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991.
992.
This study investigated the biological conversion of crude glycerol generated from a commercial biodiesel production plant as a by-product to 1,3-propanediol (1,3-PD). Statistical analysis was employed to derive a statistical model for the individual and interactive effects of glycerol, (NH4)2SO4, trace elements, pH, and cultivation time on the four objectives: 1,3-PD concentration, yield, selectivity, and productivity. Optimum conditions for each objective with its maximum value were predicted by statistical optimization, and experiments under the optimum conditions verified the predictions. In addition, by systematic analysis of the values of four objectives, optimum conditions for 1,3-PD concentration (49.8 g/L initial glycerol, 4.0 g/L of (NH4)2SO4, 2.0 mL/L of trace element, pH 7.5, and 11.2 h of cultivation time) were determined to be the global optimum culture conditions for 1,3-PD production. Under these conditions, we could achieve high 1,3-PD yield (47.4%), 1,3-PD selectivity (88.8%), and 1,3-PD productivity (2.1/g/L/h) as well as high 1,3-PD concentration (23.6 g/L). 相似文献
993.
Kie Yong Cho Hyun-Ji Kim Xuan Huy Do Jin Young Seo Jae-Woo Choi Sang-Hyup Lee Ho Gyu Yoon Seung Sang Hwang Kyung-Youl Baek 《Research on Chemical Intermediates》2018,44(8):4663-4684
Two series of water-soluble metalloporphyrin-cored amphiphilic star block copolymers were synthesized by controlled radical polymerizations such as atom transfer radical polymerization (ATRP) and reversible addition fragmentation chain transfer (RAFT), which gave eight amphiphilic block copolymer arm chains consisting of poly(n-butyl acrylate-b-poly(ethylene glycol) methyl ether methacylate) (PnBA-b-PEGMEMA, Mn,GPC = 78,000, Mw/Mn = 1.2, 70 wt% of PPEGMEMA) and poly(styrene-b-2-dimethylamino ethyl acrylate) (PS-b-PDMAEA, Mn,GPC = 83,000, Mw/Mn = 1.2, 67 wt% of PDMAEA), yielding porphyrin(Pd)-(PnBA-b-PPEGMEMA)8 and porphyrin(Pd)-(PS-b-PDMAEA)8, respectively. Obtained metalloporphyrin polymer photocatalysts were homogeneously solubilized in water to apply to the removal of chlorophenols in water, and was distinguished from conventional water-insoluble small molecular metalloporphyrin photocatalysts. Notably, we found that the water-soluble star block copolymers with hydrophobic–hydrophilic core–shell structures more effectively decomposed the chlorophenol, 2,4,6-trichlorophenol (2,4,6-TCP), in water under visible light irradiation (k = 1.39 h?1, t1/2 = 0.5 h) in comparison to the corresponding water-soluble star homopolymer, because the hydrophobic core near the metalloporphyrin effectively captured and decomposed the hydrophobic chlorophenols in water. 相似文献
994.
A continuous flow reaction system was developed for the synthesis of 2,2,2-trichloroacetophenone derivatives. When aryl propiolic acids and water were mixed with trichloroisocyanuric acid in DMF at 5?°C, the 2,2,2-trichloroacetophenone derivatives were formed within 5?min with good yields. In addition, the resulting mixture was flowed to react with amines to give the corresponding benzamide. This flow reaction system provided higher yields within shorter times than the batch reaction system. 相似文献
995.
A Bio‐inspired Cu4O4 Cubane: Effective Molecular Catalysts for Electrocatalytic Water Oxidation in Aqueous Solution 下载免费PDF全文
Xin Jiang Jian Li Bing Yang Xiang‐Zhu Wei Bo‐Wei Dong Yi Kao Mao‐Yong Huang Prof. Chen‐Ho Tung Prof. Li‐Zhu Wu 《Angewandte Chemie (International ed. in English)》2018,57(26):7850-7854
Inspired by the cubic Mn4CaO5 cluster of natural oxygen‐evolving complex in Photosystem II, tetrametallic molecular water oxidation catalysts, especially M4O4 cubane‐like clusters (M=transition metals), have aroused great interest in developing highly active and robust catalysts for water oxidation. Among these M4O4 clusters, however, copper‐based molecular catalysts are poorly understood. Now, bio‐inspired Cu4O4 cubanes are presented as effective molecular catalysts for electrocatalytic water oxidation in aqueous solution (pH 12). The exceptional catalytic activity is manifested with a turnover frequency (TOF) of 267 s?1 for [(LGly‐Cu)4] at 1.70 V and 105 s?1 for [(LGlu‐Cu)4] at 1.56 V. Electrochemical and spectroscopic study revealed a successive two‐electron transfer process in the Cu4O4 cubanes to form high‐valent CuIII and CuIIIO. intermediates during the catalysis. 相似文献
996.
Porous glass plates were modified via their interaction with molybdenum(V) chloride, followed by a treatment with humid air at 473°C. The extent of the reaction is characterized on the basis of IR spectra of OH groups on the starting glass surface and grafted layer. The photochromism of the resulting plates is exhibited under their UV irradiation as a progressive blue coloration. The suggested photoreduction mechanism consists in splitting-off oxygen atoms from bridge bonds?Mo?O?Mo?, with transition of molybdenum atoms to the pentavalent state. The subsequent discoloration of the plates is provided by their heating in air at 473°C. The full reversibility of the photoreduction and oxidation processes is observed in their multiple repetitions. 相似文献
997.
Bing Tian Zhao Tae In Kim Young Ho Kim Jong Seong Kang Byung Sun Min 《Natural product research》2018,32(2):239-242
We have developed a new method to simultaneously determine five marker compounds in Menthae Herba via HPLC/PDA – including hesperidin (1), rosmarinic acid (2), diosmin (3), didymin (4) and buddleoside (5). The newly developed method was successfully used to analyse for two species (Mentha arvensis L. and Mentha haplocalyx Briq.) of Menthae Herba, and the satisfactory results were obtained from the validation of developed method. The pattern analysis could greatly discriminate between M. arvensis L. and M. haplocalyx Briq. In conclusion, the proposed HPLC/PDA method is suitable for quality evaluation of Menthae Herba. 相似文献
998.
Babu B. Chandrasekaran J. Jayaramakrishnan V. Ho Mon-Shu Thirupugalmani K. Chandrasekar S. Thirumurugan R. 《Journal of Thermal Analysis and Calorimetry》2018,134(2):1059-1070
Journal of Thermal Analysis and Calorimetry - Organic co-crystals fashioned with two or more different constituents through intermolecular non-covalent interactions (hydrogen and halogen bonds)... 相似文献
999.
Highly Emissive Fused Heterocyclic Alkynylgold(III) Complexes for Multiple Color Emission Spanning from Green to Red for Solution‐Processable Organic Light‐Emitting Devices 下载免费PDF全文
Dr. Man‐Chung Tang Chin‐Ho Lee Dr. Maggie Ng Yi‐Chun Wong Dr. Mei‐Yee Chan Prof. Dr. Vivian Wing‐Wah Yam 《Angewandte Chemie (International ed. in English)》2018,57(19):5463-5466
A new class of fused heterocyclic tridentate ligand‐containing alkynylgold(III) complexes with tunable emission color has been successfully designed and synthesized. Structural modification of the σ‐donating fused heterocyclic alkynyl ligands, including substituted fluorene, carbazole, and triphenylamine, enables a large spectral shift of about 110 nm (ca. 3310 cm?1) that covers the green to red region to be realized with the same tridentate ligand‐containing alkynylgold(III) complexes in solid‐state thin films. Interestingly, the energy of the excimeric emission can be controlled by the rational design of the fused heterocyclic alkynyl ligands. Superior solution‐processable organic light‐emitting devices (OLEDs) with high external quantum efficiencies (EQEs) of 12.2, 13.5, 9.3, and 5.2 % were obtained with green, yellow, orange, and red emission. These high EQE values are comparable to those of the vacuum‐deposited OLEDs based on structurally related alkynylgold(III) complexes. 相似文献
1000.
A Zero‐Dimensional Organic Seesaw‐Shaped Tin Bromide with Highly Efficient Strongly Stokes‐Shifted Deep‐Red Emission 下载免费PDF全文
Chenkun Zhou Dr. Haoran Lin Prof. Hongliang Shi Yu Tian Chongin Pak Prof. Michael Shatruk Yan Zhou Dr. Peter Djurovich Dr. Mao‐Hua Du Prof. Biwu Ma 《Angewandte Chemie (International ed. in English)》2018,57(4):1021-1024
The synthesis and characterization is reported of (C9NH20)2SnBr4, a novel organic metal halide hybrid with a zero‐dimensional (0D) structure, in which individual seesaw‐shaped tin (II) bromide anions (SnBr42?) are co‐crystallized with 1‐butyl‐1‐methylpyrrolidinium cations (C9NH20+). Upon photoexcitation, the bulk crystals exhibit a highly efficient broadband deep‐red emission peaked at 695 nm, with a large Stokes shift of 332 nm and a high quantum efficiency of around 46 %. The unique photophysical properties of this hybrid material are attributed to two major factors: 1) the 0D structure allowing the bulk crystals to exhibit the intrinsic properties of individual SnBr42? species, and 2) the seesaw structure enabling a pronounced excited state structural deformation as confirmed by density functional theory (DFT) calculations. 相似文献