CuSO4·5H2O在用KBr压片法制样时所发生的固相反应的研究

用Ｘ射线衍射法和ＦＴ－ＩＲ法研究了ＣｕＳＯ４·５Ｈ２Ｏ在用ＫＢｒ压片法制样过程中所发生的固相反应．主要产物为：Ｋ２Ｃｕ（ＳＯ４）２·６Ｈ２Ｏ和ＣｕＢｒ２。     

碱金属碘酸盐赝二元系固溶体的研究

碱金属碘酸盐形成的二十一个赝二元系中,六个体系为机械混合物,九个体系是形成化合物的(其中三个是离子化合物),其余六个体系形成连续固溶体。本文对KIO₃-NH₄IO₃,RbIO₃-NH₄IO₄等赝二元系形成的连续固溶体进行了研究。NH₄IO₃中加入KIO₃或RbIO₃时,随加入量增加,NH< 关键词：     

富硅超稳八面沸石研究：制备,表征,稳定性,羟基酸性及催化活性

用(NH_4)_2SiF_6二次合成法制备了Si/Al=4.2～7.1、结晶度大于94％的系列八面沸石(FSY样品),再于500℃水热处理得到相应的US-SY样品。XRD、DTA及IR研究发现US-SY样品较FSY样品有更高的热稳定性、骨架稳定性和酸强度,其裂解、歧化活性也优于FSY样品。     

Micro-scale mechanics of the surface- nanocrystalline Al-alloy material

Recentresearchesshowthatthehighstrengthnano-structuredmaterialscanbefabricatedbyusingsomeadvancedtechniques,andthemechanicalbehavioroftheconventionalmaterialscanbeimprovedbyusingasurface-nanocrystallinetechnique.Forexample,byusingthesevereplasticdeformation(SPD)method,onecanfabricatethenanocrystallinematerials[15].TheadoptedSPDmethodsmainlyincludethelargetorsionmethod[1],thelargepressingmethod[4]andtheultrasonicshotpeening(USP)method[5],etc.Theconstructionfeaturesofboththenano-structuredbl…     

非晶态离子导体Li2B2O4晶化前期的离子导电性

本文研究了非晶态离子导体Li₂B₂O₄的离子电导率与温度的关系,特别着重于晶化前期的离子迁移特性。当温度低于T_K(≈310℃)时,离子电导率遵从Arrhenius关系。当高于晶化温度(≈411℃)时,以晶态中的离子迁移为主。在T_kc时,电导率偏离热激活机制呈反常增高。我们把这一过程称为晶化前期过程。可以用自由体积模型进行描述。晶化前期又可分为两部分:当温度低于、T_p(≈380℃)时,由于自由体积的重新分布,导致了电导率的增高;当T>T_p时,出现了少量微晶,但晶化量小于5%,由于非晶母体与微晶之间的界面效应使得离子导电性显著增强。可以通过室温淬火,把晶化前期非晶态的状态保持到室温,从而有可能制备出离子电导率高于纯非晶态的材料。 关键词：     

Li2K(IO3)3与Li2NH4(IO3)3的晶体结构

本文用X射线粉末法测定了Li₂K(IO₃)₃与Li₂NH₄(IO₃)₃的晶体结构和原子参数。发现Li₃K(IO₃)₃,Li₂NH₄(IO₃)₃与Li₂Rb(IO₃)₃同晶型,属单斜晶系,空间群为P2₁/α,每个单胞含有四个化合式量。室温的点阵常数分别为α=11.198?,b=11.046?,c=8.254?,β=111.53°,及α=11.327?,b=11.078?,c=8.341?,β=111.87°。讨论了二元化合物的形成与离子半径的关系。 关键词：     

12C6+离子辐照对阿维链霉菌代谢效应研究

对12C6+ 离子辐照诱变高产阿维链霉菌株ZJAV-Y1-203 和原始菌株ZJAV-A-1 的摇瓶发酵pH 值、菌体浓度、碳源和氮源代谢进行了测定,研究了12C6+ 辐照对阿维链霉菌的代谢效应。在发酵前期(48h),原始菌株发酵液pH 值低于突变菌株;在发酵96~196 h,诱变高产菌株ZJAV-Y1-203 繁殖快,生长旺盛,N的利用率高;菌体浓度大于原始菌株的浓度,且发酵液的pH 稳定,菌体处于代谢相对更稳定期;在发酵144~240 h,诱变高产菌株ZJAV-Y1-203 对糖源消耗低于原始菌株ZJAV-A-1。这些结果表明,12C6+ 离子辐照对阿维链霉菌代谢影响有利于阿维菌素合成。pH value, mycelium concentration, carbon source and nitrogen metabolism in flask fermentation of the mutant high-producing strain ZJAV-Y1-203 and the original strain ZJAV-A1 have been investigated, in order to show the metabolic effect of avermitilis irradiated by ion beam of 12C6. In early stage (48 h) of the fermentation, pH value of the original fermentation was lower than that of the mutant strains. In 96~196 h of fermentation, the nitrogen utilization in the strains ZJAV-Y1-203 was higher than that in the original strains, its reproductive was fast, and its growing was vigorous. The mycelium concentration of ZJAV-Y1-203 was greater than the original strain, and the pH value of fermentation were stable, so its metabolism was relatively more stable. In 144240 h of fermentation, the strain ZJAV-Y1-203 on sugar consumption was less than the original strains. The effect of 12C6 ion irradiation on metabolism of Streptomyces avermitilis is conducive to the synthesis of avermectin.     

基于变长度染色体混沌遗传算法的专用交通道优化

大型运动会要求主办方在规定时间内将相关人员从运动员村运送至指定比赛场馆.基于大城市日趋严重的交通拥堵,为满足运送时间的要求,通常在城市公共交通网络中设置专用交通道.但专用交通道的设置会对城市公共交通产生影响,最小化其对城市公共交通影响是专用交通道优化问题的关键.针对此类问题,在给出了改进的混合整数规划模型的基础上,提出了基于问题特性的变长度染色体混沌遗传算法,包括变长度染色体编码、混沌个体初始化、交叉操作、变异操作、适应度函数的计算和不可行解的惩罚、修复策略等.最后,以经典算例和随机生成算例对算法有效性进行了验证.     

四阶p-Laplacian方程多时滞问题周期解的存在性

通过使用Mawhin连续性定理,研究四阶p-Laplacian微分方程多时滞问题(φ_p(x″(t)))″+f(t,x″(t))+(?)β_i(t)g(x(t-γ_i(t)))=p(t)周期解的存在性,并得到了存在周期解的充分性条件     

Metal‐Free Oxidative B−N Coupling of nido‐Carborane with N‐Heterocycles

A general method for the oxidative substitution of nido‐carborane (7,8‐C₂B₉H₁₂^?) with N‐heterocycles has been developed by using 2,3‐dichloro‐5,6‐dicyanobenzoquinone (DDQ) as an oxidant. This metal‐free B?N coupling strategy, in both inter‐ and intramolecular fashions, gave rise to a wide array of charge‐compensated, boron‐substituted nido‐carboranes in high yields (up to 97 %) with excellent functional‐group tolerance under mild reaction conditions. The reaction mechanism was investigated by density‐functional theory (DFT) calculations. A successive single‐electron transfer (SET), B?H hydrogen‐atom transfer (HAT), and nucleophilic attack pathway is proposed. This method provides a new approach to nitrogen‐containing carboranes with potential applications in medicine and materials.