甲烷氧化偶联催化剂La2O3／SrCO3—BaCO3的催化活性与表征

在甲烷氧化偶联制Ｃ２烃的研究中，人们发现碱土金属与稀土金属组成的复合氧化物催化剂具有高的催化活性［１，２］．稀土化合物作为有希望的工业催化剂之一，已受到广泛的关注．一般认为，它们含有的氧空位对活化甲烷的有效氧物种有利．Ｄｅｂｅｙ等在１％Ｓｒ／Ｌａ２Ｏ...     

Pressurized gradient capillary electrochromatographic separation of eighteen amino acid derivatives

A pressurized gradient capillary electrochromatography (pCEC) instrument was developed to separate 18 amino acid derivatives. A reversed-phase C18 column (3 microm, 130 mm x 75 microm I.D.) and an acetate buffer (50 mmol/l NaAc, pH 6.4) with an ion-pair reagent (1% N,N-dimethylformamide) were used to separate derivatized amino acids from a standard solution (2 microg/ml), and the wavelength of the UV-Vis detector was 360 nm. The pressure on the capillary column was kept at approx. 70 Pa and 3 kV positive voltage was added on the outlet end of column. The effect of voltage on the eluting order of amino acids and the resolution of separation were studied, and it was found that when the voltage was higher than 3 kV, the adsorption of amino acids in the porous C18 column occurred. The effect of salt concentration, injection volume, and column length on the separation of amino acids was determined. The amino acid sample was separated by pCEC, and RSDs of the migration times of each amino acid were all less than 2.5%.     

Preparation of multihollow P(St-MAA) particles by sequence soap-free/soap emulsion polymerization and followed by stepwise alkali/acid posttreatment

The effects of ionic emulsifier, sodium dodecylbenzene sulfate (SDBS), on the formation of the multihollow structures in sub-micron sized polymer particles produced by alkali/acid posttreatment were investigated. The original latex particles with narrow size distribution were synthesized by a new sequence emulsifier-free/emulsifier emulsion copolymerization of styrene (St) and methacrylic acid (MAA). Results indicated that the pore size decreased and the pore number increased with the increase of SDBS amount, and the morphology of the posttreated latex particles was also significantly influenced by the introducing time of SDBS in the preparation of the original latex particles, and a suitable introducing time was 3 h of polymerization.     

ON PGLAR PRODUCT OPERATOR

Let H be a Hilbert space, and let A be a linear bounded operator on H. For \(\lambda \in \rho (A)\), the \({U_\lambda } = {(A - \lambda )^{ * - 1}}(A - \lambda )\) is called polar.Produot operator. In this paper, we discuss the properties of \({U_\lambda }\) and the relation between \({U_\lambda }\) and A. We obtain tbe following results. Definition. Let B be a linear bounded operator on H, suppose \(0 \in \rho (B)\). For every \(x,y \in H\), we definite \([x,y] = (Bx,y)(H,B)\)(or (H, [·,·]) is called a non- degenerate bilinear space (it is obvious that if B=B*,then (H,B)is a space with an indefinite metric; and that if B>0, then (H,B) is a Hilbert Space. If an operator U(A) satisfies \[[Ux,Uy] = [x,y]([Ax,y] = [x,Ay]),x,y \in H\] then the operator U(A) is called a wvitary (self adjoint) on (H,B). Theorem I . Suppose A is a linear bounded operator on H, (1) If \(0 \in \rho (A)\), then \(U = {A^{ * - 1}}A\) is a unitary operator on (H,A) or (H, A*), and \(\sigma (U) = \frac{1}{{\sigma (U)}}\). (2) If there is a complex number \(\alpha \), such that \({\mathop{\rm Im}\nolimits} A \ge \alpha > 0\) then a)\(0 \in \rho (A)\), and the operator \(U = {A^{ * - 1}}A\) is a unitary on Hilbert space \((H,{\mathop{\rm Im}\nolimits} A) and 1 \in \rho (U)\);b) there exist two Hilbert spaces \((H,{v_1}),(H,{v_2})\), such that A, A* are all the unitary operator from (H,v1) onto (H,v2), and there are two spectral measures \(\{ E_\lambda ^i,\lambda \in [\alpha ,\chi ] \subset (0,2\pi )\} ,i = 1,2,\), such that \(AE_\Delta ^1H \subset E_\Delta ^2H,{A^ * }E_\Delta ^1H \subset E_\Delta ^2H\) for any \(\Delta = (\lambda ,u] \subset (0,2\pi ]\). (3) If \(0 \in \rho (A) \cap \rho ({\mathop{\rm Im}\nolimits} A)\) then the operator \(U = {A^{ * - 1}}A\) is a unitary on \((H,{\mathop{\rm Im}\nolimits} A)\). with an indefinite met He, and \(1 \in \rho (U)\). (4) For any complex number \(\lambda = r{e^{i\theta }},\left| \lambda \right| > \left\| A \right\|\), then \({U_\lambda }\) must be a unitary operator on the Hilbert space \(\left( {H,{\mathop{\rm Im}\nolimits} (\frac{1}{{i\lambda }}A + iI)} \right),and - {e^{i2\theta }} \in \rho ({U_\lambda })\) Theorem 2. (1) A is a normal operator iff there exists a complex number \(\lambda \), \(\lambda \in \rho (A)\), such that \(\frac{{\partial {U_\lambda }}}{{\partial \lambda }}{U_\lambda } = {U_\lambda }\frac{{\partial {U_\lambda }}}{{\partial \lambda }}\),where \(\frac{\partial }{{\partial \lambda }}\) is the directional derivative. (2) If there exists a complex number \(\alpha ,{\mathop{\rm Im}\nolimits} A \ge \alpha > 0\) then A is a normal operator iff \(U = {A^{ * - 1}}A\) is also. (3) If A is a hyperiwrmal or a subnormal, then for every \(\lambda \in \rho (A),\sigma ({U_\lambda })\) lies on the circle. 3, 4期 关于极?积算子炉一U 499 Theorem 3? Let A be a linear bounded operator on Hm Suppose 0￡p(J.)? (1) If U=А*~гА is a unitary operator in a certain non-degenerate bilinear space (H} 1 J |Л|>1 入 J Ш=1 solmble iff (l)cr(ü) =-=i=-, (2) the operotor Ui= f XdE\ is unitarity equivalent to cr(C7) J |л|>1 the operator ül_1 == ШЕ1, 、 J 1Л|>1 If the conditions (1),(2) are satified, then we have (3) the subspace JJi?^2 of H reduces any solution of the equation A*"1 A — U, and 1 AI (Ягея*)1 = ^Uo where Ъ is any in vertible self-adjoint on (i?i?J?2) L, and bv Uo (Uo = Jiai i ЫЕ1 )}⑷41Я1фя, = , Ла = A1ü2, if the operator V is to realize TJt and Ut^unitary equivalence^ then Ai = VSf where S is any invertible on Нг and SvUi. " Corollary. Swpp)se operator U is a normal on a certain Hilbert space(Hy v) (^the U is similar to a certain normal operator on IT), if U satisfies the conditions (1)、(2) of Theorem^ on ?S,v) ? Then the general form of the solution of А*~гА = U is A = vA'y where A' is same as A in Theorem^. Theorem 5. Let U be a linear bounded operator on H. Suppose O?p(J.)and p(ü) is a simply connected region, then the equation А*~гЛ = U is a solvable iff there exists a certain space {H,v) with a indefinite metric, such that U is a unitary operator on (Hf 丨）. If is a unitary operator on ?H,v),then there exists a particular solution of I X+$ А*~гА = U: Ar = 2e v [ (?7 —X)_1+X], where eie ? p (JJ), and the general form of the solution is Аж АУ, wliere V is any in vertible self-adjoint on (H, -u)and VvU,     

Itosides A – I,New Phenolic Glycosides from Itoa orientalis

Eight new benzoylated gentisyl alcohol (=2‐(hydroxymethyl)benzene‐1,4‐diol) glucosides, itosides A–H ( 1 – 8 ), together with the new pyrocatechol (=benzene‐1,2‐diol) glycoside itoside I ( 9 ) were isolated from the bark and twigs of Itoa orientalis (Flacourtiaceae). In itosides B–D ( 2 – 4 ), the gentisyl alcohol moiety was esterified by 1‐hydroxy‐6‐oxocyclohex‐2‐ene‐1‐carboxylic acid, while itosides E–H ( 5 – 8 ) contained instead an additional 2‐hydroxybenzoic acid moiety. The compounds were accompanied by the known derivatives 4‐hydroxytremulacin ( 10 ), poliothyrsoside ( 11 ), poliothyrsin ( 12 ), homaloside D ( 13 ), tremulacin, and pyrocatechol β‐D ‐glucopyranoside. The structures of the new compounds were elucidated by spectral and chemical methods.     

微波等离子体炬发射光谱法去溶系统性能的研究

用微波等离子体矩（MPT）作激发光源，等离子体的工作气体为氩气，研究了气动雾化进样去溶系统的工作参数对分析性能的影响，探讨了水冷凝与浓硫酸吸收二者协同去溶的相关性，结果表明，OH （Q1带，带头谱线为308.520nm）的发射强度即可判别样品去溶效果。     

Electrochemical Characteristics of Mg0.9Ti0.1-xZrxNi （x=0.02, 0.04, 0.06） Alloys

Mg-based hydrogen storage alloys Mg0.9Ti0.1-xZrxNi (x=0.02, 0.04, 0.06) were successfully prepared by means of mechanical alloying (MA). The effects of Zr addition on the discharge capacity and the cycle performance of the Mg-based electrodes were also studied. It was found that the discharge capacities were improved with addition of a small amount of Zr and the cycle performances of the alloy were stabilized with the addition of Ti. The effects of surface modification or coating on the properties of Mg0.9Ti0.06Zr0.04Ni were also studied. The results indicated that coating with graphite improved both the discharge capacity and cycle life of the amorphous Mg0.9Ti0.06Zr0.04Ni electrode.     

新型水溶性膦铑络合物催化烯烃的氢甲酰化反应研究

新型水溶性膦铑络合物催化烯烃的氢甲酰化反应研究燕远勇，左焕培，金子林（大连理工大学化工学院，大连１１６０１２）关键词烯烃，水溶性膦铑络合催化剂，氢甲酰化，醛．１．前言为克服催化剂的流失和与反应产物的分离困难，近年来均相催化的一个重要进展是开发了以磺化...     

Cl+C2H6→HCl+C2H5反应的准经典轨线研究

用三原子模型的准经典轨线方法研究了Ｃｌ与Ｃ２Ｈ６（ｖ＝０，ｊ）的反应。计算结果表明，反应产物ＨＣｌ的角度分布基本上为各向同性，其振动分布处于基态，与实验结果相一致。对反应轨线的研究表明，该反应为一直接反应，而且反应碰撞在低及高的碰撞参数下的机理不一样，在低碰撞参数下反应碰撞是直接完成的，产物ＨＣｌ以向后散射为主，转动基本上是冷的，但比高碰撞参数下的热。在高的碰撞参数下则生成短寿命的碰撞复合物，产物     

Synthesis, crystal structure and magnetic behavior of two cobalt coordination polymers with 1,2-bis(1,2,4-triazol-1-yl)ethane and dicyanamide

Two cobalt(II) coordination polymers formed from bte (bte = 1,2-bis(1,2,4-triazol-1-yl)ethane), namely [Co(bte)₂(dca)₂]_n (1) and {[Co(bte)(dca)₂] · H₂O}_n (2), have been synthesized and characterized by elementary analyses, IR, thermogravimetric analyses, X-ray diffraction analyses and magnetic measurements. Compound 1 is a double-chain with Co(II) centers bridged by bte, containing metallocycles of [Co₂(bte)₂] and trans dca as termination ligands. In 2, each Co(II) center is bonded by two bridging bte ligands and four dca as μ-1,5-dca in different orientations in the 3D network.