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91.
以聚乙二醇为模板剂制备MoS2空心微球 总被引:1,自引:0,他引:1
以聚乙二醇(PEG)为模板剂, 采用软模板法制备出MoS2空心微球, 并采用X射线衍射仪(XRD)、红外光谱仪(IR)和扫描电子显微镜(SEM)对产物进行表征. 结果表明, 所制备的MoS2为粒径约2-7 μm的空心微球, 但结晶程度较差, 需通过退火工艺进行改善; 聚乙二醇与MoS2发生了较为强烈的有机-无机杂化作用, 其浓度和分子量对产物形貌调控均有重要影响. 同时, 结合红外光谱分析, 对MoS2空心微球的形成机理进行了初步的探讨. 相似文献
92.
将胶体晶体阵列(crystalline colloidal arrays,CCA)的Bragg衍射特性与水凝胶的刺激响应性功能结合起来,可制成一种有效的对特定分子具有识别和响应能力的传感材料.采用无皂乳液聚合制备的单分散聚(苯乙烯-4-苯乙烯磺酸钠)纳米颗粒,通过表面电荷的静电斥力可自组装形成CCA,经光聚合固定在水凝胶网络内形成聚合胶体晶阵(polymerized CCA).在水凝胶网络中用共价结合引入生物素分子,通过强的亲和相互作用可与蛋白质亲和素生成生物素-亲和素复合物,在水凝胶网络中形成交联点,引起水凝胶体积相变,进而导致CCA晶面间距发生改变,从而引发Bragg衍射波长发生相应的移动. 相似文献
93.
94.
通过CO2激光器熔融不同直径的熔锥光纤以得到相应直径的石英玻璃微球,利用此微球和熔锥光纤,构造了球微腔耦合系统。实验中利用光腰直径为3.1μm的熔锥光纤与直径为143.1μm的石英玻璃微球进行耦合,通过最大分辨力为1pm的可调谐半导体激光器对该耦合系统进行光谱扫描,发现石英玻璃微球的吸收光谱中出现分立的结构共振峰。利用光学微球腔理论讨论了石英玻璃微球吸收光谱中的结构共振,并用米氏散射理论公式对一阶TE模共振峰的位置以及它们的间隔进行了计算,共振峰位置实验结果与理论结果的误差仅为0.03%,表明实验与计算结果相符。 相似文献
95.
Xueyu Qiu Yadong Han Xiuli Zhuang Xuesi Chen Yuesheng Li Xiabin Jing 《Journal of nanoparticle research》2007,9(5):901-908
Nano-hydroxyapatite (HA)/poly(l-lactide) (PLLA) composite microspheres with relatively uniform size distribution were prepared by a solid-in-oil-in-water
(s/o/w) emusion solvent evaporation method. The encapsulation of the HA nanopaticles in microshperes was significantly improved
by grafting PLLA on the surface of the HA nanoparticles (p-HA) during emulsion process. This procedure gave a possibility
to obtain p-HA/PLLA composite microspheres with uniform morphology and the encapsulated p-HA nanoparticle loading reached
up to 40 wt% (33 wt% of pure HA) in the p-HA/PLLA composite microspheres. The microstructure of composite microspheres from
core-shell to single phase changed with the variation of p-HA to PLLA ratios. p-HA/PLLA composite microspheres with the diameter
range of 2–3 μm were obtained. The entrapment efficiency of p-HA in microspheres could high up to 90 wt% and that of HA was
only 13 wt%. Surface and bulk characterizations of the composite microspheres were performed by measurements such as wide
angle X-ray diffraction (WAXD), thermal gravimetric analysis (TGA), environmental scanning electron microscope (ESEM) and
transmission electron microscopy (TEM). 相似文献
96.
97.
Ting-Hao Chung 《Journal of magnetism and magnetic materials》2009,321(10):1635-1638
Surface-functionalized magnetic poly(styrene-glycidyl methacrylate) (PS-GMA) microspheres were prepared and coupled with Sca-1 antibody for cell selection from murine bone marrow mononuclear cells (MNCs). Biotinylated Sca-1 antibody could be directly coupled to avidin-bound magnetic microspheres. Alternatively, oxidized goat anti-mouse antibody was covalently bound onto the amino group-containing magnetic microspheres in a site-directed manner, and the resultant conjugate was coupled with non-modified Sca-1 antibody. Using the indirect antibody-bound magnetic microspheres, the purity of isolated Sca-1+ cells increased with bead-to-cell ratio. Using a bead-to-cell ratio of 10 beads/cell, a purity of 85% Sca-1+ cells corresponding to a 17-fold enrichment was achieved. 相似文献
98.
Tae Hoon Kim 《Molecular Crystals and Liquid Crystals》2017,652(1):230-241
Reduction-responsive cystamine-incorporated gelatin microspheres were prepared by an emulsification method. On SEM micrograph, the microsphere, prepared at pH 9.0 and at the carboxyl/amino group molar ratio of 1:1, was sphere-like and its diameter was a few to 100 µm. The gelatin to cystamine ratio of the microsphere was about 1:0.2 (w/w), determined by energy dispersive X-ray spectroscopy. Two endothermic peaks were observed around 92°C and 126°C, which were thought to be the melting point of gelatin-rich phase and that of cystamine-rich phase, respectively. The microsphere released its payload (FITC-dextran) in dithiothreitol (a reducing agent) concentration-dependent manner. 相似文献
99.
Nuttapol Risangud Thomas R. Congdon Daniel J. Keddie Paul Wilson Kristian Kempe David M. Haddleton 《Journal of polymer science. Part A, Polymer chemistry》2016,54(17):2698-2705
The synthesis of two types of isocyanate side chain containing copolymers, poly(methyl methacrylate‐co‐isocyanatoethyl methacrylate) (P(MMA‐co‐IEM)) and poly(benzyl methacrylate‐co‐isocyanatoethyl methacrylate) (P(BnMA‐co‐IEM)), which were synthesized by Cu(0)‐mediated radical polymerization, is reported. Polymerization proceeded to high conversion giving polymers of relatively narrow molar mass distributions. The incorporation of the bulky aromatic groups in the latter copolymer rendered it sufficiently stable toward hydrolysis and enabled the isolation of the product and its characterization by 1H and 13C NMR, and FTIR spectroscopy and SEC. Both P(MMA‐co‐IEM) and P(BnMA‐co‐IEM) were functionalized with dibutylamine, octylamine, and (R)‐(+)‐α‐methylbenzyl‐amine, which further proved the successful incorporation of the isocyanate groups. Furthermore, P(BnMA‐co‐IEM) was used for the fabrication of liquid core microcapsules via oil‐in‐water interfacial polymerization with diethylenetriamine as crosslinker. The particles obtained were in the size range of 10–90 µm in diameter independent of the composition of copolymer. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 2698–2705 相似文献
100.
Superabsorbent polymers (SAPs) and composites (SAPCs) were prepared entirely by graft copolymerization of polyacrylamide (PAM) onto hydroxyethyl cellulose (HEC), using potassium persulfate (KPS) as an initiator, and N,N′-methylenebisacrylamide (MBA) as a crosslinker, in an aqueous solution. The extent of grafting was evaluated from % grafting efficiency (%GE) for various HEC/AM ratios, and a near optimal ratio was determined. Influences of various preparation parameters, i.e., the ratio of HEC/AM, amount of initiator and crosslinker, reaction temperature and time, and amount of filler on water swelling capacity of SAPs and SAPCs were studied. An FT-IR determination confirmed that the PAM was successfully grafted onto the HEC backbone, by showing absorption bands of the HEC backbone and new absorption bands from the grafted copolymer. The swelling capacity of SAPs and SAPCs depended strongly on different parameters, and the maximum swelling capacity was over 426 g/g and 538 g/g for the SAPs and SAPCs, respectively. 相似文献