全文获取类型
收费全文 | 548篇 |
免费 | 32篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 12篇 |
化学工业 | 105篇 |
金属工艺 | 23篇 |
机械仪表 | 40篇 |
建筑科学 | 9篇 |
能源动力 | 11篇 |
轻工业 | 84篇 |
水利工程 | 6篇 |
石油天然气 | 1篇 |
无线电 | 102篇 |
一般工业技术 | 96篇 |
冶金工业 | 21篇 |
原子能技术 | 10篇 |
自动化技术 | 62篇 |
出版年
2023年 | 7篇 |
2022年 | 9篇 |
2021年 | 23篇 |
2020年 | 15篇 |
2019年 | 20篇 |
2018年 | 16篇 |
2017年 | 21篇 |
2016年 | 15篇 |
2015年 | 21篇 |
2014年 | 28篇 |
2013年 | 43篇 |
2012年 | 50篇 |
2011年 | 55篇 |
2010年 | 34篇 |
2009年 | 39篇 |
2008年 | 28篇 |
2007年 | 20篇 |
2006年 | 18篇 |
2005年 | 10篇 |
2004年 | 20篇 |
2003年 | 17篇 |
2002年 | 10篇 |
2001年 | 9篇 |
2000年 | 10篇 |
1999年 | 6篇 |
1998年 | 8篇 |
1997年 | 4篇 |
1996年 | 6篇 |
1995年 | 8篇 |
1994年 | 1篇 |
1993年 | 4篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1979年 | 1篇 |
排序方式: 共有582条查询结果,搜索用时 0 毫秒
31.
Seulah Lee Yeon Ji Suh Seonguk Yang Dong Geun Hong Akihito Ishigami Hangun Kim Jae-Seoun Hur Seung-Cheol Chang Jaewon Lee 《International journal of molecular sciences》2021,22(4)
Oxidative stress, mitochondrial dysfunction, and neuroinflammation are strongly associated with the pathogenesis of Parkinson’s disease (PD), which suggests that anti-oxidative and anti-inflammatory compounds might provide an alternative treatment for PD. Here, we evaluated the neuroprotective effects of evernic aid (EA), which was screened from a lichen library provided by the Korean Lichen Research Institute at Sunchon National University. EA is a secondary metabolite generated by lichens, including Ramalina, Evernia, and Hypogymnia, and several studies have described its anticancer, antifungal, and antimicrobial effects. However, the neuroprotective effects of EA have not been studied. We found that EA protected primary cultured neurons against 1-methyl-4-phenylpyridium (MPP+)-induced cell death, mitochondrial dysfunction, and oxidative stress, and effectively reduced MPP+-induced astroglial activation by inhibiting the NF-κB pathway. In vivo, EA ameliorated MPTP-induced motor dysfunction, dopaminergic neuronal loss, and neuroinflammation in the nigrostriatal pathway in C57BL/6 mice. Taken together, our findings demonstrate that EA has neuroprotective and anti-inflammatory effects in PD models and suggest that EA is a potential therapeutic candidate for PD. 相似文献
32.
Md Saifur Rahman Md Badrul Alam Young Kyun Kim Mst Hur Madina Ismail Fliss Sang Han Lee Jin Cheol Yoo 《International journal of molecular sciences》2021,22(10)
In this study, we investigate the immunomodulatory effects of a novel antimicrobial peptide, YD1, isolated from Kimchi, in both in vitro and in vivo models. We establish that YD1 exerts its anti-inflammatory effects via up-regulation of the Nrf2 pathway, resulting in the production of HO-1, which suppresses activation of the NF-κB pathway, including the subsequent proinflammatory cytokines IL-1β, IL-6, and TNF-α. We also found that YD1 robustly suppresses nitric oxide (NO) and prostaglandin E2 (PGE2) production by down-regulating the expression of the upstream genes, iNOS and COX-2, acting as a strong antioxidant. Collectively, YD1 exhibits vigorous anti-inflammatory and antioxidant activity, presenting it as an interesting potential therapeutic agent. 相似文献
33.
Gyu-Hong Kang Young-Dae Son Gyu-Tak Kim Jin Hur 《Industry Applications, IEEE Transactions on》2009,45(1):161-167
This paper presents a novel design method to reduce the cogging torque of interior-type permanent-magnet (PM) motor. In the design method, the optimal notches are put on the rotor pole face, which have an effect on the variation of PM shape or the residual flux density of PM. Through the space harmonic field analysis, the positions of notches are found, and the optimal shapes of notches are determined by using finite element method. The validity of the proposed method is confirmed by experiments. 相似文献
34.
Management of foreign exchange risk is considered to be as important as trading results in firm performance when international trading and transaction of different kind of currencies are getting popular. Most previous researches on this issue have been based on the foreign exchange market and financial investing and accounting, focusing on theoretical point of view. And it is difficult to apply these research results to each company, since all companies in industry have different financial circumstances. In this paper, the solution for the foreign exchange management is proposed using GA and VaR which is very practical to export-oriented companies. The developed software enables a user to specify the criteria for the foreign exchange trading condition, constraints on dealing amount, GA operator and penalty, and variables in VaR. This approach is useful for managing foreign exchange holdings of a company in a practical way, analyzing past exchange rate trend with dealing results. 相似文献
35.
The independence of processes in queueing systems is generally assumed when developing queueing models. However, real systems often involve several process dependencies, and failure to take these into consideration can lead to serious underestimation of the performance measures. We consider herein a single server queueing system with a Markov renewal process (MRP) for its arrival process and a general service time distribution, and derive the distribution function and correlation coefficient of the departure process. Since the departure process also often corresponds to an arrival process in downstream queues, the results obtained here can be used to derive a better approximation of the performance measures of a non-product form general queueing network. 相似文献
36.
Dietary conjugated linoleic acid (CLA) treatment reduced color a*- and b*-values of cooked chicken breast rolls. Sensory panels rated the color of cooked chicken rolls with CLA treatments darker than the control. The production of carbon monoxide (CO) in cooked chicken rolls increased dramatically after irradiation and was correlated with the increased redness of cooked chicken rolls after irradiation. Consumer test indicated that the color of cooked chicken rolls after irradiation was preferred to the nonirradiated, but no preference for the color among the three CLA treatments was found. Irradiation greatly increased volatile production and induced a metallic off-flavor in chicken rolls. Sensory evaluation indicated that the hardness of chicken rolls increased and juiciness decreased as the dietary level of CLA increased. 相似文献
37.
As pervasive computing is widely adopted and reliable networks are becoming more easily accessible, there is a rapidly growing need to develop a mechanism to analyze and evaluate the performance of ubiquitous environments. This paper presents an information processing model which characterizes a ubiquitous environment where a variety of pieces of information need to be exchanged among devices within a system. The proposed model not only provides analytical tools to evaluate the performance of devices, but also makes it possible to identify key factors in designing a ubiquitous environment. For illustrative purposes, a test bed is constructed and the performance of the system is assessed based on the proposed model. 相似文献
38.
Woo-Yong Lee Kyeong Hur Taeyoung Kim Doo-Seop Eom Jong-Ok Kim 《Wireless Personal Communications》2012,63(1):241-260
The task of formulating an efficient system for determining the location of an object, results in the creation of a wide number
of applications and services. For this reason, most wireless sensor network applications assume the availability of sensor
location information. In this paper, an indoor localization scheme, which is based on synchronized sensor nodes, is proposed.
It is efficient in terms of power consumption and location update rate. Furthermore, it resolves the scalability problem usually
found in most conventional indoor localization systems in large scale indoor environments. The performance of the proposed
scheme is evaluated through experimental implementation and is compared with the Cricket system. The results demonstrate that
the proposed scheme is a promising and feasible localization system for a large scale indoor environment. 相似文献
39.
Jongsoo Jurng Nahmkeon Hur Kwang Ho Kim Chun Sik Lee 《Journal of Mechanical Science and Technology》1993,7(4):312-319
A numerical simulation is carried out to analyze the flow field of cooling air through the radiator and engine compartment. In order to consider the strong effect of the suction-type flow by the cooling fan at engine idling condition, a potential flow analysis is attempted by the assumption of a line sink located at the position of the cooling fan. The governing equations for steady two-dimensional, incompressible, turbulent flow are solved with the two-equationk-ε model for turbulence. The velocity profiles in the underhood engine compartment and around the front-end of a real vehicle are measured to compare with the numerical results. The agreement between the numerical and experimental results is fairly good. It is concluded that a two-dimensional computation is a fast and efficient tool for predicting the effect of front-end design on the cooling air flow through the radiator. 相似文献
40.
Junbeom Hur Dongyoung Koo Seong Oun Hwang Kyungtae Kang 《Computers & Mathematics with Applications》2013,65(9):1310-1317
Attribute-based encryption (ABE) is a promising cryptographic primitive for fine-grained access control of distributed data. In ciphertext policy attribute-based encryption (CP-ABE), each user is associated with a set of attributes and data are encrypted with access policies on attributes. A user is able to decrypt a ciphertext if and only if his attributes satisfy the access policy embedded in the ciphertext. However, key escrow is inherent in ABE systems. A curious key generation center in that construction has the power to decrypt every ciphertext. We found that most of the existing ABE schemes depending on a single key authority suffer from the key escrow problem. In this study, we propose a novel CP-ABE key issuing architecture that solves the key escrow problem. The proposed scheme separates the power of issuing user keys into two parties: the key generation center and the attribute authority. In the proposed construction, the key generation center and the attribute authority issue different parts of secret key components to users through a secure two-party computation protocol such that none of them can determine the whole set of keys of users individually. We demonstrate how the proposed key issuing protocol can be applied in the existing CP-ABE scheme and resolve the key escrow problem. 相似文献