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41.
The sensing characteristics of an amperometric NOx sensor with yttria-stabilized zirconia and a La-based perovskite-type oxide
sensing electrode were examined. La1-xSrxMO3 (M = Co, Mn, x = 0, 0.2, 0.4, 0.6) were synthesized using the spray pyrolysis method. The NO2 response of a sensor fabricated with La1-xSrxMnO3 increased with increasing amount of Sr, and the trend was in contrast to that of the sensors fabricated with La1-xSrxCoO3. LaSr0.2MnO3 was determined to be the most appropriate material for the sensor in terms of a high NO2 response and low O2 current. In order to discuss the effects of Sr addition to La-based perovskite oxides for the sensor, NO adsorption and desorption
properties of oxides and the relationship between the oxidation number of the B-site cation and Sr substitution were examined
using temperature-programmed desorption and X-ray photoelectron spectroscopy, respectively. 相似文献
42.
Karaki F Kabasawa Y Yanagimoto T Umeda N Firman Urano Y Nagano T Otani Y Ohwada T 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(4):1127-1141
Although many organic/inorganic compounds that release nitric oxide (NO) upon photoirradiation (phototriggered caged-NOs) have been reported, their photoabsorption wavelengths mostly lie in the UV region, because X-NO bonds (X=heteroatom and metal) generally have rather strong π-bond character. Thus, it is intrinsically difficult to generate organic compounds that release NO under visible light irradiation. Herein, the structures and properties of N-pyramidal nitrosamine derivatives of 7-azabicyclo[2.2.1]heptanes that release NO under visible light irradiation are described. Bathochromic shifts of the absorptions of these nitrosamines, attributed to HOMO (n)-LUMO (π*) transitions associated with the nonplanar structure of the N-NO moiety, enable the molecules to absorb visible light, which results in N-NO bond cleavage. Thus, these compounds are innate organic caged-NOs that are uncaged by visible light. 相似文献
43.
Taisei Ueda Naoyoshi Yatsuzuka Shin‐Ichi Nagai Kumiko Okada Emi Takeichi Hiromi Segi Jinsaku Sakakibara 《Journal of heterocyclic chemistry》2001,38(1):141-145
Oxidation of 7,8‐diaminotheophylline (1) with lead tetraacetate in refluxing toluene gave a mixture of 3‐amino‐5,7‐dimethylpyrimido[4,5‐e][1,2,4]triazine‐6,8‐dione ( 2 ) and 6‐cyanoimino‐5‐diazo‐1,3‐dimethylpyrimidine‐2,4‐dione ( 4 ). The latter was transformed to 2 by the reaction with 1‐propanethiol in quantitative yield. The reaction of 4 with methanol, ethanol and 1‐propanol in the presence of rhodium ( II ) acetate gave 5‐alkoxy‐6‐(2‐alkyl‐3‐isoureido)‐1,3‐dimethylpyrimidine‐2,4‐diones ( 7a‐c ). A similar reaction of 4 with alkylamines such as n‐propylamine, n‐butylamine, isobutylamine and n‐hexylamine gave a mixture of 7‐alkyl‐8‐aminotheophyllines ( 8a‐d ) and (5‐alkylamino‐1,3‐dimethyl‐2,4‐dioxopyrimidin‐6‐yl)cyanamides ( 9a‐d ). 相似文献
44.
Hiroaki Umeda Shiro Koseki Umpei Nagashima Michael W. Schmidt 《Journal of computational chemistry》2001,22(12):1243-1251
The quasi‐degenerate multireference second‐order perturbation theory (MRMP2) routines in the GAMESS suite of program codes have been parallelized using a distributed data interface (DDI). Two typical kinds of molecules were chosen for examination of parallelization speedup using one to eight PCs gathered as a cluster and connected by Fast Ethernet. The first example, in which total energies of several low‐lying electronic states have been obtained for niobium monohydride, give parallelization speedup of 7.15 when eight PCs were used as a cluster. The second example is the ground‐state total energy for a medium sized molecule, 4a,4b,8a,9a‐tetrahydro‐pyridino[1′,2′‐4,3]imidazo‐lidino[1,5‐a]pyridine. When distributed memory is employed, the parallelization speedup improves to 6.84 for the MRMP2 calculations when an eight‐PC cluster is used. These results demonstrate that our efforts to achieve the parallelization of MRMP2 routines have been successful. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1243–1251, 2001 相似文献
45.
基于小波变换的分形随机信号希尔伯特变换的波形估计 总被引:1,自引:0,他引:1
非平稳1/f类分形随机过程是一类重要的弱自相似随机过程,其典型例子是分形布朗运动,作者考察了弱自相似过程的希尔伯特变换,证明了希尔伯特变换具有弱自相似不变性,进而利用分形布朗运动的希尔伯特变换BH(t)小波系数能量向低频集中的特性,采用最优门限方法实现BH(t)的波形估计。 相似文献
46.
47.
Lei Gao Koji Narita Taro Ozaki Naoyoshi Kumakura Pamela Gan Atsushi Minami Chengwei Liu Xiaoguang Lei Ken Shirasu Hideaki Oikawa 《Tetrahedron letters》2018,59(12):1136-1139
Two homologous gene clusters for the biosynthesis of sesterterpenes betaestacins were identified from two phytopathogens, Phoma betae and Colletotrichum orbiculare. Heterologous expression of identified oxidation enzymes with previously-characterized PbTS1 (BtcAPb) resulted in the production of seven novel sesterterpenes. Although both strains possessed homologous enzymes, oxidation state of corresponding products were different from each other, suggesting that structural diversification of sesterterpene skeletons might be achieved by these homologous enzymes with different functions. 相似文献
48.
Maezaki N Tominaga H Kojima N Yanai M Urabe D Tanaka T 《Chemical communications (Cambridge, England)》2004,(4):406-407
The first and concise total synthesis of murisolin (1) was accomplished using asymmetric alkynylation and Sonogashira coupling as the key steps. The threo/trans/threo-type THF ring moiety was constructed with excellent stereoselectivity by asymmetric alkynylation of 1,6-heptadiyne to alpha-tetrahydrofuranic aldehyde, which was also prepared via the asymmetric alkynylation. 相似文献
49.
Maezaki N Tominaga H Kojima N Yanai M Urabe D Ueki R Tanaka T Yamori T 《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(21):6237-6245
Convergent total syntheses of murisolin (1), natural 16,19-cis-murisolin 2, and unnatural 16,19-cis-murisolin 3 were accomplished by asymmetric alkynylation of alpha-tetrahydrofuranic aldehyde with a diyne and Sonogashira coupling with a gamma-lactone segment as the key steps. Stereoisomers of alpha-tetrahydrofuranic aldehyde were synthesized with high optical purity and the asymmetric alkynylation of these with 1,6-heptadiyne proceeded in good yield and with high diastereoselectivity. The cell-growth inhibition profile and COMPARE analysis of the synthetic compounds 1-3 were also investigated. 相似文献
50.
Kaoru Dokko Soichi Horikoshi Takashi Itoh Matsuhiko Nishizawa Takayuki Abe Minoru Umeda Isamu Uchida 《Journal of Solid State Electrochemistry》2002,6(3):188-193
A microelectrode technique was applied to investigate the electrochemical properties of LiMn2O4 particles at elevated temperatures. Cyclic voltammograms of LiMn2O4 were measured after the particles were exposed to the electrolytes. This technique results in rapid and precise evaluation
of the redox behavior of the materials. A significant capacity fading was observed in 1 M LiPF6/EC+PC electrolytic solution, which indicates that both LiMn2O4 and LiPF6 participate in the reaction to produce an inert material on the particle surface. Next, the capacity fading for two different
BET surface area particles were compared using 1 M LiPF6/EC+PC at 50 °C. The reaction was found not to be controlled by the surface area. Finally, a Li1.1Mn1.9O4 particle was employed. The fading in discharge was ca. 10% for 50 cycles even at 50 °C, which means that the partial substitution
of Mn in LiMn2O4 by Li substantially enhanced the capacity stability.
Electronic Publication 相似文献