全文获取类型
收费全文 | 464篇 |
免费 | 12篇 |
专业分类
化学 | 366篇 |
晶体学 | 2篇 |
力学 | 4篇 |
数学 | 3篇 |
物理学 | 101篇 |
出版年
2023年 | 2篇 |
2021年 | 5篇 |
2020年 | 8篇 |
2019年 | 11篇 |
2017年 | 3篇 |
2016年 | 7篇 |
2015年 | 8篇 |
2014年 | 8篇 |
2013年 | 19篇 |
2012年 | 17篇 |
2011年 | 31篇 |
2010年 | 13篇 |
2009年 | 15篇 |
2008年 | 29篇 |
2007年 | 18篇 |
2006年 | 21篇 |
2005年 | 19篇 |
2004年 | 31篇 |
2003年 | 21篇 |
2002年 | 20篇 |
2001年 | 17篇 |
2000年 | 7篇 |
1999年 | 16篇 |
1997年 | 2篇 |
1996年 | 10篇 |
1995年 | 2篇 |
1993年 | 4篇 |
1992年 | 7篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 5篇 |
1987年 | 6篇 |
1985年 | 15篇 |
1984年 | 12篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 7篇 |
1980年 | 3篇 |
1979年 | 9篇 |
1978年 | 4篇 |
1977年 | 4篇 |
1976年 | 2篇 |
1975年 | 5篇 |
1974年 | 3篇 |
1973年 | 2篇 |
1970年 | 3篇 |
1968年 | 2篇 |
1967年 | 2篇 |
1960年 | 1篇 |
排序方式: 共有476条查询结果,搜索用时 15 毫秒
71.
Analysis of Cu segregation to oxide–metal interface of Ni‐based alloy in a metal‐dusting environment
Takashi Doi Kazuyuki Kitamura Yoshitaka Nishiyama Nobuo Otsuka Takeo Kudo Masugu Sato Eiji Ikenaga Shigenori Ueda Keisuke Kobayashi 《Surface and interface analysis : SIA》2008,40(10):1374-1381
Hard X‐ray photoelectron spectroscopy (HX‐PES) has been realized using high‐brilliance synchrotron radiation. High‐energy photon excitation enables us to probe photoelectrons with larger escape depth compared to conventional PES. This allows us to conduct, without destruction, a study of the embedded interface of materials as the oxide‐ metal interface. We apply HX‐PES to investigate for Cu segregation in the oxide–metal interface during metal‐dusting corrosion. The effective concentration of Cu in the segregation was estimated a few times higher than the bulk concentration. These results on the interface layer can explain the variation in the corrosion resistance. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
72.
Oxidative Annulation of Arenecarboxylic and Acrylic Acids with Alkynes under Ambient Conditions Catalyzed by an Electron‐Deficient Rhodium(III) Complex 下载免费PDF全文
Eiji Kudo Dr. Yu Shibata Mutsumi Yamazaki Koji Masutomi Dr. Yuta Miyauchi Miho Fukui Haruki Sugiyama Prof. Dr. Hidehiro Uekusa Prof. Dr. Tetsuya Satoh Prof. Dr. Masahiro Miura Prof. Dr. Ken Tanaka 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(40):14190-14194
It has been established that an electron‐deficient CpE rhodium(III) complex catalyzes the oxidative [4+2] annulation of substituted arenecarboxylic and acrylic acids with alkynes under ambient conditions (at RT–40 °C, under air) without using excess amounts of substrates to produce the corresponding substituted isocoumarins and α‐pyrones in high yields. Minor modification of reaction conditions depending on the coordination ability of alkynes realized the high efficiency. 相似文献
73.
2‐Deoxystreptamine (2DOS) is the unique chemically stable aminocyclitol scaffold of clinically important aminoglycoside antibiotics such as neomycin, kanamycin, and gentamicin, which are produced by Actinomycetes. The 2DOS core can be decorated with various deoxyaminosugars to make structurally diverse pseudo‐oligosaccharides. After the discovery of biosynthetic gene clusters for 2DOS‐containing aminoglycoside antibiotics, the function of each biosynthetic enzyme has been extensively elucidated. The common biosynthetic intermediates 2DOS, paromamine and ribostamycin are constructed by conserved enzymes encoded in the gene clusters. The biosynthetic intermediates are then converted to characteristic architectures by unique enzymes encoded in each biosynthetic gene cluster. In this Personal Account, we summarize both common biosynthetic pathways and the pathways used for structural diversification.
74.
Manaka Y Kudo Y Yoshimine H Kawasaki T Kajikawa K Okahata Y 《Chemical communications (Cambridge, England)》2007,(34):3574-3576
Protein bindings onto a gold surface were detected simultaneously by QCM (delta F(water)) and anomalous reflection (deltaR) of gold on the same surface in aqueous solutions; the obtained delta F(water)/deltaR values correlated with surface areas and viscosity of proteins. 相似文献
75.
Kouki Ikuta Tsutomu Kudo Noboru Yoshikane Nilesh J. Vasa Yuji Oki Mitsuo Maeda 《Optical Review》1999,6(5):464-470
Improvement of an infrared light detection and ranging (IR-lidar) system for a short range (0–1000 m) and with high resolution is studied to enhance a geometrical form factor. Theoretical modeling of Mie scattering echo signals agrees with the experimental results. Introduction of a lens in front of the detector is effective for increasing the geometrical form factor, and a significant improvement in the received signal intensity is achieved, especially for short-range measurements around 100 m. This is useful for the IR-lidar system with a detector diameter of less than 1 mm. In the theoretical model, a ray-tracing technique was applied and a transmitting laser beam with Gaussian profile was considered for better accuracy. 相似文献
76.
T. Sekine M. Konishi H. Kudo K. Tagami S. Uchida 《Journal of Radioanalytical and Nuclear Chemistry》1999,239(3):483-487
A95mTc tracer with an excellent quality was prepared by a simple sublimation method after α-bombardment of niobium metal. Technetium-95m
produced by the93Nb(α,2n)95mTc reaction was separated from the niobium targets in a quartz tube by heating at 1100°C in an oxygen gas flow. Technetium-95m
sublimed as an oxide was deposited on the inner wall of the quartz tube outside an electric furnace, and then collected as
a pertechnetate solution by washing with water. The ICP-MS analysis of the95mTc solution revealed its excellent quality, compared to a95mTc solution prepared from the same targets through a wet chemical separation method and a commercial95mTc solution. With this tracer, the precision of ICP-MS analysis of99Tc in environmental samples are highly improved. 相似文献
77.
Y. Nagame I. Nishinaka Y. L. Zhao K. Tsukada S. Ichikawa Z. Qin H. Ikezoe Y. Oura K. Sueki H. Nakahara M. Tanikawa T. Ohtsuki S. Goto H. Kudo Y. Hamajima K. Takamiya K. Nakanishi H. Baba 《Journal of Radioanalytical and Nuclear Chemistry》1999,239(1):97-101
The correlation among the fission threshold energy, the scission configuration and the mass yield distribution has been studied
in proton-induced fission of light actinides. It was found that there exist at least two fission paths from the threshold
region to the scission. The elongated scission configuration is related with the fission process that goes over a higher threshold
energy and results in a symmetric mass division mode, while the compact scission configuration with the process that experiences
a lower threshold and ends up with an asymmetric mass division mode. 相似文献
78.
Selective formation of thecis isomer of the nitridotechnetium(V) complex with 2,2′:6′,2″-terpyridine
T. Takayama S. Oshikiri T. Sekine H. Kudo 《Journal of Radioanalytical and Nuclear Chemistry》1999,239(2):397-400
The reaction of [TcNCl2(PPh3)2] with 2,2′:6′,2″-terpyridine producedcis-[TcNCl2(terpy)] selectively. The resulting complexes were characterized by1H NMR and IR spectroscopy. The geometries of thecis andtrans isomers were estimated by theoretical calculations following a density functional method. Thecis isomer is likely more stable than thetrans one with respect to thetrans influence of the nitrido ligand. Furthermore, the behavior of nitridotechnetium complexes in polar solvents was compared
to Os-analogues. 相似文献
79.
Mariame A. Hassan Loreto B. Feril Kosho Suzuki Nobuki Kudo Katsuro Tachibana Takashi Kondo 《Ultrasonics sonochemistry》2009,16(3):372-378
Three novel lipid-shell-type microbubbles (MBs), AS-0100, BG6356A and BG6356B, have been evaluated for their impact on ultrasound (US)-induced cell death and free radicals production. Previously studied and well-characterized US exposure conditions were employed in which human myelomonocytic lymphoma U937 cells were exposed to 1 MHz pulsed US beam (0.3 W/cm2, 10% duty factor) for 1 min with or without MBs. Three different concentrations of each MB were used. Apoptosis and cell lysis were assessed by examining phosphatidylserine externalization and by counting viable cells, respectively, 6 h post-exposure. Free radicals production and scavenging activities were evaluated using electron paramagnetic resonance (EPR)-spin trapping. The results showed that only AS-0100 and BG6356A were able to enhance the US-induced apoptosis, mainly by increasing the secondary necrosis. Apoptosis and cell lysis seemed to depend more on mechanical forces exerted by oscillating MBs while free radicals played a trivial role. BG series MBs exhibited pronounced scavenging activities. Generally, despite the need for further optimization, AS-0100 and BG6356A appear to be promising as adjuncts in cases where US-induced cell death is required. 相似文献
80.
H. Kudo S. Sudo T. Oka Y. Hama A. Oshima M. Washio T. Murakami 《Radiation Physics and Chemistry》2009,78(12):1067-1070
Ion-beam irradiation effects on polyimide, Kapton™, were studied with respect to optical and electronic properties. Stack films of Kapton™ (12.5 μm thick) were irradiated to various ion beams in air or vacuo at room temperature and subjected to ultraviolet–visible (UV–vis) spectroscopy, and change in absorbance and energy gap is discussed. The UV–vis absorption spectrum, which is assigned to the transition of electrons in benzene rings from π to π* orbital, upon He2+ (6 MeV/u) irradiation in air, shifted towards longer wavelength direction for all cases, and the shift was more obvious for higher linear energy transfer (LET) ion beams. The energy gap of the transition was estimated, and the H+ and He2+ ion beams caused little change in the transition energy gap Eg, while the heavier ions such as C6+ and Si14+ caused more significant decrease. This decrease is assumed to the structural changes around benzene rings, and the infrared spectroscopy revealed breakage in imide groups next to benzene ring in the repeating unit of polyimide. 相似文献