全文获取类型
收费全文 | 230篇 |
免费 | 1篇 |
学科分类
数理化 | 231篇 |
出版年
2023年 | 1篇 |
2022年 | 5篇 |
2021年 | 2篇 |
2020年 | 4篇 |
2019年 | 2篇 |
2018年 | 10篇 |
2017年 | 7篇 |
2016年 | 8篇 |
2015年 | 7篇 |
2014年 | 14篇 |
2013年 | 11篇 |
2012年 | 12篇 |
2011年 | 18篇 |
2010年 | 8篇 |
2009年 | 3篇 |
2008年 | 7篇 |
2007年 | 9篇 |
2006年 | 10篇 |
2005年 | 9篇 |
2004年 | 7篇 |
2003年 | 6篇 |
2002年 | 4篇 |
2001年 | 8篇 |
2000年 | 5篇 |
1999年 | 2篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 4篇 |
1980年 | 1篇 |
1979年 | 4篇 |
1976年 | 1篇 |
1975年 | 6篇 |
1974年 | 3篇 |
1973年 | 3篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1965年 | 3篇 |
排序方式: 共有231条查询结果,搜索用时 15 毫秒
1.
2.
N. Shiran A. Gektin S. Neicheva V. Voronova V. Kornienko K. Shimamura N. Ichinose 《Radiation measurements》2004,38(4-6):459-462
Absorption, emission and thermoluminescence (TL) of as-grown and X-irradiated pure and Ce-doped LiCaAlF6 (LiCAF) and LiSrAlF6 (LiSAF) crystals have been analyzed. It is shown that the energy storage is defined by the dissimilarity of basic matrix properties, intrinsic defect structure, preferred Ce3+ ion disposition and charge compensation defect type. This is the reason of higher colorability and TL efficiency of as-grown Ce:LiSAF compared to Ce:LiCAF. Pre-filling of ultra-deep traps leads to enormous increases in the TL response. Due to these properties Ce:LiSAF and Ce:LiCAF are promising thermoluminescent dosimetric materials. 相似文献
3.
The allure of metal–organic frameworks (MOFs) in heterogeneous electrocatalysis is that catalytically active sites may be designed a priori with an unparalleled degree of control. An emerging strategy to generate coordinatively-unsaturated active sites is through the use of organic linkers that lack a functional group that would usually bind with the metal nodes. To execute this strategy, we synthesize a model MOF, Ni-MOF-74 and incorporate a fraction of 2-hydroxyterephthalic acid in place of 2,5-dihydroxyterephthalic acid. The defective MOF, Ni-MOF-74D, is evaluated vs. the nominally defect-free Ni-MOF-74 with a host of ex situ and in situ spectroscopic and electroanalytical techniques, using the oxidation of hydroxymethylfurtural (HMF) as a model reaction. The data indicates that Ni-MOF-74D features a set of 4-coordinate Ni–O4 sites that exhibit unique vibrational signatures, redox potentials, binding motifs to HMF, and consequently superior electrocatalytic activity relative to the original Ni-MOF-74 MOF, being able to convert HMF to the desired 2,5-furandicarboxylic acid at 95% yield and 80% faradaic efficiency. Furthermore, having such rationally well-defined catalytic sites coupled with in situ Raman and infrared spectroelectrochemical measurements enabled the deduction of the reaction mechanism in which co-adsorbed *OH functions as a proton acceptor in the alcohol oxidation step and carries implications for catalyst design for heterogeneous electrosynthetic reactions en route to the electrification of the chemical industry.The allure of metal–organic frameworks (MOFs) in heterogeneous electrocatalysis is that catalytically active sites may be designed a priori with an unparalleled degree of control. 相似文献
4.
Structurally novel cyclitols, 1-aryl-1-deoxyconduritols F, were efficiently prepared from d-xylose, utilizing RCM as a key step. Various aromatic residues were incorporated in the cyclitol skeleton with total stereochemical control, utilizing a diastereoselective aryl cuprate addition to a gamma-alkoxy enoate. The synthetic route establishes a firm foundation for a practical synthesis of the antitumor alkaloid pancratistatin and its aryl analogues. [structure: see text] 相似文献
5.
A. V. Kravtsov E. D. Ivanchina A. V. Kornienko 《Reaction Kinetics and Catalysis Letters》1997,61(1):161-166
A new method for computer prediction of the catalytic activity dependence on service life and technological conditions for
bifunctional Pt catalysts has been proposed. The proposed method is based on physical and chemical laws of multicomponent
hydrocarbon transformations on polymetallic catalysts and takes into account deactivation of acidic (Al) and metallic (Pt)
sites. It allows to calculate the product composition and catalytic activity level for real industrial units as a function
of their technological parameters and raw material characteristics. 相似文献
6.
7.
V. V. Kornienko G. Kh. Kitaeva I. I. Naumova A. N. Tuchak A. N. Penin P. V. Yakunin 《Optics and Spectroscopy》2014,116(4):520-528
Principal parameters of the nonlinear-optical crystals are analyzed, which govern the spectral sensitivity of the terahertz wave detectors based on the frequency conversion from terahertz to optical range. A method is developed and experimentally demonstrated for characterizing these parameters. The method is founded on the spontaneous parametric down-conversion spectra observation without external terahertz wave radiation. 相似文献
8.
T. A. Kenova I. S. Vasilieva V. L. Kornienko V. P. Varnin 《Russian Journal of Electrochemistry》2013,49(11):1086-1091
The kinetics and selectivity of the oxidation of thiocyanate on a boron-doped diamond (BDD) electrode in a 0.5 M solution of H2SO4 were studied. An analysis of the cyclic voltammetry curves showed that the oxidation of SCN? was irreversible and occurred with diffusion control in the range of water decomposition potentials. The obtained kinetic dependences can be described by the pseudo-first order equation. The apparent rate constant depends on the current density and initial concentration of the reagent. The main product of oxidation at low current density and high concentration of SCN? was CN?. 相似文献
9.
A. M. Kosheleva N. V. Chaenko G. V. Kornienko V. I. Vlasenko V. L. Kornienko 《Russian Journal of Electrochemistry》2013,49(1):96-99
The process of nonanol-1 oxidation is studied on the nickel oxide electrode with the use of chemically bound active oxygen forms (AOF) electrochemically generated in situ from O2, H2O2, and H2O. The effect of electrolysis conditions (AOF generation schemes, current density, passed charge) on the yield of pelargonic acid is studied. The oxidation proceeds most efficiently at the current density of 5–10 mA cm?2 as the theoretical charge is passed in the paired electrolysis mode. The current efficiency with respect to pelargonic acid is 83.7%; the substance yield is 83.8%. In addition to pelargonic acid, several oxidation side-products are found in the electrolyte. Their content increases with the increase in the charge passed as a result of further oxidation of pelargonic acid. 相似文献
10.