全文获取类型
收费全文 | 81599篇 |
免费 | 5135篇 |
国内免费 | 1101篇 |
学科分类
工业技术 | 87835篇 |
出版年
2023年 | 931篇 |
2022年 | 943篇 |
2021年 | 2423篇 |
2020年 | 1960篇 |
2019年 | 1938篇 |
2018年 | 2305篇 |
2017年 | 2299篇 |
2016年 | 2577篇 |
2015年 | 2326篇 |
2014年 | 3444篇 |
2013年 | 5072篇 |
2012年 | 5202篇 |
2011年 | 6151篇 |
2010年 | 4608篇 |
2009年 | 4756篇 |
2008年 | 4648篇 |
2007年 | 3896篇 |
2006年 | 3548篇 |
2005年 | 2938篇 |
2004年 | 2642篇 |
2003年 | 2685篇 |
2002年 | 2671篇 |
2001年 | 2209篇 |
2000年 | 1665篇 |
1999年 | 1470篇 |
1998年 | 2427篇 |
1997年 | 1581篇 |
1996年 | 1283篇 |
1995年 | 1017篇 |
1994年 | 854篇 |
1993年 | 736篇 |
1992年 | 520篇 |
1991年 | 493篇 |
1990年 | 478篇 |
1989年 | 438篇 |
1988年 | 377篇 |
1987年 | 311篇 |
1986年 | 246篇 |
1985年 | 241篇 |
1984年 | 196篇 |
1983年 | 139篇 |
1982年 | 109篇 |
1981年 | 97篇 |
1980年 | 114篇 |
1979年 | 80篇 |
1978年 | 91篇 |
1977年 | 96篇 |
1976年 | 137篇 |
1975年 | 63篇 |
1973年 | 58篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Jang Hyun-Joo Lee Hyun-Jin Yoon Dong-Kyu Ji Da-Som Kim Ji-Han Lee Chi-Ho 《Food science and biotechnology》2018,27(1):219-225
Food Science and Biotechnology - This study aims to investigate antioxidative and antibacterial properties of fresh garlic (non-aged, NG) and aged garlic (AG) by-products extracted with distilled... 相似文献
32.
Wireless Personal Communications - The purpose of this study is to construct a structural equation model of shared bicycle added psychological factors proceeding from the theory of planned... 相似文献
33.
Jae-Sung Kim Seok-Jun Mun Euni Cho Donggyu Kim Wooic Son Hye-In Jeon Hyo Keun Kim Kiseok Jang Chul-Su Yang 《International journal of molecular sciences》2020,21(22)
Dense granule proteins (GRAs) are essential components in Toxoplasma gondii, which are suggested to be promising serodiagnostic markers in toxoplasmosis. In this study, we investigated the function of GRA9 in host response and the associated regulatory mechanism, which were unknown. We found that GRA9 interacts with NLR family pyrin domain containing 3 (NLRP3) involved in inflammation by forming the NLRP3 inflammasome. The C-terminal of GRA9 (GRA9C) is essential for GRA9–NLRP3 interaction by disrupting the NLRP3 inflammasome through blocking the binding of apoptotic speck-containing (ASC)-NLRP3. Notably, Q200 of GRA9C is essential for the interaction of NLRP3 and blocking the conjugation of ASC. Recombinant GRA9C (rGRA9C) showed an anti-inflammatory effect and the elimination of bacteria by converting M1 to M2 macrophages. In vivo, rGRA9C increased the anti-inflammatory and bactericidal effects and subsequent anti-septic activity in CLP- and E. coli- or P. aeruginosa-induced sepsis model mice by increasing M2 polarization. Taken together, our findings defined a role of T. gondii GRA9 associated with NLRP3 in host macrophages, suggesting its potential as a new candidate therapeutic agent for sepsis. 相似文献
34.
Chang-Won Kim Wi Sung Yoo Hyunsu Lim Ilhan Yu Hunhee Cho Kyung-In Kang 《International Journal of Project Management》2018,36(5):730-743
An early-warning performance monitoring system (EPMS) is proposed to objectively measure and monitor the performance of a project for early detection of inherent poor performance problems. The EPMS is built based on project progress data and consists of a database of business information, an optimized theoretical model used as a performance measurement baseline, and an index for monitoring and forecasting the performance. By monitoring the performance through an application of the EPMS to the Korean construction project, the quarterly variation of index was found to differ by project type. These results could explain the environmental changes in the project execution. Therefore, the EPMS is expected to be an alternative for objective performance monitoring and forecasting while applying the existing methods is difficult because of the limited available data on performance indicators. The development procedures may also be useful to researchers interested in approaches to quantitatively analyze trends in various industries. 相似文献
35.
Many studies have demonstrated the strong relationships between physiological responses and driving stress, but they have done little to build a model that could be used to identify a driver's stress accurately in real time. The objective of this study is to develop a model that accurately classifies driving stress by monitoring physiological responses—specifically galvanic skin response (GSR). GSR data were collected from nine drivers with licenses obtained in the US in real road driving situations with two stress conditions—rest period (low stress) and highway or city driving (high stress). The validation drive was performed by one driver with licenses obtained in South Korea in real long‐term road driving situations with two stress conditions—rural area (low stress) and highway or highway under construction (high stress). Those two conditions were used to build a binary logistic regression model to classify low stress or high stress based on a driver's measured hand GSR. The overall classification accuracy of the developed model was found to be 85.3%, and the accuracy of cross validation, with a testing dataset, was found to be 83.2%. A simple logit model was developed to identify drivers' stress by incorporating their GSR data. The developed model can be embedded in a wearable device equipped with GSR sensors for drivers to detect their stress level in real time. 相似文献
36.
Multimedia Tools and Applications - This study relates to a method for analyzing speech anxiety by processing biosignals in real time. In the previous study, the effect of galvanic skin response... 相似文献
37.
Multimedia Tools and Applications - This paper proposed an MAC (Media Access Control) operation method based on the CCH (Control Channel) and SCH (Service Channel) control mode of the WAVE... 相似文献
38.
39.
Yoon Hyuk Kim Batbayar Khuyagbaatar Kyungsoo Kim 《Journal of Mechanical Science and Technology》2018,32(1):1-10
The human cervical spine is a complex structure that is the most frequently injured site among all spinal injuries. Therefore, understanding of the cervical spine injury and dysfunction, and also biomechanical response to external stimuli is important. Finite element (FE) modeling can help researchers to access the internal stresses and strains in the bones, ligaments and soft tissues more realistically, and it has been widely adopted for spine biomechanics research. Although in recent years numerous techniques have been developed, there are no recent literature reviews on FE models of the cervical spine. Our objective was to present recent advances in FE modeling of the human cervical spine in terms of component modeling, material properties, and validation procedures. Model applications and further development are also discussed. The integration of new technologies will allow us to generate more accurate and comprehensive model of the cervical spine, which can increase efficiency and model applicability. Finally, the FE modeling can help to facilitate diagnosis, treatment, and prevention technologies for cervical spine injuries. 相似文献
40.
Wireless Networks - Vehicular communication is one of the critical technologies in intelligent transportation system to provide connectivity between vehicles, road side units, and pedestrians.... 相似文献