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821.
Pullin等人曾对全氟碘代烷与三级胺的相互作用进行了研究,发现R_(?)I与NR_3能形成电荷转移络合物,即:R_(?)…I…NR_3。但此后却未见到有关反应的报道。我们发现在钯催化剂存在下,全氟碘化物与三乙胺能发生反应,反应条件较为温和,产物为氟代烷基烯基二乙基胺1。反应可能是在三乙胺中先产生一个双键,然后β碳原子接上一个全氟烷基。1的IR和NMR与Blanc报道的一致。化合物1经水解可得胺基烯酮2。在酸溶液中水解时,速度明显加快,而在碱溶液中,不仅不能加快水解速度,而且还有副反应发生。我们对化合物2进 相似文献
822.
The concept of fuzzy theory is described in order to provide the analyst with the means for dealing with vague statements, uncertain observations or the fuzziness of human perception and interpretation, in general. In a theoretical part, basic notions of fuzzy theory are given, such as types of membership functions, operations with fuzzy sets, definitions of fuzzy numbers, points, functions, and relations, and the use of linguistic variables. The difference between fuzziness and probability is outlined. The applications section demonstrates advantages of fuzzy theory methods compared to common mathematical methods with respect to data handling for calibration of analytical methods, to classification of Chromatographie and spectroscopic patterns, to component identification and multicomponent analysis, and to designing fuzzy expert systems for selection of analytical procedures. 相似文献
823.
Ariel Fernández 《Theoretical chemistry accounts》1985,67(3):229-233
A structurally stable model of the standard adiabatic gradient field of the potential energy surface for certain pericyclic reactions is derived.These reactions are not subjected to the principles of orbital isomerism or to the Woodward-Hoffmann rules.Use is made of a principle established by Ariel Fernández and Oktay Sinanolu which precludes direct meta-IRC connections between transition states.It is shown that Jahn-Teller isomers of the singlet biradicals involved in the process are not interconvertible since the biradical configuration is not a transition state but a critical point with Hessian matrix with two negative eigenvalues.The topological features of the PES obtained by combinatorial methods are in full agreement with earlier results obtained from MINDO calculations. 相似文献
824.
四元体系KCl-ZnCl2-HCl(~10.61%)-H2O(298.15K)的相平衡及其固相化合物 总被引:1,自引:0,他引:1
0引言研究发现,卤化物KX与ZnX2组成的复盐化合物是一种良好的激光基质材料犤1犦,在掺杂了稀土离子的这些化合物中已经实现了低温或室温下的激光输出犤2,3犦。在卤化物中,氯化物的发光强度又大于氟化物犤4犦。因此,我们以KCl与ZnCl2为研究对象,通过盐酸溶液中的相化学反应来了解它们之间可能形成新化合物的种类和溶液中的反应行为。本文对KCl与ZnCl2在25℃11%的盐酸-水四元体系中的相平衡关系进行了研究,并从体系中发现并得到了未见文献报道的5∶4型新化合物5KCl·4ZnCl2·3H2O。1实验部分1.1药品及… 相似文献
825.
在以加氢汽油为溶剂,MoCl_3(C_7H_(15)COO)_2(Mo)为主催化剂,(i-Bu)_2AlO〈O〉(Al)为助催化剂合成1,2-聚丁二烯的二元催化体系中,添加BF_3CH3·OEt_2等,对体系的催化活性影响显著。以的混合物为第三组份加入催化体系,较大幅度提高了钼系催化体系的活性。在Mo/Bd=8.0×10~(-5)(摩尔比),聚合5小时,丁二烯转化率可达到70%。初步搞清了钼催化体系合成的1,2-聚丁二烯中产生凝胶的条件,推测了凝胶的生成原因,考察了聚合条件对催化活性、分子量及微观结构含量的影响。 相似文献
826.
研究了第二过渡金属化合物对TiCl4/AleT1.46cL1.54催化丁二烯环化三聚的多金属协同效应。结果表明,极少量的第二过渡金属化合物,如Cr,(acac)3,Mn(acac)3,NiCl2,ZrCl4等加入TiCl4/AlEt1.46Cl1.54体系后不同程度地提高了丁二烯环化三聚的选择性,并改变了体系的最大速率和催化剂效率。 相似文献
827.
The system BaF2/AlF3 is investigated by X-ray and D.T.A., and the liquid-solid phase diagram is established. Five ternary fluorides are disclosed: trimorphic BaAlF5, Ba3Al2F12, Ba5AlF19, polymorphic Ba3AlF9 and Ba5AlF13. Neutron thermodiffractometry experiments are performed to specify some parts of the diagram. The cell parameters of the fluorides are given and the results are discussed and compared with those of the previous works. 相似文献
828.
A laboratory information management system (LIMS) can make a major contribution to the quality and therefore to the efficiency
and competitiveness of a laboratory. Since it can impact all aspects of a laboratory's organization it must be the key if
not the principal player of the laboratory's quality system. It should support the laboratory in establishing, maintaining
and applying quality procedures thereby enabling the laboratory to achieve its quality goals. As a tool, LIMS permits the
laboratory to input and use its own know-how and experience to optimize the total organization (internal and external) and
workflow of generated information. However, perceived "quality" in the context of an LIMS, can be viewed as being made up
of different facets such as the security, reliability and accessibility of information as well as its turn around time and
production cost. This paper reviews the role of a LIMS in the laboratory and the contribution that both system design and
functionality can have on "building quality ".
Received: 5 October 1998 · Accepted: 20 October 1998 相似文献
829.
The binuclear complex [Cu2(TS)(H2O)]·CH3OH, where TS denotes the binucleating ligand derived from the schiff base N,N′-bis(3-carboxylsalidene)trimethylenediamine, was obtained from the self-decomposition of mononuclear complex Na2CuTS·H2O. It crystallizes in the monoclinic system, space group P21/c. The lattice parameters are a=11.935(2)?,b=15.667(3)?,c=11.621(2)?,β=111.60(3)°,V=2020.2(7)?3, Z=4 with R=0.0467. The structure is made of binuclear units, in which two copper atoms are bridged by two phenolic oxygen atoms. The “inside”copper atom is coordinated by two nitrogens, two phenolic oxygens in a planar coordi-nation site, the copper atom deviates from the mean plane by 0.47?. The “outside” copper atom is five coordinated by two phenolic oxygen atoms、two equatorial carboxyl oxygen atoms and one axial water oxygen atom in a distorted tetragonal cone site, the copper atom is pulled out of the equatorial plane by 0.46?. 相似文献
830.