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31.
固体氩中一氧化氮的低温氧化   总被引:1,自引:0,他引:1  
王雪峰  许颜正  余敏  郑企克 《化学学报》1996,54(12):1186-1193
本文研究了在低温固体Ar中NO和O~2的反应。采用Ar作基质, 将NO和O~2分层沉积或混合沉积在低温基板上, 通过逐渐升温来控制扩散速率, 在温度10K-35K范围内, 从样品付里叶变换红外光谱的变化, 首次观察了NO和O~2反应中间体的生成和转化, 由此给出了反应机理, 即NO在Ar基质中首先发生扩散和聚合, 生成cis-(NO)~2, 随后与氧反应生成asym-N~2O~3和iso-N~2O~4, 而asym-N~2O~3进一步氧化生成N~2O~4(D~2~h)。  相似文献   
32.
石春山  叶泽人 《化学学报》1989,47(11):1056-1060
建立了Eu^2^+离子f→f跃迁发射产生的判据运用这-判据预测, 设计并合成了近四十种掺Eu^2^+的复合氟化物, 在这些基质中均观察到Eu^2^+的f-f跃迁尖峰发射。本文对所提供的判据从化学键性质和晶场效应方面作了简要解析, 并对判据的运用条件作了讨论。  相似文献   
33.
以高纯氧化钇中稀土杂质的ICP-AES测定为例, 研究了基体对分析元素谱线强度的影响及基体效应与工作条件的关系, 指出基体效应除主要来自分析物进样效率的降低外, 大量基体进入ICP降低了激发温度并对分析物的电离产生抑制作用, 提出用Se内标法代替通常的基体匹配法来补偿基体效应。进行了折衷条件选择及联样量确定等研究。实样分析表明, 内标法和基体匹配法所得结果一致, 加入回收率为87-120%, 精度也符合分析要求。  相似文献   
34.
王振清  周哲人  沈含熙 《化学学报》1988,46(10):995-1000
本文将CPA-矩阵法用于光度分析中同时对多元素的测定, 确定了在SAF为显色剂、DTMAB为胶束增敏剂的配合体系中以CPA-矩阵法计算Mo、W、Ti三元素含量的各种最佳实验条件, 建立了在该体系中同时测定互相干扰的Mo、W、Ti三元素的分光光度法. 总结了进行多组份测定时选择分析波长的四项原则, 并依此确定了6个测定波长: 510、512、514、516、518、520nm为Mo、W、Ti三元素的测定波长. 依本文建立的方法, 通过对任意含量配比的三元素混合试样进行测定结果极为满意, 方法具有稳定、准确、简便、快速和经济等特点, 便于推广应用.  相似文献   
35.
《Composite Interfaces》2013,20(6):515-546
In this paper, a brief review of the fiber-matrix interphase/interface region is given for carbon- and glass-fiber composites. The substructure of the interphase/interface region is discussed in terms of three interphases: (a) the fiber interphase (FI), (b) the sizing interphase (SI), and (c) the matrix interphase (MI), and two interface regions: (a) the FI-SI interface and (b) the SI-MI interface. These substructures are a synthesis of the ideas advanced by Ishida and Koenig and Drzal. The schematic model of interphase deformation behavior originally given by Bascom is reconstructed to include research results from the above researchers. To systematically probe adhesion at the SI-MI interface, functionalized self-assembled monolayers (SAMs) using bonding and non-bonding C11- type trichlorosilanes are prepared using the research of Menzel and Heise, and that of Cave and Kinloch as a guide. Results from this research are compared with short chain bonding and nonbonding silanes prepared by aqueous and non-aqueous deposition processes. The data were interpreted using the mechanisms proposed by Sharpe, Ishida and Koenig, and Drzal and the mathematical equation proposed by Nardin and Ward. For the non-bonding short-chain silane deposited by aqueous deposition, 90% of the adhesion was found to be due to mechanical interlocking, with the remaining adhesion due to physicochemical interactions. For the bonding short-chain silane deposited by aqueous deposition, the interface strength relative to the non-bonding short-chain silane increased by 31%. However the interfacial shear strength (IFSS) of this system was approximately 40% lower than the comparable bonding SAM interface. This difference was interpreted in terms of the propensity of the C3-alkylamine to form cyclic ring structures in the MI region as described by Ishida, Koenig, et al. The SAM data also indicates that 70-85% of the maximum IFSS is obtained with 25-50% of the surface covered with functional groups. This suggests that steric hindrance, due to the size of the DGEBA molecules, restricts access to the functional groups on the surface. Therefore, only 35% of the surface functional groups are accessible for bonding in the DGEBA/m-PDA epoxy resin system.  相似文献   
36.
《Composite Interfaces》2013,20(8):633-644
The poor hydrolytic stability of silane interphase greatly limits the use of fiber reinforced composites (FRC) in demanding applications in which the FRC part is permanently exposed to a moist environment such as in prosthetic dentistry and orthodontics. To improve hydrolytic stability of the interphase between the matrix composed of a blend of triethyleneglycol dimethacrylate (TEGMA) and bisphenol A glycidylmethacrylate (Bis–GMA) monomers and glass or alumina oxide fibers, a two-step hydrosilylation procedure was employed. The process consisted of creating hydride intermediate on the fiber surface followed by hydrosilylation reaction attaching the unsaturated organic monomer (Bis–GMA) forming stable –Si–C bonds. Infrared spectroscopy (FTIR) confirmed formation of the hydride intermediate on the surface and then, attachment of the appropriate organic compound in the second step. The amount of deposited interphase and its stability was significantly enhanced compared to standard silanization treatment. Fracture surfaces were observed by scanning electron microscopy (SEM) before and after environmental exposure proving that the most stable interfacial bond was obtained with the two-step treated fibers. It was concluded that hydrosilylation provides a viable alternative to silanization for both glass and ceramic fibers in composites intended for applications requiring enhanced hydrolytic stability of the composite parts.  相似文献   
37.
豆育升  文振翼  张棣 《化学学报》1991,49(7):665-670
本文计算了d^3电子组态在C2v场中的全部能量矩阵元, 微扰算符包括静电算符、晶场算符和旋轨偶合算符, 讨论了拟合了Cs2CoCl4的电子光谱。  相似文献   
38.
应用"相应轨道变换"和"广义"密度矩阵的方法,向MOPAC程序包中加入了新的功能,使其能处理电子转移反应中的部分参数。然后用此程序包中AM1方法对具有螺环结构的分子进行处理,计算了化合物在不同外加电场强度下的势能面、反应热ΔE,重组能λ及电子转移矩阵元V~A~B,结果表明,λ,V~A~B受外加电场的影响较小,而ΔE则与之成正比。对标题化合物1的计算结果也同abinitio法的结果进行了比较,发现其变化趋势完全一致,这说明本方法在计算电子转移方面是可靠的。与abinitio方法相比,本程序不仅适用于计算较大体系(如生物大分子),而且还具有速度快,耗时少的优点。  相似文献   
39.
Let {Ln(A,λ)(x)}n≥0 be the sequence of monic Laguerre matrix polynomials defined on [0, ∞) by Ln(A,λ)(x)=n!/(-λ)n∑nk=0(-λ)κ/k!(n-1)! (A I)n[(A I)k]-1 xk,where A ∈ Cr×r. It is known that {Ln(A,λ)(x)}n≥0 is orthogonal with respect to a matrix moment functional when A satisfies the spectral condition that Re(z) > - 1 for every z ∈σ(A).In this note we show that forA such that σ(A) does not contain negative integers, the Laguerre matrix polynomials Ln(A,λ) (x) are orthogonal with respect to a non-diagonal SobolevLaguerre matrix moment functional, which extends two cases: the above matrix case and the known scalar case.  相似文献   
40.
本文讨论了一种直接在时域范围内求解线性时不变网络的状态方程(X=AX)解析解的一种方法。当系数矩阵A的特征值出现重根时利用奇异值分解的方法求广义特征向量然后求解。对非齐次状态方程(XAXBU)首先用扩展状态空间的方法把它化为齐次方程。  相似文献   
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