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81.
二乙基二硫代氨甲酸银体系流动注射法测定砷 总被引:1,自引:0,他引:1
本文设计了一种AgDDC流动注射-分光光度法测定砷的系统。该系统采用自制的氢化物发生及吸装置,将液体流路和载气流路结合在一起。 相似文献
82.
83.
The relativistic ground and low-lying excited state potential energy curves of AgH and AuH in the presence of a cylindrical
harmonic confining potential were calculated using the multi-state multi-reference perturbation theory with the spin-free
no-pair Hamiltonian obtained via the third-order Douglas–Kroll transformation, incorporated with the full two-electron Breit–Pauli
spin–orbit operator. The spectroscopic parameters were obtained for both the scalar- and quasi-relativistic potentials. The
spin–orbit coupling constants were calculated for several strengths of the confining potential, and the effects of the applied
potential on the coupling constants were analyzed using configuration interaction.
This paper is dedicated to Serafín Fraga—colleague, mentor, and friend. 相似文献
84.
IntroductionSupportedPt-Sncatalystsareimpo~inthepdrileumandpthechendcalindustricsbecauseoftheirsuperiorcatalyticperformances.Forexample,Pt-Snsupportedonaneutralsupporthasbeenreportedtoexhibithighdehydrogenationselectivityanddebilitythansupportedplatinumca… 相似文献
85.
高分散直接甲醇燃料电池Pt/C阴极电催化剂的制备过程机理与表征 总被引:4,自引:1,他引:4
通过调变的多元醇法制备了40%Pt/C直接甲醇燃料电池阴极电催化剂,应用透射电镜(TEM)及X射线衍射(XRD)方法表征催化剂.结果表明,由该制备方法可得到高分散,金属粒子粒径分布窄的高载量贵金属催化剂.TEM统计结果表明,调变多元醇法制备的40%Pt/C催化剂的金属粒子平均粒径约为2.9nm.直接甲醇燃料电池单池性能测试表明,该方法制得的40%Pt/C的电催化氧还原能力比同型商品催化剂更好.另外,利用UV-Vis光谱研究了催化剂的制备过程.结果表明,在调变的多元醇法中,Pt4+的还原是一步完成的. 相似文献
86.
2-(3,5-二氯-2-吡啶偶氮)-5-二甲氨基苯胺与铂(Ⅳ)显色反应的研究 总被引:8,自引:0,他引:8
研究了2-(3,5-二氯-2-吡啶偶氮)-5-二甲氨基苯胺(3,5-diCl-PADMA)与铂(Ⅳ)的显色反应及铂配合物的质子化行为。结果表明,在0.04~0.48mol/L的H2SO4溶液中,于加热的条件下,试剂可与铂(Ⅳ)形成稳定的1∶2绿蓝色PtL2H2+2配合物,其最大吸收波长位于634nm,表观摩尔吸光系数为9.73×104L·mol-1·cm-1,桑德尔灵敏度为0.002μg·cm-2。铂配合物的三级质子化常数分别为:lgKa1=3.91,lgKa2=-2.21,lgKa3=-3.37。较大量的常见金属离子及除钯、钌外的其它贵金属离子不干扰测定。利用Pt,Pd与试剂反应所需的温度差异,可以用差减法消除微量Pd的干扰.铂(Ⅳ)浓度在每10mL0~7.5μg范围内符合比尔定律。所拟方法用于二次合金管理样-88及催化剂中微量铂的测定,结果满意。 相似文献
87.
Further studies on dppm-stabilized mixed-metal clusters: X-ray structure of PdPtCoCl(CO)3(μ-dppm)2
1
Pierre Braunstein Claude de Bellefon Yves Dusausoy Daniel Bayeul 《Journal of Cluster Science》1995,6(1):175-185
The metalloligated mixed-metal cluster [PdPtCo2(CO)7(-dppm)2] (2) (dppm = -Ph2PCH2PPh2) possesses numerous potential reaction centers (e.g., metal(s), metal-metal bonds, CO, and dppm ligands) and this has previously led to an investigation of the site selectivity of reactions with nucleophiles. The exocyclic CO(CO)4 fragment was substituted with a chloride ligand and the resulting chiral, triangular cluster PdPtCoCl(CO)3(-dppm)2 (4) has been structurally characterized. The Pd-Co and Pt-Co edges of this almost equilateral triangle are bridged by a dppm ligand, and two of the three carbonyls borne by the Co atom are semi-triply bridging above and below the plane of the metals. The Co(CO)3P fragment behaves as an anionic 4-electron donor organometallic bridging group toward thed
9-d
9 Pd(I)-Pt(I) unit. Crystal data for4, monoclinic space groupP21/n with Z=4 in a unit cell of dimensionsa=12.291(3),b=19.321(4),c=23.680(5) Å,=100.05(2)°. The structure has been solved from diffractometer data by Patterson, Fourier methods and refined by full-matrix least squares on the basis of 3512 observed reflections (l>3) toR(F) andR
w(F) values of 0.059 and 0.061.Dedicated to Professor L. F. Dahl on the occasion of his 65th birthday, with our sincere congratulations and best wishes. 相似文献
88.
B. M. Bulychev V. N. Verbetskii A. I. Sizov T. M. Zvukova V. K. Genchel’ V. N. Fokin 《Russian Chemical Bulletin》2007,56(7):1305-1312
Crystallization of non-solvated aluminum hydride from a diethyl ether-benzene mixed solvent was studied. The desolvation of
AlH3·(Et2O)x etherate in solution and the crystallization of α-AlH3 during polythermal heating of the solution occur only in the presence of ≥10 wt.% LiAlH4. The process is multistage, and the crystallization begins with the formation of the AlH3·0.25Et2O solvate, which recrystallizes in the solid phase into γ-AlH3 and then α-AlH3. Four crystalline modifications of aluminum hydride were characterized by X-ray diffraction and electron microscopy.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1259–1265, July, 2007. 相似文献
89.
A. A. Bogdanov Yu. V. Kosmotynskaya K. I. Yakovlev N. A. Kas’yanenko 《Journal of Structural Chemistry》2006,47(1):178-185
A comparison has been made of conformational changes in the DNA molecule during its interaction in solution with different binuclear coordination compounds of platinum [Pt(NH3)2Cl-R-Pt(NH3)2Cl]Cl2 in cis and trans conformations, which contain cytosine, pyrazine, and carboxypyrazine as the common ligand (R). The influence of concentration of the components, and in particular, of ionic strength of the solution on the complexation process was studied. The influence of the nature of the common ligand, and of cis and trans conformations of coordination compounds on the character of their interaction with DNA was considered. A comparison was made between the structures of DNA complexes with mono-and binuclear compounds with the same set of ligands in the platinum coordination sphere. 相似文献
90.
本文研究了Cp_2ZrH_2与丙烯酸和Cp_2Zr(H)Cl与丙烯酸钠、巴豆酸钠的反应。产物由IR 1~H和~(13)CNMR、ESR谱、气相色谱以及化学方法分析鉴定。产物水解得到与底物相应的饱和酸.用~1H NMR方法考察了Cp_2ZrH_2与丙烯酸的反应过程,用IR方法考察了Cp_2Zr(H)Cl与丙烯酸钠的反应过程。实验结果表明,上面两种反应首先消除H_2或NaCl,形成锆氧健,然后碳碳双键还原生成二茂锆羧酸盐配合物,其中羧酸根离子与二茂锆桥式双齿配位。 相似文献