全文获取类型
收费全文 | 867篇 |
免费 | 10篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 10篇 |
综合类 | 1篇 |
化学工业 | 86篇 |
金属工艺 | 8篇 |
机械仪表 | 9篇 |
建筑科学 | 44篇 |
能源动力 | 18篇 |
轻工业 | 76篇 |
水利工程 | 6篇 |
石油天然气 | 4篇 |
无线电 | 71篇 |
一般工业技术 | 107篇 |
冶金工业 | 367篇 |
原子能技术 | 2篇 |
自动化技术 | 72篇 |
出版年
2022年 | 13篇 |
2021年 | 9篇 |
2020年 | 10篇 |
2019年 | 7篇 |
2018年 | 6篇 |
2017年 | 8篇 |
2016年 | 7篇 |
2015年 | 9篇 |
2014年 | 8篇 |
2013年 | 33篇 |
2012年 | 20篇 |
2011年 | 31篇 |
2010年 | 16篇 |
2009年 | 28篇 |
2008年 | 36篇 |
2007年 | 27篇 |
2006年 | 26篇 |
2005年 | 18篇 |
2004年 | 18篇 |
2003年 | 10篇 |
2002年 | 21篇 |
2001年 | 12篇 |
2000年 | 14篇 |
1999年 | 26篇 |
1998年 | 73篇 |
1997年 | 54篇 |
1996年 | 33篇 |
1995年 | 19篇 |
1994年 | 29篇 |
1993年 | 31篇 |
1992年 | 9篇 |
1991年 | 11篇 |
1990年 | 11篇 |
1989年 | 13篇 |
1988年 | 12篇 |
1987年 | 15篇 |
1986年 | 11篇 |
1985年 | 11篇 |
1984年 | 8篇 |
1983年 | 6篇 |
1982年 | 7篇 |
1981年 | 6篇 |
1980年 | 8篇 |
1979年 | 7篇 |
1978年 | 6篇 |
1977年 | 14篇 |
1976年 | 18篇 |
1975年 | 7篇 |
1971年 | 7篇 |
1961年 | 6篇 |
排序方式: 共有881条查询结果,搜索用时 15 毫秒
71.
Interactions of refractory materials with molten gasifier slags 总被引:1,自引:0,他引:1
Jinichiro Nakano Seetharaman Sridhar James BennettKyei-Sing Kwong Tyler Moss 《International Journal of Hydrogen Energy》2011,36(7):4595-4604
The current study focuses on the analysis of sessile-drop interfacial reactions between two synthetic slags (based on average ash chemistries of coal and petcoke feedstock) and two refractory materials (90 wt% Cr2O3-10 wt% Al2O3 and 100 wt% Al2O3), using a Confocal Scanning Laser Microscope (CSLM). Ground slag samples (less than 325 mesh) were placed at specific microstructure locations on refractory substrates and heated to 1500 °C in an atmosphere of CO/CO2 gas mixture (volume ratio = 1.8), using a gold-image heating chamber. Cross-sections of the slag/refractory interface indicated unique slag penetration into preferred areas of the refractory and grain dissolution into the slag which promoted spalling of the refractory. Initially, the slag attacked both grain boundaries and fine microstructure areas, freeing alumina grains into the slag. The formation of VOx-based crystalline material in the petcoke slag was found to alter the liquid composition. Chemical spalling of Cr-containing crystal layer also facilitated degradation of the refractory. 相似文献
72.
We provide a response to a commentary by Wiers and Stacy (see record 2009-24669-003) on our model of the alcohol–behavior link (see record 2009-09537-002). Whereas Wiers and Stacy generally supported our model, they took issue with our conceptualization of the alcohol expectancy construct. We address the major concerns of Wiers and Stacy by demonstrating that our own view is consistent with basic cognitive scientific conceptualizations of the nature of associative and propositional reasoning within a dual-systems framework. In clarifying these issues, we maintain that although the predictions presented by Wiers and Stacy are important and useful in this area, they are predictions that can be derived from our original formulation of the alcohol–behavior link. We conclude that this kind of useful debate can only aid the generation of conceptually consistent and testable models that will advance the understanding of the alcohol–behavior link. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
73.
74.
M.L. Lombardi A. FavalliJ.M. Goda K.D. IanakievC.E. Moss 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2011,652(1):112-115
A flux monitor diode is being explored as an option for measurement of the output of an X-ray tube that is used for active transmission measurements on a pipe containing UF6 gas. The measured flux can be used to correct for any instabilities in the X-ray tube or the high voltage power supply. For this measurement, we are using a silicon junction p-n photodiode, model AXUV100GX, developed by International Radiation Detectors, Inc. (IRD, Inc.). This diode has a silicon thickness of 104 μ and a thin (3-7 nm) silicon dioxide junction passivating, protective entrance window. These diodes have been extensively tested for radiation hardness in the UV range. However, we intend to operate mainly in the 10-40 keV X-ray region. We are performing radiation hardness testing over this energy range, with the energy spectrum that would pass through the diode during normal operation. A long-term measurement was performed at a high flux, which simulated over 80 years of operation. No significant degradation was seen over this time. Fluctuations were found to be within the 0.1% operationally acceptable error range. After irradiation, an I-V characterization showed a temporary irradiation effect which decayed over time. This effect is small because we operate the diode without external bias. 相似文献
75.
76.
77.
SA Gould EE Moore FA Moore JB Haenel JM Burch H Sehgal L Sehgal R DeWoskin GS Moss 《Canadian Metallurgical Quarterly》1997,43(2):325-31; discussion 331-2
We have previously documented the safety of 1 unit (50 gram) of human polymerized hemoglobin (Poly SFH-P) in healthy volunteers. This report describes the first patient trial to assess the therapeutic benefit of Poly SFH-P in acute blood loss. Thirty-nine patients received 1 (n = 14), 2 (n = 2), 3 (n = 15), or 6 (n = 8) units of Poly SFH-P instead of red cells as part of their blood replacement after trauma and urgent surgery. There were no safety issues related to the infusion of Poly SFH-P. The plasma hemoglobin concentration ([Hb]) after the infusion of 6 units (300 gram) of Poly SFH-P was 4.8 +/- 0.8 g/dL (mean +/- SD). Although the red cell [Hb] fell to 2.9 +/- 1.2 g/dL, the total [Hb] was maintained at 7.5 +/- 1.2 g/dL. Poly SFH-P maintained total [Hb], despite the marked fall in red cell [Hb] due to blood loss. The utilization of O2 (extraction ratio) was 27 +/- 16% from the red cells and 37 +/- 13% from the Poly SFH-P. Twenty-three patients (59%) avoided allogeneic transfusions during the first 24 hours after blood loss. Poly SFH-P effectively loads and unloads O2 and maintains total hemoglobin in lieu of red cells after acute blood loss, thereby reducing allogeneic transfusions. Poly SFH-P seems to be a clinically useful blood substitute. 相似文献
78.
Measurements have been made on the heat transfer to granular material in a plasma reactor having a multijet mixing chamber. The temperature distribution over the cross section has been measured by a spectral method and by calorimetry. The granular-material flow rate affects the heat flux to the walls. The measurements are fitted to an equation in dimensionless parameters.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 58, No. 5, pp. 824–828, May, 1990. 相似文献
79.
A low-cost test solution for wireless phone RFICs 总被引:3,自引:0,他引:3
This article describes an IBM approach for testing high-volume, complex RFICs at a fraction of the cost of the integrated circuit. This approach uses a personal computer, a fast benchtop dc parametric analyzer, and RF-to-analog circuits to test an RFIC during the manufacturing process. The described system and methodology are specifically designed for high-volume test, where test cost is extremely important; they are not recommended for lower-volume products (less than 1 million per month). This article describes the system architecture and discusses design, maintenance, and implementation considerations. The system is designed to reduce the cost of a complex RFIC manufacturing test to equal that of a discrete component, such as a resistor or capacitor. Given the relatively easy implementation and the drastic cost reduction associated with the test solution, this architecture establishes a new standard for the future of RF test. In fact, this architecture may result in the fastest RF tester currently available. 相似文献
80.
Grigsby Jim; Brega Angela G.; Engle Karen; Leehey Maureen A.; Hagerman Randi J; Tassone Flora; Hessl David; Hagerman Paul J.; Cogswell Jennifer B.; Bennett Rachael E.; Cook Kylee; Hall Deborah A.; Bounds Lanee S.; Paulich Marsha J.; Reynolds Ann 《Canadian Metallurgical Quarterly》2008,22(1):48
Fragile X-associated tremor/ataxia syndrome (FXTAS) develops in a subset of fragile X premutation carriers and involves gait ataxia, action tremor, Parkinsonism, peripheral neuropathy, autonomic disorders, and cognitive impairment. The study was designed to define the nature of cognitive deficits affecting male premutation carriers with and without FXTAS. A sample of 109 men underwent motor, cognitive, genetic, and neurologic testing, as well as brain magnetic resonance imaging. Subjects were classified into 3 groups: (a) asymptomatic premutation carriers, (b) premutation carriers with FXTAS, and (c) normal controls. Men with FXTAS performed worse than controls on mental status, intelligence, executive cognitive functioning (ECF), working memory, remote recall of information, declarative learning and memory, information processing speed, and temporal sequencing, as well as 1 measure of visuospatial functioning. Language and verbal comprehension were spared. Asymptomatic carriers performed worse than controls on ECF and declarative learning and memory. This comprehensive examination of cognitive impairment in male premutation carriers suggests that FXTAS involves substantial executive impairment and diffuse deficits in other cognitive functions. Longitudinal research currently underway will provide insight into the progression of the disorder. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献