全文获取类型
收费全文 | 44篇 |
免费 | 5篇 |
专业分类
化学工业 | 13篇 |
机械仪表 | 1篇 |
建筑科学 | 1篇 |
能源动力 | 1篇 |
轻工业 | 3篇 |
无线电 | 3篇 |
一般工业技术 | 18篇 |
冶金工业 | 8篇 |
自动化技术 | 1篇 |
出版年
2022年 | 1篇 |
2021年 | 3篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 5篇 |
2016年 | 5篇 |
2015年 | 3篇 |
2014年 | 1篇 |
2013年 | 3篇 |
2012年 | 2篇 |
2009年 | 1篇 |
2008年 | 1篇 |
2006年 | 1篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1993年 | 2篇 |
1988年 | 1篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1970年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有49条查询结果,搜索用时 15 毫秒
21.
Immobilization of a molybdenum-glycine Schiff base complex onto the supercages of zeolite Y was achieved through the flexible ligand method. The prepared material was characterized by different physicochemical techniques. FT-IR spectroscopy confirmed the immobilization of the complex onto the nanocages of zeolite Y. X-ray diffraction analysis revealed that textural properties of zeolite Y support were preserved during the immobilization process. Nitrogen adsorption–desorption analysis demonstrated the decrease in surface area of the prepared material in comparison with parent zeolite Y. Inductively coupled plasma optical emission spectroscopy showed the presence of 0.75 mmol g?1 molybdenum in the final material. The obtained material exhibited high catalytic activity, stability, and recyclability in the epoxidation of olefins with tert-butylhydroperoxide as oxidant. 相似文献
22.
23.
R. Saidur M. Rezaei W.K. Muzammil M.H. Hassan S. Paria M. Hasanuzzaman 《Renewable & Sustainable Energy Reviews》2012,16(8):5649-5659
The focus of this study is to review the latest developments and technologies on waste heat recovery of exhaust gas from internal combustion engines (ICE). These include thermoelectric generators (TEG), organic Rankine cycle (ORC), six-stroke cycle IC engine and new developments on turbocharger technology. Furthermore, the study looked into the potential energy savings and performances of those technologies. The current worldwide trend of increasing energy demand in transportation sector are one of the many segments that is responsible for the growing share of fossil fuel usage and indirectly contribute to the release of harmful greenhouse gas (GHG) emissions. It is hoped that with the latest findings on exhaust heat recovery to increase the efficiency of ICEs, world energy demand on the depleting fossil fuel reserves would be reduced and hence the impact of global warming due to the GHG emissions would fade away. 相似文献
24.
We study the impact of correlated neuronal firing rate variability on the accuracy with which an encoded quantity can be extracted from a population of neurons. Contrary to widespread belief, correlations in the variabilities of neuronal firing rates do not, in general, limit the increase in coding accuracy provided by using large populations of encoding neurons. Furthermore, in some cases, but not all, correlations improve the accuracy of a population code. 相似文献
25.
Activated carbons were prepared by two chemical methods and the adsorption of Cu (II) on activated carbons from aqueous solution containing amino groups was studied. The first method involved the chlorination of activated carbon following by substitution of chloride groups with amino groups, and the second involved the nitrilation of activated carbon with reduction of nitro groups to amino groups. Resultant activated carbons were characterized in terms of porous structure, elemental analysis, FTIR spectroscopy, XPS, Boehm titration, and pHzpc. Kinetic and equilibrium tests were performed for copper adsorption in the batch mode. Also, adsorption mechanism and effect of pH on the adsorption of Cu (II) ions were discussed. Adsorption study shows enhanced adsorption for copper on the modified activated carbons, mainly by the presence of amino groups, and the Freundlich model is applicable for the activated carbons. It is suggested that binding of nitrogen atoms with Cu (II) ions is stronger than that with H+ions due to relatively higher divalent charge or stronger electrostatic force. 相似文献
26.
Effects of cannabinoid on expression of beta-type transforming growth factors (TGF-beta 1, -beta 2 and -beta 3), insulin-like growth factor-I (IGF-I) and c-myc genes in the uteri of adult ovariectomized mice were examined using Northern blot hybridization. Mice were exposed to 9-ene-tetrahydrocannabinol (THC) alone or in combination with an injection of estradiol-17 beta (E2) and/or progesterone (P4), and uteri were analyzed at various times thereafter. TGF-beta isoform messenger RNAs (mRNAs) persisted in ovariectomized uteri and their levels were not altered after THC treatment, whereas an injection of E2 caused a modest increase in TGF-beta 1 and -beta 3 mRNA levels at 24 h. Imposition of THC treatment advanced the stimulatory effects of E2 by changing the timing for the peak of TGF-beta 3 mRNA levels to 12 h. In comparison, E2 treatment substantially elevated the levels of TGF-beta 2 mRNA at 6 h, and THC potentiated this E2 response without affecting the timing for the response. Imposition of P4 treatment did not antagonize any of these responses. P4 treatment alone or with THC had insignificant effects on mRNA levels for these TGF-beta isoforms. Uterine levels of IGF-I and c-myc mRNAs were low in ovariectomized mice and THC did not alter these mRNA levels. In contrast, E2 treatment induced a rapid, but transient, increase in IGF-I and c-myc mRNAs, and THC antagonized the rapid c-myc mRNA response and altered the timing of the IGF-I mRNA response. P4 treatment alone also caused the transient induction of these mRNAs, but THC failed to antagonize these effects. An injection of P4 plus E2 resulted in further modest increases in IGF-I and c-myc mRNA levels as compared to E2 or P4 treatment alone. However, THC did not antagonize these transient stimulatory effects of the combined ovarian steroids. The data suggest that THC should not be classified as estrogenic or antiestrogenic. However, this compound can modulate (potentiate, antagonize and/or alter timing) the effects of ovarian steroids on uterine gene expression. 相似文献
27.
Paria Soleimani Rassoul Noorossana S. T. A. Niaki 《The International Journal of Advanced Manufacturing Technology》2013,67(5-8):1857-1865
Recently, many researchers and practitioners have shown interest on profile monitoring as a relatively new subarea of statistical process control. One main reason for this interest, and perhaps a key factor for the contributions of many researchers to this field, is the various applications of profile monitoring in real life. Although one can easily encounter many univariate applications of profile monitoring in service and manufacturing environments, there exist situations where quality of a product or process needs to be modeled in multivariate terms. In this paper, we investigate monitoring of multivariate simple linear profiles in phase II when independence assumption of observations within profile is violated. A remedial measure based on a transformation method is proposed to remove the autocorrelation structure within multivariate profiles, and numerical simulation is used as a vehicle to evaluate the effect of the proposed solution. Finally, a case study is considered to show the application of the model in practice. 相似文献
28.
Mangalkanti Paria Chinmay K. Maiti N. B. Chakrabarti 《Journal of Materials Science》1982,17(5):1459-1464
Lithium ferrite, Li0.5Fe2.5O4, has been prepared by decomposition of organometallic complexes at 800° C, and the optimization of heating schedule for conversion into ferrite has been studied. The effects of addition of glass, essential for adhesion of the ferrite film to alumina substrates, and bismuth oxide, as a sintering aid, on the properties and densification of lithium ferrite have been examined. X-ray diffraction, electron probe micro analysis (EPMA) and scanning electron microscopy (SEM) techniques have been used to study the solubility and distribution of bismuth oxide, grain growth and pore morphology. It has been found that the addition of bismuth oxide (up to 1.5 wt%) improves densification and increases resistivity of the lithium ferrite but the addition of glass causes a reduction of the resistivity. Although bismuth oxide forms a solid solution, it is not uniformly distributed throughout the ferrite phase. It is shown that the addition of bismuth oxide improves the insertion loss in microwave devices fabricated using ferrimagnetic pastes. 相似文献
29.
BC Paria W Ma DM Andrenyak PC Schmid HH Schmid DE Moody H Deng A Makriyannis SK Dey 《Canadian Metallurgical Quarterly》1998,58(6):1490-1495
We examined the relative importance of G (Gi) protein-coupled brain-type (CB1-R) and spleen-type (CB2-R) cannabinoid receptors in preimplantation embryo development using agonists and antagonists specific to CB1-R and CB2-R. The results establish that endogenous cannabinoid ligands, anandamide and sn-2 arachidonoylglycerol, arrest embryo development in vitro, and this effect is reversed by CB1-R antagonists SR141716A or AM 251, but not by SR144528, a CB2-R antagonist. A CB2-R selective agonist AM 663 failed to affect embryo development. These results suggest that cannabinoid effects on embryo development are mediated by CB1-R. We also observed that delta9-tetrahydrocannabinol ([-]THC) infused in the presence of cytochrome P450 inhibitors interfered with blastocyst implantation. This adverse effect was reversed by coinfusion of SR141716A. The less active stereoisomer (+)THC plus the inhibitors failed to affect implantation. Analysis of tissue levels demonstrated that uterine accumulation of (-)THC occurred when it was infused in the presence of the P450 inhibitors. These results demonstrate that the uterus and perhaps the embryo have the cytochrome P450 enzymes to metabolize (-)THC and neutralize its adverse effects on implantation. Collectively, the present study demonstrates that cannabinoid effects on embryo development and implantation are mediated by embryonic and/or uterine CB1-R, but not CB2-R. 相似文献
30.
PC Schmid BC Paria RJ Krebsbach HH Schmid SK Dey 《Canadian Metallurgical Quarterly》1997,94(8):4188-4192
Anandamide (N-arachidonoylethanolamine) is an endogenous ligand for both the brain-type (CB1-R) and spleen-type (CB2-R) cannabinoid receptors. This investigation demonstrates that the periimplantation mouse uterus contains the highest levels of anandamide (142-1345 pmol/micromol lipid P; 1-7 microg/g wet weight) yet discovered in a mammalian tissue. The levels fluctuate with the state of pregnancy; down-regulation of anandamide levels is associated with uterine receptivity, while up-regulation is correlated with uterine refractoriness to embryo implantation. Anandamide levels are highest during the nonreceptive phase in the pseudopregnant uterus and in the interimplantation sites, and lowest at the site of embryo implantation. The lower levels of uterine anandamide at the implantation sites may be a mechanism by which implanting embryos protect themselves from the detrimental effects of this endogenous ligand. We also observed a reduced rate of zona-hatching of blastocysts in vitro in the presence of anandamide, and inhibition of implantation by systemic administration of a synthetic cannabinoid agonist CP 55,940. These adverse effects were reversed by SR141716A, a specific CB1-R antagonist. Taken together, the results suggest that an aberrant synthesis of anandamide and/or expression of the cannabinoid receptors in the uterus/embryo may account for early pregnancy failure or female infertility. 相似文献