全文获取类型
收费全文 | 94篇 |
免费 | 1篇 |
专业分类
化学工业 | 14篇 |
金属工艺 | 1篇 |
机械仪表 | 1篇 |
建筑科学 | 6篇 |
矿业工程 | 5篇 |
能源动力 | 1篇 |
轻工业 | 6篇 |
无线电 | 5篇 |
一般工业技术 | 12篇 |
冶金工业 | 5篇 |
自动化技术 | 39篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 3篇 |
2020年 | 2篇 |
2019年 | 1篇 |
2017年 | 2篇 |
2016年 | 1篇 |
2015年 | 1篇 |
2014年 | 2篇 |
2013年 | 8篇 |
2012年 | 2篇 |
2011年 | 9篇 |
2010年 | 5篇 |
2009年 | 5篇 |
2008年 | 7篇 |
2007年 | 2篇 |
2006年 | 3篇 |
2005年 | 3篇 |
2004年 | 3篇 |
2003年 | 4篇 |
2002年 | 3篇 |
2001年 | 2篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1994年 | 1篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1976年 | 2篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1970年 | 2篇 |
排序方式: 共有95条查询结果,搜索用时 15 毫秒
41.
42.
Clint D. McCullough Geneviève Marchand Jörg Unseld 《Mine Water and the Environment》2013,32(4):302-313
In an arid climate, pit lake evaporation rates can exceed influx rates, causing the lake to function as a hydraulic terminal sink, with water levels in the pit remaining below surrounding groundwater levels. We present case studies from Western Australia for two mines nearing closure. At the first site, modelling indicates that waste dump covers for the potentially acid forming (PAF) material would not be successful over the long term (1,000 years or more). The second site is a case study where PAF management is limited by the current waste rock dump location and suitable cover materials. Pit lake water balance modelling using Goldsim software indicated that both pit lakes would function as hydraulic terminal sinks if not backfilled above long-term equilibrium water levels. Poor water quality will likely develop as evapoconcentration increases contaminant concentrations, providing a potential threat to local wildlife. Even so, the best current opportunity to limit the risk of contaminant migration and protect regional groundwater environments may be to limit backfill and intentionally produce a terminal sink pit lake. 相似文献
43.
Recently, AMT has issued an extended version of Fortran Plus [1] which allows software to be developed without the developer needing to take explicit accout of the grid size of the target processor. Fortran-Plus and its extension, Fortran Plus Enhanced [2], have been developed for use on the AMT DAP 510 array processor. This machine has 1024 processors arranged in a square grid with nearest neighbour and wraparound connections. It is interesting to enquire whether the performance of code generated by the Fortran-Plus Enhanced compiler is, for a particular application, superior to that generated by the Fortran-Plus compiler from a program which recognises and is tailored to fit the characteristic features of the DAP 510. In this paper the performances of two implementations of an algorithm for the eigensolution of real tridiagonal symmetric matrices are compared. The algorithm is characterised by its heavy use of matrix operations, all of which can be efficiently implemented on an array processor. Some of the constituent operations commonly occur in other applications while others are specific to the problem being addressed. 相似文献
44.
Mauricio Santillana Clint Dawson 《Computer Methods in Applied Mechanics and Engineering》2010,199(23-24):1424-1436
In this paper, we study a local discontinuous Galerkin (LDG) method to approximate solutions of a doubly nonlinear diffusion equation, known in the literature as the diffusive wave approximation of the shallow water equations (DSW). This equation arises in shallow water flow models when special assumptions are used to simplify the shallow water equations and contains as particular cases: the Porous Medium equation and the parabolic p-Laplacian. Continuous in time a priori error estimates are established between the approximate solutions obtained using the proposed LDG method and weak solutions to the DSW equation under physically consistent assumptions. The results of numerical experiments in 2D are presented to verify the numerical accuracy of the method, and to show the qualitative properties of water flow captured by the DSW equation, when used as a model to simulate an idealized dam break problem with vegetation. 相似文献
45.
46.
Smith CB Anderson JE Massaro RD Tatineni B Kam KC Tepper GC 《Applied spectroscopy》2008,62(6):604-610
An in situ mesopourous surface imprinted polymeric (SIP) sensor was synthesized for a highly sensitive, selective, and kinetically faster detection of the high-vapor-pressure nerve gas surrogate methyl salicylate (MES). Visual detection occurred on the filtrate thin films at 25 pM. Other nerve gas surrogates, TP, DMP, DMMP, PMP, and 1,4-thioxane, were tested and showed a decrease in sensitivity compared to MES. In addition, 2,6-dipicolinic acid (DPA), a biological indicator, was also investigated and showed a decrease in sensitivity compared to MES. Finally, the detection plateau was reached at 40 s and at 1.5 x 10(-4) M from pH 6-11. 相似文献
47.
Robert Moskovitch Dima Stopel Clint Feher Nir Nissim Nathalie Japkowicz Yuval Elovici 《Journal in Computer Virology》2009,5(4):295-308
The recent growth in network usage has motivated the creation of new malicious code for various purposes. Today’s signature-based
antiviruses are very accurate for known malicious code, but can not detect new malicious code. Recently, classification algorithms
were used successfully for the detection of unknown malicious code. But, these studies involved a test collection with a limited
size and the same malicious: benign file ratio in both the training and test sets, a situation which does not reflect real-life
conditions. We present a methodology for the detection of unknown malicious code, which examines concepts from text categorization,
based on n-grams extraction from the binary code and feature selection. We performed an extensive evaluation, consisting of a test collection
of more than 30,000 files, in which we investigated the class imbalance problem. In real-life scenarios, the malicious file
content is expected to be low, about 10% of the total files. For practical purposes, it is unclear as to what the corresponding
percentage in the training set should be. Our results indicate that greater than 95% accuracy can be achieved through the
use of a training set that has a malicious file content of less than 33.3%. 相似文献
48.
Clint J. Grafelman 《Journal of Failure Analysis and Prevention》2008,8(6):498-504
Freeze-drying is utilized in the biopharmaceutical industry to give higher stability, broader temperature tolerance, and longer
shelf-life to formulations that are unstable in aqueous solution (Green and Perry, Perry’s Chemical Engineers’ Handbook, 1997).
Freeze-drying equipment consists of a drying chamber, condensers, a cooling system, and a vacuum system. The drying chamber
is where the product is placed to undergo the lyophilization process. The chamber has two access points: a maintenance door,
located in a mechanical room, and a slot door, located in a sterile clean room. The maintenance door permits entry into the
chamber. The slot door facilitates tray loading and unloading from the clean room using an automatic tray handling system.
At 9:26 AM on March 2, 2008, a freeze-dryer failed during the steam-in-place (SIP) cycle. As a result of the failure, the
slot door was plastically deformed. Several items in the proximity of the slot door sustained damage. Fortunately, no personnel
were inside the clean room when the event occurred; there were no injuries or loss of life. The impact to production was severe.
The event removed the freeze dryer from service for approximately 2 months, reducing bulk powder production capacity by 33%
during the time it was down. The failure occurred because the slot door was not closed properly when the SIP cycle began.
Instead of being completely restrained, it was allowed to become simply-supported, seriously compromising its pressure-containing
ability. 相似文献
49.
Advancement of therapeutic protein therapies can be hindered by their poor stability and short in vivo half-life. There is emerging evidence that biocompatible zwitterionic materials can prevent nonspecific interactions within proteins systems that contribute to protein instability. Here, zwitterionic hydrogel beads are synthesized from poly(sulfobetaine methyl methacrylate), pSB, using an inverse emulsion, free radical polymerization reaction technique. The transport properties within the zwitterionic hydrogels were characterized using 1H NMR diffusometry. Equilibrium water content as high as 0.90 was measured for the synthesized hydrogels. Our study revealed that the pSB hydrogels are nontoxic, ion responsive, and their swelling is temperature dependent. The zwitterionic hydrogel beads were capable of undergoing lyophilization without aggregation. Hydrogel beads were loaded with a model protein, bovine serum albumin (BSA), using a postfabrication loading technique. The protein loading was studied using confocal laser microscopy, indicating homogenous protein dispersion of up to 40 μg BSA/mg hydrogel within the beads. Furthermore, the release rate of the protein from the synthesized hydrogel was studied at different crosslinker to monomer ratios. The protein encapsulated within the zwitterionic hydrogel had slower rates of thermal aggregation compared to nonencapsulated protein in solution. Furthermore, the protein-loaded inside the zwitterionic hydrogel better maintained its bioactivity. 相似文献
50.
Reaction of silica (SiO2 ) with triethanolamine (TEA, N(CH2 CH2 OH)3 ) and ethylene glycol (EG) under conditions (∼200°C) where byproduct water is removed resulted in the formation of the neutral silatrane glycolate complex, N(CH2 CH2 O)3 SiOCH2 CH2 OH (or TEASiOCH2 CH2 OH) in essentially quantitative yield. Solutions of this neutral precursor in EG, when rapidly pyrolyzed and then oxidized at 500°C, formed porous ceramic powders with high specific surface areas (>500 m2 /g). These powders were nitrided via ammonolysis in a fluidized-bed reactor at temperatures of 700°-1000°C. The resulting nitrided powders were characterized by thermal and chemical analyses, diffuse reflectance infrared spectroscopy, gas sorption, and X-ray photoelectron spectroscopy. The apparent activation energy for the nitridation process was determined to be 54 kJ/mol. Following nitridation, the powders were amorphous and had nitrogen contents as high as 21 wt% with retained surface areas >300 m2 /g at 1000°C. Under the nitridation conditions used, the extent of nitrogen incorporation correlated linearly with increases in material density. This linearity suggested that the change in density occurred primarily because of changes in coordination that occurred as trivalent nitrogen replaced divalent oxygen in the glass structure and nominally because of viscous flow. The linear density increase also suggested that pore trapping did not occur under these processing conditions. This work serves as a model for ongoing studies on the nitridation of high-surface-area ceramic powders produced by the rapid pyrolysis of mixed-metal TEA alkoxides. 相似文献