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481.
N—酰化壳聚糖膜性能的研究 总被引:6,自引:1,他引:5
讨论了一系列N-酰化壳聚糖膜的抗张强度、透水性、VB_(12)的透过性、透氧性以及血液相容性。N-已酰化壳聚糖膜具有良好的血液相容性。在制膜过程中,加入分子量为1500的聚乙二醇为致孔剂,则可使N-己酰化壳聚糖膜的渗透性有较大提高。同时保持较好的血液相容性和强度。 相似文献
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483.
本文用DSC技术研究了物理老化对PEK-C、PES-C及其共混物和复合材料玻璃化转变的影响.老化时间(t)延长,玻璃化转变温度(T_g)、热焓松弛峰温(T_(max))、峰高(△C_(pmax))和热焓(△H)提高;△H与lgt成线性关系.碳黑或碳纤维对PES-C的物理老化行为无影响,而反应性乙炔端基砜(ATS)固化物能限制PEK-C和PES-C在T_g以下温度的物理老化过程.利用物理老化能更为方便地判断多相体系的相容性,结果表明PEK-C/PSF为相容体系,而PEK-C/PES-C相容性较差. 相似文献
484.
抗凝血聚氨酯材料的研究进展 总被引:7,自引:0,他引:7
聚氨酯由于其优良的抗凝血性能和良好的物理机械性能而成为目前研究和应用最广的一种生物医用高分子材料。本文就嵌段型聚氨酯、拦枝型聚氨酯、离子型聚氨酯及其它具有良好发展前景的聚氨酯抗凝血材料的研究进展作扼要综述。 相似文献
485.
Dual-phase polymer electrolyte with enhanced phase compatibility based on Poly(MMA-g-PVC)/PMMA 总被引:1,自引:0,他引:1
A new plasticized dual-phase polymer electrolyte (DPE) with enhanced phase compatibility based on Poly(MMA-g-PVC)/PMMA blends has been studied. For the DPE, PMMA is selectively impregnated with the lithium salt solution forming an ion-conducting network, while Poly(MMA-g-PVC) produces good mechanical strength. Their chemical characters, thermal behavior, morphology, ionic conductivity and interfacial compatibility with lithium metal electrode were characterized by using of infrared spectroscopy (IR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), optical microscopic images, alternating current impedance (AC impedance) and linear sweep voltammetry (LSV), respectively. The ionic conductivity of DPE increases with the ratio of PMMA/Poly(MMA-g-PVC) (by weight), and the absorbed liquid electrolyte in the polymer blends plays the first important way in this behavior. Room-temperature ionic conductivity of the order of 10−3 S cm−1 has been achieved for DPE, in addition, the DPE also shows good compatibility with Li electrodes and sufficient electrochemical stability for safe operation in Li batteries. 相似文献
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487.
V. Soria C. M. Gómez P. Rodriguez M. J. Parets A. Campos 《Colloid and polymer science》1994,272(5):497-503
The viscosity behaviour of dilute dimethylformamide solutions of poly(vinylidene fluoride)-poly (methyl methacrylate) and poly(vinylidene fluoride)-polystyrene has been studied at 25°C. The polymer concentration ranges are such that neither phase separation nor microgel formation occurs, although we are very close to theta conditions. The intrinsic viscosity and viscosity interaction parameter of the ternary mixtures have been calculated. The estimation of the compatibility of the above polymer pairs has been studied based on: a) specific viscosities; b) viscosity interaction parameters, according to Krigbaum and Wall formalism, and c) viscosity interaction parameters of a system formed by a dilute probe polymer in the presence of a matrix polymer and a small molecule solvent. 相似文献
488.
M. E. S. Ribeiro E Silva J. Caetano Machado V. Mano G. Goulart Silva 《Journal of Polymer Science.Polymer Physics》2003,41(13):1493-1500
Positron annihilation lifetime spectroscopy and differential scanning calorimetry (DSC) measurements were performed for blends of polyacrylamide (PAM) and poly(ethylene glycol) (PEG) and blends of poly(dimethylacrylamide) (PDMAM) and PEG. The samples were prepared by codissolution in a concentration range of 0–100 wt % PEG. The thermal behavior, characterized by DSC measurements, showed similar variations of the glass‐transition temperatures (Tg's) with the PEG concentration for the two systems. Pure PAM and PDMAM presented Tg's of 188 and 111 °C, respectively. A relatively small and nearly linearly decreasing Tg was observed for the two systems in the range of 20–80 wt % PEG. PEG crystals were present in all blend compositions, and no melting point depression was observed. The thermal results pointed to the partial miscibility of the blends. The degree of crystallinity of PEG increased with increasing PEG concentration for the PDMAM/PEG systems. The ortho‐positronium lifetime (τ3) increased with increasing PEG concentration for both blends. However, the parameter of the ortho‐positronium formation probability (I3) decreased with the PEG concentration. The product τI3, which was proportional to the total free volume fraction, was approximately constant with the PEG concentration for PDMAM blends and increased with the PEG concentration for PAM systems. This result may be interpreted as a consequence of a more heterogeneous structure in PAM blends. Scanning electron microscopy micrographs of blends with 40 and 80 wt % PEG provided evidence of the regions associated with PEG crystallites. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 1493–1500, 2003 相似文献
489.
In this study, heparin was immobilized onto cellulose acetate hollow fibers to improve the anticoagulation performance during hemodialysis. In vitro evaluation was carried out using mini‐hemodialyzer circulating with fresh porcine whole blood to simulate kidney therapy. The dialysis performance and hemocompatibility were estimated. The results showed that heparinized hemodialyzer could be used through out the whole dialysis time (4 hr) without injecting additional heparin to prevent coagulation in the dialysis system. In addition, the hemocompatibility was evaluated by measuring activated partial thromboplastin time (APTT), prothrombin time (PT), and fibrinogen time (FT). The complete blood count (CBC) including red blood cell (RBC), hemoglobin (Hgb), hematocrit (Hct), white blood cell (WBC), and platelet were determined. The results showed that heparinization could keep the CBC stable during dialysis, whereas unmodified cellulose acetate hemodialyzer would cause a decrease in RBC unless heparin was injected during dialysis. Heparinized hemodialyzer showed longer APTT, PT, and FT than unmodified hemodialyzer. Heparinized hemodialyzer also showed slightly higher clearance than unmodified hemodialyzer. These results indicated that the dialysis performance and hemocompatibility of cellulose acetate hemodialyzer could be improved by the immobilization of heparin. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
490.
HaiTaoLI ZhiYUAN XinFuCHEN BinLIU BinSHEN BingLinHE 《中国化学快报》2004,15(4):449-452
Crosslinked macroporous polyacrylamide (PAM) was prepared with inverse phase suspension polymerization technique.After treatment with hydrazine,the polymer was functionalized with chloroacetic acid,trifluoroacetic acid diethylenetriaminepentaacetic acid (DEPAA),and maleic acid,respectively,and PAM based adsorbents beating carboxyl functional groups for low density lipoprotein (LDL) apheresis use were obtained.The blood compatibility and the adsorption properties for plasma lipoproteins of PAM based adsorbents were investigated. 相似文献