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排序方式: 共有223条查询结果,搜索用时 14 毫秒
131.
Juan Yun Xihong Li Xuetong Fan Yao Tang Yao Xiao Sen Wan 《Radiation Physics and Chemistry》2012,81(8):1198-1202
Gamma irradiation is highly effective in inactivating microorganisms in various foods and offers a safe alternative method of food decontamination. In the present study, soybeans (Glycine max L. Merrill) were treated with 0, 1.0, 3.0, 5.0 and 10.0 KGy of gamma irradiation. Microbial populations on soybeans, isoflavone, tocopherol contents, raffinose family oligosaccharides, color and sensory properties were evaluated as a function of irradiation dose. The results indicated that gamma irradiation reduced aerobic bacterial and fungal load. Irradiation at the doses applied did not cause any significant change (p>0.05) in the contents of isoflavone of soybeans, but decreased tocopherol contents. The content of key flatulence-producing raffinose family oligosaccharides in irradiated soybeans (10.0 kGy) decreased by 82.1% compared to the control. Sensory analysis showed that the odor of the soybeans was organoleptically acceptable at doses up to 5.0 kGy and no significant differences were observed between irradiated and nonirradiated samples in flavor, texture and color after irradiation. 相似文献
132.
V. V. Krasil’nikov S. E. Savotchenko 《Russian Journal of Physical Chemistry B, Focus on Physics》2013,7(6):745-747
The Schlögl model of a chemical reaction is generalized to take into account the correlation effects arising from the finiteness of the correlation time. This generalization is based on a generalization of Fisher’s equation with a memory function and cubic nonlinearity. Oscillatory states are demonstrated to be possible in such a system. The dissipative structure existence conditions are specified. 相似文献
133.
《Polyhedron》1986,5(7):1291-1295
A series of bis-(dioctylphosphinyl)-alkanes [(DOPO)2R], has been prepared and employed as liquid-liquid extractants for molybdenum(VI) from hydrochloric acid solutions [R = p-CH2C6H4CH2 or (CH2n(n = 2, 3, 4, 5, 8 or 10)]. These bis-type ligands were found to be much more efficient extractants than trioctylphosphine oxide and benzyl-dioctylphosphine oxide. The formula of the molybdenum(VI) extracted by (DOPO)2(CH2)5 into the organic phase was determined to be MoO2[(DOPO)2(CH2)5](Cl)2. 相似文献
134.
《Journal of Non》2006,352(30-31):3196-3199
The expressions for the phonon frequencies of Zr55Cu30Al10Ni15 bulk metallic glass employing a simple model given by Bhatia and Singh for a hypothetical one-component metallic glass are derived both for longitudinal and transverse modes of excitations. The model assumes a central force, effective between the nearest neighbours, and a volume dependent force. Both types of excitations of phonons are computed for the Zr55Cu30Al10Ni15 bulk metallic glass for the first time both for self-consistent screening of conduction electrons with and without the inclusion of correlation effects. Phonon frequency expressions reproduce the main characteristic features of the dispersion curves. The theoretical results predicted are in a good agreement with available experimental data of different quaternary bulk metallic glasses having same constituents. These are also compared to the theoretical results of a quaternary glass to have an insight of the structural behavior of the glass under consideration. 相似文献
135.
《Journal of membrane science》1997,132(1):1-21
Electro-osmotic pumping (EOP) theory and its characteristics (transport numbers, brine concentration, current density, current efficiency, electro-osmotic coefficients, etc.) of Selemion AMV and CMV ion-exchange membranes were studied. The brine concentration increased with increase in current density and feed water concentration. Current efficiency was nearly constant in a wide range of current densities and feed water concentrations. The water flow through the membranes also increased with increasing current density and feed water concentration. The increase in water flow increased the current efficiency significantly. Consequently, water flow through electrodialysis (ED) membranes had a positive effect on ED. Electro-osmotic coefficients decreased with increasing feed water concentration. Osmotic flow in EOP-ED decreased relative to the total flow with increasing current density while the electro-osmotic flow increased relative to the osmotic flow. Osmotic flow significantly contributes to the total water flow in EOP. Selemion AMV and CMV membranes performed well for salt concentration. A simple membrane potential measurement has been demonstrated to function reasonably satisfactorily to predict membrane performance for salt concentration. 相似文献
136.
V. Buršíková M. Hartmanová V. Navrátil C. Mansilla 《Russian Journal of Electrochemistry》2013,49(7):619-627
The study of polycrystalline CeO2 + xSm2O3 (x = 0, 10.9–15.9 mol %) thin films deposited by Electron Beam Physical Vapour Deposition (EB-PVD) and Ionic Beam Assisted Deposition (IBAD) techniques on the Si substrate was devoted to the influence of deposition conditions used, namely composition x, deposition temperature T dep and Ar+ ion bombardment, on the (micro)hardness, H pl and elastic modulus, Y with respect to the film structure and microstructure. These mechanical characteristics were investigated by the depth sensing indentation (DSI) technique as the functions of relative indentation depth h rel = h max/t and the values obtained were compared with those obtained by the classical Vickers technique. Results of this study are described and discussed. 相似文献
137.
《Journal of fluorine chemistry》1986,34(2):191-200
The isocyanate RfCH2NCO (Rf=CF3(C2F5)2C)reacts under strongly acidic conditions to form the salt RfCH2NH3(+)HSO4(−)(1) which yields, on treatment with sodium nitrite the diazaoalkane RfCHN2 (3). Dissolution of (1) in D.M.S.O. gives, by a remarkable decomposition reaction, the alkane RfH (2). Reaction of (3) with excess sodium nitrite affords the isocyanate RfNCO (4) which is stable to water,but which reacts with ammia to give the urea RfNHCONH2 (5); this latter was not readily hydrolysed .Photolysis of (3) yields the diazadiene RfCHNNCH Rf (7). Thermolysis of (3) alone afforded the diazadiene (7), but reaction in the presence of copper (II) perchlorate afforded (7) and the aldehyde RfCHO (6) 相似文献
138.
《Particuology》2018
There have been few investigations of effects of electrical charge, carried by lab-generated particles, on filtration efficiency testing. Here, we measured the elementary charge on particles and the fraction of particles carrying that charge with a combined electrometer, differential mobility analyzer, and scanning mobility particle sizer. A typical solid NaCl aerosol and liquid diethylhexyl sebacate (DEHS) aerosol were generated with Collison and Laskin nebulizers, respectively. Our experimental results showed that NaCl aerosols carried more charge after aerosol generation. The average net elementary charge per particle was approximately 0.07. The NaCl aerosol was overall positively charged but contained a mixture of neutral and charged particles. Individual particles could carry at most four elementary charges. According to constant theorem, we speculated that original NaCl aerosol contained 17% neutral, 45% positive-, and 38% negative-charged particles in the diameter range from 30 to 300 nm. A Kr-85 neutralizer was used to decrease the charge on the NaCl particles. Our results indicated that the DEHS aerosol was electrically neutral. The effects of electric charge on particle collection by electret and electroneutral high efficiency particulate air (HEPA) filters were analyzed. Theoretical calculations suggested that charges on original NaCl aerosol particles enhanced the filtration efficiency of HEPA filters. 相似文献
139.
《Arabian Journal of Chemistry》2020,13(10):7247-7263
High performance electric double-layer capacitors (EDLCs) based on poly (vinyl alcohol) (PVA): ammonium thiocyanate (NH4SCN):Cu(II)-complex plasticized with glycerol (GLY) have been fabricated. The maximum DC ionic conductivity (σDC) of 2.25 × 10-3 S cm−1 is achieved at ambient temperature. The X-ray diffraction (XRD) patterns confirmed that the addition of both Cu(II)–complex and GLY enhanced the amorphous region within the samples. Through the Fourier transform infrared (FTIR) the interactions between the host polymer and other components of the prepared electrolyte are observed. The FESEM images reveal that the surface morphology of the samples showed a uniform smooth surface at high GLY concentration. This is in good agreement with the XRD and FTIR results. Transference numbers of ion (tion) and electron (tel) for the highest conducting composite polymer electrolyte (CPE) are recognized to be 0.971 and 0.029, respectively. The linear sweep voltammetry (LSV) revealed that the electrochemical stability window for the CPE is 2.15 V. These high values of tion and potential stability established the suitability of the synthesized systems for EDLC application. Cyclic voltammetry (CV) offered nearly rectangular shape with the lack of Faradaic peak. The specific capacitance and energy density of the EDLC are nearly constant within 1000 cycles at a current density of 0.5 mA/cm2 with average of 155.322F/g and 17.473 Wh/Kg, respectively. The energy density of the EDLC in the current work is in the range of battery specific energy. The EDLC performance was found to be stable over 1000 cycles. The low value of equivalent series resistance reveals that the EDLC has good electrolyte-electrode contact. The EDLC exhibited the initial high power density of 4.960 × 103 W/Kg. 相似文献
140.
《中国化学快报》2020,31(9):2516-2519
Pathogen infection is the main cause of human morbidity and death. Traditional antibiotics usually sterilize bacteria in chemical ways, which tends to develop serious antibiotic resistance. Cationic polymers exhibit good bacterial inhibition with less resistance, but often face severe cytotoxicity toward normal cells. The optimization of polymeric antimicrobials for enhanced bactericidal capacity and improved biocompatibility is quite meaningful. In addition, photodynamic therapy (PDT) is a therapeutic modality with less susceptibility to develop resistance. Herein, a typical commercial polymeric antimicrobial, polyhexamethylene guanidine (PHMG) was selected for current proof-of-concept optimization due to its excellent bactericidal capacity but moderate biocompatibility. Eosin-Y (EoS) was copolymerized to afford EoS-labeled polymer conjugates, poly(2-(dimethylamino) ethyl methacrylate-co-eosin), P(DMAEMA-co-EoS), which was conjugated with PHMG to afford a novel polymeric antimicrobial, P(DMAEMA-co-EoS)-b-PHMG-b-P(DMAEMA-co-EoS), noted as PEoS-PHMG. It could efficiently kill broad-spectrum bacteria by physical damage and photodynamic therapy. Compared with PHMG, the bacterial inhibition of PEoS-PHMG was potentiated after the functionalization. Furthermore, PEoS-PHMG exhibited low cytotoxicity and minimal hemolysis, which was demonstrated by cell viability assays toward LO2 cells and RAW 264.7 cells as well as hemolytic assays against red blood cells. These results confirmed that the resultant PEoS-PHMG could act as promising alternative antibacterial materials with excellent broad-spectrum bacterial inhibition and favorable biocompatibility. 相似文献