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911.
Effect of Erbium on the Photocatalytic Activity of TiO2/Ag Nanocomposites under Visible Light Irradiation 下载免费PDF全文
Natarajan Prakash Rajan Karthikeyan Dr. Dheivasigamani Thangaraju Dr. Mani Navaneethan Dr. Mukannan Arivanandhan Tadanobu Koyama Prof. Yasuhiro Hayakawa 《Chemphyschem》2015,16(14):3084-3092
Erbium co‐doped TiO2/Ag catalysts are synthesized by using a simple, one‐step solvothermal method and characterized by X‐ray diffraction, field‐emission scanning electron microscopy, transmission electron microscopy, Raman analysis, X‐ray photoelectron spectroscopy, and diffuse reflectance spectroscopy. The catalysts exhibit anatase crystal structures with increased visible light absorption compared with pure TiO2. Enhanced photocatalytic activity is observed with Er co‐doped TiO2/Ag nanocomposites for Rhodamine B degradation under visible light irradiation. The photocatalytic activity of 1 % Er co‐doped TiO2/Ag is much higher than that of TiO2/Ag, TiO2/Er, pure TiO2, and commercial Degussa P25. The kinetics of the degradation process are studied and the pseudo‐first‐order rate constant (k) and half‐life time (t1/2) of the reaction are calculated. The enhanced activity might be accredited to the efficient separation of electron–hole pairs by silver and higher visible light absorption of TiO2 induced by Er. 相似文献
912.
Synthesis of a Double Helicene by a Palladium‐Catalyzed Cross‐Coupling Reaction: Structure and Physical Properties 下载免费PDF全文
Hitoshi Kashihara Prof.Dr. Toshio Asada Prof.Dr. Ken Kamikawa 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(17):6523-6527
For this study, twisted π‐extended helicene 1 and double helicene 2 with a helicene framework were synthesized through palladium‐catalyzed C?H arylation or Suzuki–Miyaura coupling reaction. X‐ray crystallography revealed grossly twisted structures that were soluble in various conventional organic solvents. Optical properties based on UV/Vis and fluorescence spectra were measured. Electrochemical properties were also studied by measurements of cyclic voltammetry in 1 and 2 , which revealed their HOMO and the LUMO energies. Theoretical calculation supports their HOMO and LUMO energies and molecular orbitals. Furthermore, a racemization process of 2 predicted that the activation free energy at 300 K would be 31.8 kcal mol?1 by DFT calculation, which indicated the static helicity at 300 K. 相似文献
913.
Nanomembrane Canister Architectures for the Visualization and Filtration of Oxyanion Toxins with One‐Step Processing 下载免费PDF全文
Dr. Ahmed Aboelmagd Prof. Sherif A. El‐Safty Dr. Mohamed A. Shenashen Dr. Emad A. Elshehy Dr. Mohamed Khairy Prof. Masaru Sakaic Dr. Hitoshi Yamaguchi 《化学:亚洲杂志》2015,10(11):2467-2478
Nanomembrane canister‐like architectures were fabricated by using hexagonal mesocylinder‐shaped aluminosilica nanotubes (MNTs)–porous anodic alumina (PAA) hybrid nanochannels. The engineering pattern of the MNTs inside a 60 μm‐long membrane channel enabled the creation of unique canister‐like channel necks and cavities. The open‐tubular canister architecture design provides controllable, reproducible, and one‐step processing patterns of visual detection and rejection/permeation of oxyanion toxins such as selenite (SeO32?) in aquatic environments (i.e., in ground and river water sources) in the Ibaraki Prefecture of Japan. The decoration of organic ligand moieties such as omega chrome black blue (OCG) into inorganic Al2O3@tubular SiO2/Al2O3 canister membrane channel cavities led to the fabrication of an optical nanomembrane sensor (ONS). The OCG ligand was not leached from the canister as observed in washing, sensing, and recovery assays of selenite anions in solution, which enabled its multiple reuse. The ONS makes a variety of alternate processing analyses of selective quantification, visual detection, rejection/permeation, and recovery of toxic selenite quick and simple without using complex instrumentation. Under optimal conditions, the ONS canister exhibited a high selectivity toward selenite anions relative to other ions and a low‐level detection limit of 0.0093 μm . Real analytical data showed that approximately 96 % of SeO32? anions can be recovered from aquatic and wastewater samples. The ONS canister holds potential for field recovery applications of toxic selenite anions from water. 相似文献
914.
Dr. Shuji Yamashita Dr. Katsutoshi Takeuchi Takuya Koyama Prof. Dr. Masayuki Inoue Prof. Dr. Yujiro Hayashi Prof. Dr. Masahiro Hirama 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(6):2621-2628
Ciguatoxins, the principal causative agents of ciguatera seafood poisoning, are extremely large polycyclic ethers. We report herein a reliable route for constructing the left wing of CTX1B, which possesses the acid/base/oxidant‐sensitive bisallylic ether moiety, by a 6‐exo radical cyclization/ring‐closing metathesis strategy. This new route enabled us to achieve the second‐generation total synthesis of CTX1B and the first synthesis of 54‐deoxyCTX1B. 相似文献
915.
Shixue Liu Takayoshi Ishimoto Michihisa Koyama 《International journal of quantum chemistry》2015,115(22):1597-1605
The OH? and OH adsorption structures on Au55 and Au13 nanoparticles surfaces are analyzed using density functional theory. The most stable OH? adsorption site of Au55 and Au13 nanoparticles is found to be the vertex top site followed by the (111)‐(100) edge bridge site. On the contrary, the stability order of OH adsorption is opposite to that of OH?. The adsorption of OH? is calculated to be weaker than that of OH, which shows different charge transfer and interactions with gold surface. Coadsorption on nanoparticles is studied to find that multiple OH? species prefer the most stable sites of single OH? adsorption. The hydrogen bonding between adsorbed OH? on gold surface is a key factor in stabilizing the adsorbates on the Au surface. © 2015 Wiley Periodicals, Inc. 相似文献
916.
Magnet Design by Integration of Layer and Chain Magnetic Systems in a π‐Stacked Pillared Layer Framework 下载免费PDF全文
Hiroki Fukunaga Prof. Dr. Hitoshi Miyasaka 《Angewandte Chemie (International ed. in English)》2015,54(2):569-573
The control of inter‐lattice magnetic interactions is a crucial issue when long‐range ordered magnets that are based on low‐dimensional magnetic frameworks are designed. A “pillared layer framework (PLF)” model could be an efficient system for this purpose. In this report, A magnet based on a π‐stacked PLF with a phase transition temperature of 82 K, which can be increased to 107 K by applying a pressure of 12.5 kbar, is rationally constructed. Two types of low‐dimensional magnetic framework systems, an electron donor/acceptor magnetic layer and a charge transfer [FeCp*2]+TCNQ.? columnar magnet ([FeCp*2]+=decamethylferrocenium; TCNQ=7,7,8,8‐tetracyano‐p‐quinodimethane), are integrated to fabricate the magnet. This synthetic strategy employing a combination of layers and chains is widely useful not only for magnet design, but also for the creation of multifunctional materials with pores and anisotropic frameworks. 相似文献
917.
Natsuki Takei Misaki Morioka Mari Yoshizato Takuya Tanaka Shin-ichi Sasaki Satoshi Ito Hitoshi Tamiaki Toru Oba 《Tetrahedron》2014
Chlorophyll derivatives that possessed a phenylsulfanyl group at the C31- or C32-position were synthesized and their optical properties were investigated. Methyl 31-phenylsulfanyl-mesopyropheophorbide-a was prepared by substitutions of the corresponding C31-hydroxy-chlorin, methyl bacteriopheophorbide-d, with thiophenol in the presence of zinc iodide or of the corresponding C31-bromo-chlorin with thiophenol. The regioisomeric C32-phenylsulfanyl-chlorin was obtained by addition of thiophenol to the C3-vinyl group of methyl pyropheophorbide-a in the presence of AIBN. Both the synthetic compounds gave similar electronic absorption and emission spectra in chloroform, but fluorescence quantum yield of the C31-sulfanyl-chlorin (0.18) was ca. 30% smaller than those of the C32-sulfanyl-chlorin (0.25) and the C3-ethyl-chlorin (0.24). These observations were consistent with their fluorescence lifetime data. It is suggested that the heavy atom effect of a sulfur atom at the C31-position can tune photophysical properties of the chlorophyll derivatives. 相似文献
918.
Kei Zaitsu Izuru Miyawaki Kiyoko Bando Hiroshi Horie Noriaki Shima Munehiro Katagi Michiaki Tatsuno Takeshi Bamba Takako Sato Akira Ishii Hitoshi Tsuchihashi Koichi Suzuki Eiichiro Fukusaki 《Analytical and bioanalytical chemistry》2014,406(5):1339-1354
The metabolic profiles of urine and blood plasma in drug-addicted rat models based on morphine (MOR), methamphetamine (MA), and cocaine (COC)-induced conditioned place preference (CPP) were investigated. Rewarding effects induced by each drug were assessed by use of the CPP model. A mass spectrometry (MS)-based metabolomics approach was applied to urine and plasma of MOR, MA, and COC-addicted rats. In total, 57 metabolites in plasma and 70 metabolites in urine were identified by gas chromatography–MS. The metabolomics approach revealed that amounts of some metabolites, including tricarboxylic acid cycle intermediates, significantly changed in the urine of MOR-addicted rats. This result indicated that disruption of energy metabolism is deeply relevant to MOR addiction. In addition, 3-hydroxybutyric acid, l-tryptophan, cystine, and n-propylamine levels were significantly changed in the plasma of MOR-addicted rats. Lactose, spermidine, and stearic acid levels were significantly changed in the urine of MA-addicted rats. Threonine, cystine, and spermidine levels were significantly increased in the plasma of COC-addicted rats. In conclusion, differences in the metabolic profiles were suggestive of different biological states of MOR, MA, and COC addiction; these may be attributed to the different actions of the drugs on the brain reward circuitry and the resulting adaptation. In addition, the results showed possibility of predict the extent of MOR addiction by metabolic profiling. This is the first study to apply metabolomics to CPP models of drug addiction, and we demonstrated that metabolomics can be a multilateral approach to investigating the mechanism of drug addiction. 相似文献
919.
Jingshan Lu Ikuko Yao Masahito Shimojo Tayo Katano Hitoshi Uchida Mitsutoshi Setou Seiji Ito 《Analytical and bioanalytical chemistry》2014,406(5):1387-1396
The nitration of tyrosine to 3-nitrotyrosine is an oxidative modification of tyrosine by nitric oxide and is associated with many diseases, and targeting of protein kinase G (PKG)-I represents a potential therapeutic strategy for pulmonary hypertension and chronic pain. The direct assignment of tyrosine residues of PKG-I has remained to be made due to the low sensitivity of the current proteomic approach. In order to assign modified tyrosine residues of PKG-I, we nitrated purified PKG-Iα expressed in insect Sf9 cells by use of peroxynitrite in vitro and analyzed the trypsin-digested fragments by matrix-assisted laser desorption/ionization–time of flight mass spectrometry and liquid chromatography-tandem mass spectrometry. Among the 21 tyrosine residues of PKG-Iα, 16 tyrosine residues were assigned in 13 fragments; and six tyrosine residues were nitrated, those at Y71, Y141, Y212, Y336, Y345, and Y567, in the peroxynitrite-treated sample. Single mutation of tyrosine residues at Y71, Y212, and Y336 to phenylalanine significantly reduced the nitration of PKG-Iα; and four mutations at Y71, Y141, Y212, and Y336 (Y4F mutant) reduced it additively. PKG-Iα activity was inhibited by peroxynitrite in a concentration-dependent manner from 30 μM to 1 mM, and this inhibition was attenuated in the Y4F mutant. These results demonstrated that PKG-Iα was nitrated at multiple tyrosine residues and that its activity was reduced by nitration of these residues. 相似文献
920.
Imai Y Abe H Goto T Yoshimura Y Kushiyama S Matsumoto H 《The journal of physical chemistry. B》2008,112(32):9841-9846
By in situ observations using simultaneous X-ray diffraction and the DSC (differential scanning calorimetry) method, the effect of water, methanol, ethanol, and benzene on the crystallization has been observed in an ionic liquid (IL)-rich phase. The IL is a hydrophilic ionic liquid, N, N-diethyl-N-methyl-N-2-methoxyethyl ammonium tetrafluoroborate, [DEME][BF4]. At a small amount of the above additional molecules in the IL, the conventional preferred orientation on the Debye rings was seen by the X-ray diffraction. At 0.9 mol % H2O, twinlike crystal domains develop extraordinary on the microdomains. By the "crystal-growth enhancement effect" at a slight amount of water, a composite domain structure, which consists of the large domain and the weakly orientated microdomains, is formed without internal strains. Above 2.9 mol % H2O, the domain structure, however, disappears completely. It is remarkable that, in a thermal cycling experiment using pure [DEME][BF4], the similar composite domain structure appeared. This is also caused by an uptake of a slight amount of water. 相似文献