全文获取类型
收费全文 | 1399篇 |
免费 | 32篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 5篇 |
综合类 | 9篇 |
化学工业 | 342篇 |
金属工艺 | 24篇 |
机械仪表 | 26篇 |
建筑科学 | 49篇 |
矿业工程 | 1篇 |
能源动力 | 17篇 |
轻工业 | 220篇 |
水利工程 | 9篇 |
无线电 | 69篇 |
一般工业技术 | 173篇 |
冶金工业 | 345篇 |
原子能技术 | 15篇 |
自动化技术 | 129篇 |
出版年
2023年 | 7篇 |
2022年 | 21篇 |
2021年 | 31篇 |
2020年 | 18篇 |
2019年 | 12篇 |
2018年 | 18篇 |
2017年 | 20篇 |
2016年 | 24篇 |
2015年 | 16篇 |
2014年 | 26篇 |
2013年 | 41篇 |
2012年 | 52篇 |
2011年 | 85篇 |
2010年 | 49篇 |
2009年 | 49篇 |
2008年 | 71篇 |
2007年 | 39篇 |
2006年 | 56篇 |
2005年 | 44篇 |
2004年 | 29篇 |
2003年 | 30篇 |
2002年 | 25篇 |
2001年 | 23篇 |
2000年 | 17篇 |
1999年 | 32篇 |
1998年 | 105篇 |
1997年 | 53篇 |
1996年 | 46篇 |
1995年 | 31篇 |
1994年 | 29篇 |
1993年 | 18篇 |
1992年 | 18篇 |
1991年 | 18篇 |
1990年 | 19篇 |
1989年 | 20篇 |
1988年 | 22篇 |
1987年 | 25篇 |
1986年 | 21篇 |
1985年 | 27篇 |
1984年 | 14篇 |
1983年 | 8篇 |
1981年 | 8篇 |
1980年 | 13篇 |
1979年 | 7篇 |
1978年 | 7篇 |
1977年 | 9篇 |
1976年 | 21篇 |
1974年 | 7篇 |
1973年 | 7篇 |
1968年 | 8篇 |
排序方式: 共有1433条查询结果,搜索用时 15 毫秒
41.
JR Krause 《Canadian Metallurgical Quarterly》1977,70(9):1072-4, 1079
Amyloid involvement of the bone marrow is not commonly diagnosed before necropsy. Paraffin sections of the trephine bone biopsy specimen are superior to marrow aspiration cell smears for the antemortem diagnosis. Thirteen cases of amyloidosis were diagnosed from the bone biopsy specimen during a ten-year period. Amyloid was detected in only two of the corresponding aspirates. Three morphologic patterns of marrow involvement were found: vascular, focal extravascular/perivascular, and diffuse. Five (38%) of the cases were associated with multiple myeloma. An abnormal immunoglobulin was detected in the serum or urine or both in ten of 11 cases when determined. Although the bone marrow may not be the best site for the diagnosis of amyloidosis, it should not be neglected and marrow biopsies taken for other diagnostic reasons may "incidentally" reveal amyloid. Amyloidosis should be included in the list of non-primary hematologic conditions of the bone marrow in which the trephine biopsy may prove useful for diagnosis. 相似文献
42.
Groenesteijn L Ellegast RP Keller K Krause F Berger H de Looze MP 《Applied ergonomics》2012,43(2):320-328
In the present study, we investigated the effect of office tasks on posture and movements in field settings, and the comfort rating for chair characteristics and correlation with type of task. The tasks studied were: computer work, telephoning, desk work and conversation. Postures, movements, chair part inclinations and comfort rating data were collected from 12 subjects. Computer work showed the lowest physical activity, together with upright trunk and head position and low backrest inclination. Conversation shows the highest activity of head legs and low back together with the highest cervical spine extension. In contrast, desk work provoked the most cervical spine flexion and showed the second lowest activity. The telephoning tasks showed medium activity and the highest kyphosis. Conversation showed the highest backrest inclination. Positive comfort relations were found for computer work and a "swing system" chair, for telephoning and an active longitudinal seat rotation, and for desk work and a chair with a three-dimensionally moveable seat. 相似文献
43.
Yanka Jeliazova Michael Kayser Beate Mildner Achim Walter Hassel Detlef Diesing 《Thin solid films》2006,500(1-2):330-335
The dielectric breakdown of thin (d = 3–4 nm) aluminium and tantalum oxide films was investigated by means of current voltage plots in metal/insulator/metal systems. Dielectric breakdown field strengths, EDB, of 0.6 GV m− 1 were found for both oxide types at room temperature. Differences appear in the temperature dependence of EDB. Tantalum oxide films show an unchanged breakdown behaviour for temperatures up to 420 K while aluminium oxide films lose already 80% of their EDB value in the same temperature range. Time-resolved investigations of the electric breakdown revealed intermediate states of both oxide types which were stable for several ms being characterized by an enhanced tunnel current. The breakdown voltage clearly scales with the oxide thickness for both oxide types. 相似文献
44.
Properties of optical coatings (e.g. low‐e or solar control) can be described and controlled using transmittance, reflectance and sheet resistance measurements. Multiple in situ transmittance measurement points allow a quick response to adjust different coating processes (layer thickness and homogeneity). For the final characterization of the coated substrate ex situ transmittance, reflectance and sheet resistance measurements are used. Accurate and reproducible measurements in a combination with Reverse Engineering methods admit monitoring all layers and in this way detecting slight drifts. 相似文献
45.
46.
T. Marszalek A. NosalR. Pfattner J. JungS. Kotarba M. Mas-TorrentB. Krause J. VecianaM. Gazicki-Lipman C. CrickertG. Schmidt C. RoviraJ. Ulanski 《Organic Electronics》2012,13(1):121-128
We report a comparative study of OFET devices based on zone-cast layers of three tetrathiafulvalene (TTF) derivatives in three configurations of electrodes in order to determine the best performing geometry. The first testing experiments were performed using SiO2/Si substrates. Then the optimum geometry was employed for the preparation of flexible OFETs using Parylene C as both substrate and dielectric layer yielding, in the best case, to devices with μFET = 0.1 cm2/V s. With the performed bending tests we determined the limit of curvature radius for which the performance of the OFETs is not deteriorated irreversibly. The investigated OFETs are sensitive to ambient atmosphere, showing reversible increase of the source to drain current upon exposition to air, what can be explained as doping of TTF derivative by oxygen or moisture. 相似文献
47.
J. Wu J. Hameury G. Failleau A. Blahut T. Vachova R. Strnad M. Krause E. Rafeld U. Hammerschmidt 《International Journal of Thermophysics》2018,39(2):23
This paper complements the existing measurement standards and literature for high-temperature guarded hot plates (HTGHPs) by addressing specific issues relating to thermal conductivity measurement of technical insulation at high temperatures. The examples given are focused on the designs of HTGHPs for measuring thin thermal insulation. The sensitivity studies have been carried out on major influencing factors that affect the thermal conductivity measurements using HTGHPs, e.g., the uncertainty of temperature measurements, plate flatness and center-guard gap design and imbalance. A new configuration of center-guard gap with triangular shape cross section has been optimized to obtain the same thermal resistance as a 2 mm wide gap with rectangular shape cross section that has been used in the HTGHPs at NPL and LNE. Recommendations have been made on the selections of heater plate materials, high-temperature high-emissivity coatings and miniature temperature sensors. For the first time, thermal stress analysis method has been applied to the field of HTGHPs, in order to estimate the effect of differential thermal expansion on the flatness of thin rigid specimens during thermal conductivity tests in a GHP. 相似文献
48.
Ramona Ritzmann Kathrin Freyler Anne Krause Albert Gollhofer 《Microgravity science and technology》2016,28(5):477-490
Scopolamine is used to counteract motion sickness in parabolic flight (PF) experiments. Although the drug’s anticholinergic properties effectively impede vomiting, recent studies document other sensory side-effects in the central nervous system that may considerably influence sensorimotor performance. This study aimed to quantify such effects in order to determine if they are of methodological and operational significance for sensorimotor control. Ten subjects of a PF campaign received a weight-sex-based dose of a subcutaneous scopolamine injection. Sensorimotor performance was recorded before medication, 20min, 2h and 4h after injection in four space-relevant paradigms: balance control in one-leg stance with eyes open (protocol 1) and closed as well as force-generating capacity in countermovement jumps and hops (protocol 2). Postural sway, forces and joint angles were recorded. Neuromuscular control was assessed by electromyography and peripheral nerve stimulation; H-reflexes and M-waves were used to monitor spinal excitability of the Ia afferent reflex circuitry and maximal motor output. (1) H-reflex amplitudes, latencies and functional reflexes remained unchanged after scopolamine injection. (2) M-waves, neuromuscular activation intensities and antagonistic muscle coordination did not change with scopolamine administration. (3) Balance performance and force-generating capacity were not impeded by scopolamine. We found no evidence for changes in sensorimotor control in response to scopolamine injection. Sensory processing of daily relevant reflexes, spinal excitability, maximal motor output and performance parameters were not sensitive to the medication. We conclude that scopolamine administration can be used to counteract motion sickness in PF without methodological and operational concerns or interference regarding sensorimotor skills associated with neuromuscular control. 相似文献
49.
Claudia Pielsticker Martin F. Brodde Lisa Raum Kerstin Jurk Beate E. Kehrel 《International journal of molecular sciences》2020,21(22)
Inflammatory processes are triggered by the fibrinolytic enzyme plasmin. Tissue-type plasminogen activator, which cleaves plasminogen to plasmin, can be activated by the cross-β-structure of misfolded proteins. Misfolded protein aggregates also represent substrates for plasmin, promoting their degradation, and are potent platelet agonists. However, the regulation of plasmin-mediated platelet activation by misfolded proteins and vice versa is incompletely understood. In this study, we hypothesize that plasmin acts as potent agonist of human platelets in vitro after short-term incubation at room temperature, and that the response to thrombospondin-1 and the bona fide misfolded proteins Eap and SCN−-denatured IgG interfere with plasmin, thereby modulating platelet activation. Plasmin dose-dependently induced CD62P surface expression on, and binding of fibrinogen to, human platelets in the absence/presence of plasma and in citrated whole blood, as analyzed by flow cytometry. Thrombospondin-1 pre-incubated with plasmin enhanced these plasmin-induced platelet responses at low concentration and diminished them at higher dose. Platelet fibrinogen binding was dose-dependently induced by the C-terminal thrombospondin-1 peptide RFYVVMWK, Eap or NaSCN-treated IgG, but diminished in the presence of plasmin. Blocking enzymatically catalyzed thiol-isomerization decreased plasmin-induced platelet responses, suggesting that plasmin activates platelets in a thiol-dependent manner. Thrombospondin-1, depending on the concentration, may act as cofactor or inhibitor of plasmin-induced platelet activation, and plasmin blocks platelet activation induced by misfolded proteins and vice versa, which might be of clinical relevance. 相似文献
50.
Ultrasound‐based,in‐line monitoring of anaerobe yeast fermentation: model,sensor design and process application 下载免费PDF全文
Sven Hoche Daniel Krause Mohamed A. Hussein Thomas Becker 《International Journal of Food Science & Technology》2016,51(3):710-719
In order to implement process analytical technology in beer manufacturing, an ultrasound‐based in‐line sensor was developed which is capable to determine sound velocity and density via the multiple reflection method. Based on a systematic study of the ternary system water–maltose–ethanol, two models were established to estimate the critical process parameters: sugar and ethanol mass fraction. The sound velocity‐based model showed unreasonable high errors although temperature variations and deviations due to dissolved CO2 were corrected. In contrast, the sound velocity–density–temperature model provided an average root mean square error of 0.53%g/g sugar and 0.26%g/g ethanol content for the main fermentation. Method, sensor and model showed the capability to capture the process signature which may be related to product and process quality. 相似文献