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411.
In this paper, we use the principle of substitution to replace sub-gaskets of the Sierpinski gasket network by an equivalent Y-network which enables the use of only the Delta–Wye transformation and the series and parallel principles to derive some two-point resistances of the Sierpinski gasket network with dimension two. 相似文献
412.
利用电沉积法将不溶于常规无机和有机溶剂的多金属氧酸盐基的配位聚合物1, [{La(H2O)5·(dipic)}{La(H2O)(dipic)}]2{Mo8O26}·10H2O溶解于离子液体[RMIM][HT]或[RMIM][HP]中, 在恒电位下电解, 得到多金属氧酸盐基的配位聚合物膜. 应用红外光谱、X射线光电子能谱和XRD粉末衍射等方法研究多金属氧酸盐基配位聚合物膜的结构, 发现其与多金属氧酸盐基配位聚合物有相同的结构. 实现了多金属氧酸盐基配位聚合物在电极上的重构设计以及多金属氧酸盐基的配位聚合物的二次加工成型. 相似文献
413.
Local electric field and configuration of CO molecules adsorbed on a nanostructured surface with nanocones 下载免费PDF全文
Based on the nanostructured surface model that the (platinum,
Pt) nanocones grow out symmetrically from a plane substrate, the
local electric field near the conical nanoparticle surface is
computed and discussed. On the basis of these results, the adsorbed
CO molecules are modelled as dipoles, and three kinds of
interactions, i.e. interactions between dipoles and local electric
field, between dipoles and dipoles, as well as between dipoles and
nanostructured substrate, are taken into account. The
spatial configuration of CO molecules adsorbed on the nanocone
surface is then given by Monte-Carlo simulation. Our results show that
the CO molecules adsorbed on the nanocone surface cause local
agglomeration under the action of an external electric field, and
this agglomeration becomes more compact with decreasing conical
angle, which results in a stronger interaction among molecules.
These results serve as a basis for explaining abnormal phenomena
such as the abnormal infrared effect (AIRE), which was found when CO
molecules were adsorbed on the nanostructured transition-metal
surface. 相似文献
414.
《Fluid Phase Equilibria》2001,178(1-2):203-208
A metal ebulliometer has been used to measure the solubility of water in 2,2-dichloro-1,1,1-trifluoroethane (HCFC 123) over the temperature range 297–354 K. Solubilities varied from 9.5×10−3 to 3.75×10−2 (mole fraction). Activity coefficients (γ∞) and distribution coefficients (K∞) were estimated. The results were used to resolve a discrepancy found in the literature concerning the vapor pressure of HCFC 123. 相似文献
415.
THE VOLUME AND TOPOLOGY OF A COMPLETE REIMANNIAN MANIFOLD 总被引:3,自引:0,他引:3
51. IntroductionAn importallt problem in memannian geometry is whether the manifold is of finite topological type. By it we mean that there is a compact domain fi C M such that M C fi ishomeomorphic to off x [0, co). If the manifold has nonnegative Ricci curvature, some important results have been obtained by mathematicans (see [1,3,4,5,6, etc.]). It is well knownthat if Ric(M)20, one has Gromvo-Bishop volume comparison theorem and for any givenPPM, r > 0,c(n)vol[B(P, 1)]rsvol[B(p, r)]sw… 相似文献
416.
灌喂氯化汞大鼠组织中汞结合金属硫蛋白的色谱/质谱联用表征研究 总被引:1,自引:0,他引:1
通过测定大鼠脏器组织中汞的总量、金属硫蛋白(MTs)含量及利用尺寸排阻色谱(SEC)与电感耦合等离子体质谱(ICP-MS)联用技术,分析了灌喂HgCl2大鼠脏器组织中汞与MTs的积累量及金属与MTs的结合形态。结果表明,灌喂HgCl2大鼠各脏器中汞的积累量显著高于其相应的对照组,特别是在肾、肝和睾丸中汞的含量较高,表明此3个脏器受汞的危害最大。MTs的含量水平说明当大鼠脏器受汞污染时,肌体中的MTs将被大量诱导产生以对重金属进行解毒。通过SEC-ICP-MS联用技术获得了组织中的金属与MTs的结合形态,其 相似文献
417.
铝基复合材料超精密加工中的刀-屑摩擦磨损性能及模型研究 总被引:1,自引:0,他引:1
通过金刚石PCD刀具对非连续SiC增强铝基复合材料的超精密车削加工试验,考察了刀具第二切削变形区(刀具前刀面-切屑间)的摩擦磨损性能,并提出了相应的模型;采用爆炸式快速落刀装置制备出切屑根并分析了积屑瘤的影响因素;采用原子力显微镜对PCD刀具的刃口磨损形貌进行观察,并分析其磨损机理.结果表明:在超精密切削加工非连续增强铝基复合材料的过程中,前刀面仍然有极小的楔型积屑瘤产生;铝基复合材料的摩擦磨损性能明显优于铝合金,且当SiC增强相达到最佳体积分数(20%~25%)时,其摩擦磨损性能最佳;从刀具的耐磨性角度考虑,在超精密加工非连续增强铝基复合材料时适宜采用金刚石刀具. 相似文献
418.
YANG Kong-qing YANG Lei GONG Bai-hua LIN Zhong-cai HE Hong-sheng HUANG Liang 《Frontiers of Physics》2008,3(1):105
Complex networks describe a wide range of systems in nature and society. Since most real systems exist in certain physical space and the distance between the nodes has influence on the connections, it is helpful to study geographical complex networks and to investigate how the geographical constrains on the connections affect the network properties. In this paper, we briefly review our recent progress on geographical complex networks with respect of statistics, modelling, robustness, and synchronizability. It has been shown that the geographical constrains tend to make the network less robust and less synchronizable. Synchronization on random networks and clustered networks is also studied. 相似文献
419.
Effect of electric field on the electronic spectrum and the persistent current of a quantum ring with two electrons 总被引:1,自引:0,他引:1 下载免费PDF全文
The effect of an electric field E on a narrow quantum ring that contains two
electrons and is threaded by a magnetic flux B has been investigated. Localization
of the electronic distribution and suppression of the Aharonov--Bohm oscillation
(ABO) are found in the two-electron ring, which are similar to those found in a
one-electron ring. However, the period of ABO in a two-electron ring is reduced by
half compared with that in a one-electron ring. Furthermore, during the variation of
B, the persistent current of the ground state may undergo a sudden change in sign.
This change is associated with a singlet--triplet transition and has no counterpart
in one-electron rings. For a given E, there exists a threshold of energy. When
the energy of the excited state exceeds the threshold, the localization would
disappear and the ABO would recover. The value of the threshold is proportional to
the magnitude of E. Once the threshold is exceeded, the persistent current is much
stronger than the current of the ground state at E=0. 相似文献
420.
分子发光法研究空间位阻效应对包络物形成的影响 总被引:2,自引:1,他引:1
利用分子发光法研究了正丁醇(n-butanol,n-Bu)和苯酚(phenol,ph)存在下空间位阻效应对β-环糊精(Cyclodextrin,β-CD)和溴代萘(Bromonaphthalene,BrN)包络物形成的影响。在各自最佳实验条件下,2-BrN/β-CD/n-Bu/ph体系的室温磷光(RTP)强度不及1-BrN/β-CD/n-Bu/ph体系的三分之一;而其荧光发射光谱较1-BrN/β-CD/n-Bu/ph发射光谱红移5~10 nm,表明BrN中溴的空间位置对包络物的形成有显著的影响。两四元体系包络常数(Kf)的测定结果也进一步说明这一点。据此,讨论了上述包络物的形成机理。 相似文献