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991.
Shuang Chen Shuxin Wang Juan Zhong Yongbo Song Dr. Jun Zhang Prof. Hongting Sheng Prof. Yong Pei Prof. Manzhou Zhu 《Angewandte Chemie (International ed. in English)》2015,54(10):3145-3149
Decreasing the core size is one of the best ways to study the evolution from AuI complexes into Au nanoclusters. Toward this goal, we successfully synthesized the [Au18(SC6H11)14] nanocluster using the [Au18(SG)14] (SG=L ‐glutathione) nanocluster as the starting material to react with cyclohexylthiol, and determined the X‐ray structure of the cyclohexylthiol‐protected [Au18(C6H11S)14] nanocluster. The [Au18(SR)14] cluster has a Au9 bi‐octahedral kernel (or inner core). This Au9 inner core is built by two octahedral Au6 cores sharing one triangular face. One transitional gold atom is found in the Au9 core, which can also be considered as part of the Au4(SR)5 staple motif. These findings offer new insight in terms of understanding the evolution from [AuI(SR)] complexes into Au nanoclusters. 相似文献
992.
通过金铜共混法制备了Au/Cu合金纳米棒,研究了铜掺杂对金纳米棒等离子体共振吸收和结构的影响,探究了Au/Cu合金纳米棒的等离子体共振拉曼增强效应.以Au/Cu合金纳米棒为基底对肺腺癌组织和癌旁正常组织进行了表面增强拉曼光谱检测.结果显示,癌变组织具有比癌旁正常组织更强的拉曼信号峰,位于1250,1344,1408,1568,1608和2560 cm~(-1)附近的拉曼峰分别与蛋白质的AmideⅡ氨基化合物、C—H弯曲振动、核酸中CH_3的对称变角振动、蛋白质色氨酸惰性环振动、蛋白质酰胺I谱带分子间反平行β-折叠的C—O健伸缩振动和蛋白质的巯基(S—H)伸缩振动有关,2936 cm~(-1)附近的拉曼峰为蛋白质CH_2的对称伸缩振动和CH_3的反对称伸缩振动共同作用产生.以铜掺杂的金纳米棒为基底的表面增强拉曼光谱法有望成为检测肺癌组织的有效手段. 相似文献
993.
通过调控过氧化氢与金纳米棒相互作用时溶液的H~+和Br~-浓度,考察了过氧化氢刻蚀金纳米棒的条件.通过静电相互作用将聚苯乙烯磺酸钠修饰到带正电的金纳米棒表面,并探讨了表面配体变化对过氧化氢与金纳米棒相互作用的影响,比较了聚苯乙烯磺酸钠浓度改变对过氧化氢刻蚀金纳米棒所引起的等离子体吸收峰的变化.结果表明,过氧化氢与金纳米棒作用过程中,H~+浓度增加可以加快刻蚀反应速率,Br~-起到稳定金离子的作用.采用聚苯乙烯磺酸钠修饰抑制了过氧化氢对金纳米棒的刻蚀,当聚苯乙烯磺酸钠与金纳米棒表面的CTAB完全作用后,复合材料电位接近零,金纳米棒的稳定性降低,继续增加聚苯乙烯磺酸钠的量至电位为负,复合材料稳定性增加. 相似文献
994.
以11-巯基十一烷酸(11-MUA)为还原剂和保护剂,通过一步水热法合成了具有强烈荧光的水溶性金纳米簇(AuNCs),基于Cu~(2+)修饰的AuNCs@11-MUA构建了"关-开"型荧光探针用于多巴胺(DA)的选择性、高灵敏检测.向AuNCs@11-MUA溶液中加入Cu~(2+)离子后,AuNCs@11-MUA的荧光发生猝灭,体系的荧光信号处于"关闭"状态.在DA存在下,由于DA与Cu~(2+)具有更强的结合力,形成比Cu~(2+)/AuNCs@11-MUA复合体更稳定的络合物,可将Cu~(2+)从AuNCs@11-MUA表面移除下来,从而使其荧光得以恢复,体系的荧光信号呈"打开"状态.AuNCs@11-MUA探针的荧光恢复程度与DA的浓度在2.0×10~(-7)~5.0×10~(-5)mol/L范围呈良好的线性关系,检出限为8.0×10~(-8)mol/L(S/N=3).将该探针应用于人血清和尿液中DA的检测,回收率为93.2%~97.3%,相对标准偏差RSD4.08%,表明该方法可应用于人体内多巴胺的检测. 相似文献
995.
S. I. Kulakovskaya L. A. Levchenko A. V. Kulikov A. P. Sadkov A. F. Shestakov D. A. Pichugina 《Russian Journal of Electrochemistry》2007,43(1):92-104
Reduction of chloroauric acid on platinum and gold electrodes in a 0.1 M tris-HCl buffer of pH 8 containing riboflavin, rutin, 1,1-dipyridyl, or 1-naphthol is studied by cyclic voltammetry and in situ ESR methods. On the basis of the obtained data it is assumed that in the buffer there occurs the reduction of Au(III) to Au(I). In the presence of 1,1-dipyridyl, there occurs the reduction of complex [Au(III)-1,1-dipyridyl]. The reduction of Au(III) in the presence of 1-naphthol is realized in the composition of complex [Au(III)-tris-1-naphthol]. The hampering of the electrode process of the Au(III) reduction in the presence of 1-naphthol is caused by the adsorption of the [tris-1-naphthol] associates at the electrode surface. The presence of Au(III) does not exert any influence on the process of electroreduction of riboflavin. The obtained results make it possible to presume that the resistance of gold-accumulating cells Micrococcus luteus toward toxic compounds that are inhibitors of the respiratory chain, such as 1,1-dipyridyl and 1-naphthol, is caused by their binding in gold-containing complexes in the composition of Au-protein. 相似文献
996.
Colloid Au (Au(nano)) with a diameter of about 10 nm was prepared and used in combination with dihexadecylphosphate (DHP) to immobilize glucose oxidase (GOD) onto the surface of a graphite electrode (GE). The direct electrochemistry of GOD confined in the composite film was investigated. The immobilized GOD displayed a pair of redox peaks with a formal potential of -0.475 mV in pH 7.0 O(2)-free phosphate buffers at scan rate of 150 mV s(-1). The GOD in the composite film retained its bioactivity and could catalyze the reduction of dissolved oxygen. Upon the addition of glucose, the reduction peak current of dissolved oxygen decreased, which could be developed for glucose determination. A calibration linear range of glucose was 0.5-9.3 mM with a detection limit of 0.1 mM and a sensitivity of 1.14 microA mM(-1). The glucose biosensor showed good reproducibility and stability. The general interferences that coexisted in human serum sample such as ascorbic acid and uric acid did not affect glucose determination. 相似文献
997.
原子表征与操控是实现原子制造必须突破的物理瓶颈之一.像差校正电子显微学方法因其优异的空间分辨率,为实现原子精细制造提供了有力的表征手段.因此,利用电子显微学手段,在原子尺度对原子制造的材料及器件进行三维结构和性能的协同表征,对于深入理解原子水平材料操控的物理机理具有非常重要的意义.纳米团簇及纳米颗粒是原子制造材料与器件研究的主要对象之一,具有丰富的物理化学性质和较高的可操纵性.本文探讨纳米团簇/颗粒结构三维定量表征、使役条件下纳米团簇/颗粒结构演变定量表征、纳米颗粒/晶粒结构-成分-磁性协同定量表征等诸多方法与实例,阐明了电子显微学表征手段的突破和发展为实现精细控制的原子制造材料提供了坚实基础. 相似文献
998.
LIU Zhongxin SONG Hongwei YU Lixin YANG Linmei & PAN Guohui . Key Laboratory of Excited State Physics Changchun Institute of Optics Fine Mechanics Physics Chinese Academy of Sciences Changchun China . Graduate School of the Chinese Academy of Sciences Beijing China 《中国科学B辑(英文版)》2005,48(5):431-435
Noble metal nanostructures have been the research focus for many decades because of their real or poten-tial applications, such as catalysis, photography, optics, electronics, optoelectronics, information storage, bio-logical and chemical sensing, surface… 相似文献
999.
《Macromolecular bioscience》2018,18(2)
Nanocarriers based on natural biomaterials such as peptides and proteins have shown great advantages in the field of nanomedicine. However, the complicated preparation process and possible denaturation of proteins may limit their further applications. Herein, a novel method is developed to prepare protein nanocluster drug delivery system based on the self‐aggregated property of proteins under the isoelectric point condition. The crosslinked protein nanoclusters, prepared by adding modified natural crosslinking agent polysaccharide, exhibit excellent stability and autofluorescent property in physiological conditions. Hemoglobin, a model protein, is chosen for preparation of drug‐loaded nanoclusters. The as‐prepared nanoclusters demonstrate a pH‐responsive drug release behavior and can successfully deliver drugs into cancer cells. Moreover, this approach can be extended to various proteins, exemplifying the universal applicability of our new preparation method for protein‐based nanoparticles. 相似文献
1000.