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141.
双酚A(bisphenol A,BPA)是一种酚类环境雌激素,即使极低剂量残留对人类健康也有危害。为了建立其简单快速并适应现场检测的免疫分析方法,必须先合成它的人工抗原并进行鉴定。通过对双酚A进行结构修饰,用碳二亚胺将结构修饰了的双酚A与牛血清蛋白相偶联,经透析得到纯的双酚A人工抗原并冷冻干燥备用。然后用紫外光谱、红外光谱和免疫方法对人工抗原进行鉴定。结果表明,合成的人工抗原紫外光谱图中具有蛋白质和双酚A的特征吸收峰;人工抗原红外光谱图中呈现双酚A和牛血清蛋白的红外特征吸收峰;通过竞争ELISA试验表明用合成的人工抗原免疫的Balb/c小鼠血清中产生了双酚A的抗体。三种方法综合鉴定结果表明双酚A人工抗原合成成功,该人工抗原可以进一步用于制备抗双酚A的单克隆抗体。 相似文献
142.
Some studies on quantum dots (QD) as donors that enhance the fluorescence of a dye as an acceptor through fluorescence resonance energy transfer (FRET) have been reported. However, in the present work we discovered that CdS quantum dots sharply quenched the fluorescence of acridine orange (AO). Also, DNA enhanced the fluorescent signals of AO quenched by CdS. The extents of enhancement were in good proportion to the DNA concentrations. Based on this, a sensitive method was employed to determine DNA with both good selectivity and sensitivity. The calibration curve was linear over 60-4,000 ng mL(-1) and the determination limit (3sigma) was 4.39 ng mL(-1). 相似文献
143.
Influence of the comatic aberration of an apertured lens on the focused polychromatic Gaussian beams
The focusing of polychromatic Gaussian beams by an apertured lens with comatic aberration is investigated in this paper. We study the influence of the comatic aberration and truncation parameter on the intensity distribution at the focal plane, and singularities and spectral behavior near the focal plane in detail. The simulation results show that the maximum intensity at the focal plane will shift and split with the gradual increment of comatic aberration. We also find that the decrease of truncation parameter will counteract the influence of comatic aberration, which leads to the intensity variation. Furthermore, the singularity transformation and spectral anomalies are discussed. It is found that with the increment of comatic aberration, some singularities are split into several new singularities, and by combining some of these new singularities with other singularities near the focal plane, they vanish or form new singularities with the continuing increase of comatic aberration. The decreasing value of truncation parameter will cause similar phenomena. 相似文献
144.
Yuanyuan Li Jie Sun Li Wang Peng Zhan Zhishen Cao Zhenlin Wang 《Applied Physics A: Materials Science & Processing》2008,92(2):291-294
A sensor based on surface plasmon resonance (SPR) of plasmonic crystals fabricated via a colloidal-crystal-assisted templating
method is studied. Plasmonic crystals are prepared by depositing a thin gold (Au) layer onto a two-dimensional array of polystyrene
spheres self-assembled on a quartz substrate. The enhanced transmission as a result of the SPR of Au plasmonic crystals, which
are immersed in different ambient liquids, are measured and compared with that of polystyrene (PS) microsphere templates of
different sizes, both before and after removal of Au nanoprisms formed on the quartz substrate through pores among the spheres.
It is found that the measured sensitivities exhibit a linear dependence on the refractive index of the surrounding medium
and are linked to coupling effects between SPRs on the corrugated Au film and nanoislands. The feasibility of the SPR system
in molecular monolayer detection is further demonstrated through a formation of alkanethiolate self-assembled monolayers on
the Au film surface, which causes a 4 nm red-shift of the main SPR.
PACS 07.07.Df; 73.20.Mf; 78.66.-w; 81.16.Dn 相似文献
145.
A comprehensive study on the efficient one‐pot synthesis of polyhedral octaphenylsilsesquioxane (OPS) is reported via the hydrolytic condensation of phenyltrimethoxysilane (PTMS) in the presence of basic catalyst to investigate the specific synthesis mechanism. The synthetic reactions are monitored with real time infrared (RTIR) spectroscopy. Then RTIR coupled with 29Si nuclear magnetic resonance spectroscopy (NMR) and matrix‐assisted laser desorption/ionization time of flight mass spectrometry (MALDI‐TOF‐MS) are used to monitor the reactions and identify the intermediary species during the reaction. The rapid hydrolysis of PTMS is detected by RTIR. Contrary to previous reports, the ladder‐like structured species are identified as intermediates during the reaction process. It is suggested that formation of caged T8 OPS is realized through the chain break and rearrangement of the ladder‐like phenyltrimethoxysilanes. Accordingly, a scheme from hydrolysis of the PTMS to formation of the OPS is provided. 相似文献
146.
Jie Wang Sun Yangang Wang Zeming Wu Chongchong Rao Pinhua 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2019,93(4):736-742
Russian Journal of Physical Chemistry A - Co-doped Bi2MoO6 photocatalyst has been synthesized by a simple and facile solvothermal method. It exhibits the flower-like microspheres composed of... 相似文献
147.
A library of rare-earth metal derivatives supported by an aminophenoxy ligand was prepared and their catalytic performance in lactide polymerization was investigated. It was found that the synthetic strategy had a profound effect on the formation of aminophenoxy rare-earth metal complexes. Amine elimination between Ln[N(SiMe3)2]3(μ-Cl)Li(THF)3 (Ln = Yb, Y) and 1 equiv. of the aminophenol [HONH] ([HONH] = ο-OCH3-C6H4NHCH2(3,5-tBu2-C6H2-2-OH)) in toluene gave the unexpected heterobimetallic bis(aminophenoxy) rare-earth metal complexes [ON]2LnLi(THF)2 (Ln = Yb ( 1 ), Y ( 2 )). When the reactions were carried out in THF and TMEDA, amine elimination produced the aminophenoxy rare-earth metal amide complexes {[ON]LnN(SiMe3)2}2 (Ln = Yb ( 5 ), Y ( 6 )) in ca 85% isolated yields. Complexes 5 and 6 could also be obtained from salt metathesis reaction of {[ON]LnCl(THF)}2 (Ln = Yb ( 3 ), Y ( 4 )) with NaN(SiMe3)2 in a 1:2 molar ratio. In addition, treatment of complexes 3 and 4 with NaOAr (Ar = &bond;C6H4-4-tBu) and (SiMe3)2NC(NPri)2Na in 1:4 and 1:2 molar ratios provided the corresponding aminophenoxy rare-earth metal derivatives {[ON](μ-OAr)Ln(μ-OAr)Na(THF)2}2 (Ln = Yb ( 7 ), Y ( 8 )) and {[ON]Ln[(iPrN)2CN(SiMe3)2]}2 (Ln = Yb ( 9 ), Y ( 10 )), respectively. These complexes were fully characterized, and their molecular structures were determined using single-crystal X-ray diffraction. Polymerization experiments showed that complexes 1 , 2 , 5 , 6 , 9 and 10 were highly active for the ring-opening polymerization of l -lactide in toluene, and complex 1 promoted l -lactide polymerization in a controlled fashion. The polymerization of rac-lactide initiated by the neutral aminophenoxy rare-earth metal complexes 5 , 6 , 9 and 10 in THF afforded heterotactic polymers. 相似文献
148.
Jie Li Prof. Dr. Shuanglin Qu Prof. Dr. Wanxiang Zhao 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(6):2380-2384
A rhodium-catalyzed remote C(sp3)−H borylation of silyl enol ethers (SEEs, E/Z mixtures) by alkene isomerization and hydroboration is reported. The reaction exhibits mild reaction conditions and excellent functional-group tolerance. This method is compatible with an array of SEEs, including linear and branched SEEs derived from aldehydes and ketones, and provides direct access to a broad range of structurally diverse 1,n-borylethers in excellent regioselectivities and good yields. These compounds are precursors to various valuable chemicals, such as 1,n-diols and aminoalcohols. 相似文献
149.
Flower-like shaped Bi12TiO20 (Bismuth Titanate)/g-C3N4 (graphite-like carbon nitride) heterojunction was prepared through hydrothermal and sonification methods for the degradation of organic pollutants by visible-light irradiation. The preparation process, chemical structures, and the mechanism of photocatalytic enhancement of the heterostructures were studied systematically. Under visible-light irradiation, the novel flower-like shaped Bi12TiO20/g-C3N4 heterojunction demonstrates prominent activities for the degradation of rhodamine B and p-nitrophenol, with the introduction of flower-like shaped Bi12TiO20 into g-C3N4 composites greatly increasing the activity of pure g-C3N4. This activity enhancement for the heterojunction could be mainly attributed to its low recombination speed of electron–hole pairs, high adsorption ability of organic pollutants, and better optical absorption ability. Moreover, in the visible-light system of Bi12TiO20/g-C3N4, •OH also contributed to the degradation of pollutants, which may explain the enhanced photocatalytic activity after the introduction of Bi12TiO20, as •OH is inactive in pure g-C3N4. Furthermore, 10 wt.% Bi12TiO20/g-C3N4 showed not only high activity but also good stability for degradation of aqueous organic pollutants, implying potential applications prospect. 相似文献