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81.
分子印迹技术制备石油有机硫组分固相萃取剂的研究   总被引:2,自引:0,他引:2  
用分子印迹技术合成了对石油有机硫组分二苯并噻吩(Dibenzothiophene,DBT)具有高效选择性的分子模板聚合物(Molecularly Imprinted Polymer,MIP),通过静态吸附的方法研究了不同功能单体和致孔剂及其用量对模板聚合物特异性识别能力的影响.实验表明,以4-乙烯基吡啶(4-VP)为功能单体,在甲苯溶剂中聚合得到的固相萃取剂对DBT具有较大的吸附富集能力和识别特性.其饱和吸附容量达到48.3mg/g.  相似文献   
82.
烟碱分子烙印聚合物的吸附特性   总被引:10,自引:0,他引:10  
刘莺  刘学良  王俊德 《分析化学》2003,31(10):1202-1206
利用分子烙印技术,以烟碱为烙印分子,甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯(EDMA)为交联剂,合成了对烟碱具有特异性作用的分子烙印聚合物P(Nic);通过平衡吸附实验,评价了其对烟碱的亲和力和选择性。与非烙印聚合物相比,P(Nic)对烟碱表现了很高的亲和力;Scatchard分析表明在P(Nic)中存在对烟碱有不同的亲和力的两类作用位点。通过与氨基吡啶类物质在P(Nic)上的吸附行为比较,表明P(Nic)对烟碱具有很好的选择性。本工作证明了用P(Nic)作为固相萃取(SPE)材料选择性地从烟草烟雾中提取烟碱的可能性。  相似文献   
83.
不对称催化是有机化学研究的前沿领域和发展方向.近10年来,手性配体的研究得到了长足的发展,大量的小分子手性配体被报道,其中许多手性配体展示了优异的催化性能.但是由于昂贵的手性配体(金属催化剂)分离、回收和再利用的问题,从而限制了小分子催化剂的应用.因此,解决手性金属催化剂的分离与回收问题是不对称催化研究领域的一个热点问题.为了解决这一关键问题,国内外科学家从负载的角度出发已经成功地发展了众多的研究方法,无机负载法、交联高分子负载法、可溶性高分子负载法、树状大分子负载法等.许多负载的手性金属催化剂已经表现出优异的催化活性和高的对映选择活性.  相似文献   
84.
Copolymers of 2-hydroxyethyl acrylate and 2-methoxyethyl acrylate with variable compositions were synthesized, fractionated, and characterized by 1H-NMR, IR, GPC, and viscometry. These copolymers were further modified via polymer analog esterification of copolymer hydroxy groups by a series of disulfide-containing carboxylic acids including lipoic acid and (n-pentyldithio) alkyl carboxylic acids (n-C5H11SS(CH2)m? COOH, m = 10, 15, 22) in the presence of 1,3-dicyclohexylcarbodiimide (DCC). Esterification reactions were quantitative for copolymers possessing hydroxy monomer contents ≤ 40% when excess acid and DCC were present for sufficiently long reaction times (2–4 days) at room temperature. Copolymer DSC analysis demonstrates a systematic variation of Tg with copolymer composition in good agreement with ideal mixing theory. These disulfide-bearing copolymers spontaneously yield two-dimensional ultrathin polymer films with side chain-dependent layer thicknesses of 20–45 Å by solution adsorption onto freshly deposited gold surfaces. Such ultrathin polymer films are expected to have diverse applications as bound polymeric surface modification reagents. © 1993 John Wiley & Sons, Inc.  相似文献   
85.
Several hydrophilic polymeric thiols were prepared from aminoactivated polymeric supports by reaction with N-acetylhomocysteinethiolactone. Supports include agaroses, cellulose, Glycophase™ controlled-pore glass, and Matrex™ acrylic beads. Thiol content in these polymers was 3–72 μmol SH/g dry polymer. Several were effective solid-phase activators of the sulfhydryl-dependent enzyme creatine phosphokinase at concentrations comparable to that of monomeric thiol required for enzyme activation. The kinetic activation curves for the polymeric and the monomeric (thioglucose) activators were similar, suggesting unhindered interaction of the enzyme with the polymeric activator.  相似文献   
86.
Uniform-sized molecularly imprinted polymer (MIP) beads were prepared using a one-step swelling and polymerization method. The obtained sulfamethazine (SMZ)-imprinted polymer showed high affinity and selectivity toward SMZ and other structurally related sulfonamides in acetonitrile or water-acetonitrile mobile phases, particularly in high aqueous systems. The column performance of the MIPs for SMZ and its analogues could be improved by elevating the column temperature and optimizing the flow rate. The hydrogen-bonding effect plays a significant role in the recognition process of SMZ-imprinted polymer systems in organic media, while the ion-exchange effect, as well as hydrophobic effect, dominates the retention mechanism in aqueous-rich media, in addition to shape recognition.  相似文献   
87.
Thionine ( 1 ) has been covalently bound to linear copoly(styrene-p-vinylbenzyl chloride) and to linear copoly(acrylic acid-2-ethylhexyl acrylate). The resulting polymeric dyes, purified by ultrafiltration, present quantum yields of singlet oxygen generation in dimethylformamide solution lower than their corresponding low-molecular-weight models thionine hydrochloride ( 1.HCl ) and N(3)-acetylthionine ( Ac-1 ), the decrease being more pronounced in the case of the polystyrene-dye photosensitizer. High chromophore concentrations within the volume encompassed by each macromolecule in the solution can explain this fall in efficiency. The free dyes thionine hydrochloride and its hydrolysis products thionoline ( 2 ) and thionol ( 3 ) behave as good singlet oxygen generators, with quantum yields of 0.71, 0.62, and 0.63, respectively. © 1993 John Wiley & Sons, Inc.  相似文献   
88.
In this paper,zinc acetate,manganese acetate and thiacetamide are used as raw materials to successfully synthesize monodispersed ZnS:Mn2+ microspheres by using hydrothermal method and taking P123 surfactant as a template. The products were characterized by XRD,STEM,FT-IR and N2 adsorption-desorption. And the results show that the diameter of this microsphere is 1.0 μm or so,which is larger than that of ZnS microsphere without Mn2+ doping,and it has monodispersion,smooth surface and uniform size. The doping of Mn2+ does not obviously change the structure of monodispersed ZnS microsphere. The photoluminescence peak lies in a wide band ranging from 450 to 650 nm,and the microspheres emit orange light; with the increase of Mn2+ concentration,fluorescence intensity of ZnS:Mn2+ microsphere changes,and when the mole ratio of Mn2+:Zn2+ is 0.3:1,the fluorescence intensity is the strongest.  相似文献   
89.
Radiation formation of polymeric nanogels   总被引:4,自引:0,他引:4  
An alternative method of synthesis of polymeric nanogels is proposed, based not on polymerization, but on intramolecular crosslinking of polymer chains, initiated by pulse irradiation in dilute aqueous solutions. Kinetic data show that for many water-soluble polymers irradiation under these conditions result in intramolecular crosslinking. Preliminary product studies on poly(vinyl alcohol) indicate that in fact internally crosslinked macromolecules can be obtained by this technique.  相似文献   
90.
表面图案化磁性复合微球的原位制备与表征   总被引:2,自引:0,他引:2  
王公正  夏慧芸  张颖  彭世杰 《化学学报》2007,65(18):2051-2056
采用反相悬浮聚合法合成了丙烯酸(AA)含量不同的N-异丙基丙烯酰胺-丙烯酸共聚物P(NIPAM-co-AA)微凝胶, 并以其作为微反应器, 通过原位外源沉积法制备了一系列微米级、表面具有图案化结构的SiO2-Fe3O4-P(NIPAM-co-AA)磁性复合微球. 实验结果表明, 复合微球的表面结构与微凝胶的组成、Fe3O4和SiO2的沉积量有关. 在微球表面进行修饰, 可得到表面带有氨基等官能基团的磁性复合材料. 将这种功能化磁性微球用于识别生物大分子并进一步用于生物医学领域具有重要的意义.  相似文献   
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