全文获取类型
收费全文 | 268篇 |
免费 | 30篇 |
国内免费 | 6篇 |
专业分类
电工技术 | 10篇 |
综合类 | 18篇 |
化学工业 | 48篇 |
金属工艺 | 73篇 |
机械仪表 | 29篇 |
建筑科学 | 10篇 |
矿业工程 | 1篇 |
能源动力 | 9篇 |
轻工业 | 4篇 |
石油天然气 | 20篇 |
无线电 | 2篇 |
一般工业技术 | 31篇 |
冶金工业 | 19篇 |
原子能技术 | 19篇 |
自动化技术 | 11篇 |
出版年
2024年 | 1篇 |
2023年 | 5篇 |
2022年 | 8篇 |
2021年 | 5篇 |
2020年 | 13篇 |
2019年 | 8篇 |
2018年 | 6篇 |
2017年 | 10篇 |
2016年 | 7篇 |
2015年 | 8篇 |
2014年 | 14篇 |
2013年 | 16篇 |
2012年 | 19篇 |
2011年 | 21篇 |
2010年 | 21篇 |
2009年 | 12篇 |
2008年 | 15篇 |
2007年 | 18篇 |
2006年 | 13篇 |
2005年 | 15篇 |
2004年 | 17篇 |
2003年 | 8篇 |
2002年 | 12篇 |
2001年 | 10篇 |
2000年 | 2篇 |
1999年 | 3篇 |
1998年 | 1篇 |
1997年 | 6篇 |
1996年 | 1篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 2篇 |
排序方式: 共有304条查询结果,搜索用时 9 毫秒
41.
Three-dimensional, transient simulations of the plasma flow inside different plasma spray torches have been performed using
a local thermodynamic equilibrium model solved by a multiscale finite-element method. The model describes the dynamics of
the arc without any further assumption on the reattachment process except for the use of an artificially high electrical conductivity
near the electrodes. Simulations of an F4-MB torch from Sulzer-Metco and two configurations of the SG-100 torch from Praxair
are presented. The simulations show that, when straight or swirl injection is used, the arc is dragged by the flow and then
jumps to form a new attachment, preferably at the opposite side of the original attachment, as has been observed experimentally.
Although the predicted reattachment frequencies are at present higher than the experimental ones, the model is suitable as
a design tool.
This article was originally published inBuilding on 100 Years of Success: Proceedings of the 2006 International Thermal Spray Conference (Seattle, WA), May 15–18, 2006, B.R. Marple, M.M. Hyland, Y.-Ch. Lau, R.S. Lima, and J. Voyer, Ed., ASM International, Materials
Park, OH, 2006. 相似文献
42.
分析了醋酸厂低压甲醇羰基化生产醋酸装置火炬头运行噪音过高的原因,认为运行噪音过高主要是由于助燃蒸汽喷射噪音所引起;比较了几种降低噪音方法的可行性;改造采用火炬头中下部的蒸汽引射空气喷嘴注入方式的方法代替火炬头顶部简单的蒸汽喷射,并加设高效盆式消声器.改造后距火炬中心80 m处的噪音强度从原来的105dB(A)降低至79 dB(A),取得了良好的效果. 相似文献
43.
某住宅倒置式屋面防水层,用自粘防水卷材铺贴完成后,在试水过程中检查发现有多处渗漏水。分析渗漏原因,研究处理方案,采用SBS防水卷材热熔法施工,解决了屋面渗漏。 相似文献
44.
In the present work, hydroxyapatite (Ca10(PO4)6(OH)2) was prepared from bovine bones with calcination method (up to 850 °C).The calcinated hydroxyapatite was powdered (30-40 μm) using a mechanical grinder; the particles were highly irregular in shape with sharp edges, angular, rounded, circular, dentric, porous and fragmented morphologies. The irregular shaped calcinated hydroxyapatite was plasma processed to produce spherical powders for thermal spray coating applications. More over; calcium phosphate silicate glass ceramics was produced by plasma melting of ball milled hydroxyapatite-borosilicate glass (50 wt.%) mixture. The samples were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffractometer (XRD) and energy dispersive X-ray analysis (EDX). The morphology was determined using scanning electron (SEM) and optical microscopy (OM). The microhardness, density and porosity measurements for the synthesized samples were made. 相似文献
45.
In this study, municipal solid waste incinerator fly ash was vitrified using a plasma torch. The fly ash contained rich Ca, causing a high basicity of 2.43. Pure quartz was used as an additive to adjust the basicity. BET surface area analysis, X-ray diffraction analysis, and a scanning electron microscope were used to examine the physical properties of slags. The chemical stability and the acid resistance of slags were evaluated using the toxicity characteristics leaching procedure and tests of acid bathing. The results indicate that the plasma torch effectively vitrified the fly ash. Anthropogenic metals with low boiling points, such as Cd, Pb, and Zn, were predominately vaporized into flue gas. Most of the metals with high boiling points, such as Cr, Cu, and Mn, remained in the slag. After the vitrification, hazardous metals were noticeably immobilized in all slags. However, the slags with higher amorphous volume fractions were more effective in metal immobilization and in resisting acid corrosion. This indicates that SiO(2) enhanced the formation of the glassy amorphous phase and improved the resistance of acid corrosion and the immobilization of hazardous metals. 相似文献
46.
Theoretical data and experimental results of the shielding jets formation and their behaviour in the blowing off air streams are considered aimed at designing welding process in the wind. 相似文献
47.
喷射清洗设备中喷管的设计与研究 总被引:1,自引:0,他引:1
首先介绍了干冰清洗和高压水射流两种工业物理清洗的原理及机理;其次,论述了喷枪的核心喷管的设计理论;接着,编制了喷管型线设计计算程序,并用该程序给出了一个算例结果;再次,用FLUENT软件对上述算例进行了数值模拟;最后,对程序计算和数值模拟这两种结果进行了比较分析. 相似文献
48.
Gustavo Femandes de Lima Glauco George Cipriano Manicoba Andres Ortiz Salazar 《机械工程与自动化:英文版》2014,(6):499-504
Plasma torch is a device that transforms electrical energy into heat carried by a gas and its safe operation is necessary to control her temperature. This paper presents the use of the Arduino board in temperature control of a plasma torch through fuzzy control. The plasma torch of this project was built so that a flow of water can circulate through your body, allowing its cooling. The cooling system mounted consists of one radiator, one expansion vase, one water pump and one temperature sensor. The heated water coming the plasma torch is passed by the temperature sensor. This is converted in a voltage and read by an analog input port of the Arduino. This processes the information received and makes the decision to turn on/off the radiator fan and/or powered the frequency inverter water pump to control the temperature. The graph of the fuzzy control showed an oscillation between 104 °F to 122 °F around the chosen reference 113 °F. The results show that it is possible to control the temperature of a plasma torch using the Arduino board and fuzzy logic. 相似文献
49.
Hyungjun Park Dong-Gyu Ahn 《The International Journal of Advanced Manufacturing Technology》2008,37(3-4):302-313
In this paper, we propose a knowledge-based method for generating a CNC torch path for laser cutting of the outlines of planar
shapes. The proposed method consists of two main phases: laser cutting knowledge construction and CNC torch path generation
using the knowledge. In the first phase, laser cutting experiments are conducted on various operating parameters, and then
empirical data are stored and analyzed to make up the knowledge of laser cutting. With this knowledge, we can inquire what
a kerf width is for specific operating parameters. In the second phase, using the knowledge of laser cutting, the CNC torch
path is generated for cutting the outlines of the given planar shapes. This phase is basically based on the offset generation
of each outline by a sequence of arc splines, where the offset distance is the same as the half of the kerf width determined
from the constructed knowledge. The proposed method based on laser cutting knowledge makes full use of arc interpolators in
CNC torch path generation. The method can efficiently reduce the number of path segments while keeping the torch path within
the desired accuracy. 相似文献
50.
火炬塔架抗震设计标准给出的钢管径厚比限值远小于非抗震要求的限值。然而,通常情况下火炬塔架设计的控制荷载是风荷载,是否仍然需要满足抗震规范径厚比限制要求缺乏足够的研究。本文以某150m高火炬塔实际工程为背景,考虑常用基本风压情况,分别按抗风和抗震要求的径厚比确定构件,比较满足抗风设计与抗震设计要求时用钢量的差别,并找出对应的大震作用下处于弹性状态的设防烈度。分析结果表明,在基本风压不大于0.55 MPa时,按抗风要求径厚比确定的构件比按抗震要求确定的构件可节省用钢量20%左右,且在7度设防烈度大震作用下,塔架可保持在弹性范围;基本风压超过0.55 MPa后,径厚比改变对用钢量的影响不明显。综合考虑,火炬塔架设计宜先以抗风要求为主进行优化设计,然后进行抗震验算。 相似文献