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  double
    Studies on Homogeneous Selective Catalytic Hydrogenation of C=C, C=O and C=N Double Bond
    C=C、C=O和C=N键的均相选择性催化加氢研究
短句来源
    DYNAMIC MECHANICAL PROPERTIES OF DOUBLE CHAIN POLYPHENYLSILSESQUIOXANE
    链聚苯基倍半硅氧烷的动态力学性质
短句来源
    Reverse Geometry Double Focusing Mass Spectrometers with High Performance
    高性能逆置聚焦质谱计
短句来源
    A more active reagent for cis-1,2-dihydroxylation of double bond——N-methy(?)morpholine-N-oxide/osmium tetroxide
    一种有效的顺式邻羟基化试剂——N-甲基吗啉-N-氧化物/四氧化锇
短句来源
    Optimum Searching Method for Parameters of Ion Optics System and Its Application to Design of Total Mass Double Focussing System
    离子光学系统参数的优选法及其在全质量聚焦系统设计中的应用
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  two
    Study on Two Peak Phenomena in Micellar Electrokinetic Capillary Chromatography
    胶束电动毛细管色谱峰现象研究
短句来源
    SYNTHESIS OF TWO NEW AMIDE - TYPE BIS - CROWN ETHERS
    两种新的酰胺型冠醚的合成
短句来源
    PRECISION OF DETERMINATION USING SINGLE WAVELENGTH APPARATUS INSTEAD OF DUAL-WAVELENGTH APPARATUS Ⅱ. DETERMINATION OF TWO COMPONENT MIXTURES BY DUAL-WAVELENGTH SPECTROPHOTOMETRY
    用单波长仪器代替波长仪器进行测定的精密度研究——Ⅱ.波长等吸收法测定组分体系
短句来源
    Schiff Bases and Secondary Amines Containing Two Benzo-15-crown-5 Units II. Potassium Ion Selective PVO Membrane Electrodes Based on Bis-Crown Ethers as Carrier
    Schiff碱型和仲胺型冠醚 Ⅱ.用冠醚作载体的PVC膜钾离子选择性电极
短句来源
    MEAN ACTIVITY COEFFICIENT OF KCI MEASURED WITH TWO ION SELECTIVE ELECTRODES
    用离子选择性电极测定KCl的平均活度系数
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  dual
    Determination of Platinum and Palladium in Minerals and Rocks with Dual Wavelength Spectrophotometric Method
    波长分光光度法同时测定矿石中铂和钯
短句来源
    Study on Paper Absorption Spectrophotonletry Ⅱ Determination of Trace Ag in Water by Dual wavelength △AMethod
    纸上吸光光度法研究 Ⅱ波长吸光度差值法测定水中痕量银
短句来源
    Dual Wavelength Spectrophotometric Determination of Trace Aluminium and Iron with Eriochrome Cyanine R
    铬菁R-波长分光光度法测定铝铁含量
短句来源
    PRECISION OF DETERMINATION USING SINGLE WAVELENGTH APPARATUS INSTEAD OF DUAL WAVELENGTH APPARATUS
    用单波长仪器代替波长仪器进行测定的精密度研究
短句来源
    Quantitative Analysis of Sucrose Fatty Acid Esters by the Dual—wavelength TLC Scan Method.
    脂肪酸蔗糖酯的波长薄层扫描定量分析
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  both
    Study of Novel Compounds Containing Both Phosphorus and Pyrethroid Skeleton Ⅱ. Synthesis of Compounds Containing Bicyclic Phosphate and 3-Substituted-2, 2-dimethylcyclopropane Carboxylate and Study of Its Reaction
    含磷拟除虫菊酯的研究——Ⅱ.含笼状环磷的取代环丙烷羧酸酯的合成及反应研究
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    The present paper provides the Raman spectra of YVO4 crystals doped with Tm3+ , Ho3+ and both of them, measured at room temperature and with the laser projections parallel and perpendicular to axis C.
    文章分别测得室温下,激发光平行、垂直晶体C轴入射时,Tm3+,Ho3-单掺和Tm3+,Ho3+掺钒酸钇晶体样品的拉曼光谱,并对其进行初步的分析。
    Photocatalytic Performance of Ti-MCM-41 Molecular Sieve Containing both Framework and Extra-framework Ti Sites in Hydroxylation of Benzene
    单金属中心Ti-MCM-41分子筛催化剂的光催化性能
短句来源
    The addition of penicillin-K increases the viscosity of both theupper phase and down phase of ASTP 1 region and ASTP2 region, and also changesthe distribution of each component in the above two phases.
    青霉素钾的加入使得水相ASTP1区和ASTP2区的上下相的粘度增加,各组分在上下相的分配发生了变化。
短句来源
    The results indicated that In(OTf)3 and FeCl3 6H2O were both good catalysts for the synthesis of bis(indolyl)methanes, but the catalytic system of FeCl3 6H2O showed better results than that of In(OTf)3 in the recycle of Lewis acids.
    结果表明,In(OTf)_3和FeCl_3·6H_2O都是很好的合成吲哚甲烷的Lewis酸催化剂,其中FeCl_3·6H_2O的催化体系更具有循环使用的效果。
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  double
We obtain a criterion for rational smoothness of an algebraic variety with a torus action, with applications to orbit closures in flag varieties, and to closures of double classes in regular group completions.
      
A Deodhar-type stratification on the double flag variety
      
We describe a partition of the double flag variety G/B+ × G/B- of a complex semisimple algebraic group G analogous to the Deodhar partition on the flag variety G/B+.
      
Also, we discuss possible connections to the positive and cluster geometry of G/B+ × G/B-, which would generalize results of Fomin and Zelevinsky on double Bruhat cells and Marsh and Rietsch on double Schubert cells.
      
Hardy Spaces on the Plane and Double Fourier Transforms
      
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  two
Motivated by the physical concept of special geometry, two mathematical constructions are studied which relate real hypersurfaces to tube domains and complex Lagrangian cones, respectively.
      
The theory is applied to the case of cubic hypersurfaces, which is the one most relevant to special geometry, obtaining the solution of the two classification problems and the description of the corresponding homogeneous special K?hler manifolds.
      
Recently, there is a renewed interest in wonderful varieties of rank two since they were shown to hold a keystone position in the theory of spherical varieties, see [L], [BP], and [K].
      
We apply this criterion of algebraic integrability to two examples: finite-zone potentials and the elliptic Calogero-Moser system.
      
There are two well known combinatorial tools in the representation theory ofSLn, the semi-standard Young tableaux and the Gelfand-Tsetlin patterns.
      
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  dual
The cohomology algebra of the classifying space of a compact Lie group admits the structure of ann-Hopf algebra, wheren is the order of the Weyl group; the homology with dual structure is also ann-Hopf algebra.
      
In a first step we prove that the Satake compactification of the modular variety of genus 2 and level 3 is the normalization of the dual of the Burkhardt quartic.
      
The second part consists in the normalization of the Burkhardt dual.
      
Finally, we study their reducibility of the action of the Casimirs on the zero-weight spaces of self-dual g-modules and obtain complete classification results for g = sln and g2.
      
This boils down to a Duistermaat-Heckman exact stationary phase calculation, involving a Poisson structure on the dual symmetric space G0/K discovered by Evens and Lu.
      
更多          
  both
Fr?nsdal [Fr1, Fr2] made a penetrating observation that both of them are quasi-Hopf algebras, obtained by twisting the standard quantum affine algebraUq(g).
      
We find closed formulas for the 1-point functions in both cases in terms of Jacobi θ-functions.
      
We characterize irreducible Hermitian symmetric spaces which are not of tube type, both in terms of
      
This partition is a refinement of the stratification into orbits both for B+ × B- and for the diagonal action of G, just as Deodhar's partition refines the orbits of B+ and B-.
      
Hardy spaces of analytic functions are studied both on strongly pseudoconvex domains in ?n and on domains of finite type in ?2.
      
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  其他


A new approximation method is proposed in this article for the discussion of molecular structures,and this new method includes the two well-known theories,molecular orbital theory and electron-pair bond theory as two special cases.Let a molecule have n bonds and let the ith bond be described by the anti-symmetrical two-electron bond function ψ_i(v_(2i-1),v_(2i)).(If there exist one- electron,three-electron or many-electron bonds,they can be similarly described by the corresponding one-electron,three-electron...

A new approximation method is proposed in this article for the discussion of molecular structures,and this new method includes the two well-known theories,molecular orbital theory and electron-pair bond theory as two special cases.Let a molecule have n bonds and let the ith bond be described by the anti-symmetrical two-electron bond function ψ_i(v_(2i-1),v_(2i)).(If there exist one- electron,three-electron or many-electron bonds,they can be similarly described by the corresponding one-electron,three-electron or many-electron bond func- tions.) Then the stationary state of the molecule is represented by the follow- ing wave function Ψ, where the summation is over all permutations of 1,2,……,2n except those within the interior of the functions,since each ψ_i is already anti-symmetrical.Obviously (2~n/((2n)/!))~(1/2) is the normalization factor. By quantum mechanics the energy of the molecule equals (1) here H_i,T_(ij) and S_(11)' are respectively the following three kinds of operators, (2) (3) (4) The third term of equation (1) is the exchange integral of electrons 1 and 1', while (1,2') is that of electrons 1 and 2'.According to the definition of bond functions,ψ_i may be written as (5) Substituting equation (5) into equation (1) and carrying out the integration over spin coordinates,we obtain (6) It can be easily seen from equation (6) that the combining energy of a mole- cule consists of two parts,one being the binding energy of the bonds represent- ed by the first term of equation (6),and the other being the interaction energy of the bonds denoted by the second term of that equation. If we choose certain functions φ_i~('s) involving several parameters and substi- tute them into equation (6),we may determine the values of those parameters by means of the variation principle. For the discussion of bond interaction energies,we develop a new method for the evaluation of certain types of three-center and four-center integrals.The interaction energy of a unit positive charge and an electron cloud of cylindrical- symmetry distribution may be written as (7) where (8) and R_0~2=a~2+b~2+c~2 The interaction energy of two electron clouds both of cylindrical-symmetry distributions with respect to their own respective axes is evaluated to be (9) (10) where is to sum over j from zero to the lesser value of n-2i and m, is to sum over i from zero to the integral one of n/2 and (n-1)/2,and is to sum over all cases satisfying the relation =m-j,while b_(n,n-2i) represents the coefficient of x~(n-2i) in the n th Legendre polynomial.

本文在分子结构理论方面,作了下列两点贡献:首先建议了用电子或多电子键函数作为近似基础,来计算分子的近似能量和近似电子云分布。这样计算得来的结果,一定会比用分子轨道理论或电子配对理论好,因为它更真实的反映了分子的化学性质,同时它也包括了后两者,而以它们为特例。我们得到了分子结合能的表示式,用表示式证明了分子结合能由两部分组成:一部分是键的结合能,另一部分是键与键间的作用能。其次是建议了一种新方法,把在计算化学键相互间的作用能中遇到的一些三中心和四中心积分,还原为容易计算的二中心积分。这方法比以往所用的好,因为它计算比较简单,同时限制性也小。

Although James and Coolidge (1933) solved the molecular hydrogen problem in almost complete agreement with experiment by using a 13-term 2-electron eigenfunction, his method can hardly be applied to more complex molecules. For this and other reasons (Coulson, 1938), it is still desirable to obtain a good one-electron eigenfunction, i.e., molecular orbital, for the hydrogen molecule. The best molecular orbital treatment available in the literature was given by Coulson (1938), who used a trial eigenfunction in...

Although James and Coolidge (1933) solved the molecular hydrogen problem in almost complete agreement with experiment by using a 13-term 2-electron eigenfunction, his method can hardly be applied to more complex molecules. For this and other reasons (Coulson, 1938), it is still desirable to obtain a good one-electron eigenfunction, i.e., molecular orbital, for the hydrogen molecule. The best molecular orbital treatment available in the literature was given by Coulson (1938), who used a trial eigenfunction in elliptical coordinates involving 5 parameters and obtained 3.603 eV for the binding energy of H_2, which is to be compared with the ex- perimental value of 4.72 eV. In the present investigation we have proposed a new type of trial eigenfunction for the molecular orbital: (1) with p = centers a, b, g, c, d,…… i = electron 1 or 2 (2) where the p's are centers along the bond axis a-b (Fig. 1). In this simple problem both the Fock and Hartree methods yield the same result. The molecular orbital ψ must satisfy the following integral equation: (3) where ε is the energy of the molecular orbital, F is the Fock operator which is equal to H+G(1), while H is the one-electron Hamiltonian operator: H = -1/2▽~2-1/r_a-1/r_b (4) and G(1) is the interaction potential (5) Substituting (1) into (3), we obtain the linear combination coefficients c_p, which must satisfy the following secular equation: (6) where is the solution of the secular determinant and The F_(pq)'s are not at first known, but depend upon the c_p's. A method of successive approximation must therefore be adopted. A set of c_p values may be assumed, the F_(pq)'s calculated, the secular determinant (7) solved, and a new set of c_p values found. This process is repeated until a "self-consistent" set of c_p values is obtained. The above procedure was first proposed by Roothaan (1951), not for H_2 but for more complex molecules. It was called by him the "LCAO SCF (linear combination of atomic orbitals self-consistent field) method". The new feature of the present investigation is that we not only use LCAO but also LCNAO (linear combination of non-atomic orbitals, such as x_g, x_c, x_d, …). The order of secular determinant (7) may be reduced to half if we replace the eigen- functions x_a, x_b .... by their symmetrical and anti-symmetrical linear combinations x_a + x_b and x_a-x_b. Numerical calculations have been carried out both for the three- and the two-centered molecular orbitals. The three-centered molecular orbital is (10) (11) where S_(ab) and S(ag) are the overlapping integrals between x_a and x_b, and between x_a and x_g respectively. The parameters a and g have 'been obtained to give minimum energy by the method described above. They are a=l.190, g=0.22, and the binding energy is 3.598 eV, which is almost as good as that obtained by Coulson (3.603 eV) using a trial function of 5 parameters. The two-centered molecular orbital is (12) (13) which gives a maximum binding energy of 3.630 eV for a=1.190 and R~(ac)=R(bd)=0.105 (Fig. 1). This result is 'better than Coulson's. If we allow different values for the ex-ponent α in x_a and x_g in equation (11), or if we use a four-centered molecular orbital, such as ψ=a(x_a + x_b) + b(x_c + x_d) with four parameters, namely α_a=α_b, α_c=α_d, R_(ac)=R_(bd) and the ratio b/a, it is possible to obtain a still better result. Extension of the present method to the treatment of more complex molecules is now under investigation.

(1)討論了用自洽勢場多中心分子軌道法來處理H_2分子的一般方法。 (2)用僅含兩個參變數三中心分子軌道進行了具體計算,求得H_2分子的結合能為3.598eV,接近於Coulson用五個參變數的雙中心分子軌道所得的結果(3.603eV)。 (3)用不在原子核上的兩中心的分子軌道求得H_2分子的結合能為3.630 eV,此上述結果為好。並指出如用不同的α值和四個或四個以上中心的分子軌道,很有可能得到更好的結果。以上處理方法有可能推廣到比H_2更為複雜的分子。

Karrer and Enslin reported that the structure of alstyrine (S_(19)H_(22)N_2), a selenium- dehydrogenation-degradation product obtained by Sharp from the alkaloid alstonine, is identical with that of corynanthyrine, α-[2-(4, 5 diethylpyridyl)]-β-ethylindole (Ⅱ), despite the fact that the melting points of these two substances have a 5°difference. In his investigation, the author of the present paper has synthesized two homologues of (II), α-(2-pyridyl)-β- methylindole (Ⅲ) and α-(2-pyridyl)-β-ethylindole (Ⅳ),...

Karrer and Enslin reported that the structure of alstyrine (S_(19)H_(22)N_2), a selenium- dehydrogenation-degradation product obtained by Sharp from the alkaloid alstonine, is identical with that of corynanthyrine, α-[2-(4, 5 diethylpyridyl)]-β-ethylindole (Ⅱ), despite the fact that the melting points of these two substances have a 5°difference. In his investigation, the author of the present paper has synthesized two homologues of (II), α-(2-pyridyl)-β- methylindole (Ⅲ) and α-(2-pyridyl)-β-ethylindole (Ⅳ), finding that the former has almost the same ultraviolet absorption spectrum as that of alsyrine and that, like alstyrine, the metho- sulphate of the compounds (Ⅲ) and (Ⅳ) gives the same red colour reaction upon treatment with dilute sodium-hydroxide solution. The Fischer indole synthesis to cyclize the phenylhydrazone of the corresponding alkyl- 2-pyridylketone in the presence of mineral acid was employed by the author in the preparation of compounds (Ⅲ) and (Ⅳ). Besides, three a-carboline derivatives, namely, 2-(cyclohexylmethyl)-β-carboline (Ⅻ), 2-[(4'-methylcyclohexyl)-methyl]-β-carboline (XIII) and 2-[(2'-methylcyclohexyl)-methyl]- β-carboline (XIV), have also been synthesized; none of them is identical with alstyrine in physical and chemical properties. The preparation of compounds (Ⅻ), ((XIII)) and ((XIV)) was carried out according to the method originated by Bischler and Napieralski. This involved the condensation of tryptamine with a suitable acid, or acid chloride, first to form an amide, which was then cyclized with phosphorus pentoxide, and finally dehydrogenated .partially with selenium. The melting points of the two α-(2-pyridyl)-β-alkylindoles, three β-carbolines, their inter- mediates, and a few derivatives of theirs are as follows: ■

1.合成了兩種吲(口朶) 衍生物:α-(2-吡啶基)-β-甲基吲(口朶) 及α-(2-吡啶基)-β-乙基吲(口朶)。前者的紫外線吸收光譜與阿爾斯泰令(alstyrine,係一種由西阿斯木鹼經硒降解後的產物)的吸收光譜極為類似;且二者有一種相同的顏色反應。因此說明阿爾斯泰令的結構可能與可利南斯令(corynanthyrine),α-[2-(4,5-雙乙吡啶基)]-β-乙基吲(口朶)相同。 2.合成了三種β-咔卟啉的衍生物:2-環己烷甲基-β-咔卟啉,2-[(4′-甲基環己烷)甲基]-β-咔卟啉及2-[(2′-甲基環已烷)甲基]-β-咔卟啉。這些化合物的化學及物理性質都和阿爾斯泰令不同。因此後者不是β-咔卟啉衍生物。

 
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