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81.
采用Bingel-Hirsch反应合成了胆固醇修饰的富勒烯(CHL-C60), 通过核磁共振(NMR)、质谱(MS)、元素分析对CHL-C60的化学结构进行了表征. γ-环糊精(γ-CD)对甾环具有较强的包结能力, 能够与CHL-C60形成包结复合物(CHL-C60/γ-CD), 从而有效提高CHL-C60的水溶性. 紫外-可见吸收光谱和荧光光谱研究结果表明, CHL-C60能够从γ-CD的疏水空腔中解离出来, 与人血清白蛋白(HSA)及牛血清白蛋白(BSA)形成稳定的复合体, 其结合常数分别为5.73×104和7.05×104 L·moL-1. 无氧条件下, CHL-C60/γ-CD通过光诱导电子转移作用断裂pBR322质粒脱氧核糖核酸(DNA), 其效率可达60.5%. 相似文献
82.
采用荧光光谱法对β-环糊精(β-CD)与柔红霉素(DNR)包结物溶液进行表征。研究了β-CD与DNR之间的超分子包结作用机理,讨论了时间、温度和β-CD浓度对包结反应的影响,建立了新的定量检测微量DNR的方法。研究结果表明,DNR本身具有天然荧光,与β-CD形成1:1的超分子包结络合物后,荧光强度增大,β-CD对DNR有较强的荧光增敏作用。在25℃,pH7.0时,包结常数K=1.26×106L/mol。β-CD增敏荧光定量测定DNR的线性回归方程为y=1.78×107x+312.76,相关系数为r=0.9953,检测下限为3.77×10-6mol/L。 相似文献
83.
Cécile Machut-Binkowski Frédéric Hapiot Roméo Cecchelli Patrick Martin Eric Monflier 《Journal of inclusion phenomena and macrocyclic chemistry》2007,57(1-4):567-572
For many commercial drugs, reaching the central nervous system in large amount without damaging the blood-brain-barrier (BBB)
remains a challenging task. We present here a supramolecular strategy aiming at using a well-defined cyclodextrin-coated liposomes
as drug carrier and adamantoyl saccharides as BBB-interacting ligands. In this study, the liposome is constituted of n-alkyldimethylammoniumcyclodextrins incorporated in the lipid bilayer of a 3/7 cholesterol/dipalmitoylphosphatidylcholine
mixture and the ligand is constituted of an adamantoylglucose molecule whose adamantoyl moiety can be included in the CD cavity.
The whole supramolecular assembly has been characterized by light-scattering and 31P NMR measurements. Toxicity and permeability studies on an in vitro model of the BBB clearly demonstrated a 5-fold improved
ability of the modified liposome to enter the BBB-endothelial cells compared to the non-coated liposome. Fluorescence labelling
of these liposomes is also displayed with DiI as a fluorescent probe. 相似文献
84.
W. A. Knig S. Lutz M. Hagen R. Krebber G. Wenz K. Baldenius J. Ehlers H. Tom Dieck 《Journal of separation science》1989,12(1):35-39
O-Perpentylated β-cyclodextrin has been evaluated as chiral stationary phase in capillary gas chromatography. Enantioselectivity is observed towards many chiral hydroxy compounds, including cyanohydrins and carbohydrates. Most importantly, the enantiomers of many olefins and alkyl halides can be resolved on this chiral phase. The thermal stability of the cyclodextrin derivative exceeds 200°C. 相似文献
85.
Makoto Fukudome 《Tetrahedron letters》2005,46(7):1115-1118
3A-Azido-3A-deoxy-altro-β-cyclodextrin, although having as many as 20 different hydroxyl groups, was selectively sulfonylated at the 2A-OH of the altrose residue by 2-mesitylenesulfonyl chloride to give 3A-azido-3A-deoxy-2A-O-mesitylenesulfonyl-altro-β-cyclodextrin. A one-pot reduction-intramolecular substitution of the latter afforded the title compound as a promising intermediate for the introduction of two different functional groups to two different positions of one sugar unit, which has not been succeeded hitherto. 相似文献
86.
利用α-环糊精(α-CD)与含有聚乙二醇(PEG)链段的聚合物Pluronic F127的超分子作用制备水凝胶.该物理交联水凝胶的交联点包括α-CD与PEG链包合物堆积形成的微晶区和聚合物疏水链段聚集区.优化水凝胶组分,得到具有较低固含量和较短凝胶化时间的体系用于胰岛素的负载和释放研究.通过X射线衍射(XRD),扫描显微镜(SEM)对水凝胶结构进行表征.通过紫外分光光度计监测胰岛素的释放过程,结果表明,水凝胶释药时间约为65 h,且释放曲线较为平缓.细胞毒性实验结果表明该水凝胶材料对细胞生长无明显抑制作用.小鼠体内释药实验结果表明该水凝胶载体对延长胰岛素的释药时间有一定效果,可作为多肽类药物的缓释体系. 相似文献
87.
88.
89.
Reynaldo Villalonga Paula Diez María Gamella Julio Reviejo José M. Pingarrón 《Electroanalysis》2011,23(8):1790-1796
A novel approach for the noncovalent functionalization of single‐walled carbon nanotubes with enzymes, using a β‐cyclodextrin‐modified pyrene derivative, mono‐6‐ethylenediamino‐(2‐pyrene carboxamido)‐6‐deoxy‐β‐cyclodextrin (Pyr‐βCD), as a molecular bridge for the construction of a supramolecular assembly between the nanotube surface and an adamantane‐modified enzyme, is reported. The Pyr‐βCD derivative was synthesized and its stacking to SWNT through π–π interactions accomplished. The functionalized nanotubes showed low capacity for the nonspecific adsorption of proteins, but were able to immobilize adamantane‐modified xanthine oxidase via host‐guest associations. This double supramolecular junctions‐based approach was employed to modify a glassy carbon electrode with the enzyme/nanotubes complex for designing a biosensor device toward xanthine. The biosensor showed fast electroanalytical response (10 s), high sensitivity (5.9 mA/M cm2) low detection limit (2 µM) and high stability. 相似文献
90.
Holm R Schönbeck C Askjær S Jensen H Westh P Østergaard J 《Journal of separation science》2011,34(22):3221-3230
The interaction of the bile salts taurocholate, taurodeoxycholate, taurochenodeoxycholate, glycocholate, glycodeoxycholate, and glycochenodeoxycholate present in man, dog, and rat with α-cyclodextrin and 2-hydroxypropyl-α-cyclodextrin was investigated by mobility shift affinity capillary electrophoresis. The cyclodextrins are applied as excipients for solubilisation of drug substances with poor aqueous solubility. Accurate determination of stability constants is challenging for weak analyte-ligand interactions such as the conjugated bile salt α-cyclodextrin interactions. A new approach for correction of medium effects due to the high additive concentrations in the background electrolyte was introduced. The use of prostaglandin A(1) as an interacting marker molecule offered a more satisfactory approach for correction than the commonly employed methods based on viscosity or current ratios. The interacting marker was chosen over a non-interacting marker to avoid the difficult validation of the non-interacting properties. The investigated bile salts all interacted with α-cyclodextrin and 2-hydroxypropyl-α-cyclodextrin. Stability constants ranging from 14 to 95 M(-1) were obtained with slightly higher affinities toward the substituted cyclodextrin. Molecular modelling demonstrated that the interaction between the two species involves the side chain of the bile salt. All together, these results indicate minor bile salt-mediated displacement of substances from α-cyclodextrin complexes in the small intestine. 相似文献