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41.
地基系数法在岩体抗滑桩内力计算中的应用 总被引:8,自引:0,他引:8
指出抗滑桩内力计算的传统方法之地基系数法应用于岩体抗滑桩时 ,存在的一些问题 .对此 ,首先根据刚性抗滑桩的受力和变形特性 ,推导了地基系数法计算刚性桩内力的计算公式 ;其次根据弹性抗滑桩的受力和变形特性 ,导出了有限差分格式 ,用以分析弹性桩全桩的内力 .同时 ,采用MATL AB数学软件 ,编写了基于文中所推公式的刚性和弹性抗滑桩内力计算程序 ,可完成全部计算和将计算结果转换成理想的可视化图形 .对于刚性抗滑桩 ,计算结果是精确的 ;对于弹性抗滑桩 ,计算结果的精度优于传统的查表手算法 .计算结果的可视化有助于抗滑桩的结构设计 相似文献
42.
对亚磷酸烷酯与丁烯二酸二烷酯的加成反应,以及膦酸丁二酸四烷酯与丙烯酸烷酯的加成反应的机理进行了讨论。提出了由亚磷酸二乙酯、反丁烯二酸二乙酯、丙烯酸乙酯等为反应原料,在碱性催化剂作用下经三步反应得到2-膦酸丁烷-1,2,4-三羧酸(PBTCA)的合成途径,产品得率为76%。采用谱学方法等初步证实了合成产物及其中间体的分子结构。并且对PBTCA的物化性质进行了探讨。 相似文献
43.
用动态毛细管流动法和液滴法对三种COP粘土稳定剂水溶液的接触角进行研究,并对三种COP粘上稳定剂与地层水中硫酸盐还原菌的作用做了实验比较.结果表明:COP_((2))的综合性能最佳.本文还提出和讨论了一剂多效问题. 相似文献
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Procedures to parametrize a set of stabilizing controllers are reviewed. These procedures are the key ones in the frequency-domain
synthesis of the optimal (minimum H
2-and H
∞-norms) controller or filter for a linear stationary system. A relationship between the parametrization procedures proposed
by different authors is shown. Examples of parametrization procedures in synthesis problems (delay problems, multichannel
filtering problems, etc.) are given
__________
Translated from Prikladnaya Mekhanika, Vol. 44, No. 6, pp. 3–27, June 2008. 相似文献
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为了抑制旋风分离器内的旋进涡核 (PVC)现象 ,对常规旋风分离器作了改进 ,在旋风分离器中心轴线处加上稳涡杆。对改进后旋风分离器内PVC的存在范围、频率和幅值进行了测定 ,结果表明 ,稳涡杆能减弱旋风分离器内的旋进涡核 相似文献
49.
《Electroanalysis》2018,30(2):386-396
Gold nanoparticles (AuNPs) have unique properties, making them attractive for electronic and energy‐conversion devices and as (electro)catalysts for electrochemical sensors. In addition to the size and shape of AuNPs, the electrocatalytic properties of AuNP‐sensors are also determined by the stabilizing agent used in their synthesis. Here, AuNPs were synthesized with citrate, alginate and quercetin, obtaining spherical and negatively charged nanoparticles. The AuNPs were used to modify glassy carbon electrodes (AuNPs/GCE), which were characterized by scanning electron microscopy and electrochemical techniques. The AuNPs/GCE showed aggregates of different sizes and degrees of dispersion on the electrode surface depending on the stabilizing agent. The AuNP's aggregates affect the homogeneity of the film, the reproducibility of the electrodes and their response in buffer solution. Finally, to evaluate the electrocatalytic ability of the AuNPs/GCE, we studied the oxidation of two analytes with opposite charges: (1) sunset yellow (negative) and (2) hydrazine (positive). Compared with GCE, the AuNPs/GCE showed good electrocatalytic properties for hydrazine, increasing the current up to 50 % and shifting the potential by almost 400 mV, depending on the AuNP used. For the negatively charged analyte, the current decreased up to 50 % and no shift in potential was observed. Thus, the electrocatalytic properties of the AuNPs showed to be highly dependent on the nature of the analyte. 相似文献
50.
Consideration is given to problems of solving the algebraic Riccati equation (ARE)—J-factorization of matrix polynomials and J-factorization of rational matrices—to which traditional solution algorithms are not applicable. In this connection, solution algorithms for these problems are discussed where the eigenvalues of the Hamiltonian matrix corresponding to the ARE and the zeros of matrix polynomials are located on the imaginary axis. Moreover, a procedure is set forth for asymptotic expansion of a stabilizing solution of the ARE in the neighborhood of a point at which the ARE has no stabilizing solution. It is shown how this expansion can be used for constructing canonical J-factorization of matrix polynomials that is nearly a noncanonical J-factorization. It is pointed out that the algorithms described can be implemented with the help of MATLAB routines 相似文献