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21.
In this monograph we describe a unique method for resolving scientific disputes: the joint design of crucial experiments by the antagonists themselves with the help of a mediator. This method was applied to the issue of the effect of participation on goal commitment and performance. In research on this topic, Latham and his colleagues had obtained markedly different results from those obtained by Erez and her colleagues. With Locke serving as a third party mediator, Latham and Erez designed four experiments to resolve the discrepancies. The experiments were conducted at the University of Washington and the University of Maryland. The results revealed that the major reason for the difference was that Erez gave very brief tell instructions to her assigned goal subjects, whereas Latham used a tell and sell approach. Four additional factors also contributed to the earlier difference in findings: goal difficulty, setting personal goals before goal treatments were introduced, self-efficacy-inducing instructions, and instructions to reject disliked goals. It was concluded that (a) the differences between Latham and Erez can be explained on the basis of differences in specific procedures, and (b) the method used to resolve this dispute should be used by other investigators. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
22.
Stow CA Walker JT Cardoch L Spence P Geron C 《Environmental science & technology》2005,39(18):6999-7004
We present N2O emission data from 11 sites in the Neuse River watershed. Emissions were measured using a static surface enclosure technique deployed on eight sites on the main river channel and three tributary sites. Ancillary data collected included dissolved oxygen, nitrate, total nitrogen, ammonium, dissolved organic carbon, total phosphorus, and temperature. Analysis using standard linear models, and classification and regression trees (CART), indicated nitrate to be the primary driving variable associated with N2O emission, although dissolved organic carbon concentration and water temperature were positively related with N2O emission as well. Relationships between nitrate concentration and N2O emission were consistent with those found in previous studies, although the data presented here represent the lower end of the range for both variables among published studies. Using our measured N2O emission rates along with literature values for the ratio of nitrogen gas to N2O produced during denitrification, we estimate N loss via denitrification in the Neuse River is approximately 17% of the annual N load delivered to the estuary. 相似文献
23.
We present a simple phenomenological theory of the optogalvanic effect based on the multiplication of an electron within the plasma. The dependence of the signal on current and pressure and its temporal behavior are predicted for atoms irradiated by chopped CW lasers and pulsed lasers. Experimental data obtained by pulsed lasers are presented and interpreted. 相似文献
24.
正海尔兹山纪念堂是一个独特的纪念场所。为了纪念耶路撒冷所有阵亡的士兵,设计中包含了他们名字。这是和平年代期冀希望的象征。尽管临近耶路撒冷繁华路段,纪念堂设计为一个平静的圣经式场地,整个空间孤隐而静谧。建筑主体空间通过挖掘山体而成,形成个人或集体纪念活动的私密空间。纪念堂上方的山体,以耶路撒冷石塑造出新的曲线。纪念堂形成一个波形漏斗状结构,缓缓通向天际。这种不规则的涡旋状结构为纪念堂营造出不断变化的自然光。 相似文献
25.
Samuel T. Ariaratnam Jason S. Lueke Erez N. Allouche 《Canadian Metallurgical Quarterly》1999,125(2):76-86
Trenchless technology is an emerging area of construction involving innovative methods, materials, and equipment used for the installation of new and the rehabilitation or replacement of existing underground infrastructure with minimal or no need for open cut excavation. This technology provides an alternative to traditional methods of open trenching construction, which is often associated with major disruptions to surface activities. The results of a survey of trenchless construction methods in Canada are presented in this paper. The survey, which was sent to 87 municipalities across Canada, provides an indication of current and future trends in the application of trenchless construction technologies in the municipal arena including type and frequency of technologies employed, percentage of projects that employed trenchless technologies, and contractor selection methods. The survey results indicate that trenchless technology is gaining increasing popularity among municipal engineers across Canada. The percentage of all municipal projects utilizing trenchless construction methods has grown over the past 5 years by 180% (new construction) and 270% (rehabilitation). The survey also revealed that the typical Canadian municipality spends $29.68∕capita on new construction of municipal service lines and $18.21∕capita on rehabilitation of existing lines. 相似文献
26.
Rajkondawar PG Liu M Dyer RM Neerchal NK Tasch U Lefcourt AM Erez B Varner MA 《Journal of dairy science》2006,89(11):4267-4275
Bovine lameness results in pain and suffering in cattle and economic loss for producers. A system for automatically detecting lame cows was developed recently that measures vertical force components attributable to individual limbs. These measurements can be used to calculate a number of limb movement variables. The objective of this investigation was to explore whether gait scores, lesion scores, or combined gait and lesion scores were more effectively captured by a set of 5 limb movement variables. A set of 700 hind limb examinations was used to create gait-based, lesion-based, and combined (gait- and lesion-based) models. Logistic regression models were constructed using 1, 2, or 3 d of measurements. Resulting models were tested on cows not used in modeling. The accuracy of lesion-score models was superior to that of gait-score models; lesion-based models generated greater values of areas under the receiving operating characteristic curves (range 0.75 to 0.84) and lower mean-squared errors (0.13 to 0.16) compared with corresponding values for the gait-based models (0.63 to 0.73 and 0.26 to 0.31 for receiving operating characteristic and mean-squared errors, respectively). These results indicate that further model development and investigation could generate automated and objective methods of lameness detection in dairy cattle. 相似文献
27.
We present a differential equations model in which contagious disease transmission is affected by contagious fear of the disease and contagious fear of the control, in this case vaccine. The three contagions are coupled. The two fears evolve and interact in ways that shape distancing behaviour, vaccine uptake, and their relaxation. These behavioural dynamics in turn can amplify or suppress disease transmission, which feeds back to affect behaviour. The model reveals several coupled contagion mechanisms for multiple epidemic waves. Methodologically, the paper advances infectious disease modelling by including human behavioural adaptation, drawing on the neuroscience of fear learning, extinction and transmission. 相似文献
28.
A newly developed personality taxonomy suggests that self-esteem, locus of control, generalized self-efficacy, and neuroticism form a broad personality trait termed core self-evaluations. The authors hypothesized that this broad trait is related to motivation and performance. To test this hypothesis, 3 studies were conducted. Study 1 showed that the 4 dispositions loaded on 1 higher order factor. Study 2 demonstrated that the higher order trait was related to task motivation and performance in a laboratory setting. Study 3 showed that the core trait was related to task activity, productivity as measured by sales volume, and the rated performance of insurance agents. Results also revealed that the core self-evaluations trait was related to goal-setting behavior. In addition, when the 4 core traits were investigated as 1 nomological network, they proved to be more consistent predictors of job behaviors than when used in isolation. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
29.
CBC MAC for Real-Time Data Sources 总被引:1,自引:0,他引:1
The Cipher Block Chaining (CBC) Message Authentication Code (MAC) is an authentication method which is widely used in practice.
It is well known that the use of the CBC MAC for variable length messages is not secure, and a few rules of thumb for the
correct use of the CBC MAC are known by folklore. The first rigorous proof of the security of CBC MAC, when used on fixed
length messages, was given only recently by Bellare et al.[3]. They also suggested variants of CBC MAC that handle variable-length
messages but in these variants the length of the message has to be known in advance (i.e., before the message is processed).
We study CBC authentication of real-time applications in which the length of the message is not known until the message ends,
and furthermore, since the application is real-time, it is not possible to start processing the authentication until after
the message ends.
We first consider a variant of CBC MAC, that we call the encrypted CBC MAC (EMAC), which handles messages of variable unknown lengths. Computing EMAC on a message is virtually as simple and as efficient
as computing the standard CBC MAC on the message. We provide a rigorous proof that its security is implied by the security
of the underlying block cipher. Next, we argue that the basic CBC MAC is secure when applied to a prefix-free message space.
A message space can be made prefix-free by also authenticating the (usually hidden) last character which marks the end of
the message.
Received 16 September 1997 and revised 24 August 1999 Online publication 2 June 2000 相似文献
30.
We propose the use of generations with modern reference counting. A reference counting collector is well suited to collect the old generation, containing a large fraction of live objects that are modified infrequently. Such a collector can be combined with a tracing collector to collect the young generation, typically containing a small fraction of live objects. We have designed such a collector appropriate for running on a multiprocessor. As our building blocks, we used the sliding‐views on‐the‐fly collectors. We have implemented the new collector on the Jikes Research Java Virtual Machine (Jikes RVM) and compared it with the concurrent reference counting collector supplied with the Jikes RVM package. Our measurements demonstrate short pause times, retaining those of the original on‐the‐fly collectors and a gain in application throughput time. It turns out that a modern reference counting collector may benefit from the use of generations. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献