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951.
Michael Limmert Ingo‐Peter Lorenz Jürgen Neubauer Axel Schulz Holger Piotrowski 《无机化学与普通化学杂志》2003,629(2):223-231
Naphtholactame as a Ligand Deprotonation of the fluorophore N‐Benz[cd]indol‐2(1H)‐on (= naphtholactame) with NaN(SiMe3)2 yields the naphtholactamate 1 , which is subsequently reacted with the chloro complexes [Ph3PAuCl] and [(Ph3P)2PtCl2]. The mono‐ and disubstitution products [Ph3PAu(C11H6NO)] ( 2 ), [(Ph3P)2PtCl(C11H6NO)] ( 3 ) and [(Ph3P)2Pt(C11H6NO)2] ( 4 ) with one ( 2 , 3 ) or two ( 4 ) metal‐N‐bonds respectively, were isolated. Substitution of chloride in the phosphanes Ph3‐nPCln with 1 leads to the naphtholactamato‐N‐phosphane derivatives Ph3‐nP(C11H6NO)n (n = 3 ( 5 ), 2 ( 6 ), 1 ( 7 )). 7 , which is particularly sensitive towards air oxygen, is readily oxidized to give the corresponding phosphane oxide Ph2P(O)(C11H6NO) ( 8 ). The ligating properties of 5 and 7 have been examined. In a two‐step reaction HAuCl4, C4H8S (= THT) and 7 yield the phosphane complex [{Ph2(C11H6NO)P}AuCl] ( 9 ). Photolytic activation of W(CO)6 in THF and subsequent addition of 5 or 7 surprisingly leads to the tetracarbonyl complexes $[(CO)_{4}\overline{W\{P(C_{11}H_{6}NO)_{2}(C_{11}H_{6}NO)\}]}$/ ( 10 ) and $[(CO)_{4}\overline{W\{PPh_{2}(C_{11}H_{6}NO)\}]}$/ ( 11 ), respectively. Both exhibit a bidentate P, O‐bound naphtholactamatophosphane ligand. The compounds have been characterized by their IR‐, NMR‐ and Mass spectra, compound 11 additionally by a single crystal structure analysis. Theoretical studies on PM3‐level for 5 , including a structure optimization and as well as an NBO analysis, have been carried out. 相似文献
952.
Stimuli-sensitive core/shell template particles for immobilizing inorganic nanoparticles in the core
We synthesize and characterize stimuli-sensitive core/shell particles with functional group (or material) localized in the core. We previously reported two types of hybrid particles prepared by using the template particles which were synthesized by soap-free emulsion copolymerization with N-isopropylacrylamide and glycidyl methacrylate (GMA) as monomers but by different preparation methods. GMA has advantages in immobilizing materials having several functional groups such as thiol ones. In this study, to obtain the suitable template particles for immobilizing any inorganic nanoparticles in the core, we investigated the effect of feed ratio of the two monomers. Obtained template particles were modified by thiol compounds to introduce ionic groups. They were characterized by dynamic light scattering and scanning electron microscopy. After in situ synthesis of magnetic nanoparticles in the templates, the hybrid particles were characterized directly by transmission electron microscopy. Consequently, we could obtain the hybrid core/shell particles which contained a large amount of magnetic nanoparticles (∼33 wt%) in the core. 相似文献
953.
954.
第二载体ZrO_2、TiO_2、γ-Al_2O_3对燃烧催化剂耐热性的影响周仁贤,郑小明,朱波,仲逸芬,陈敏(杭州大学化学系,杭州,310028)关键词催化氧化,钯,铂,第二载体燃烧催化剂多数采用堇青石陶瓷蜂窝体为载体基体,活性氧化铝为涂层料。很多结晶态... 相似文献
955.
Beata Godlewska-ykiewicz Julita Malejko Piotr Haaburda Barbara Leniewska Anatol Kojo 《Microchemical Journal》2007,85(2):314-320
A novel flow-injection chemiluminescent (CL) method of determination of trace amounts of Pt(IV) based on its catalytic effect on the reaction of oxidation of luminol in alkaline solution is proposed. The method employs on-line separation of analyte on the column containing green algae Chlorella vulgaris immobilized on Cellex-T support. The application of biosorption process for elimination of interferences resulted in the increase in the tolerable matrix ions concentration by several orders of magnitude. The influence of dissolved organic matter on chemiluminescence of luminol was eliminated by means of a reversed phase C18 column. Under optimized conditions the suitable selectivity, good sensitivity, and low limit of detection (LOD = 0.057 ng mL− 1) of the method were obtained. The method was applied to the analysis of spiked river water samples. 相似文献
956.
本研究工作发现:硫代米蚩酮(TMK)可作光度法测定铂(Ⅳ)的新显色剂。与一般光度测铂方法不同,在最佳条件(1mL1%乳化剂OP,2mLpH2.2邻苯二甲酸氢钾-盐酸缓冲溶液,1.2mL0.5mg/mLTMK乙醇溶液存在)下,只需在室温放置20min即显色完全,灵敏度高(ε=1.69×10 ̄5L·mol ̄(-1)·cm ̄(-1)),对比度大(△λ)=95nm),线性范围较宽(0~14μg/(25mL),对含Au:pt=1∶2.3~2.3∶1范围内的混合物在较宽波长范围(510~580nm)符合吸光度加和原理,可望用双波长分光光度法不经分离同时测定铂和金。 相似文献
957.
Rene J. LeBlanc Christopher T. Williams 《Journal of molecular catalysis. A, Chemical》2004,220(2):207-214
The adsorption of the chiral modifier cinchonidine on platinum in ethanol as a function of temperature has been studied with surface-enhanced Raman spectroscopy (SERS). The temperature range chosen was from 30 to 70 °C, within which both the activity and selectivity of cinchonidine-modified Pt catalysts have been shown to change dramatically. Platinum surfaces were modified with 260 μM cinchonidine in ethanol, and examined both in pure ethanol and in the modifying solution itself. Adsorbed cinchonidine under pure ethanol was found to partially desorb as the temperature was raised, accompanied by an increase in the average tilt of the quinoline group with respect to the surface. In contrast, the presence of solution-phase cinchonidine resulted in an increase in the cinchonidine surface coverage and average tilt as temperature was raised. In a previous study [J. Mol. Catal. A 212 (2004) 277] we showed that hydrogen causes a dramatic enhancement in the SERS response of adsorbed cinchonidine. This was attributed to a conversion of cinchonidine to 10,11-dihydrocinchonidine on the Pt surface and a more flat orientation of the quinoline group. In both pure ethanol and in 260 μM cinchonidine, the presence of hydrogen causes a significant decrease in the alkaloid SERS bands at temperatures above 40 °C. In addition, the average tilt of the quinoline group increases significantly at these elevated temperatures. The temperature-dependence of 10,11-dihydrocinchonidine adsorption was also investigated, and is almost identical to that observed for cinchonidine in the presence of hydrogen. This lends further support to the conclusion that cinchonidine is being hydrogenated on the Pt surface in the presence of hydrogen. The significant changes observed on the cinchonidine-modified Pt surface above 40 °C correlate well with reported decreases in enantioselectivity and turn-over frequency at similar temperatures during ethyl pyruvate hydrogenation. 相似文献
958.
The reactions of platinum(II) iodide with triethyl‐ or trimethylsulfonium iodide in acetonitrile solution lead to the formation of crystalline products (Et3S)2[PtI6] ( 1 ) and [Me3S]2[PtI6]·CH3CN ( 2 ), respectively. The formation of Pt(IV) complexes may be explained either by disproportionation of PtI2 or oxidation by oxygen. Palladium(II) iodide reacts with triethylsulfonium iodide to give the palladium(II) complex (Et3S)2[PdI4] ( 3 ). The crystal structures of 1 – 3 were determined by single‐crystal X‐ray diffraction. In the crystal structures, the compounds 2 and 3 exhibit an extensive hydrogen‐bonding network. 相似文献
959.
《Electroanalysis》2006,18(18):1763-1770
Poly(L ‐lactide) stabilized gold nanoparticles (designated as PLA–AuNP) with an average particle size of ca. 10 nm were used to modify a disposable screen‐printed carbon electrode (SPE) for the detection of As(III) by differential pulse anodic stripping voltammetry. Gold modification was evaluated by cyclic voltammetry, whereas scanning electron microscopy and transmission electron microscopy revealed the size and distribution of gold nanoparticles. The PLA–AuNP/SPE was applied effectively to detect toxic As(III) in HCl medium. Under the optimal experimental conditions, a linear calibration curve up to 4 ppm with a detection limit (S/N=3) of 0.09 ppb was obtained. The sensitivity was good enough to detect As(III) at levels lower than the current EPA standard (10 ppb). Most importantly, the PLA–AuNP/SPE can be tolerable from the interference of Cu, Cd, Fe, Zn, Mn, and Ni and hence provides a direct and selective detection method for As(III) in natural waters. Practical utility of the PLA–AuNP/SPE was demonstrated to detect As(III) in “Blackfoot” disease endemic village groundwater from southwestern coast area of Taiwan (Pei‐Men). 相似文献
960.
甲基环戊烷在铂催化剂上氢解的动力学研究 总被引:1,自引:0,他引:1
研究了甲基环戊烷在负载型铂催化剂上的氢解动力学,建立了新的动力学模型,在Pt/SiO2上,两个平行反应(一个生成正己烷,另一个生成甲基戊烷)在甲基环戊烷吸附脱氢过程中存在显著的焓变差异,而C-C键断裂活化能则相近,在Al2O3负载铂催化剂上,反应的表现活经能仅是在Pt/SiO2上的一半,这是由于Cl离子的存在,改变了铂的催化性能,导致缺电子铂颗粒的形成,使反应速率的控制步骤从在Pt/SiO2上的C 相似文献