全文获取类型
收费全文 | 216篇 |
免费 | 1篇 |
专业分类
化学工业 | 16篇 |
金属工艺 | 2篇 |
机械仪表 | 7篇 |
建筑科学 | 7篇 |
能源动力 | 22篇 |
轻工业 | 89篇 |
石油天然气 | 1篇 |
无线电 | 8篇 |
一般工业技术 | 18篇 |
冶金工业 | 40篇 |
自动化技术 | 7篇 |
出版年
2022年 | 1篇 |
2018年 | 2篇 |
2017年 | 2篇 |
2016年 | 1篇 |
2014年 | 8篇 |
2013年 | 8篇 |
2012年 | 13篇 |
2011年 | 24篇 |
2010年 | 11篇 |
2009年 | 4篇 |
2008年 | 13篇 |
2007年 | 14篇 |
2006年 | 14篇 |
2005年 | 16篇 |
2004年 | 17篇 |
2003年 | 8篇 |
2002年 | 6篇 |
2001年 | 1篇 |
2000年 | 2篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1990年 | 4篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 4篇 |
1984年 | 2篇 |
1983年 | 6篇 |
1982年 | 1篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1979年 | 3篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1969年 | 1篇 |
1964年 | 2篇 |
1962年 | 1篇 |
1958年 | 1篇 |
排序方式: 共有217条查询结果,搜索用时 15 毫秒
1.
Reed M. Izatt Steven R. Izatt Don W. Mcbride Jr. Jerald S. Bradshaw James J. Christensen 《Israel journal of chemistry》1985,25(1):27-32
Macrocycle-mediated fluxes of Cd(NO3)2 and of several binary mixtures of Cd(NO3)2 with the nitrate salt of either Na+, K+, Rb+ Cs+, Ag+, Ca2+, Sr2+, Pb2+, Zn2+, or Cu2+ have been determined in a H2O-CHCl3–H2O liquid membrane system. Of the macrocycles studied, 2.2 and 2.2DD most successfully transported Cd2+ In the Cd2+–Mn+ mixtures, Cd2+ was transported selectively with 2.2 when Mn+ was either an alkali or an alkaline earth cation. However, when Mn+ was either Ag+, Pb2+, or Cu2+ the Cd2+ flux was reduced sharply. Generally, cation flux was greater for 2.2DD than for 2.2 with selectivity for Cd2+ being altered also in several cases. Relative fluxes from binary cation mixtures depend on metal cation radius, macrocycle cavity diameter, ligand ring substituent and log K for metal ion-macrocycle interaction. 相似文献
2.
Mladejovsky Michael G. Eddington Donald K. Evans Jerald R. Dobelle William H. 《IEEE transactions on bio-medical engineering》1976,(4):286-296
Electrical stimulation of the visual cortex of the brain results in punctate photic sensations called ``phosphenes.' This suggests the concept of producing artificial vision for the blind by implanting arrays of electrodes, producing scoreboard-like displays. Electrical stimulation of the cochlea, VIIIth nerve, and auditory cortex produces analogous auditory sensations called ``audenes,' which might be used to provide artificial hearing for the deaf. 相似文献
3.
Experimental investigation of low-velocity impact characteristics of woven glass fiber epoxy matrix composite laminates of EP3 grade 总被引:1,自引:0,他引:1
This work presents the results of an experimental investigation concerning the low-velocity impact behavior of woven glass fiber epoxy matrix composite laminates. Experimental test were performed according to ASTM standards using an instrumented falling weight impact testing machine. Impact test were conducted to characterize the type and extent of the damage observed in laminate for range of thickness subjected to different impact velocities. Correlation of the residual indentation of the impacted specimens provides a criterion for the extent of the damage. As the impact energy was increased, the samples experienced one of two types of damages: a crack from the center of the laminate to the edge, or significant damage consisting of a dent localized in the region of impact. The history of relevant kinematical, dynamic and energetic quantities, both to synthesize the dependency of the energy parameters and force threshold values on the impact velocity are discussed. 相似文献
4.
Optimizing the hydrogen (H2) yield at several initial pH conditions in a mixed batch anaerobic mesophilic culture fed with glucose and linoleic acid (LA) was performed using a three factor three level Box–Benkhen design (BBD). Based on the BBD approach, a statistical model was developed to predict the H2 yield. The variables considered for the experimental design were the LA concentration, the initial pH and the number of times glucose was added to the culture. The D-optimality method predicted a maximum H2 yield of 3.49 mol H2 mol glucose−1 for cultures fed 1.9 g l−1 LA, maintained at an initial pH of 5.15 and received 1.79 glucose additions. The response outcome (H2 yield of 3.38 ± 0.22 mol mol glucose−1) at the nearest setting of the experimental factors (2.0 g l−1 LA, an initial pH of 5.0 and two glucose additions) was 3.3% less than the predicted maximum value. The model provides a useful approach for predicting H2 production when H2 consumers are inhibited in mixed batch anaerobic cultures. 相似文献
5.
Evidence of perchlorate (ClO4-) reduction in plant tissues (poplar tree) using radio-labeled 36ClO4-
Phytoremediation of perchlorate (ClO4) by poplar trees Populus deltoidex nigrawas investigated using small cuttings growing in hydroponic Hoagland solution and plant tissue cultures, consisting of spherical photosynthetic cell aggregates (i.e. nodules) developing in Murashige and Skoog culture medium. Both plants and nodules were grown under a 16 h/8 h photoperiod cycle and under sterile conditions. Degradation experiments, performed by the incubation of pregrown plants and nodules in the presence of 36Cl radio-labeled ClO4- (25 mg L(-1)), showed a reduction of the initial ClO4- concentration in the solution of about 50% after 30 d of incubation. Analysis of the distribution of radioactivity in different plant fractions indicated that 27.4% of the total was translocated to the leaves, while 66.9% remained in the solution. Very little radioactivity (less than 3.0%) was detected in the other parts of the plants. 32.0% of the radioactivity recovered in the solution was shown to consist of 36Cl- and 68.0% of nontransformed 36ClO4-. The radioactivity recovered in the leaf extracts was distributed as chloride (36Cl-) (1.6% of the total), chlorite (36ClO2-) (2.4%), chlorate (36ClO3-) (4.8%), nontransformed 36ClO4- (21.6%), and an unidentified organic compound (1.4%). The radioactivity recovered in the solution containing submerged nodules consisted of 36Cl- (6.4% of the total), 36ClO3- (1.3%), and nontransformed 36ClO4- (51.5%). Radioactivity detected in the nodule extracts was distributed as 36Cl- (2.0% of the total), 36ClO2- (5.2%), 36ClO3- (6.4%), 36ClO4- (22.7%), and an unidentified organic compound (0.5%). These results provide evidence of perchlorate reduction inside poplar tree tissues. 36ClO4- is partially reduced to 36ClO3-, 36ClO2-, and 36Cl-. 相似文献
6.
7.
J. Jerald P. Asokan G. Prabaharan R. Saravanan 《The International Journal of Advanced Manufacturing Technology》2005,25(9-10):964-971
The increased use of flexible manufacturing systems (FMS) to efficiently provide customers with diversified products has created a significant set of operational challenges. Although extensive research has been conducted on design and operational problems of automated manufacturing systems, many problems remain unsolved. In particular, the scheduling task, the control problem during the operation, is of importance owing to the dynamic nature of the FMS such as flexible parts, tools and automated guided vehicle (AGV) routings. The FMS scheduling problem has been tackled by various traditional optimisation techniques. While these methods can give an optimal solution to small-scale problems, they are often inefficient when applied to larger-scale problems. In this work, different scheduling mechanisms are designed to generate optimum scheduling; these include non-traditional approaches such as genetic algorithm (GA), simulated annealing (SA) algorithm, memetic algorithm (MA) and particle swarm algorithm (PSA) by considering multiple objectives, i.e., minimising the idle time of the machine and minimising the total penalty cost for not meeting the deadline concurrently. The memetic algorithm presented here is essentially a genetic algorithm with an element of simulated annealing. The results of the different optimisation algorithms (memetic algorithm, genetic algorithm, simulated annealing, and particle swarm algorithm) are compared and conclusions are presented . 相似文献
8.
Comments on an article by Bushman and Anderson (see record 2001-17729-001). We are concerned that Bushman and Anderson's article on media violence contains data that are incorrect or irreproducible. This is a serious issue; the article has already been referenced by numerous other formal papers according to a Google scholarly article search as well as in a statement to the U.S. Senate, in legal proceedings, and in California State law (Assembly Bill 1179 in 2005). (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
9.
Temperature-programmed desorption (TPD) was used to determine whether inert gases influence the desorption step in the oxidation of carbon by CO2. Surface oxides were formed on a graphite by reacting it at 1200 K with CO2, and then quenching the reaction. The oxides then were removed by TPD to 1373 K, using He, Ar and Kr as carrier gases in separate desorptions. The oxides appeared as CO2 and CO in the desorption carrier gases; some CO2 was observed between 800 and 1050 K, but above 1050 K the product was almost entirely CO. The CO2 desorption showed no effect from changing the carrier gas, but temperature of CO desorption peak and amount of CO desorbed by 1373 K both depended on which gas was used as a carrier. This shows that nonreactive gases affect the desorption step of the C-CO2 reaction. Involved in the desorption step is movement of some surface oxide species to desorption sites; the nonreactive-gas influence occurs because the nonreactive gases affect this surface transport. In the presence of Ar and Kr, transport rates of surface oxides to desorption sites were higher than they were in the presence of He. Under reaction conditions this can result in greater CO desorption rates and faster overall reaction rates in the presence of Ar and Kr than occur in the presence of He. 相似文献
10.