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61.
本文研究了丙烯酸酯共聚物载体对驱蚊剂N,N-二乙基间甲苯酰胺(DETA)慢释放行为的控制,探讨了单体配比、共聚物分子量以及DETA含量对释放速率的影响。结果表明。增加亲水性单体丙烯酸(AA),可提高DETA的释放速率;降低共聚物数均分子量,会减少DETA的释放量;剂型中DETA含量与释放量存在线性正比关系,但DETA的含量增加并不导致释放有效时间的线性增加。本文还就共聚物膜的透湿性和碱溶性作了研究,亲水性单体AA的增加同样导致透湿性和碱溶性的增加。制备的聚合物驱蚊剂经现场应用试验,表明具有良好的长效驱蚊特性。 相似文献
62.
淀粉接枝丙烯酸乙酯及其增容性 总被引:5,自引:0,他引:5
研究了在挤出机中采用高温和剪切力的作用直接引发淀粉与丙烯酸乙酯的接枝共聚合反应.讨论了反应条件对接枝反应的影响,研究了接枝物在淀粉与聚乙烯共混物中的增容作用.实验结果表明,高温和剪切力可以引发淀粉与丙烯酸乙酯的接枝共聚合反应.接枝物作为增容剂,可以明显地改善淀粉与聚乙烯共混物的力学性能和流变性能. 相似文献
63.
The copolymerization of styrene (St) with maleic anhydride (MAh) performed at 22 °C in the presence of dibenzyl trithiocarbonate exhibits controlled nature evidenced by: narrow molecular weight distribution, controlled molecular weight and first-order polymerization kinetics. The composition analysis of the copolymers obtained by 13C NMR spectra shows the molar fraction of St in obtained copolymers is almost equal to 0.5 throughout the copolymerization. The sequence structure of the copolymer was obtained from DEPT experiments by recording the spectra at π/4 and 3π/4, and then combining them together, the results showed that the copolymers obtained possessed well-defined alternating structure. The experiment shows that charge-transfer-complex formed from St and MAh participates in both initiation and chain growth throughout the copolymerization. 相似文献
64.
以聚丙烯微孔膜为基材,通过扩散控制原位共聚合的方法在人填充了组成沿膜的厚度方向逐渐改变的无规共聚物,X-光电子能谱(XPS)、全反射红外光谱(ATR)以及动态粘弹谱的分析结果。说明所制备得到的合膜具有明显的渐变聚合物性质。 相似文献
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67.
Kyoko Nozaki 《Journal of polymer science. Part A, Polymer chemistry》2004,42(2):215-221
Two examples of asymmetric alternating copolymerization, (1) the alternating copolymerization of α‐olefins (monosubstituted ethenes) with carbon monoxide and (2) the alternating copolymerization of meso‐epoxide with carbon dioxide, are described, and the meaning of chirality in polymer synthesis is emphasized. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 215–221, 2004 相似文献
68.
研究了丙烯腈/苯乙烯(AN/St)悬浮共聚体系中AN在水/油两相间的分配及其对AN/St共聚物组成的影响.结果表明,AN分配于水/油两相间,使油相AN的含量低于相同单体配料比的本体聚合,导致生成的AN/St共聚物组成偏离本体共聚.为了准确预测进而控制AN/St悬浮共聚物的组成,提出了在考虑AN相分配的基础上计算AN/St悬浮共聚物组成的模型.计算结果与实验值一致,计算中用到的油相实际竞聚率与本体聚合相同,但该悬浮聚合的表观竞聚率随水/油比的变化而发生较大改变. 相似文献
69.
Jin Ho Lee Heoung Woo Kim Pyong Ki Pak Hai Bang Lee 《Journal of polymer science. Part A, Polymer chemistry》1994,32(8):1569-1579
Functional group gradient surfaces where the density of functional groups changes gradually along the sample length were prepared. The functional group (? COOH, ? CONH2, and ? OH group) gradient surfaces were produced by the treatment of low-density PE sheets using a corona with gradually increasing power, followed by the graft copolymerization of acrylic acid and subsequent substitution reaction of carboxylic acid groups to amide or hydroxyl groups. The prepared gradient surfaces were characterized by the measurement of water contact angle, FTIR-ATR, and ESCA. The gradient surfaces prepared can be used to systematically investigate the interactions of biological or other species in terms of the surface functional groups and their density of polymeric materials. © 1994 John Wiley & Sons, Inc. 相似文献
70.
H. A. S. Schoonbrood M. A. T. Van Den Boom A. L. German J. Hutovic 《Journal of polymer science. Part A, Polymer chemistry》1994,32(12):2311-2325
Simple equations describing monomer partitioning in latices during intervals 2 and 3 in emulsion polymerization with any number of low to moderately water soluble monomers were derived from the extended Morton equation by making various assumptions. It appears that it is mainly the combinatorial entropy of mixing that governs the partitioning behavior, and that other contributions to the free energy of the monomers in the polymer particles are marginal. Experimental results with styrene, methyl methacrylate, and methyl acrylate confirm the validity of the assumptions. In interval 3 of emulsion polymerization the sum of all contributions to the free energy of the monomers in the particles other than the combinatorial entropy of mixing can be taken as a constant that is dependent only on the monomer composition in the particles and independent of the degree of swelling of the particles. The only parameters one needs to know to calculate the monomer concentrations in all phases with help of the derived equations, are the saturation concentrations of each monomer in the polymer particles, and the saturation concentrations of each monomer in the aqueous phase. © 1994 John Wiley & Sons, Inc. 相似文献