全文获取类型
收费全文 | 184篇 |
免费 | 1篇 |
专业分类
化学 | 82篇 |
晶体学 | 2篇 |
数学 | 43篇 |
物理学 | 58篇 |
出版年
2022年 | 2篇 |
2017年 | 3篇 |
2016年 | 2篇 |
2014年 | 4篇 |
2013年 | 8篇 |
2012年 | 6篇 |
2011年 | 6篇 |
2010年 | 4篇 |
2008年 | 5篇 |
2007年 | 5篇 |
2006年 | 16篇 |
2005年 | 12篇 |
2004年 | 12篇 |
2003年 | 3篇 |
2002年 | 5篇 |
2001年 | 2篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1998年 | 3篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 4篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1979年 | 2篇 |
1977年 | 2篇 |
1975年 | 4篇 |
1973年 | 2篇 |
1970年 | 3篇 |
1958年 | 2篇 |
1944年 | 2篇 |
1934年 | 2篇 |
1931年 | 2篇 |
1930年 | 2篇 |
1924年 | 2篇 |
1923年 | 2篇 |
1916年 | 2篇 |
1915年 | 1篇 |
1914年 | 3篇 |
1913年 | 1篇 |
1912年 | 1篇 |
1907年 | 2篇 |
1906年 | 1篇 |
1900年 | 1篇 |
1894年 | 1篇 |
1892年 | 1篇 |
1890年 | 2篇 |
1889年 | 2篇 |
排序方式: 共有185条查询结果,搜索用时 15 毫秒
161.
162.
163.
T. A. Luther R. S. Herbst D. R. Peterman R. D. Tillotson T. G. Garn V. A. Babain I. V. Smirnov E. S. Stoyanov N. G. Antonov 《Journal of Radioanalytical and Nuclear Chemistry》2006,267(3):603-613
Summary Scientists at the Idaho National Laboratory (INL) and Khlopin Radium Institute (KRI) collaboratively developed and validated
the concept of a Universal Extraction (UNEX) process for simultaneously removing the major radionuclides (Cs, Sr, actinides,
and lanthanides) from acidic radioactive waste in a single solvent extraction process. The process chemistry is unique and
complicated, since the extractants, chlorinated cobalt dicarbollide (CCD), polyethylene glycol (PEG), and diphenyl-N,N-di-n-butylcarbamoylmethylphosphine oxide (Ph2CMPO), operatesynergistically to extract the major radionuclides.A combination of classical chemistry techniques, infrared
(IR) spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy were utilized to identify and explain the structures
formed in the organic phase with protons or metal ions. Model systems, CCD-PEG and CCD-bidentate organophosphorus compounds
were studied and possible structures of complexes, existing in the organic phase, are proposed and properties of the UNEX
extractant are discussed. 相似文献
164.
The zero set of one general multivariate polynomial is enclosed by unions and intersections of funnel-shaped unbounded sets. There are sharper enclosures for the zero set of a polynomial in two complex variables with complex interval coefficients. Common zeros of a polynomial system can be located by an appropriate intersection of these enclosure sets in an appropriate space. The resulting domain is directly brought into polynomial equation solvers. 相似文献
165.
166.
We have investigated all-optical analog-to-digital quantization by broadening the pulse spectrum in a chalcogenide (As2S3) waveguide and subsequently slicing the measured spectrum using an array of filters. Pulse spectral broadening was measured for 8 different power levels in a 6 cm long As2S3 waveguide and used to analyze an 8-level all-optical quantization scheme employing filters with full-width at half-maximum (FWHM) bandwidth of 2 nm. A supercontinuum spectrum with −15 dB spectral width up to 324 nm was observed experimentally at large powers. This large spectral broadening, combined with filtering using a 128 channel arrayed waveguide grating (AWG) with 2 nm filter spacing, has the potential for all-optical quantization with 7-bit resolution. In order to encode the quantized signal we propose an encoder scheme which can be implemented using optical Exclusive-OR gates. Demonstrating all-optical quantization using a planar waveguide is an important step towards realizing all-optical A/D conversion on a chip. 相似文献
167.
This paper deals with the growth of coloured zirconium oxide crystals, cubic stabilized with yttrium oxide. The host material–zirconia–is colourless. To generate colourations minor concentrations of 3d- and 4f-elements are incorporated into the lattice. The resulting colours are dependent on the ions' valence and the local crystal symmetry. Both, the possibility to change the ions' valence by heat treatment, and the possibility to change the local crystal symmetry by alteration of the starting yttria concentration, are discussed in the following. 相似文献
168.
Distance algorithms are most frequently used in robotics to determine the distance between two obstacles in the environment of a robot or between a sensor point and an object. We extend the multibody simulation package MOBILE for an application of accurate algorithms for distance computation between objects represented by convex or non-convex polyhedra. These objects are represented by their vertices and oriented facets. As an application example, a multibody system is discussed where a sensor point moves close to a non-convex obstacle. The computed results show that the algorithms developed are suitable for accurate real-time multibody simulations. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
169.
In this paper, we present an integrated environment for validated modeling and simulation of kinematics and dynamics of various classes of mechanical systems SMARTMOBILE ( S imulation and M odeling of dyn A mics in MOBILE: R eliable and T emplate–based) built on top of the non-validated tool MOBILE. We outline the main features of SMARTMOBILE and its applicability area. The functionality of the new tool and the importance of the application of validated techniques are demonstrated. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
170.
Metal Sulfide Cluster Complexes and their Biogeochemical Importance
in the Environment 总被引:1,自引:0,他引:1
Aqueous clusters of FeS, ZnS and CuS constitute a major fraction of the dissolved metal load in anoxic oceanic, sedimentary,
freshwater and deep ocean vent environments. Their ubiquity explains how metals are transported in anoxic environmental systems.
Thermodynamic and kinetic considerations show that they have high stability in oxic aqueous environments, and are also a significant
fraction of the total metal load in oxic river waters. Molecular modeling indicates that the clusters are very similar to
the basic structural elements of the first condensed phase forming from aqueous solutions in the Fe–S, Zn–S and Cu–S systems.
The structure of the first condensed phase is determined by the structure of the cluster in solution. This provides an alternative
explanation of Ostwald’s Rule, where the most soluble, metastable phases form before the stable phases. For example, in the
case of FeS, we showed that the first condensed phase is nanoparticulate, metastable mackinawite with a particle size of 2 nm
consisting of about 150 FeS subunits, representing the end of a continuum between aqueous FeS clusters and condensed material.
These metal sulfide clusters and nanoparticles are significant in biogeochemistry. Metal sulfide clusters reduce sulfide and
metal toxicity and help drive ecology. FeS cluster formation drives vent ecology and AgS cluster formation detoxifies Ag in
Daphnia magna neonates. We also note a new reaction between FeS and DNA and discuss the potential role of FeS clusters in denaturing DNA.
An erratum to this article is available at . 相似文献