全文获取类型
收费全文 | 77篇 |
免费 | 2篇 |
国内免费 | 1篇 |
专业分类
化学 | 54篇 |
晶体学 | 3篇 |
力学 | 4篇 |
物理学 | 19篇 |
出版年
2024年 | 1篇 |
2023年 | 1篇 |
2022年 | 3篇 |
2021年 | 3篇 |
2020年 | 4篇 |
2017年 | 3篇 |
2016年 | 10篇 |
2015年 | 3篇 |
2014年 | 5篇 |
2013年 | 3篇 |
2012年 | 5篇 |
2011年 | 6篇 |
2010年 | 1篇 |
2009年 | 2篇 |
2008年 | 3篇 |
2007年 | 11篇 |
2006年 | 1篇 |
2005年 | 2篇 |
2004年 | 4篇 |
2002年 | 2篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
排序方式: 共有80条查询结果,搜索用时 15 毫秒
51.
A. M. Yusof C. H. Chia A. K. H. Wood 《Journal of Radioanalytical and Nuclear Chemistry》2007,273(3):533-538
Inorganic Cr(III) and Cr(VI) have contrasting biological, geochemical and toxicology effects. Cr(III) is considered as an
essential species for the proper functioning of living organisms but Cr(VI) is toxic for the biological systems. An off-line
speciation method using Chelex-100 has been practiced for speciation to Cr(III) and Cr(VI) from surface waters of rivers.
The underlying principal of this separation method is based on the ability of cationic Cr(III) to be retained by the resin
Chelex-100 while the anionic Cr(VI) remained in the sample matrices. The efficiency of this technique was improved by studying
the effect of resin pH. Quantitative determination using inductively coupled plasma-mass spectrometry (ICP-MS) and instrumental
neutron activation analysis (INAA) was carried out after the separation to determine the total Cr and Cr(VI) in the liquid
matrices. The precision and the accuracy of the quantitative analysis were evaluated by using standard reference material
NRCC CASS-2 Intercomparison of INAA and ICP-MS results were determined. The quantity of inorganic Cr(III) and Cr(VI) in the
surface water of rivers in the vicinity of industrial areas was investigated together with the determination of the physical
properties of the water rivers during sampling. 相似文献
52.
Emmy Fadhiza Damit Nor Saadah M. Yusof Azhar Ariffin M. Niyaz Khan 《Journal of the Iranian Chemical Society》2012,9(5):723-727
The values of pseudo-first-order rate constants (k obs) for the acetolysis of phthalic anhydride (PAn) increase from 6.60?×?10?7 to 31.5?×?10?7?s?1 with the increase in temperature from 30 to 50?°C. These values of k obs give activation parameters ?H* and ?S* as 14.4?±?0.4?kcal?mol?1 and ?39.1?±?1.3?cal?K?1?mol?1, respectively. The values of k obs remain essentially unchanged with the increase in the content of CS (CS?=?CH3CN or THF) from 0 to 40?% v/v in mixed AcOH?CCS solvents. These observations have been explained qualitatively. 相似文献
53.
Power JG Gai W Gold SH Kinkead AK Konecny R Jing C Liu W Yusof Z 《Physical review letters》2004,92(16):164801
We report a new regime of single-surface multipactor that was observed during high-power testing of an 11.424-GHz alumina-based dielectric-loaded accelerating structure. Previous experimental observations of single-surface multipactor on a dielectric occurred in cases for which the rf electric field was tangential and the rf power flow was normal to the dielectric surface (such as on rf windows) and found that the fraction of power absorbed at saturation is approximately 1%, independent of the incident power. In this new regime, in which strong normal and tangential rf electric fields are present and the power flow is parallel to the surface, the fraction of power absorbed at saturation is an increasing function of the incident power, and more than half of the incident power can be absorbed. A simple model is presented to explain the experimental results. 相似文献
54.
A. M. Yusof V. Thanapalasingham A. K. H. Wood 《Journal of Radioanalytical and Nuclear Chemistry》2007,273(3):525-531
Inductively coupled plasma-mass spectrometry (ICP-MS) and neutron activation analysis (NAA) were employed in the determination
of heavy metal concentrations in water, plant and sediment samples to assess the extent of heavy metal pollution in a river
system which is located within an industrial zone. Elemental concentrations of As, Pb, Hg, Cr, Cu, Cd, Ni and Zn were measured
in the samples. Statistical analysis was performed on the data obtained to look for trends in the pollution pattern of these
elements on the river system. The trend in concentrations of heavy metals pollution in water samples is in the order of Zn
> Cu > Ni > Cr > As > Pb > Hg > Cd, whereas in plants the order is Zn > Cr > Cu > Pb > Ni > As > Hg > Cd and in sediments
Zn > Cu > Pb > Ni > As > Hg. 相似文献
55.
Lycopene is a well-known compound found commonly in tomatoes which brings wide range of health benefits against cardiovascular diseases and cancers. From an anti-cancer perspective, lycopene is often associated with reduced risk of prostate cancer and people often look for it as a dietary supplement which may help to prevent cancer. Previous scientific evidence exhibited that the anti-cancer activity of lycopene relies on its ability to suppress oncogene expressions and induce proapoptotic pathways. To further explore the real potential of lycopene in cancer prevention, this review discusses the new insights and perspectives on the anti-cancer activities of lycopene which could help to drive new direction for research. The relationship between inflammation and cancer is being highlighted, whereby lycopene suppresses cancer via resolution of inflammation are also discussed herein. The immune system was found to be a part of the anti-cancer system of lycopene as it modulates immune cells to suppress tumor growth and progression. Lycopene, which is under the family of carotenoids, was found to play special role in suppressing lung cancer. 相似文献
56.
Mohd Yusof Norfadzlia Muda Azah Kamilah Pratama Satrya Fajri Carbo-Dorca Ramon 《Molecular diversity》2022,26(3):1609-1619
Molecular Diversity - Amphetamine-type stimulants (ATS) drug analysis and identification are challenging and critical nowadays with the emergence production of new synthetic ATS drugs with... 相似文献
57.
M. M. Quazi M. A. Fazal A. S. M. A. Haseeb Farazila Yusof H. H. Masjuki A. Arslan 《固体与材料科学评论》2016,41(2):106-131
Aluminum (Al) and its alloys have widespread engineering applications because of their higher strength to weight ratio, ductility, and formability. However, in various applications, mechanical properties such as hardness, corrosion, wear, and fatigue resistance are prerequisite at near surface regions. Such localized modification without affecting the bulk phase can be performed by various surface-engineering approaches including electro-deposition, physical and chemical vapor depositions, thermal spraying, plasma spraying, and organic polymeric coatings. Delamination failure of such coatings from the substrate is often inevitable due to the difference in film-to-substrate elastic modulus associated with the aforementioned processes. Recently, researchers have adopted a new approach of laser surface engineering to modify the near surface regions of metallic substrate by laser beams resulting in superior mechanical properties with the formation of novel microstructures. In this article, the recent developments in the surface modification of Al and its alloy by laser treatment are reviewed. Processing parameters and resulting microstructures of Al and its alloys are briefly summarized, along with their impact on mechanical properties. Finally, this article concludes future research directions. 相似文献
58.
59.
A. Nata Atmaja H. Abu Kassim N. Yusof 《The European Physical Journal C - Particles and Fields》2015,75(11):565
We study the screening length \(L_{\mathrm{max}}\) of a moving quark–antiquark pair in a hot plasma, which lives in a two sphere, \(S^2\), using the AdS/CFT correspondence in which the corresponding background metric is the four-dimensional Schwarzschild–AdS black hole. The geodesic of both ends of the string at the boundary, interpreted as the quark–antiquark pair, is given by a stationary motion in the equatorial plane by which the separation length L of both ends of the string is parallel to the angular velocity \(\omega \). The screening length and total energy H of the quark–antiquark pair are computed numerically and show that the plots are bounded from below by some functions related to the momentum transfer \(P_c\) of the drag force configuration. We compare the result by computing the screening length in the reference frame of the moving quark–antiquark pair, in which the background metrics are “Boost-AdS” and Kerr–AdS black holes. Comparing both black holes, we argue that the mass parameters \(M_{\mathrm{Sch}}\) of the Schwarzschild–AdS black hole and \(M_{\mathrm{Kerr}}\) of the Kerr–AdS black hole are related at high temperature by \(M_{\mathrm{Kerr}}=M_{\mathrm{Sch}}(1-a^2l^2)^{3/2}\), where a is the angular momentum parameter and l is the AdS curvature. 相似文献
60.
The application of ultrasonics in metal forming applications has been shown to reduce the forming load significantly in many research studies. The load reduction has been related to the stress superposition effect, rise in temperature and change in the friction condition between the specimen and die interfaces. This paper reports an investigation into the effects of superimposed ultrasonic oscillation of the die in compression tests on aluminium specimens. In particular, a finite element model is developed to simulate uniaxial compression and to model the effects of a change in the friction boundary condition when ultrasonic excitation is applied to the lower platen. The model predictions of the stress-strain relationship can be compared with test data to provide some insights into the effects of the interfacial condition. The paper shows how the analysis of the test data, combined with finite element models of ultrasonic compression test simulations, allows some initial conclusions to be drawn regarding the influence of the interfacial friction during ultrasonic compression. 相似文献