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Transient and Persistent Room‐Temperature Mechanoluminescence from a White‐Light‐Emitting AIEgen with Tricolor Emission Switching Triggered by Light 下载免费PDF全文
Jian‐An Li Jinghong Zhou Dr. Zhu Mao Dr. Zongliang Xie Dr. Zhan Yang Prof. Bingjia Xu Prof. Cong Liu Xin Chen Dingyang Ren Hui Pan Prof. Guang Shi Prof. Yi Zhang Prof. Zhenguo Chi 《Angewandte Chemie (International ed. in English)》2018,57(22):6449-6453
Persistent luminescence from purely organic materials is basically triggered by light and electricity, which largely confines its practical applications. A purely organic AIEgen exhibits not only persistent photoluminescence, but also transient and persistent room‐temperature mechanoluminescence. By simply turning on and off a UV lamp, tricolor emission switching between blue, white, and yellow was achieved. The data from single‐crystal structure analysis and theoretical calculation suggest that mechanism of the observed persistent mechanoluminescence (pML) is correlated with the strong spin–orbit coupling of the bromine atom, as well as the formation of H‐aggregates and restriction of intramolecular motions in noncentrosymmetric crystal structure. These results outline a fundamental principle for the development of new pML materials, providing an important step forward in expanding the application scope of persistent luminescence. 相似文献
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Synthesis of 1,4‐Cyclohexanedimethanol, 1,4‐Cyclohexanedicarboxylic Acid and 1,2‐Cyclohexanedicarboxylates from Formaldehyde,Crotonaldehyde and Acrylate/Fumarate 下载免费PDF全文
Dr. Yancheng Hu Zhitong Zhao Dr. Yanting Liu Prof. Guangyi Li Prof. Aiqin Wang Prof. Yu Cong Prof. Tao Zhang Prof. Feng Wang Prof. Ning Li 《Angewandte Chemie (International ed. in English)》2018,57(23):6901-6905
Valuable polyester monomers and plasticizers—1,4‐cyclohexanedimethanol (CHDM), 1,4‐cyclohexanedicarboxylic acid (CHDA), and 1,2‐cyclohexanedicarboxylates—have been prepared by a new strategy. The synthetic processes involve a proline‐catalyzed formal [3+1+2] cycloaddition of formaldehyde, crotonaldehyde, and acrylate (or fumarate). CHDM is produced after a subsequent hydrogenation step over a commercially available Cu/Zn/Al catalyst and a one‐pot hydrogenation/oxidation/hydrolysis process yields CHDA, whereas 1,2‐cyclohexanedicarboxylate is obtained by a Pd/C‐catalyzed tandem decarbonylation/hydrogenation step. 相似文献
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研究了入射光波长与S0→S2跃迁共振的情形下,卟啉镍配合物(NiP)的振动拉曼光谱。用时间域方法计算了NiP的共振拉曼强度和吸收光谱。结果表明,相对于基态,S2态NiP的分子构型沿着ν8和ν2简正坐标有较大的位移。这些简正坐标主要涉及卟啉环的CαCm键和CβCβ键伸缩运动,以及CαCmCα变角运动。与基态相比, S2态的CβCβ、 CαCm和CαN键分别增大0.27、 0.14、 0.07 pm,而CαCβ键则减小0.20 pm,与前人的赝势分子轨道计算(SPMO)结果相近。还从RR强度角度讨论了S2态的Jahn-Teller畸变。 相似文献
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Cong‐Duan Vo Julien Rosselgong Steven P. Armes Nicola Tirelli 《Journal of polymer science. Part A, Polymer chemistry》2010,48(9):2032-2043
Homopolymerization and diblock copolymerization of 2‐hydroxypropyl acrylate (HPA) has been conducted using reversible addition fragmentation chain transfer (RAFT) chemistry in tert‐butanol at 80 °C. PHPA homopolymers were obtained with high conversions and narrow molecular weight distributions over a wide range of target degrees of polymerization. Like its poly(2‐hydroxyethyl methacrylate) isomer, PHPA homopolymer exhibits inverse temperature solubility in dilute aqueous solution, with cloud points increasing systematically on lowering the mean chain length. The nature of the end groups is shown to significantly affect the cloud point, whereas no effect of concentration was observed over the PHPA concentration range investigated. Various thermoresponsive PHPA‐based diblock copolymers were prepared via one‐pot syntheses in which the second block was either permanently hydrophilic or pH‐responsive. Preliminary studies confirmed that poly(ethylene oxide)‐poly(2‐hydroxypropyl acrylate) (PEO45‐PHPA48) and poly(2‐hydroxypropyl acrylate)‐ poly(2‐hydroxyethyl acrylate) (PHPA49‐PHEA68)diblock copolymers formed well‐defined PHPA‐core micelles in 10 mM sodium nitrate solution at 40 °C and 70 °C with mean hydrodynamic diameters of 20 nm and 35 nm, respectively. In contrast, most other PHPA‐based diblock copolymers investigated formed larger colloidal aggregates in 10 mM NaNO3 solution at elevated temperatures. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2032–2043, 2010 相似文献
98.
以有限元法为理论基础,通过运行大型有限元软件,成功构建了铰链式六面顶压机配套顶锤的有限元理论模型,并确立了碳化钨顶锤的破裂判据。模拟结果表明:以小斜边末尾处为应力参考点,依据第四强度理论,能够对碳化钨顶锤的性能进行更加合理的数值分析。依据此判据可知:在顶锤锤面及小斜边附近,裂纹高发区分布在小斜边附近;在顶锤轴向上,裂纹高发区分布在距离顶锤锤面30 mm处。铰链式六面顶压机配套碳化钨顶锤的有限元模型以及碳化钨顶锤破裂判据的成功构建,为实现新型碳化钨顶锤的设计与研究奠定了基础,对促进实现铰链式六面顶压机腔体大型化具有现实意义。 相似文献
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