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101.
Dr. Jan Schwabedissen Pia C. Trapp Dr. Hans-Georg Stammler Prof. Dr. Norbert W. Mitzel Zhuang Wu Xianxu Chu Prof. Dr. Xiaoqing Zeng 《ChemistryOpen》2020,9(9):913-920
Difluorothiophosphoryl isocyanate, F2P(S)NCO was characterized with UV/vis, NMR, IR (gas and Ar-matrix), and Raman (liquid) spectroscopy. Its molecular structure was also established by means of gas electron diffraction (GED) and single crystal X-ray diffraction (XRD) in the gas phase and solid state, respectively. The analysis of the spectroscopic data and molecular structures is complemented by extensive quantum-chemical calculations. Theoretically, the Cs symmetric syn-conformer is predicted to be the most stable conformation. Rotation about the P−N bond requires about 9 kJ mol−1 and the predicted existence of an anti-conformer is dependent on the quantum-chemical method used. This syn-orientation of the isocyanate group is the only one found in the gas phase and contained likewise in the crystal. The overall molecular structure is very similar in gas and solid, despite in the solid state the molecules arrange through intramolecular O⋅⋅⋅F contacts into layers, which are further interconnected by S⋅⋅⋅N, S⋅⋅⋅C and C⋅⋅⋅F contacts. Additionally, the photodecomposition of F2P(S)NCO to form CO, F2P(S)N, and F2PNCO is observed in the solid Ar-matrix. 相似文献
102.
Antibody drug conjugates are cytotoxic pharmaceuticals, designed to destroy malignant cells. A cytotoxic molecule is attached to an antibody that binds specific to a cancer‐cell surface. Given the high toxicity of the drugs, strict safety standards have to be kept. For this reason, an antibody drug conjugates model was developed with fluorescein 5‐isothiocyanate as the nontoxic payload surrogate. Due to the similar hydrophobicity, this model is used to establish a suitable purification process and characterization method for antibody drug conjugates. Because of the pH dependent solubility of fluorescein, the hydrophobicity of conjugates can be modulated by the pH value. Based on the complex heterogeneity and hydrophobicity of the conjugates a chromatographic purification is challenging. Hydrophobic interaction chromatography is used for analytical as well as for preparative separation. Because of the increased hydrophobicity of the conjugates compared to native antibody, hydrophobic interaction chromatography often suffer from resolution and recovery problems. Conjugates were separated differing on the number of payloads attached to the antibody. For this matter, the drug–antibody ratio is determined and used as a quantitative term. The conjugates are purified at high recoveries and resolution by step gradients using suitable resins, allowing the separation of the target drug–antibody ratio. 相似文献
103.
Keisuke Kurita Shin-Ichi Watabe Shin-Ichiro Nishimura Shigeru Ishii 《Journal of polymer science. Part A, Polymer chemistry》1996,34(3):429-438
Linear polybiurets have been synthesized by polyaddition of benzyloxyamine and diisocyanates, and properties of the novel polymeric materials have been elucidated. Prior to polymerization, model reactions between benzyloxyamine and phenyl isocyanate were examined in detail and proved to be controlled by the molar ratio of reagents and by catalysts to give the urea (1:1 adduct) and/or biuret (1:2 adduct). Under appropriate conditions, the biuret was synthesized in a quantitative yield. Polymerization of equimolar amounts of benzyloxyamine and diphenylmethane or hexamethylene diisocyanate proceeded smoothly to give polybiurets with inherent viscosities up to 0.52 dL/g. The benzyl group of the model biuret and polybiuret could be removed by catalytic hydrogenation. Both the N-benzyloxy-type and N-hydroxy-type polybiurets showed excellent solubility in common organic solvents. The two kinds of polybiurets as well as model biurets adsorbed metal cations efficiently. The N-hydroxybiuret structure exhibited particularly high affinity for iron(III) and was useful for selective removal of iron from metal cation mixtures. © 1996 John Wiley & Sons, Inc. 相似文献
104.
顶空固相微萃取-气相色谱-质谱法测定废水中痕量挥发性烷基硫化物 总被引:3,自引:0,他引:3
建立了顶空固相微萃取(HS-SPME)和气相色谱/质谱(GC/MS)联用测定人工湿地废水中的痕量挥发性烷基硫化物的方法。针对废水中两种主要的挥发性烷基硫化物(二甲基硫、二甲基二硫),详细研究了萃取纤维头的种类、萃取时间、萃取温度、pH值、离子强度、样品量及解析条件对HS-SPME的影响。载气为高纯氦气,流速为1.0mL/min,色谱柱为DB-5ms毛细管柱(0.25μm,30m×0.32mm),柱温:25℃(5min)■40℃(1min)■60℃(5min);在优化的实验条件下,本法测定二甲基硫及二甲基二硫的线性范围分别为10~10000ng/L和1~10000ng/L;检出限(3σ)分别为1.9ng/L和1.8ng/L;相对标准偏差小于10%;回收率分别为81.0%~94.6%和84.0%~100.9%。用二乙基硫为内标物质,将本法用于人工湿地废水中主要的烷基硫化物二甲基硫和二甲基二硫的测定,获得满意结果。 相似文献
105.
Adiabatic calorimetry is a suitable method for investigations of reactions because the generated heat remains completely in the reactor. For the investigation of organic reactions, the adiabatic precision calorimeter ACTRON 5 is used. The alcoholyses of phenyl isocyanate and 1,2-butyleneoxide were investigated. The temperature-time course was estimated by means of the nonlinear program TA-kin. Inclusion of the concentration-time course in the estimation procedure led to an increase in the reliability of the parameters. Probes were taken during isoperibolic measurements and were analysed by means of HPLC. 相似文献
106.
107.
108.
109.
烷基芳基磺酸钠对烷烃的乳化性能 总被引:3,自引:2,他引:3
采用分水时间法考察了结构明确的高纯度烷基芳基磺酸钠在烷烃中的乳化现象。 以液态石蜡为油相,讨论了乳化剂浓度对乳状液稳定性的影响,确定了最适宜的乳化剂浓度,并研究了烷基链长度、芳基结构和芳基在烷基链位置对形成的乳状液稳定性的影响关系,考察了不同油相对乳状液稳定性的影响。 结果表明,最适宜的乳化剂质量分数为0.1%;当固定芳基结构时,随着烷基链上碳数的增加,乳状液稳定性线性增强;当固定烷基链碳数时,随着芳基上碳原子的增加,乳状液稳定性增强;随着芳基位置向烷基链中间位置移动,乳状液稳定性增强;随着油相分子量的增加,能形成稳定乳状液所需的乳化剂的分子量随之递增。 相似文献
110.
Susruta Majumdar 《合成通讯》2013,43(23):3537-3548
We report a novel synthesis of N‐alkyl‐N‐alkyloxycarbonylaminomethyl (NANAOCAM) prodrugs of acetaminophen, theophylline, and 6‐mercaptopurine by alkylation of the corresponding drug molecule with N‐alkyl‐N‐alkyloxycarbonylaminomethyl chlorides in good yield. Most of the alkylating agents were efficiently synthesized by chloromethylation of N‐alkyl carbamic acid alkyl esters, which in turn were made from alkyl amines and alkyl chloroformates. In cases where the alkyl chloroformates were not available, synthesis of N‐alkyl carbamic acid alkyl esters was accomplished by converting an alcohol to a chloroformate or to an activated acylating agent such as acyl imidazoles or p‐nitrophenylcarbonate esters, followed by their reaction with alkyl amines. 相似文献