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891.
Jian Zhang Bin Wang Ming Li Min-Jian Zhao Jian-Rong Li 《Journal of Coordination Chemistry》2016,69(14):2193-2199
Through ligand modification, we have replaced the central benzene ring of H2TDBA ([1,1′:3′,1″-terphenyl]-4,4″-dicarboxylic acid) with the pyridine structurally related ligand H2PDDA (4,4′-(pyridine-2,6-diyl)dibenzoic acid), which makes the central pyridine ring of H2PDDA more coplanar with two benzene rings on both sides of the ligand. The modification results in a dramatically different linkage configuration, thereby allowing structural changes to the metal-organic frameworks (MOFs). Two 2-D MOFs, [Cu(TDBA)(DMA)2]·H2O (BUT-221, DMA = N,N-dimethylacetamide), and [Cu3(PDDA)3(DMA)2(H2O)]·5H2O (BUT-223) have been synthesized through reactions of two ditopic carboxylate ligands with Cu(NO3)2·3H2O under solvothermal conditions, and characterized by single-crystal X-ray diffraction, powder X-ray diffraction, thermogravimetric analysis and infrared spectroscopy. Topological analysis shows that BUT-221 is a twofold parallel interpenetrating 44 2-D network with a skl topology, while BUT-223 is a 2-D network with a kgm topology. 相似文献
892.
A new carboline alkaloid, 1-(7-methoxy-quinolinyl-4′-yl)-3,4-dihydro-β-carboline (1), was isolated from the leaves and twigs of Trigonostemon lii Y.T. Chang, together with three known ones, trigonostemonines C and D (2 and 3), and trigonoliimine A (4). Their structures were elucidated by spectroscopic analyses, including 2D-NMR techniques. 相似文献
893.
Xue Xie Jianming Zhou Lin Sun Hongda Zhang Yiwu Zhao Yaling Song 《Natural product research》2016,30(2):150-156
One new flavonol glycoside, 6-hydroxykaempferol-3-O-β-D-glucoside-7-O-β-D-glucuronide (1), together with eight known flavonoids and three known quinochalcones, was isolated from the florets of Carthamus tinctorius L. Their structures were determined by extensive spectroscopic analyses. Their cardioprotective effects against H2O2-induced apoptosis in H9c2 cells were also evaluated; compounds 1, 2, 4–5, 7–10 and 12 provided significant protective effects on H2O2-induced H9c2 cells at the concentration of 25 μg/mL. 相似文献
894.
Lin-Feng Dai Qian Liang Tie Liu Ming-Yu He Ping Zhao 《Natural product research》2016,30(14):1639-1645
One new tigliane-type diterpene, 4-deoxy-4(β)H-8-hydroperoxyphorbol-12-benzoate-13-isobutyrate (1), together with two known diterpenoids, 3-acetyl-5,8-dibenzoyl-14α-propanoyl-13,17-epoxy-7-myrsinaone diterpene with C9–C10 cyclised to form an additional lactone ring (2), Euphodendriane A (3) have been isolated from the whole plants of Euphorbia dracunculoides Lam. Their structures were elucidated by means of extensive spectroscopic analysis (NMR and HR-ESI-MS) and comparison with data reported in the literature. This is the first isolation of 8-hydroperoxy tigliane diterpene (1) from the genus of Euphorbia. All compounds were evaluated for their antifungal activities. 相似文献
895.
Hongguang Lu Yadan Zheng Xiaowei Zhao Lijuan Wang Suqian Ma Xiongqi Han Bin Xu Wenjing Tian Hui Gao 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2016,128(1):163-167
The development of organic fluorophores with efficient solid‐state emissions or aggregated‐state emissions in the red to near‐infrared region is still challenging. Reported herein are fluorophores having aggregation‐induced emission ranging from the orange to far red/near‐infrared (FR/NIR) region. The bioimaging performance of the designed fluorophore is shown to have potential as FR/NIR fluorescent probes for biological applications. 相似文献
896.
Graphene Oxide/Polyacrylamide/Aluminum Ion Cross‐Linked Carboxymethyl Hemicellulose Nanocomposite Hydrogels with Very Tough and Elastic Properties 下载免费PDF全文
Weiqing Kong Danyang Huang Guibin Xu Prof. Junli Ren Prof. Chuanfu Liu Prof. Lihong Zhao Prof. Runcang Sun 《化学:亚洲杂志》2016,11(11):1697-1704
Development of high‐strength hydrogels has recently attracted ever‐increasing attention. In this work, a new design strategy has been proposed to prepare graphene oxide (GO)/polyacrylamide (PAM)/aluminum ion (Al3+)‐cross‐linked carboxymethyl hemicellulose (Al‐CMH) nanocomposite hydrogels with very tough and elastic properties. GO/PAM/Al‐CMH hydrogels were synthesized by introducing graphene oxide (GO) into PAM/CMH hydrogel, followed by ionic cross‐linking of Al3+. The nanocomposite hydrogels were characterized by means of FTIR, X‐ray diffraction (XRD), and scanning electron microscopy/energy‐dispersive X‐ray analysis (SEM‐EDX) along with their swelling and mechanical properties. The maximum compressive strength and the Young's modulus of GO3.5/PAM/Al‐CMH0.45 hydrogel achieved values of up to 1.12 and 13.27 MPa, increased by approximately 6488 and 18330 % relative to the PAM hydrogel (0.017 and 0.072 MPa). The as‐prepared GO/PAM/Al‐CMH nanocomposite hydrogels possess high strength and great elasticity giving them potential in bioengineering and drug‐delivery system applications. 相似文献
897.
Increasing the CO2/N2 Selectivity with a Higher Surface Density of Pyridinic Lewis Basic Sites in Porous Carbon Derived from a Pyridyl‐Ligand‐Based Metal–Organic Framework 下载免费PDF全文
Dr. Liangjun Li Ying Wang Dr. Xin Gu Dr. Qipeng Yang Prof. Xuebo Zhao 《化学:亚洲杂志》2016,11(13):1913-1920
The development of functional porous carbon with high CO2/N2 selectivity is of great importance for CO2 capture. In this paper, a type of porous carbon with doped pyridinic sites (termed MOFC) was prepared from the carbonization of a pyridyl‐ligand based MOF. Four MOFCs derived from different carbonizing temperatures were prepared. Structural studies revealed high contents of pyridinic‐N groups and nearly the same pore‐size distributions for these MOFCs. Gas‐sorption studies revealed outstanding CO2 uptake at low pressures and room temperature. Owing to the high content of pyridinic‐N groups, the CO2/N2 selectivity on these MOFCs exhibits values of about 40–50, which are among the top values in carbon materials. Further correlation studies demonstrated that the CO2/N2 selectivities show a positive linear relationship with the surface density of pyridinic‐N groups, thus validating the synergistic effect of the doped pyridinic‐N groups on CO2 adsorption selectivity. 相似文献
898.
Highly Contorted 1,2,5‐Thiadiazole‐Fused Aromatics for Solution‐Processed Field‐Effect Transistors: Synthesis and Properties 下载免费PDF全文
Xin Shi Shuli Liu Chunming Liu Yueming Hu Saihua Shi Dr. Nina Fu Dr. Baomin Zhao Prof. Dr. Zhaohui Wang Prof. Dr. Wei Huang 《化学:亚洲杂志》2016,11(15):2188-2200
A straightforward strategy has been used to construct 1,2,5‐thiadiazole‐fused 12‐ring π systems through twofold Stille coupling and subsequent cyclodehydrogenation by utilizing the building blocks of naphthodithiophene and 5,6‐substituted benzo[b]‐2,1,3‐thiadidazole. Molecules 1 a and 1 b , which exhibit highly contorted π surfaces, show a butterfly‐shaped conformation according to DFT calculations. Within the molecules, a plane‐to‐plane angle of 44.8° was found. UV/Vis absorption, thermogravimetric analysis, differential scanning calorimetry, and cyclic voltammetry (CV) were used to study their physical properties. Strong intermolecular interactions of the nonplanar molecules were also observed by concentration‐dependent 1H NMR spectroscopy measurements and thin‐film XRD characterization. The low‐lying LUMO and high‐lying HOMO levels of the molecules are ?3.73 and ?5.48 eV, respectively, as estimated from CV measurements; this indicates their potential as semiconducting materials for solution‐processed organic field‐effect transistors (OFETS). A field‐effect hole mobility of up to 0.035 cm2 V?1 s?1, a threshold voltage of 6.98 V, and a current on/off ratio of 8.65×105 in air for 1 a have been demonstrated with the top‐contact bottom‐gate field‐effect transistor device structures; this represents an important step toward the solution‐processed OFET application of contorted aromatics. 相似文献
899.
Synthesis,Structures, and Photocatalytic Properties of Zinc(II) and Cobalt(II) Supramolecular Complexes Constructed with Flexible Bis(thiabendazole) and Dicarboxylate Linkers 下载免费PDF全文
Three coordination complexes, namely, [Zn(btbp)(3‐npa)]n ( 1 ), [Co(btbh)(3‐npa)]n ( 2 ), and {[Co(btbb)(5‐nipa)(H2O)] · H2O}n ( 3 ) (btbp = 1,3‐bis(thiabendazole)propane, btbh = 1,6‐bis(thiabendazole)hexane, btbb = 1,4‐bis(thiabendazole)butane, 3‐H2npa = 3‐nitrophthalic acid and 5‐H2nipa = 5‐nitroisophthalic acid) were synthesized under hydrothermal conditions and characterized by physicochemical and spectroscopic methods as well as by single‐crystal X‐ray diffraction. Complex 1 features a fascinating meso‐helical chain, which is further extended into a 2D supramolecular framework involving π ··· π stacking interactions. Complexes 2 and 3 show dinuclear structures. Complex 2 is further connected through C–H ··· O hydrogen bonding interactions to afford a 2D supramolecular layer, whereas complex 3 is further extended to a rare 2‐nodal (3,4)‐connected supramolecular sheet with a point symbol of {3.42.5.6.7}2{3.82} by O–H ··· O hydrogen bonding interactions. The electrochemical behaviors of the two cobalt complexes 2 and 3 were reported. Moreover, the luminescent properties for 1 and the photocatalytic properties for the complexes were investigated. 相似文献
900.
利用叶立德活性聚合方法制备了两种基于聚亚甲基的大分子单体. 其中一种是以叶立德活性聚合制备的主链链端含有羟基的聚亚甲基(PM-OH)为原料, 通过链端羟基的基团转换, 得到链端含有甲基丙烯酸酯基的大分子单体. 另一种则是以硼烷-四氢呋喃(BH3-THF)和二乙烯基苯反应得到的三烷基硼中间体为催化剂和引发剂, 然后进行叶立德活性聚合, 再经过二水合氧化三甲胺(TAO)的氧化, 最终得到基于聚亚甲基的一端含有羟基另一端含有苯乙烯基的大分子单体. 通过高温核磁氢谱、傅立叶红外光谱和高温凝胶色谱法表征了这两种大分子单体的链结构和分子量及其分布. 相似文献