group show significant upfield shifts as compared to those of ring A. The probable structures were described on the basis of a metal-non-bonded hydrogen interaction, trons effect and ligand-ligand interaction. There may exist three conformation isomers in the [Pd(phen)(asn)]Cl.3H2O complex at room temperature. The preferred conformation isomer is about 相似文献
77.
提出一种时域微波层析成像新技术,分别通过非线性最优化方法、正则化方法、Cole-Cole建模方法,有效地克服了时域微波成像技术在筛查早期乳腺肿瘤出现的成像问题非线性、病态特性及乳腺组织色散特性等困难.在二维的数值算例中,考虑噪声影响,仿真结果初步证实:该技术检测小尺寸乳腺肿瘤是可行的;易于发现浅层肿瘤;且反演静态电导率的精度最高. 相似文献
78.
提出了一种闭环辨识和2自由度控制器组结合的设计方法,从前馆控制器和反馈控制器两方面,根据预测误差,适当地选择辨识对象和加权函数,闭环辨识与控制器设计相结合,仿真结果证实,辨识容易,设计简单,方法有效。 相似文献
79.
在既有建筑旁边修建新的建筑物时,为避免对原有建筑物基础的影响,采用合理的上部结构与基础设计,可减少对地基的处理,节省造价。 相似文献
80.
Guangdong Sun Yi Huang Lingling Lv Dapeng Li Qinguo Fan Yongqiang Li Jianzhong Shao 《Journal of polymer science. Part A, Polymer chemistry》2021,59(15):1686-1700
In situ viscosity kinetics models for blue light induced radical polymerization of acrylamide (AM) were proposed and established with camphorquinone/4-(dimethylamino)-2-ethylbenzoate/diphenyl iodonium hexafluorophosphateas the photoinitiators. In order to minimize the impact of shear effect on polymer network, a constant shear stress technique of photo-rheometry was proposed to characterize in-situ viscosity behavior of acrylamide solution during the photopolymerization. The effect of various factors, for example, the dosages of initiator, monomer, and light intensities, on viscosity, polymerization and gelation behavior of AM solution was systematically analyzed. The viscosity advancement behavior was shaped by the joint action of the movement, growth and entanglement of molecular chains, and shear orientation. Different power-law kinetic models were found in three curves, time-related viscosity, shear rate-related viscosity and time-related shear rate. Such school of thought on constructing the viscosity advancement model provides a new theory and method of systematical studying on the photorheological theories. Furthermore, a trinitarian theoretical model that represented the access from the microscopic kinetics of free radical polymerization to the movement behavior of polymer chains was successfully established by mapping the photoinduced viscosity kinetics model onto the polymerization and crosslinking kinetics model. 相似文献