全文获取类型
收费全文 | 1530篇 |
免费 | 89篇 |
国内免费 | 184篇 |
专业分类
电工技术 | 23篇 |
综合类 | 84篇 |
化学工业 | 235篇 |
金属工艺 | 133篇 |
机械仪表 | 82篇 |
建筑科学 | 57篇 |
矿业工程 | 6篇 |
能源动力 | 26篇 |
轻工业 | 115篇 |
水利工程 | 29篇 |
石油天然气 | 53篇 |
无线电 | 122篇 |
一般工业技术 | 613篇 |
冶金工业 | 52篇 |
原子能技术 | 30篇 |
自动化技术 | 143篇 |
出版年
2024年 | 27篇 |
2023年 | 92篇 |
2022年 | 130篇 |
2021年 | 109篇 |
2020年 | 38篇 |
2019年 | 23篇 |
2018年 | 18篇 |
2017年 | 23篇 |
2016年 | 19篇 |
2015年 | 23篇 |
2014年 | 24篇 |
2013年 | 28篇 |
2012年 | 181篇 |
2011年 | 222篇 |
2010年 | 51篇 |
2009年 | 32篇 |
2008年 | 113篇 |
2007年 | 96篇 |
2006年 | 93篇 |
2005年 | 77篇 |
2004年 | 61篇 |
2003年 | 34篇 |
2002年 | 27篇 |
2001年 | 36篇 |
2000年 | 25篇 |
1999年 | 44篇 |
1998年 | 22篇 |
1997年 | 31篇 |
1996年 | 24篇 |
1995年 | 26篇 |
1994年 | 13篇 |
1993年 | 7篇 |
1992年 | 10篇 |
1991年 | 7篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1987年 | 3篇 |
1985年 | 2篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1980年 | 1篇 |
排序方式: 共有1803条查询结果,搜索用时 15 毫秒
91.
92.
Zhang Fuyin 《电气》1997,(2)
l-Introducti0nUptol995,powerplantsdirectlyunderNortheastChinaElectricP0werGroupCorPorati0n(NEPGC)possessed44setsof2O0MWthermalp0wergeneratingunits.Theseunitstake0nthemajorelectricit}generationofthepowernetwork.Most0ftheirb0ilersareHG670/l40typesuperhighpressure,intermediatereheat,singledrumnaturalcirculationpulverized-c0alfiredboilersproducedbyHarbinBoilerWorks,andthemainandauxiliaryequipmentweremadeintheperiodfromthelatel97Ostotheearlyl980s.Owingt0thebackwardnessinequipmenttechnology… 相似文献
93.
Carbon solubility in MnFe melts (xMn=0083-0706, xFe=0034-0715) was measured experimentally at various temperatures. By thermodynamic derivation and calculation, the relationship between activity coefficient of carbon in infinite dilute solution of manganese in MnC system and temperature was obtained. Using GibbsDuhem relationship, the experimental results of this study, and experimental data obtained by strict thermodynamic derivation and calculation in references, the relationships between other thermodynamic properties (εCC, εCCC, εCFe, εCCFe, and εCFeFe) in MnFeC system and temperature were obtained. 相似文献
94.
The key to multi-sensor image fusion is the fusion of infrared and visible images. Fusion of infrared and visible images with generative adversarial network(GAN) has great advantages in automatic feature extraction and subjective vision improvement. Due to different principle between infrared and visible imaging, the blur phenomenon of edge and texture is caused in the fusion result of GAN. For this purpose, this paper conducts a novel generative adversarial network with blur suppression. Specif... 相似文献
95.
This paper aims to provide an efficient and straightforward structural form-finding method for designers to extrapolate component forms during the conceptual stage. The core idea is to optimize the classical method of structural form-finding based on principal stress lines by using parametric tools. The traditional operating process of this method relies excessively on the designer's engineering experience and lacks precision. Meanwhile, the current optimization work for this method is overly complicated for architects, and limitations in component type and final result exist. Therefore, to facilitate an architect's conceptual work, the optimization metrics of the method in this paper are set as simplicity, practicality, freedom, and rapid feedback. For that reason, this paper optimizes the method from three aspects: modeling strategy for continuum structures, classification processing of data by using the k-nearest neighbor algorithm, and topological form-finding process based on stress lines. Eventually, it allows architects to create structural texture with formal aesthetics and modify it in real time on the basis of structural analysis results. This paper also explores a comprehensive application strategy with internal force analysis diagramming to form-finding. The finite element analysis tool Karamba3D verifies the structural performance of the form-finding method. The performance is compared with that of the conventional form, and the comparison results show the practicality and potential of the strategy in this paper. 相似文献
96.
<正>Last year,China rubber industry had a"perturbed year",it entered 2014 in optimism and steps into 2015 in pessimism.According to the statistics of China Rubber Industry Association on 46 main tire enterprises,obvious deviation showed in the main indicators of tire industry,that is,the output increased 相似文献
97.
作者结合工作经验,就建筑外墙保温技术应用、建筑外墙保温技术的种类、建筑外墙保温节能材料及外墙保温隔热技术等问题进行了探讨,供同行参考借鉴。 相似文献
98.
Dimethyl phthalate esters (DMPE) can easily be released into the environment from plastic products. As endocrine disruptors, DMPE mimic estrogenic activities in animals and humans. The metabolites of DMPE are suspected to cause even more serious health problems. Among the common sterilization techniques adopted in the study of DMPE degradation, the average loss of the parent DMPE compounds after autoclaving was as high as 21.26%. In contrast, the loss after 0.2 microm filtration was significantly lower at 2.28%. It is suggested that filtration should be used over autoclaving for sterilizing DMPE. The environmental fate of DMPE under sulfate-reducing condition was simulated and studied in microcosm system. It was observed that dimethyl phthalate (DMP), dimethyl isophthalate (DMI) and dimethyl terephthalate (DMT) could not be mineralized over an extended period of 6 months, but with the transformation to the respective monomethyl phthalate and/or phthalic acid. The dominant species of microorganisms utilizing individual DMPE isomer as the sole carbon source were isolated and identified as facultative anaerobe Thauera sp., Xanthobacter sp. and Agrobacterium sp. for DMP, DMI and DMT, respectively. This study illustrates that the detrimental DMPE and their natural metabolites may accumulate in the sulfate-reducing environment. Accordingly, proper surveillance program should be devised to monitor both the parent compounds and degradation intermediates of DMPE in order to protect the aquatic ecosystem and human health. 相似文献
99.
Xuewen Mu Yun Xu Zheng Wang Dunyun Shi 《Frontiers of Chemical Science and Engineering》2023,17(2):123
The two-electron cytoplasmic reductase NAD(P)H:quinone oxidoreductase 1 is expressed in many tissues. NAD(P)H:quinone oxidoreductase 1 is well-known for being highly expressed in most cancers. Therefore, it could be a target for cancer therapy. Because it is a quinone reductase, many bioimaging probes based on quinone structures target NAD(P)H:quinone oxidoreductase 1 to diagnose tumours. Its expression is higher in tumours than in normal tissues, and using target drugs such as β-lapachone to reduce side effects in normal tissues can help. However, the physicochemical properties of β-lapachone limit its application. The problem can be solved by using nanosystems to deliver β-lapachone. This mini-review summarizes quinone-based fluorescent, near-infrared and two-photon fluorescent probes, as well as nanosystems for delivering the NAD(P)H:quinone oxidoreductase 1-activating drug β-lapachone. This review provides valuable information for the future development of probes and nano-delivery systems that target NAD(P)H:quinone oxidoreductase 1. 相似文献
100.
Liu Y Ye Q Shen M Shi J Chen J Pan H Shi Y 《Environmental science & technology》2011,45(13):5710-5716
A novel solid amine sorbent was prepared using KIT-6-type mesoporous silica modified with tetraethylenepentamine (TEPA). Its adsorption behavior toward CO(2) from simulated flue gases is investigated using an adsorption column. The adsorption capacities at temperatures of 303, 313, 333, 343, and 353 K are 2.10, 2.29, 2.58, 2.85, and 2.71 mmol g(-1), respectively. Experimental adsorption isotherms were obtained, and the average isosteric heat of adsorption was 43.8 kJ/mol. The adsorption capacity increases to 3.2 mmol g(-1) when the relative humidity (RH) of the simulated flue gas reaches 37%. The adsorption capacity is inhibited slightly by the presence of SO(2) at concentrations lower than 300 ppm but is not significantly influenced by NO at concentrations up to 400 ppm. The adsorbent is completely regenerated in 10 min at 393 K and a pressure of 5 KPa, with expected consumption energy of about 1.41 MJ kg(-1) CO(2). The adsorption capacity remains almost the same after 10 cycles of adsorption/regeneration with adsorption conditions of 10 vol % CO(2), 100 ppm SO(2), 200 ppm NO, 100% relative humidity, and a temperature of 393 K. The solid amine sorbent, KIT-6(TEPA), performs excellently for CO(2) capture and its separation from flue gas. 相似文献