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991.
Huang Z Pu F Hu D Wang C Ren J Qu X 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(13):3774-3780
Precise organization of metallic nanoclusters on DNA scaffolds holds great interest for nanopatterned materials that may find uses in electronics, sensors, medicine, and many other fields. Herein, we report the site-specific growth of fluorescent silver nanoclusters by using a mismatched double-stranded DNA template. Few-atom, molecular-scale Ag clusters are found to localize at the mismatched site and the metallized DNA retains its integrity. The DNA-encapsulated nanoclusters can be utilized as functional biological probes to identify single-nucleotide polymorphisms by taking advantage of the very bright fluorescence and excellent photostability of the nanoclusters. This approach offers the possibility of constructing novel DNA-based nanomaterials and nanomechanical devices with more sophisticated functions and will be highly beneficial in future biochemical, pharmaceutical, nanomechanical, and electronic applications. 相似文献
992.
993.
采用基于密度泛函理论的第一性原理方法,计算和分析Ag(111)/Al(111)界面体系的能量与电子结构,讨论Ag中加入的Be、Mg、Al、Ca、Ni、Sn合金化元素对Ag/Al界面性质的影响.结果表明:Ni原子倾向于界面处的取代位置,而Be、Mg原子倾向于靠近界面处的取代位置,Al、Ca、Sn原子倾向于远离界面处的取代位置;合金元素Be、Mg、Al、Ca、Ni、Sn的加入均会使Ag/Al界面的稳定性降低,其中Ca元素的影响程度最大,分离功降低到0.923 J/m~2,界面能增至0.703 J/m~2;通过电子结构计算结果分析认为,导致界面稳定性下降的主要原因应是合金化元素的加入使界面间形成的Ag-Al共价键强度降低引起. 相似文献
994.
Nano Ag-enhanced photoelectric conversion efficiency in all-inorganic,hole-transporting-layer-free CsPbIBr2 perovskite solar cells 下载免费PDF全文
Youming Huang 《中国物理 B》2022,31(12):128802-128802
All-inorganic, hole-transporting-layer-free CsPbIBr2 perovskite solar cells have great potential for development, but their device performance needs to be further improved. Recently, metal nanostructures have been successfully applied in the field of solar cells to improve their performance. Nano Ag-enhanced power conversion efficiency (PCE) in one CsPbIBr2 perovskite solar cell utilizing localized surface plasmons of Ag nanoparticles (NPs) on the surface has been researched experimentally and by simulation in this paper. The localized surface plasmon resonance of Ag NPs has a near-field enhancement effect, which is expected to improve the light absorption of CsPbIBr2 perovskite photovoltaic devices. In addition, Ag NPs have a forward-scattering effect on the incident light, which can also improve the performance of CsPbIBr2-based perovskite photovoltaic devices. By directly assembling Ag NPs (with a size of about 150 nm) on the surface of fluorine-doped tin oxide it is found when the particle surface coverage is 10%, the CsPbIBr2 perovskite photovoltaic device achieves a best PCE of 2.7%, which is 9.76% higher than that of the control group. Without changing any existing structure in the ready-made solar cell, this facile and efficient method has huge applications. To the best of our knowledge, this paper is the first report on nano Ag-enhanced photoelectric conversion efficiency in this kind of CsPbIBr2 perovskite solar cell. 相似文献
995.
Jun Ren 《Molecular physics》2013,111(14):1829-1844
We present a detailed study of optical absorption spectra of finite-size structures, using a method based on time-dependent density-functional theory (TDDFT), which involves a self-consistent field for the propagation of the Kohn–Sham wavefunctions in real-time. Although our approach does not provide a straightforward assignment of absorption features to corresponding transitions between Kohn–Sham orbitals, as is the case in frequency-domain TDDFT methods, it allows the use of larger timesteps while conserving total energy and maintaining stable dipole moment oscillations. These features enable us to study larger systems more efficiently. We demonstrate the efficiency of our method by applying it to a hydrogen-terminated silicon cluster consisting of 364 atoms, with and without P impurities. For cases where direct comparison to experiment can be made, we reproduce the absorption features of fifteen small molecules [N2, O2, O3, NO2, N2O, NH3, H2O, H2CO, H2CO3, CO2, CH4, C2H2, C2H4, C2H6, C6H6] and find generally good agreement with experimental measurements. Our results are useful for the detection and the determination of orientation of these molecules. 相似文献
996.
Silver films were deposited on glass substrates under different deposition conditions, i.e. different film thicknesses, deposition rates and deposition angles. Their optical properties were measured by spectrophotometry in the spectral range of 185–3300 nm. The Kramers–Kronig method was used to analyze the reflectivity curves of the silver films to obtain their optical constants. The influence of substrate temperature on the microstructure of thin metallic films, the structure zone model (SZM), is well established, whereas there has been some previous work on the influence of film thickness and morphology, deposition rate and deposition angle on the microstructure and morphology of thin films. An effective medium approximation (EMA) analysis was used to establish the relationship between the atomic force microscopy results, SZM predictions and EMA results, and hence the optical properties of silver thin films. The predictions of the Drude free-electron theory are compared with experimental results for dielectric functions of Ag films produced under different deposition conditions. The real part of the dielectric constant increases with film thickness and decreases with increasing deposition rate and with increasing incidence angle, whereas the imaginary part of the dielectric constant decreases with increasing film thickness and deposition rate and with decreasing incidence angle over the whole energy range measured, including the interaband and interband regions. 相似文献
997.
通过优化薄膜硅基太阳能电池的背反电极,使背反电极表面出现均匀的类金字塔结构,能够增大入射光在结区的有效光程,提高光子的捕获率,进而会提高薄膜硅基太阳能电池的光电转换效率.本文采用磁控溅射技术在载玻片上制得Ag/AZO(ZnO∶Al)导电薄膜.在控制其它溅射参量为最优化的情况下,研究了衬底温度对Ag/AZO导电薄膜光电性能及其表面形貌的影响.研究表明:随着衬底温度的增加,薄膜的雾度在可见光范围内先增大后减小;当衬底温度为500℃时,雾度取得最大值,在可见光范围内平均达到了95%以上;电阻率随着衬底温度的增加逐渐增大,且衬底温度超过500℃时电阻率急剧增大.在综合考虑其光电性能的情况下,实验得到当衬底温度为500℃时,所获得的叠层薄膜表面雾度值最好且电阻率很小,这将有助于改善太阳能电池的性能. 相似文献
998.
ß. Иuëëep 《Isotopes in environmental and health studies》2013,49(11):400-405
Es wird die Isotopenübertragung im thermodynamischen Gleichgewicht zwischen deuteriertem Wasser und Wasserdampf natürlicher Isotopenzusammensetzung in einen Inertgasstrom, in Abhängigkeit von Temperatur, Mengenstrom des Gases, Geometrie der Versuchsanordnung und Natur des Gases untersucht. Für die globale Übertragungszahl und den Gesamtwiderstand werden Beziehungen abgeleitet, deren Gültigkeit experimentell geprüft werden kann. Auf Grund der experimentellen Ergebnisse wird gefolgert, daβ für die untersuchte Isotopenübertragung der Diffusionswiderstand bestimmend ist. 相似文献
999.
G. Hübner 《Isotopes in environmental and health studies》2013,49(3):116-119
Es wird ein Überblick über Aufgabenstellung und Ergebnisse neuerer Arbeiten der Abteihmg für Physiologie und Biochemie des Instituts für stabile Isotope gegeben. Die Arbeiten umfassen methodische Fortschritte bei der Anwendung stabiler Isotope in der Biologie, Untersuchungen zum Eiweiß- und Aminosäurestoffwechsel bei Pflanzen und das Studium der Wirkung von schwerem Wasser auf physiologische und biochemische Reaktionen. 相似文献
1000.
Zur Unlersuchung des Materia1transports aus einem Elektrolyten in eine feste Metallprobe während mechanischer Bearbeitung wurde ein Schichtabtragungsverfahren mit Messung der Restaktivität eingesetzt. Die einzelnen abgetragenen Schichten waren etwa 1 μm dick. Das Verfahren wurde an Cu-Material erprobt, in das 65Zn aus einer ZnCl2-Lösung eingedrungen war. Die Probenbearbeitung erfolgte auf tribogalvanischem Wege. 相似文献