A Novel Method to Synthesize Polyorganozircosilazane

A new kind of polyorganozircosilazane as Si/Zr/C/N-based ceramic precursor was synthesized from the condensation reaction of hexamethyleyclotrisilazane lithium salts(D3^NLi）and zirconium tetrachloride(ZrCl4).In the presence of N,N,N’,N’-tetramethyl ethylene diamine(TMEDA),polyorganozircosilazane was obtained in high yield.     

Optimization technique based on learning automata

Optimization techniques are finding increasingly numerous applications in process design, in parallel to the increase of computer sophistication. The process synthesis problem can be stated as a largescale constrained optimization problem involving numerous local optima and presenting a nonlinear and nonconvex character. To solve this kind of problem, the classical optimization methods can lead to analytical and numerical difficulties. This paper describes the feasibility of an optimization technique based on learning systems which can take into consideration all the prior information concerning the process to be optimized and improve their behavior with time. This information generally occurs in a very complex analytical, empirical, or know-how form. Computer simulations related to chemical engineering problems (benzene chlorination, distillation sequence) and numerical examples are presented. The results illustrate both the performance and the implementation simplicity of this method.Nomenclature c _i penalty probability - cp precision parameter on constraints - D variation domain of the variablex - f(·) objective function - g(·) constraints - i,j indexes - k iteration number - N number of actions - P probability distribution vector - p _i ith component of the vectorP as iterationk - r number of reactors in the flowsheet - u(k) discrete value or action chosen by the algorithm at iterationk - u _i discrete value of the optimization variable in [u _min,u _max] - u _min lowest value of the optimization variable - u _max largest value of the optimization variable - Z random number - x variable for the criterion function - xp precision parameter on criterion function - W(k) performance index unit output at iterationk - ₀, ₁ reinforcement scheme parameters - _p sum of the probability distribution vector components     

在DBU存在下酞菁锰配合物的合成及溶剂影响

在强有机碱１，８－二氮杂双环［５，４，０］十一－７烯（简称ＤＢＵ）存在下，ＭｎＣｌ２与邻二氰基苯在某些二元醇溶剂中可高效合成Ｍｎ（Ⅱ）Ｐｃ（Ｐｃ表示酞菁），同时研究了不同溶剂对合成产物的物种及产率的影响和不同氧化态锰的酞菁配合物在一些醇溶剂中的互变现象     

一步法合成苯乙烯催化剂表面积炭对活性的影响

应用ＥＳＲ，空气气氛下ＤＴＡ，氢气氛下ＴＰＳＲ，ＩＲ等技术手段，对反应后催化剂的积炭行为进行了研究。结果表明，反应后的催化剂表面不同程度地存在着不同类型和积炭，积炭是催化剂失活的主要原因。     

纳米复合固体超强酸SO_4~(2-)/ZrO_2-Fe_2O_3的制备及其催化合成硝基苯的研究

采用纳米化学技术制备了新型的纳米复合固体超强酸催化剂SO42-/ZrO2-Fe2O3,并用XRD、TEM进行了表征.结果表明:所研制的SO42-/ZrO2-Fe2O3催化剂为晶态纳米粒子,平均粒径为30 nm,分散性较好;当活化温度为580℃,反应温度为75℃,n(硝酸)/n(苯)=2,m(苯)/m(催化剂)=20,催化反应时间5 h时,硝基苯收率可达89.6%.     

双甲基丙烯酰氧苯基丙烷与苯乙烯共聚物的光学性能

标题共聚物的耐冲击性与丙烯酸酯均聚物相比有明显改善,但随着双烯单体含量的降低,共聚物的耐热性和表面硬度有所下降。丙烯酸酯含量为70%的共聚物的吸收紫外光能力最强(<370nm全吸收),含量为5%～10%的共聚物耐吸水性、耐酸耐碱性及耐冲击性最好。     

Synthesis,characterization, spectroscopy and thermal analysis of rare earth picrate complexes with <Emphasis Type="Italic">L</Emphasis>-lysine

Summary Rare earth picrate (RE) complexes with L-lysine (Lys) were synthesized and characterized. Elemental analysis (CHN), EDTA titrations and thermogravimetry data suggest a general formula RE(pic)₃·2Lys·2H₂O, where RE=La-Lu (without Pm) and Y, pic=picrate). IR spectra suggest that Lys is coordinated to the central ion through the nitrogen of the α-amino group. Parameters obtained from the absorption spectrum of the Nd compound indicated that the metal-ligand bonds are essentially electrostatic. Emission spectrum and biexponential behavior of the luminescence decay of the Eu compound suggest the existence of polymeric species. Thermogravimetric/derivative thermogravimetric (TG/DTG) and differential scanning calorimetry (DSC) curves of all complexes are very similar, with five events. The final products are the corresponding rare earth oxides and their X-ray diffraction patterns are identical to the calcinated oxides.</o:p>     

中环萜类化合物的合成

本文综述了中环萜类化合物的各种合成方法,它们根据成环方式可以分为四类:1.双环或三环化合物的桥键断裂,2.无环化合物的环合,3.常规环化合物的环扩大,4.大环化合物的环缩小。     

超声波辐射下的固—液相转移催化法合成苯乙酰基芳基硫脲化合物

合成酸基硫减类化合物常用的方法是固一液相转移催化法“‘．因超声波辐射可以加快有机合成反应，提高产率，本文采用了超声波辐射与相转移催化相结合的方法，以聚乙二醇一400（PEG－400）为催化剂，二氯甲烷为溶剂，在常温下合成了10种N一苯乙酸基一N‘一芳基硫腺新化合物，产率大部分比相应的相转移催化法合成高．本法条件温和、操作简便、产率较高．仪器为CQ－250型超声波清洗器，频率33土2kHZ；PE1730FT－IR红外光谱仪，溪化钾压片；BRUKERAC七0核磁共振仪，CDCI。为溶剂，TMS为内标；PE－2400CHN元素分析仪．化合物（皿…