全文获取类型
收费全文 | 1148篇 |
免费 | 5篇 |
专业分类
电工技术 | 13篇 |
化学工业 | 66篇 |
金属工艺 | 13篇 |
机械仪表 | 22篇 |
建筑科学 | 3篇 |
矿业工程 | 16篇 |
能源动力 | 2篇 |
轻工业 | 12篇 |
水利工程 | 9篇 |
石油天然气 | 46篇 |
无线电 | 52篇 |
一般工业技术 | 80篇 |
冶金工业 | 758篇 |
原子能技术 | 38篇 |
自动化技术 | 23篇 |
出版年
2022年 | 8篇 |
2019年 | 5篇 |
2018年 | 7篇 |
2017年 | 14篇 |
2016年 | 26篇 |
2015年 | 13篇 |
2014年 | 7篇 |
2013年 | 12篇 |
2012年 | 16篇 |
2011年 | 13篇 |
2010年 | 14篇 |
2009年 | 12篇 |
2008年 | 14篇 |
2007年 | 11篇 |
2006年 | 8篇 |
2005年 | 7篇 |
2004年 | 10篇 |
2003年 | 12篇 |
2002年 | 9篇 |
2001年 | 5篇 |
2000年 | 12篇 |
1999年 | 22篇 |
1998年 | 173篇 |
1997年 | 124篇 |
1996年 | 84篇 |
1995年 | 47篇 |
1994年 | 46篇 |
1993年 | 54篇 |
1992年 | 15篇 |
1991年 | 12篇 |
1990年 | 11篇 |
1989年 | 6篇 |
1988年 | 5篇 |
1987年 | 8篇 |
1986年 | 12篇 |
1985年 | 11篇 |
1984年 | 6篇 |
1983年 | 7篇 |
1982年 | 15篇 |
1981年 | 11篇 |
1980年 | 26篇 |
1979年 | 5篇 |
1978年 | 10篇 |
1977年 | 46篇 |
1976年 | 106篇 |
1974年 | 6篇 |
1971年 | 7篇 |
1969年 | 4篇 |
1968年 | 4篇 |
1966年 | 6篇 |
排序方式: 共有1153条查询结果,搜索用时 718 毫秒
11.
A. S. Nikiforov V. I. Vlasov V. I. Davydov P. G. Dobrygin A. I. Kachurin O. A. Krivyakov D. A. Kukiev A. S. Polyakov V. F. Savelev S. N. Filippov 《Atomic Energy》1989,67(1):501-506
Translated from Atomnaya Énergiya, Vol. 67, No. 1, pp. 11–15, July, 1989. 相似文献
12.
13.
Kutepov A. M. Maksimov A. I. Nikiforov A. Yu. Titov V. A. 《Theoretical Foundations of Chemical Engineering》2003,37(4):339-346
A glow-discharge plasma bounded by a chemically reactive surface is studied. It is shown that the investigation of the properties of such systems must take into account heterogeneous reactions and chemical feedback. A study is undertaken to explore the dynamics of attaining the steady-state values of the discharge current and the plasma glow intensity in a case where there is gas desorption from the boundary surface. A formal model of the process is proposed that takes into account the accumulation of negative ions in the bulk of the positive column of the discharge. This model enables one to qualitatively explain the experimentally observed dynamic features of a plasma. 相似文献
14.
VS Ramachandran 《Canadian Metallurgical Quarterly》1995,4(1):22-51
Patients with right parietal lesions often deny their paralysis (anosognosia), but do they have "tacit" knowledge of their paralysis? I devised three novel tests to explore this. First, the patients were given a choice between a bimanual task (e.g., tying shoe laces) vs a unimanual one (e.g., threading a bolt). They chose the former on 17 of 18 trials and, surprisingly, showed no frustration or learning despite repeated failed attempts. I conclude that they have no tacit knowledge of paralysis (or, if such knowledge exists, it is not available for this particular task). Second, I used a "virtual reality box" to convey the optical illusion to the patient that she was moving her paralyzed left hand up and down to the rhythm of a metronome, and yet she showed no sign of surprise. Third, I irrigated patient BM's left ear canal with cold water, a procedure that is known to shift that patient's spatial frame of reference by stimulating the vestibular system. Surprisingly, this allowed her "repressed" memory of the paralysis to come to the surface; she said she had been paralyzed continuously for several days. I suggest that the vestibular stimulation produces these remarkable effects by mimicking REM sleep. These patients also employ a whole arsenal of grossly exaggerated Freudian "defense mechanisms" to account for their paralysis. To explain this, I propose that in normal individuals the left hemisphere ordinarily deals with small, local anomalies by trying to impose consistency but, when the anomaly exceeds threshold, an interaction with the right hemisphere forces a "paradigm shift." A failure of this process, in patients with right hemisphere damage, might partially account for anosognosia. Finally, I present a new conceptual framework that may help link several psychological and neurological phenomena such as Freudian defense mechanisms, vestibular stimulation, anosognosia, memory repression, visual illusions, anterograde amnesia, REM sleep, dreaming, and humor. 相似文献
15.
Kul’chin Yu. N. Gribova V. V. Timchenko V. A. Polonik M. V. Pivovarov D. S. Yatsko D. S. Nikiforov P. A. Nikitin A. I. 《Automation and Remote Control》2022,83(1):138-152
Automation and Remote Control - The paper presents the results of studying the “directed energy deposition” additive technological process aimed at improving the mechanical properties... 相似文献
16.
A number of studies have examined bradykinin-induced sensitization of primary afferent neurons to mechanical or thermal stimuli. However, bradykinin-induced sensitization to other chemical stimuli has not been systematically addressed. We used primary cultures of dorsal root ganglion neurons from neonatal rats to determine whether bradykinin alters the responsiveness of individual neurons to capsaicin and protons. An increase in the concentration of free intracellular Ca2+ was used as a measure of a response to capsaicin or low pH. Pretreatment with bradykinin (30 nM) increased the proportion of "intermediate-size" (240-320 microm2) dorsal root ganglion neurons that responded to capsaicin (100 nM) or low pH (6.1). However, among "small-size" (160-239 microm2) neurons, bradykinin increased the proportion of neurons that responded to low pH (6.1) but not to capsaicin (10 or 100 nM). Because treatment with arachidonic acid (10 microM) did not mimic the effect of bradykinin and inhibition of cyclo-oxygenase and lipoxygenase with 5,8,11,14-eicosatetraynoic acid (10 microM) did not inhibit the effect of bradykinin on the response to capsaicin, it is not likely that the bradykinin-induced enhancement of neuronal responsiveness is mediated by arachidonic acid or its metabolites in this model. These results support the hypothesis that bradykinin sensitizes primary afferent neurons to other chemicals such as protons that are present in inflamed tissue, particularly by recruiting additional sensory neurons to respond to a given chemical stimulus. An increase in the number of responsive nociceptors that innervate inflamed tissue would contribute to hyperalgesia via spatial summation on spinal neurons in the pathway for pain. Furthermore, since bradykinin enhanced the responsiveness of small-size neurons that responded to protons but not to capsaicin, these data suggest that bradykinin-induced sensitization to protons and capsaicin occur by different mechanisms. 相似文献
17.
Rat adrenal chromaffin cells attached to either collagen-coated dextran (Cytodex 3) or glass bead microcarriers, both of 90-200 microns diameter, were used as dopamine-secreting implants in the caudate-putamen of rats with 6-hydroxydopamine-induced unilateral lesions of the substantia nigra. As controls, beads without cells and cells in suspension alone were implanted. Chromaffin cells adhered to microcarriers reduced apomorphine-induced rotation by 75% in lesioned animals. Animals that were lesioned but not receiving cell implants or receiving beads alone showed no reduction. Animals implanted with cells not attached to beads also showed a reduction in rotation but this effect lasted less than three months. Microcarrier-attached cells, however, maintained their effect in reducing rotation for at least eight months (rotations were reduced from a control mean of 10.9 +/- 1.4 to 3.6 +/- 1.1 turns/min) without any "drop-off" of the effect. Histological examination showed that eight months post-implant the cells pre-adhered to beads were still present and could be stained by anti-tyrosine hydroxylase antibody. Sections stained with hematoxylin-eosin showed no signs of an inflammatory response. In contrast to beads implanted into the striatum, Cytodex bead implants injected into the lateral ventricle induced a histopathological response appearing to involve the ependyma and choroid plexus. Results suggest that the striatal parenchyma but not the ventricle is amenable to studies using the microcarrier approach to transplantation. 相似文献
18.
Pedro Casas Lionel Fillatre Sandrine Vaton Igor Nikiforov 《Journal of Network and Systems Management》2011,19(1):58-83
This paper presents a novel approach to deal with dynamic and highly uncertain traffic in dynamic network scenarios. The Reactive
Robust Routing (RRR) approach is introduced, a combination of proactive and reactive techniques to improve network efficiency
and robustness, simplifying network operation. RRR optimizes routing for normal-operation traffic, using a time-varying extension
of the already established Robust Routing technique that outperforms the stable approach. To deal with anomalous and unexpected
traffic variations, RRR uses a fast anomaly detection and localization algorithm that rapidly detects and localizes abrupt
changes in traffic flows, permitting an accurate routing adaptation. This algorithm presents well-established optimality properties
in terms of detection/localization rates and localization delay, which allows for generalization of results, independently
of particular evaluations. The algorithm is based on a novel parsimonious model for traffic demands which allows for detection
of anomalies using easily available aggregated-traffic measurements, reducing the overheads of data collection. 相似文献
19.
P. D. Drobintsev V. P. Kotlyarov I. V. Nikiforov A. A. Letichevsky 《Automatic Control and Computer Sciences》2016,50(7):486-492
The paper presents a technology to effort reduction in developing test suites for industrial software products based on an incremental technology. The main problems to be solved by incremental technology are full automation design of test scenarios and significant reducing of test explosion. The proposed approach provides solutions to the mentioned problems through joint co-working of the designer and the customer with usage of formal models; and through methods of symbolic verification with automatic generation of test suites with the toolset VRS/TAT. 相似文献
20.
M Pazianas M Zaidi CL Huang BS Moonga VS Shankar 《Canadian Metallurgical Quarterly》1993,192(3):1100-1105
We demonstrated previously that osteoclasts possess a divalent cation-sensitive "receptor", the Ca2+ receptor. Activation of the Ca2+ receptor by the surrogate cation Ni2+ was shown to elicit an increase in cytosolic [Ca2+] to a peak value followed by an exponential decline. In the present study we examined the influence of surface membrane voltage on the kinetics of Ca2+ receptor inactivation. The K+ ionophore, valinomycin was applied to intercept the declining phase of the cytosolic [Ca2+] transient elicited by application of between 50 microM- and 5 mM-[Ni2+]. This resulted in a sustained elevation of cytosolic [Ca2+] or even a 'hump' followed by a gradual decline. Such a kinetic alteration persisted in a Ca(2+)-free solution, but was abolished in high extracellular [K+] (105 mM). Thus, we demonstrate for the first time to our knowledge, a modulatory effect of membrane potential on the function of the osteoclast Ca2+ receptor. 相似文献