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991.
Pumping through Porous Hydrophobic/Oleophilic Materials: An Alternative Technology for Oil Spill Remediation
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Jin Ge Yin‐Dong Ye Hong‐Bin Yao Xi Zhu Xu Wang Liang Wu Jin‐Long Wang Prof. Hang Ding Prof. Ni Yong Prof. Ling‐Hui He Prof. Dr. Shu‐Hong Yu 《Angewandte Chemie (International ed. in English)》2014,53(14):3612-3616
Recently, porous hydrophobic/oleophilic materials (PHOMs) have been shown to be the most promising candidates for cleaning up oil spills; however, due to their limited absorption capacity, a large quantity of PHOMs would be consumed in oil spill remediation, causing serious economic problems. In addition, the complicated and time‐consuming process of oil recovery from these sorbents is also an obstacle to their practical application. To solve the above problems, we apply external pumping on PHOMs to realize the continuous collection of oil spills in situ from the water surface with high speed and efficiency. Based on this novel design, oil/water separation and oil collection can be simultaneously achieved in the remediation of oil spills, and the oil sorption capacity is no longer limited to the volume and weight of the sorption material. This novel external pumping technique may bring PHOMs a step closer to practical application in oil spill remediation. 相似文献
992.
993.
Highly Luminescent N‐Doped Carbon Quantum Dots as an Effective Multifunctional Fluorescence Sensing Platform
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Dr. Zhaosheng Qian Juanjuan Ma Xiaoyue Shan Dr. Hui Feng Prof. Linxiang Shao Prof. Jianrong Chen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(8):2254-2263
The doping of carbon quantum dots with nitrogen provides a promising direction to improve fluorescence performance and broaden their applications in sensing systems. Herein we report a one‐pot solvothermal synthesis of N‐doped carbon quantum dots (NCQDs) and the synthesis of a series of NCQDs with different nitrogen contents. The as‐prepared NCQDs were compared with carbon quantum dots (CQDs); the introduction of nitrogen atoms largely increased the quantum yield of NCQDs and highest emission efficiency is up to 36.3 %. The fluorescence enhancement may originate from more polyaromatic structures induced by incorporated nitrogen atoms and protonation of nitrogen atoms on dots. It was found that NCQDs can act as a multifunctional fluorescence sensing platform because they can be used to detect pH values, AgI, and FeIII in aqueous solution. The fluorescence intensity of NCQDs is inversely proportional to pH values across a broad range from 5.0 to 13.5, which indicates that NCQDs can be devised as an effective pH indicator. Selective detection of AgI and FeIII was achieved based on their distinctive fluorescence influence because AgI can significantly enhance the fluorescence whereas FeIII can greatly quench the fluorescence. The quantitative determination of AgI can be accomplished with NCQDs by using the linear relationship between fluorescence intensity of NCQDs and concentration of AgI. The sensitive detection of H2O2 was developed by taking advantage of the distinct quenching ability of FeIII and FeII toward the fluorescence of NCQDs. Cellular toxicity test showed NCQDs still retain low toxicity to cells despite the introduction of a great deal of nitrogen atoms. Moreover, bioimaging experiments demonstrated that NCQDs have stronger resistance to photobleaching than CQDs and more excellent fluorescence labeling performance. 相似文献
994.
Chemical and Toxicological Investigations of a Previously Unknown Poisonous European Mushroom Tricholoma terreum
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Xia Yin Dr. Tao Feng Prof. Jian‐Hua Shang Yun‐Li Zhao Fang Wang Zheng‐Hui Li Ze‐Jun Dong Prof. Dr. Xiao‐Dong Luo Prof. Dr. Ji‐Kai Liu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(23):7001-7009
The established tradition of consuming and marketing wild mushrooms has focused attention on mycotoxicity, which has become a global issue. In the present study, we describe the toxins found in a previously unknown poisonous European mushroom Tricholoma terreum. Fifteen new triterpenoids terreolides A–F ( 1 – 6 ) and saponaceolides H–P ( 8 – 16 ) were isolated from the fruiting bodies of the toxic mushroom T. terreum. Terreolides A–C ( 1 – 3 ) possessed a unique 5/6/7 trioxaspiroketal system, whereas terreolides D–F ( 4 – 6 ) possessed an unprecedented carbon skeleton. Two abundant compounds in the mushroom, saponaceolide B ( 7 ) and saponaceolide M ( 13 ), displayed acute toxicity, with LD50 values of 88.3 and 63.7 mg kg?1 when administered orally in mice. Both compounds were found to increase serum creatine kinase levels in mice, indicating that T. terreum may be the cause of mushroom poisoning ultimately leading to rhabdomyolysis. 相似文献
995.
Phosphine‐Catalyzed [3+2] Cycloaddition Reactions of Azomethine Imines with Electron‐Deficient Alkenes: A Facile Access to Dinitrogen‐Fused Heterocycles
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Zhen Li Hao Yu Honglei Liu Lei Zhang Hui Jiang Bo Wang Prof. Dr. Hongchao Guo 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(6):1731-1736
An efficient method for the phosphine‐catalyzed [3+2] cycloaddition reaction of azomethine imines with diphenylsulfonyl alkenes to give dinitrogen‐fused bi‐ or tricyclic heterocyclic compounds in high yields has been described. Moreover, two phenylsulfonyl groups installed on the heterocyclic products could be conveniently removed or transformed to other functional groups, making the reaction more useful. 相似文献
996.
Rationally Investigating the Influence of T1 Location on Electroluminescence Performance of Aryl Amine Modified Phosphine Oxide Materials
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Chunmiao Han Liping Zhu Jing Li Fangchao Zhao Dr. Hui Xu Prof. Dongge Ma Prof. Pengfei Yan 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(49):16350-16359
The correspondence between triplet location effect and host‐localized triplet–triplet annihilation and triplet–polaron quenching effects was performed on the basis of a series of naphthyldiphenylamine (DPNA)‐modified phosphine oxide hosts. The number and ratio of DPNA and diphenylphosphine oxide was adjusted to afford symmetrical and unsymmetrical molecular structures and different electronic environments. As designed, the first triplet (T1) states were successfully localized on the specific DPNA chromophores. Owing to the meso‐ and multi‐insulating linkages, identical optical properties and comparable electrical performance was observed, including the same first singlet (S1) and T1 energy levels to support the similar singlet and triplet energy transfer and the close frontier molecular orbital energy levels. This established the basis of rational investigation on T1 location effect without interference from other optoelectronic factors. 相似文献
997.
A New Class of Tunable Dendritic Diphosphine Ligands: Synthesis and Applications in the Ru‐Catalyzed Asymmetric Hydrogenation of Functionalized Ketones
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Dr. Baode Ma Tingting Miao Yihua Sun Yanmei He Dr. Ji Liu Dr. Yu Feng Prof. Dr. Hui Chen Prof. Dr. Qing‐Hua Fan 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(32):9969-9978
A series of tunable G0–G3 dendritic 2,2′‐bis(diphenylphosphino)‐1,1′‐binaphthyl (BINAP) ligands was prepared by attaching polyaryl ether dendrons onto the four phenyl rings on the P atoms. Their ruthenium complexes were employed in the asymmetric hydrogenation of β‐ketoesters, α‐ketoesters, and α‐ketoamides to reveal the effects of dendron size on the catalytic properties. The second‐ and third‐generation catalysts exhibited excellent enantioselectivities, which are remarkably higher than those obtained from the small molecular catalysts and the first‐generation catalyst. Molecular modeling indicates that the incorporation of bulky dendritic wedges can influence the steric environments around the metal center. In addition, the ruthenium catalyst bearing a second‐generation dendritic ligand could be recycled and reused seven times without any obvious decrease in enantioselectivity. 相似文献
998.
Highly Enantioselective Catalytic System for Asymmetric Copolymerization of Carbon Dioxide and Cyclohexene Oxide
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Yuan‐Zhao Hua Liu‐Jie Lu Pei‐Jin Huang Dong‐Hui Wei Prof. Ming‐Sheng Tang Prof. Dr. Min‐Can Wang Prof. Dr. Jun‐Biao Chang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(39):12394-12398
A new ligand can be easily prepared, and its intramolecular dinuclear zinc complexes act as a high performance catalyst for the asymmetric alternating copolymerization of cyclohexene oxide and CO2 under very mild conditions (1 atm CO2, room temperature), affording completely alternating polycarbonates with up to 93.8 % enantiomeric excess (ee) and 98 % yield. A high Mn value of 28 600 and a relatively narrow polydispersity (Mw/Mn ratio) of 1.43 were also achieved. 相似文献
999.
Synthesis,Thermal Behavior,and Dehydrogenation Kinetics Study of Lithiated Ethylenediamine
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Juner Chen Dr. Guotao Wu Prof. Zhitao Xiong Dr. Hui Wu Dr. Yong Shen Chua Dr. Wei Zhou Bin Liu Xiaohua Ju Prof. Ping Chen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(42):13636-13643
The lithiation of ethylenediamine by LiH is a stepwise process to form the partially lithiated intermediates LiN(H)CH2CH2NH2 and [LiN(H)CH2CH2NH2][LiN(H)CH2CH2N(H)Li]2 prior to the formation of dilithiated ethylenediamine LiN(H)CH2CH2N(H)Li. A reversible phase transformation between the partial and dilithiated species was observed. One dimensional {LinNn} ladders and three‐dimensional network structures were found in the crystal structures of LiN(H)CH2CH2NH2 and LiN(H)CH2CH2N(H)Li, respectively. LiN(H)CH2CH2N(H)Li undergoes dehydrogenation with an activation energy of 181±8 kJ mol?1, whereas the partially lithiated ethylenediamine compounds were polymerized and released ammonia at elevated temperatures. The dynamical dehydrogenation mechanism of the dilithiated ethylenediamine compounds was investigated by using the Johnson‐Mehl‐Avrami equation. 相似文献
1000.
We have previously reported the preparation of acetyl and benzoyl phenyl-thiosemicarbazone derivatives of chitosan and their antimicrobial activities. The purpose of this study was to further assess the relationship between chemical structure and antimicrobial activity of chloracetyl phenyl-thiosemicarbazone-chitosan. Ten new chloracetyl phenyl-thiosemicarbazone-chitosans were prepared, and their structures were characterized using FT-IR and elemental analysis. The synthesized compounds were tested against four species of bacteria and four crop-threatening pathogenic fungi. Different molecular weights and concentrations were evaluated. The antifungal activities of the synthesized compounds were related to the positive polarity of the N4 atom and the distribution of the electron atmosphere in the C=S group. All chitosan compounds had inhibitory effects when tested with bacteria. The minimum MIC and MBC with Escherichia coli were 7.03 and 56.25 μg mL?1, respectively. 相似文献