全文获取类型
收费全文 | 2715篇 |
免费 | 335篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 34篇 |
化学工业 | 696篇 |
金属工艺 | 130篇 |
机械仪表 | 181篇 |
建筑科学 | 25篇 |
矿业工程 | 1篇 |
能源动力 | 105篇 |
轻工业 | 182篇 |
水利工程 | 3篇 |
无线电 | 518篇 |
一般工业技术 | 741篇 |
冶金工业 | 112篇 |
原子能技术 | 46篇 |
自动化技术 | 279篇 |
出版年
2024年 | 2篇 |
2023年 | 37篇 |
2022年 | 30篇 |
2021年 | 98篇 |
2020年 | 78篇 |
2019年 | 114篇 |
2018年 | 121篇 |
2017年 | 129篇 |
2016年 | 164篇 |
2015年 | 116篇 |
2014年 | 165篇 |
2013年 | 199篇 |
2012年 | 242篇 |
2011年 | 264篇 |
2010年 | 153篇 |
2009年 | 190篇 |
2008年 | 164篇 |
2007年 | 114篇 |
2006年 | 109篇 |
2005年 | 80篇 |
2004年 | 77篇 |
2003年 | 87篇 |
2002年 | 76篇 |
2001年 | 54篇 |
2000年 | 40篇 |
1999年 | 31篇 |
1998年 | 27篇 |
1997年 | 22篇 |
1996年 | 21篇 |
1995年 | 15篇 |
1994年 | 5篇 |
1993年 | 6篇 |
1992年 | 6篇 |
1991年 | 3篇 |
1990年 | 5篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
排序方式: 共有3053条查询结果,搜索用时 328 毫秒
101.
Joo Hee Kim Seok Hyun Nam Catherine W. Rico Mi Young Kang 《International Journal of Food Science & Technology》2012,47(6):1176-1182
The antioxidative and anti‐allergic activities of fresh and aged black garlic extracts were investigated. The garlic samples were extracted with 70% ethanol (v/v) and the total phenolic content was measured. The antioxidant capacity of extracts was assessed by determining the scavenging activities on 1,1‐diphenyl‐2‐picrylhydrazyl and hydroxyl radicals, ferricyanide reducing power, ferrous ion‐chelating ability and inhibitory effect on linoleic acid peroxidation. The anti‐allergic activity of extracts was analysed by measuring their inhibitory effects against β‐hexosaminidase release. The aged black garlic exhibited significantly higher phenolic content and greater antioxidative activity than fresh garlic. Both garlic extracts showed strong antioxidant capacity in a dose‐dependent manner. On the other hand, a considerably higher suppression of β‐hexosaminidase release was found in fresh garlic extract at lower concentration compared with that of the black garlic. Results of this study illustrate that ageing of garlic could enhance its antioxidant capacity, but could decrease its anti‐allergic activity. 相似文献
102.
Hoon Chae Park Hang Seok Choi Ji Eun Lee 《Korean Journal of Chemical Engineering》2016,33(4):1159-1169
Rapid quenching of volatiles in fast pyrolysis is important for achieving high yield and quality of the bio-oil product, but few studies have examined the condensation of volatiles and their related heat exchangers. Accordingly, we have studied the condensation characteristics of volatiles by varying heat transfer conditions in a direct contact heat exchanger. As the mass flow rate ratio of quenching oil to pyrolysis gas increased, the heat transfer rate and yield of bio-oil increased. The heat transfer rate and yield of bio-oil reached a maximum value at an intermediate air-to-quenching oil mass flow rate ratio. Additionally, the heat transfer rate and yield of bio-oil decreased as the temperature of the quenching oil increased. Experiments were also conducted to derive an empirical relationship for the volumetric heat transfer coefficient for direct contact heat exchangers. 相似文献
103.
Jae Mo Yang Byung Seok Ko Chulhwan Park Byungtae Yoo Dongil Shin Jae Wook Ko 《Korean Journal of Chemical Engineering》2014,31(3):393-401
To increase awareness of safety in facilities where hazards may exist, operators, managers, and executive officers on the site should be able to monitor such facilities. However, most compressed natural gas (CNG) service stations in Korea use only local-mode monitoring, with only on-site operators to monitor the facility. To complement this local-mode monitoring, an online safety management system called Ubiquitous-gas safety management system (U-GSMS) was developed. The U-GSMS consists largely of software and hardware. The software consists of systems that can manage safety and operations, while the hardware consists of sensors installed in the gas facility and wireless communication systems using a ubiquitous sensor network (USN) technology that facilitates communication between sensors as well as between sensors and other devices. As these systems are web-based, on-site operators as well as managers and executive officers at the headquarters can more effectively and efficiently perform monitoring and safety management. 相似文献
104.
Jun Ho Yeom Keeman Kim Young Seok Lee Hyoung Chan Kim Sangjun Oh Kihak Im Charles Kessel 《Fusion Engineering and Design》2013,88(6-8):742-745
A conceptual design study for a steady-state Korean fusion DEMO reactor (K-DEMO) has been initiated. Two peculiar features need to be noted. First, the major radius is designed to be just below 6.5 m, considering practical engineering feasibilities. But still, high magnetic field at the plasma center around 8 T is expected to be achieved by using current state-of-the-art high performance Nb3Sn strand technology. Second, a two-stage development plan is being considered. In the first stage, K-DEMO will demonstrate a net electricity generation but will also act as a component test facility. Then, after a major upgrade, K-DEMO is expected to show a net electric generation on the order of 300 MWe and the competitiveness in cost of electricity (COE). Feasibility of such a practical, near-future demonstration reactor is studied in this paper, based on a zero dimensional system analysis code study. It was shown that a net electric generation on the order of 300 MWe can be achieved below the optimistic βN limit of 5. The elongation of K-DEMO is around 1.8 with single null configuration. Detailed optimization process and the resultant various plasma parameters are described. 相似文献
105.
Junghyun Kim Joon Hyuk Suh Hyun-Deok Cho Wonjae Kang Yong Seok Choi 《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2016,33(3):420-432
A multi-class, multi-residue analytical method based on LC-MS/MS detection was developed for the screening and confirmation of 28 veterinary drug and metabolite residues in flatfish, shrimp and eel. The chosen veterinary drugs are prohibited or unauthorised compounds in Korea, which were categorised into various chemical classes including nitroimidazoles, benzimidazoles, sulfones, quinolones, macrolides, phenothiazines, pyrethroids and others. To achieve fast and simultaneous extraction of various analytes, a simple and generic liquid extraction procedure using EDTA-ammonium acetate buffer and acetonitrile, without further clean-up steps, was applied to sample preparation. The final extracts were analysed by ultra-high-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS). The method was validated for each compound in each matrix at three different concentrations (5, 10 and 20 ng g–1) in accordance with Codex guidelines (CAC/GL 71-2009). For most compounds, the recoveries were in the range of 60–110%, and precision, expressed as the relative standard deviation (RSD), was in the range of 5–15%. The detection capabilities (CCβs) were below or equal to 5 ng g–1, which indicates that the developed method is sufficient to detect illegal fishery products containing the target compounds above the residue limit (10 ng g–1) of the new regulatory system (Positive List System – PLS). 相似文献
106.
Young K. Chung Kyung Y. Chang Hoon S. Park Mi‐Hee Kim Kang‐Min Lee Tae‐Seok Lim Hyung W. Kim 《Hemodialysis international. International Symposium on Home Hemodialysis》2014,18(2):551-555
Carbamazepine (CBZ) intoxication can be associated with severe toxicity, including neurological and cardio‐respiratory abnormalities. Highly protein‐bound, CBZ is not removed efficiently through conventional hemodialysis. Charcoal hemoperfusion is the most effective extracorporeal elimination therapy for CBZ intoxication. Recent reports have indicated that continuous venovenous hemodiafiltration (CVVHDF), albumin‐enhanced continuous venovenous hemodialysis, high‐flux hemodialysis and plasma exchange can be as effective as charcoal hemoperfusion. In contrast to recent reports, which demonstrated the effectiveness of CVVHDF with high dialysate flow in CBZ intoxication, we observed that serum CBZ level was decreased minimally by albumin‐enhanced CVVHDF with low dialysate flow. Therefore, albumin‐enhanced CVVHDF with high dialysate flow should be considered in severe CBZ intoxication, if hemoperfusion is unavailable because of the lack of facilities or if it cannot be performed. 相似文献
107.
108.
Man Hoi Koo Hong Seok Lim Hak In Gimm Hong Hee Yoo 《Journal of Mechanical Science and Technology》2009,23(4):964-967
A new manufacturing technology is being employed to build a new type of armored vehicle. While thick panels are welded together
in the old manufacturing technology, relatively thin panels are welded to a frame structure in the new manufacturing technology.
The structural integrity of the new type of armor vehicles can be maintained mainly by the frame structures while the panel
thickness is reduced significantly to reduce the total vehicle weight. Since the dynamic characteristics of a frame-panel
hybrid structure are different from those of the old type of structure which consists of only thick panels, they should be
identified to achieve a good performance of the vehicle. For this purpose, a proper FE model of the hybrid type of structure
needs to be developed. In the present study, FE models are proposed to represent the frame-panel hybrid type structure efficiently.
The impact energy propagation, the transient response and the modal characteristics are investigated with the FE models.
This paper was presented at the 4th Asian Conference on Multibody Dynamics(ACMD2008), Jeju, Korea, August 20–23, 2008.
Hong-Hee Yoo received a B.S. and M.S. degree in Mechanical Engineering from Seoul National University in 1980 and 1982. He then went on
to receive his Ph.D. degree from Michigan State University in 1989. Dr. Yoo is currently a Professor at the School of Mechanical
Engineering at Hanyang University in Seoul, Korea. His research interests are in the area of Flexible body dynamics, vibration. 相似文献
109.
Hydrogen discharge technique of high-strength low alloy steel for high-pressure gaseous hydrogen storage tank was developed by using an electrochemical technique. The electrochemical hydrogen discharge of high-strength low alloy steel were investigated in a deaerated borate buffer solution (0.3 M H3BO3 + 0.074 M N2B4O7, pH = 8.4). By applying a potential of +630 mVSCE which is higher than the hydrogen equilibrium potentials and lower than the pitting potential, the oxidation reaction of metal (Fe → Fe2+ + 2e−) is limited and oxidation reaction of the hydrogen (H2 + 2OH− → 2H2O + 2e−) was induced simultaneously. Thus, the pre-charged hydrogen inside the specimen was eliminated effectively without any damage to the specimen. The electrochemical hydrogen discharge method was performed at 25 °C, 50 °C and 75 °C. The efficiency of hydrogen discharge was accelerated with increasing temperature because the exchange current density of hydrogen is increased with temperature. 相似文献
110.
Vincent Lemiale Yuri Estrin Hyoung Seop Kim Robert O’Donnell 《Metallurgical and Materials Transactions A》2011,42(10):3006-3012
Grain refinement by plastic deformation is becoming increasingly popular as a way of producing metals with improved properties,
such as higher mechanical strength. Surface treatment techniques in which a metallic substrate is bombarded with metallic
particles can generate nanocrystalline layers in the impact zone. Understanding the physical mechanisms underlying this grain
refinement is crucial for achieving an improvement of existing experimental processes. In this article, we propose a numerical
framework combining finite element (FE) simulations with a dislocation-based material model to predict the evolution of the
microstructure under particle impact. A single particle normally impacting on a metallic substrate was simulated at different
initial velocities. The simulations were compared with previously reported numerical and experimental data. The results indicate
that our model accurately captures the grain refinement in the impact zone for a broad range of velocities. This approach
provides valuable information on the formation of nanocrystalline layers in both the substrate and the impacting particle.
Its potential applications include processes involving surface treatment by high velocity particles, such as shot peening,
surface mechanical attrition treatment, kinetic metallization, cold spray, etc. 相似文献