关于多级火箭的最佳质量比(英文)

In 1955-1956, M. Vertregt introduced the problem about the least take-off weight of step-rockets and gave a matbematieal model of this problem as well as some calculations~[1]. In 1957, M. L, Williams followed up the study and pointed Out that G_(CN) and G_(TN) satisfied the following relation~[2] G_(CN)=[V_(CN)~((1))+V_(CN)~((2))]G_(TN)+V_(CN)~((3))G_n, thereby developing the mathematical model in [1]. For details see [2] (in which the significance of symbols, such as G_(CN) etc. was explained).     

Synthesis and anticonvulsant activity of 7-benzylamino-4,5-dihydro-［1,2,4］triazolo［4,3-a］quinolines

A series of 7-substituted-benzylamino-4,5-dihydro-［1,2,4］triazolo［4,3-a］quinoline derivatives was synthesized and evaluated for their anticonvulsant activity. The subcutaneous pentylenetetrazole test (sc-PTZ) demonstrated that the most effective compound in controlling the sc-PTZ induced seizure was 7-(3-bromine-benzylamino)-4,5-dihydro-［1,2,4］triazolo［4,3-a］quinoline (4j) with an ED₅₀ of 5.0 mg/kg and the PI of 20.7, which was also safer than the reference drugs. And the maximal electroshock test (MES) demonstrated that among these derivatives, 7-(3-fluorobenzylamino) -4,5-dihydro-［1,2,4］trizolo［4,3-a］quinoline (4i), with an ED₅₀ of 15.3 mg/kg and the PI of 7.2, was the safest in MES test. Furthermore, their neurotoxicities were measured by the rotarod neurotoxicity test, and the results showed that all derivatives possessed lower neurotoxicity.     

南京大学理科1990年在校外其他刊物上发表的学术论文

数学系作者刊物及期数或出版单位论文题目苏煌城,林平APPI宜ed Math.&Mech.199。;11:4Uniform differenee scheme for a singularlyPerturbed linear znd order hyPerbolie Problemwith zerotho川er reduced equationShen Zuhe,V7olfe MANonlin以Ana.Theory,Meth-。ds and APPlieations 1990;15:A Note on the ComPar如n of the Kantoroviehandm‘x〕re theorenls (3)产JnoldNoumaier,Shen ZUheJ .Math.Ana.APP.19901 49(2);The kraWCZyko讲rator and kanlorovieh,5 the-OrelnShen Zuhe,V犷olfe MA同上1990;153(l)on th…     

Magnetic properties of heteropolyoxometalates

The progress of the study on the magnetic properties of heteropolyoxometalates during the late decade is reviewed. Some anions of heteropolyoxometalates containing magnetic atoms, such as [M4(H2O)4(PW9O34)2]10- and[M4(H2O)4(P2W15O56)2]16-[M = Co(Ⅱ), Zn( Ⅱ ), Cu( Ⅱ ), Mn(Ⅱ ), Ni(Ⅱ)], and [GaW9O37M3(H2O)3]n-[M = Fe(Ⅲ), Cu(Ⅱ), Co(Ⅱ)] showed ferromagnetic and antiferromagnetic properties. The combination of heteropoly anions and organic π-donor of TTF+ (te-trathiofulvalene cation) results in a variety of magnetic properties. Furthermore, there is an interaction between the inorganic and organic components. The electrocrystallization technique can prepare the organic-inorganic salts of this kind, which will become the new member of molecular magnetic materials. Heteropoly blue is a kind of the mixed-valence complexes and its reduction electrons can be delocalized over anionic framework. The further study on the magnetic properties of heteropolyoxometalates will provide important information for the design of molecular materials.     

Catalytically Active Metal Nanoclusters Inside Cross-linked Functional Polymers:An Overview

1 Results Metal (0) nanoclusters (MNs), "strange morsels of matter"[1], are nanosized systems that are crucial components of industrially relevant catalysts (e. g. NH3 synthesis, catalytic reforming of alkanes, etc.). In recent years MNs have attracted an unprecedented attention among researchers acting in University, Scheme 1 Graphical model for the generation of size-controlled Pd0 nanoclusters inside metallated resins.a) PdⅡ is homogeneously dispersed inside the polymerGovernmental Institutions and Industry[2] and when MNs are to be utilized for catalytic purposes, their dispersion onto suitable supports is mandatory. We have started in the early nineties a long-prospects project aimed at supporting the choice of employing cross-linked functional polymers as supports of M0 nanoclusters to give M0/CFPs catalysts suitable to be utilized in the liquid phase (Scheme 1[3]). The major prospects offered by these catalysts are a) facile preparation, b) multi-functionality (exemplified by the current industrial synthesis of methyl isobutyl ketone from acetone and dihydrogen), c) re-usability, d) lack of pyrophoricity, e) easiness in obtaining polymetallic nanoclusters or nanoaggregates[2], f) reasonable chemical, thermal and mechanical stability[2]. A thorough account on the synthesis, chemistry and catalytic activity of M0/CFPs materials is available in Ref.[2].     

Sources of matrix-bound phosphine in advanced wastewater treatment system

Phosphine (PH3), a highly toxic and reductive gas, has been explored in biogases and it proves also to be ubiquitous even in remote atmospheric air at a concentration in the order of (pg-ng) /m^3 [3]. For more than one hundred years, sources and mechanisms of biological phosphine formation in natural and engineered environments have been investigated and discussed. Anaerobic environments were reported to be the main source of phosphine emission.     

COCLEFT EXTENSIONS OF HOPF ALGEBRAS

~~COCLEFT EXTENSIONS OF HOPF ALGEBRAS[1] Sweedler,M.E., Cohomology of algebras over Hopf algebras, Trans.Amer. Math, Soc. 133 (1968),205-239. [2] Doi,Y. Cohomologies over commutative Hopf algebras, J.Math.Soc.Japan 25(4) (1973), 680-706. [3] Schneid…     

多复变数函数论的几个问题(四)—准多圆柱

Consider the power series of several complex variables z_1m,…,z_nIn A. in 1962, the domain of the convergence of the series (A) was discussed and the concepts of "domains of the complete n-circular type" (the 2n-dimension) and "conjugate convergent radii" etc. were used. However, the author did not point out how to compute each conjugate radius, only the expression connecting each conjugate convergent radius was given and it is not correct [See《Some Problems of the Theory of Functions of Several Complex Variables (Ⅰ)》, The Convergent Set of the Power Series of Several Complex Variables, Section 13, 《Journal of South China Institutc of Technology》No.1, 1978, PP.82-101] and (Ⅵ) respectively.In 1972, C. pointed out that the convergent set of the series (A) is the same as its absolute convergent set [See 1973, 22, 10 141,1972, 185-195.]. But how large is such a point set? In Problem(I), not only its size had been computed, but also incidentally we obtained the conclusion that the convergent set of the series (A) is the same as its absolute conveagent set CSee remark 6.1].In Problem (Ⅰ), we first computed the convergent set which is also the absolute convergent set of the series of functions of several complex variablesp_0(z_1,…,z_n)+P_1)(z_1,…z_n)+…+P_m(z_1,…,z_n)+…(B)[See section 3], and incidentally we derived Cauchy-Hadamard formula for computing the convergent radius of the power series of a single complex variable. Secondly, we introduced the transformation of models [See section 1] thus the required results were obtained. The concepts of the convergent measure, convergent set and convergent limit etc. were used above.In Problem (Ⅱ)[The Convergent Domain of the Power Series of Several Complex Variables, See 《Journal of South Chiua Institute of Technology》No. 1; 1978, PP. 102- 120], we constructed the convergent domains whieh are also the absolute convergent domains of various dimensions by means of the convergent set which is also the absolute convergent set of the series (A) [See theory 1.8]. The concepts of the convergent radius and convergent domain were used here.In Problem (Ⅲ), the concept of the convergent bound was used, and we pointed out that there is at least one singular manifold and it is at least (n-1) -dimensional on the (2n-1)-dimensional convergent bound, and we gave the equation satisfied by singular manifolds; Two examples were given; in one of which the unique (n-1)—dimensional manifold was computed; and in the other, the only n number of (2n-2) - dimensional manifold were obtained [in the book of, A. cited above, in the discussion on the domain of the complete n-circular type (the 2n-dimension), it was only pointed out that the series (A) has at least one singular point on the bound of the domain, and the author did not point out the way to find the singular point].In Problem (IV), we discussed a wider kind of domains which were named the 2n-dimensional pseudomulticylinder, the 2n-dimensional convergent domain of the series (A) is its special case [See theory 4].A number of the above conclusions also hold for problems of various domains where the dimension number is less than 2n.     

一类微生物培养模型的一致持续生存

In this paper, by applying the uniform persistence of infinite dimensional dynamical systems in paper［1］［2］， the model in paper ［3］ is analysised, and the sufficient conditions of the uniform persistence are obtained. And the method of proof in this paper simplifies that of the paper ［3］ and moreover, the method is more easier to be improved.     

Geochronology of source materials from high-pressure and ultrahigh-pressure metamorphic rocks in Jurassic sedimentary rocks of Hefei Basin

Eclogite cobbles were discovered by Wang et al. (2001) in the Fenghuangtai Formation of the northern margin of Dabie Mountains in the Dushan area of Anhui Province, China[1]. They proposed that after the formation during the Triassic, the high-pressure (HP) and ultra-high-pressure (UHP) metamorphic rocks reached the sur-face through exhumation and uplifting before the late Ju-rassic. However, they have not provided any evidence about isotopic ages. One kind of cobbles of HP-UHP rocks w…     

一类变时滞反应扩散静态递归神经网络解的P阶有界性和P阶全局指数稳定性

利用Lyapunov泛函与不等式技巧研究了一类变时滞反应扩散静态递归神经网络解的P阶一致有界,P阶一致最终有界和P阶全局指数稳定性,获得了易于验证的代数判据.     

Study of the Solutions for a Class of Nonlinear Dynamical Systems

Ｔｈｅａｕｔｈｏｒｓｈａｖｅｅｘｐｌｏｒｅｄｔｈｅｆｏｕｒｔｈｏｒｄｅｒｄｉｆｆｅｒｅｎｔｉａｌｅｑｕａｔｉｏｎｏｆｔｈｅｆｏｒｍｘ┉ ａｘ… ｂｘ ｃｘ· ｈ(ｘ) =0ｔｈｅｙｓｈｏｗｅｄｔｈａｔｔｈｅｔｒｉｖｉａｌｓｏｌｕｔｉｏｎｉｓａｓｙｍｐｔｏｔｉｃａｌｌｙｓｔａｂｌｅ .ＢａｓｅｄｏｎｔｈｅｃｏｎｃｌｕｓｉｏｎｓｏｆＲｅｆ.〔1〕,ｗｅｓｈａｌｌｂｅｃｏｎｃｅｒｎｅｄｈｅｒｅｗｉｔｈｆｏｕｒｔｈｏｒｄｅｒｎｏｎｌｉｎｅａｒｄｉｆｆｅｒｅｎｔｉａｌｅｑｕａｔｉｏｎｏｆｔｈｅｆｏｒｍｘ┉ φ(ｔ,ｘ…     

一类四阶非线性微分方程解的有界性及稳定性

本文利用Liapunov函数方法，研究了一类四阶非线性微分方程解的稳定性及有界性，得出了解的有界性及稳定性存在的充分条件。     

一类四阶非线性微分方程解的有界性及稳定性

运用Liapunov函数方法，研究了一类四阶非线性微分方程解的有界性和稳定性，给出了解的有界性和稳定性的充分条件，所得结果包含并改进了已有文献的一些结论．     

关于时滞差分系统稳定性和有界性的一些推广

基于泛函微分方程的部分变元的稳定性和有界性,对有限时滞差分系统定义了关于部分变元的稳定性和有界性等概念．藉助比较原理,建立了利用离散的李雅普诺夫泛函或李雅普诺夫函数判别解的稳定性或有界性的准则．从而推广了已有的相应结果,并丰富了时滞差分系统定性理论的内容．     

Yoshizawa稳定性和有界性定理的注记

研究了Yoshizawa稳定性和有界性.利用常微分方程定性理论中公认的普遍且强有力的Liapunov第二方法,将某些稳定性和有界性定理的条件减弱,并给出证明,从而改进了全局一致渐近稳定的定义.     

一阶脉冲偏微分系统的有界性

给出一阶脉冲偏微分系统的有界性定理。     

一类三阶非线性系统解的稳定性和有界性

对一类三阶非线性系统进行了研究,利用“类比法”构造了此类非线性系统的Liapunov函数,从而研究了非线性系统解的稳定性和有界性,得到了该类系统稳定性和有界性的条件,同时给出了系统平凡解的不稳定性。     

关于两个测度的稳定性和有界性的比较结果

给出了一个比较原理，并利用比较方法给出了若干个非自治微分系统关于两个测度的稳定性和有界性结果．     

非线性Galerkin方法的有界性和稳定性分析

考虑了在谱离散和有限元离散情形下，数值求解非线性发展方程的一种全离散非线性Ｇａｌｅｒｋｉｎ方法，并分析了数值解的有界性和稳定性条件，其有界性条件仅仅依赖于粗网格参数Ｈ．