全文获取类型
收费全文 | 184篇 |
免费 | 4篇 |
专业分类
化学 | 131篇 |
力学 | 4篇 |
数学 | 25篇 |
物理学 | 28篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 2篇 |
2020年 | 3篇 |
2019年 | 4篇 |
2016年 | 1篇 |
2015年 | 1篇 |
2014年 | 2篇 |
2013年 | 7篇 |
2012年 | 13篇 |
2011年 | 16篇 |
2010年 | 8篇 |
2009年 | 7篇 |
2008年 | 9篇 |
2007年 | 12篇 |
2006年 | 6篇 |
2005年 | 2篇 |
2004年 | 9篇 |
2003年 | 4篇 |
2002年 | 9篇 |
2001年 | 3篇 |
2000年 | 7篇 |
1999年 | 4篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1994年 | 5篇 |
1991年 | 5篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1987年 | 3篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 4篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 6篇 |
1978年 | 3篇 |
1977年 | 1篇 |
1975年 | 1篇 |
1973年 | 2篇 |
1971年 | 1篇 |
1968年 | 2篇 |
1962年 | 2篇 |
1933年 | 1篇 |
1930年 | 2篇 |
1929年 | 1篇 |
1928年 | 1篇 |
排序方式: 共有188条查询结果,搜索用时 390 毫秒
81.
Kenjiro Ogawa 《Discrete Mathematics》2009,309(11):3659-3663
In the upper bound graph of a poset P, the vertex set is V(P) and xy is an edge if there exists an m∈V(P) with x,y≤Pm. We show some characterizations on split upper bound graphs, threshold upper bound graphs and difference upper bound graphs in terms of m-subposets and canonical posets. 相似文献
82.
Oxide and silver paste were applied on the BaO-doped Bi2O3 electrolyte and their behavior was studied as a function of temperature and oxygen partial pressure. Interface resistance of most oxide/electrolyte were of the same order of magnitude with those of Ag paste/electrolyte in air (300–500°C). A high electrode capacitance of (0.8–1.7)×10?2 F/cm2 was observed for the silver electrode at 450°C in the PO2 region of 1–10?5 atm. 相似文献
83.
Helmut Bnnemann Charles Grard Werner Kopp Wichard Pump Kenjiro Tanaka Günther Wilke 《Angewandte Chemie (International ed. in English)》1973,12(12):964-975
The following report describes the preparation and reactions of organocobalt compounds, especially the thermally unstable tris(π-allyl)cobalt and cyclooctenylcobalt compounds. The stoichiometric and catalytic transformations of these highly reactive organocobalt systems give an insight into the rôle of cobalt in homogeneous catalysis involving alkenes and alkynes. 相似文献
84.
Michiaki Kumagai Yutaka Imai Teisaku Nakamura Yuichi Yamasaki Masaki Sekino Shoogo Ueno Kenjiro Hanaoka Kazuya Kikuchi Tetsuo Nagano Eiji Kaneko Kentaro Shimokado Kazunori Kataoka 《Colloids and surfaces. B, Biointerfaces》2007,56(1-2):174-Optics
PEG-coated β-FeOOH nanoparticles were prepared through electrostatic complex formation of iron oxide nanoparticles with poly(ethylene glycol)-poly(aspartic acid) block copolymer [PEG-P(Asp)] in distilled water. By dynamic light scattering (DLS) measurement, the nanopaticle size was determined to be 70 nm with narrow distribution. The FT-IR and zeta potential experimental results proved that PEG-PAsp molecules bound to the surface of the iron oxide nanoparticles via the coordination between the carboxylic acid residues in the PAsp segment of the block copolymer and the surface Fe of the β-FeOOH nanoparticles. The PEG-coated nanoparticles revealed excellent solubility and stability in aqueous solution as well as in physiological saline. In vivo MRI experiments on tumor-bearing mice demonstrated that the PEG-coated nanoparticles prepared by the current approach achieved an appreciable accumulation into solid tumor, suggesting their potential utility as tumor-selective MRI contrast agents. 相似文献
85.
Mifune M Minato K Kitamura Y Okazaki K Iwado A Akizawa H Haginaka J Motohashi N Saito Y 《Talanta》2004,63(4):1035-1038
To develop easy-to-prepare stationary phases for HPLC, we investigated anion-exchange silica gels, Nucleosil 5SB (Nuc), modified with metal-porphines and -phthalocyanines (M-P). The modified silica gels (M-PN) were evaluated for the availability as a stationary phase of HPLC for the separation of π-electron-rich polyaromatic hydrocarbons (PAHs) in polar and non-polar eluents. Separation ability of silica gels modified with Cu-phthalocyanine derivative (Cu-PCSN) was comparable to that of the silica gels binding Cu-PCS through sulfonamide bonds; however, the latter requires troublesome procedures for the preparation. The PAHs tested interact with Cu-PCSN in non-polar organic eluents through their π-electrons similarly as in the case of the PYE column®, in which interaction with PAHs was reported to be only the π-π-electron interaction. 相似文献
86.
Kazuo Eda Yuichi Iriki Kenjiro Kawamura Takeshi Ikuki Masahiko Hayashi 《Journal of solid state chemistry》2007,180(12):3588-3593
We succeeded to prepare novel [Mo36O112(H2O)16]8− ({Mo36}) compounds by using 1,3-diamino-2-propanol (βOHC3-DA) and 1,3,5-tris(aminomethyl)benzene (MES-TA)+1,3-diaminopropane (C3-DA) as linkers, and determined their crystal structures. We have confirmed they have unique two-dimensional (2-D) molybdenum oxide frameworks, which are formed by condensation of {Mo36}s. Side-staggered arrays of {Mo36}s, connected in lying position by eight bridges per a {Mo36}, are formed in the compound with βOHC3-DA, while herringbone arrays of {Mo36}s, connected in standing position by four bridges per a {Mo36}, are built in the compound with MES-TA+C3-DA. The latter compound exhibited non-stoichiometric property, and its composition and cell parameters varied depending on the relative concentration of MES-TA in the mother solution. 相似文献
87.
Kenjiro Takazawa 《Mathematical Programming》2008,115(2):223-237
88.
Poompat Rattanatraicharoen Yoko Tanaka Keiko Shintaku Takuro Kawaguchi Kazuhiro Yamabuki Tsutomu Oishi Kenjiro Onimura 《Journal of polymer science. Part A, Polymer chemistry》2013,51(6):1315-1322
Optically active poly(m‐phenylene)s substituted with chiral oxazoline derivatives have been synthesized by the nickel‐catalyzed Yamamoto coupling reaction of optically active (S)‐4‐benzyl‐2‐(3,5‐dihalidephenyl)oxazoline derivatives (X = Br or I). The structures and chiroptical properties of the polymers were characterized by spectroscopic methods and thermal gravimetric analyses. The polymers showed higher absolute optical specific rotation values than their corresponding monomer, and showed a Cotton effect at transition region of conjugated main chain. The optical activities of the polymers should be attributed to the higher order structure such as helical conformations. Moreover, the helical conformation could be induced by addition of metal salts into polymer solutions. The polymers showed good thermal stabilities, which was attributable to the oxazoline side chains. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013 相似文献
89.
90.
Shigeru Furuichi Ken Kuriyama Kenjiro Yanagi 《Linear algebra and its applications》2009,430(8-9):2271-2276
In this short paper, we study some trace inequalities of the products of the matrices and the power of matrices by the use of elementary calculations. 相似文献