全文获取类型
收费全文 | 279篇 |
免费 | 30篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 4篇 |
综合类 | 1篇 |
化学工业 | 80篇 |
金属工艺 | 9篇 |
机械仪表 | 6篇 |
建筑科学 | 9篇 |
能源动力 | 8篇 |
轻工业 | 36篇 |
水利工程 | 5篇 |
无线电 | 36篇 |
一般工业技术 | 63篇 |
冶金工业 | 14篇 |
原子能技术 | 2篇 |
自动化技术 | 38篇 |
出版年
2024年 | 1篇 |
2023年 | 13篇 |
2022年 | 35篇 |
2021年 | 33篇 |
2020年 | 13篇 |
2019年 | 19篇 |
2018年 | 20篇 |
2017年 | 19篇 |
2016年 | 24篇 |
2015年 | 11篇 |
2014年 | 14篇 |
2013年 | 25篇 |
2012年 | 16篇 |
2011年 | 10篇 |
2010年 | 6篇 |
2009年 | 6篇 |
2008年 | 7篇 |
2007年 | 3篇 |
2006年 | 5篇 |
2005年 | 2篇 |
2004年 | 2篇 |
2003年 | 3篇 |
2002年 | 3篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1998年 | 4篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1992年 | 1篇 |
1989年 | 2篇 |
1983年 | 1篇 |
1979年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有311条查询结果,搜索用时 15 毫秒
101.
Muhammad Waseem Muhammad Ajmal Joo Heon Lee Tae-Woong Kim 《Water Resources Management》2016,30(12):4221-4231
Several drought indices have been developed based on a single variable or multiple variables using very complex calculations. Antecedent conditions are quite significant for analyzing physical processes involved in the conceptual rainfall-runoff modeling and for proper assessment of drought. However, not much attention has been paid to these conditions in the development of drought indices. Hence, we developed an alternative index for drought assessment, i.e., the antecedent condition-based multivariate drought index (AMDI), by taking into consideration all of the forms of drought, including meteorological, agricultural, and hydrological drought, in combination with the antecedent drought conditions. By comparing the AMDI with the standardized precipitation index (SPI) and reconnaissance drought index (RDI), it was revealed that in most cases, the drought trend was more or less the same. However, some discrepancies were also observed. Moreover, by considering additional factors, i.e., the antecedent soil moisture conditions and balance, an approximately 6 % difference in the drought frequency was observed compared to that of the SPI and RDI results, leading to a significant and proper drought assessment. The AMDI was also identified as a multi-scalar, multivariate index, which aggregates the effects of multiple drought forms by maintaining the continuity during month-to-month transitions. Hence, we concluded that the AMDI could be considered as an alternative tool for significant drought assessment. 相似文献
102.
103.
Khalid Shah Ullah Sehat Ali Numan Alam Aftab Rasheed Nasir Fayaz Muhammad Ahmad Masood 《Multimedia Tools and Applications》2021,80(6):9371-9391
Multimedia Tools and Applications - For Collaborative Virtual Environments (CVEs), many interaction techniques have been developed. Depending on the purpose of the collaborative work, techniques of... 相似文献
104.
Aftab Ahmed Khan Abdulaziz Abdullah Al Kheraif Jamaluddin Syed Darshan Devang Divakar Jukka Pekka Matinlinna 《The Journal of Adhesion》2018,94(3):167-180
This laboratory study aimed to enhance the adhesion strength of resin cement to zirconia by infusing carbon nanotubes (CNTs) in experimental silane primers. Eighteen ZrO2 blanks were pretreated with Rocatec? Soft, and divided into six groups: Group 1: Monobond® S silane (control); Group 2: 0.5 wt.% single-walled CNTs blended Monobond® S; Group 3: 0.5 wt.% multiple-walled CNTs blended Monobond® S; Group 4: a blend of 1.0 vol.% 3-acryloxypropyltrimethoxysilane (ACPS) + 0.5 vol.% bis-1,2-(triethoxysilyl)ethane (BTSE); Group 5: 0.5 wt.% single-walled CNTs blended in 1.0 vol.% ACPS + 0.5 vol.% BTSE; and Group 6: 0.5 wt.% multiple-walled CNTs blended in 1.0 vol.% ACPS + 0.5 vol.% BTSE. Next, resin composite stubs were prepared on treated ZrO2 surfaces. The specimens were stored in distilled water at 37°C ± 2°C for 2 months and 4 months. According to analysis of variance (ANOVA) and Tukey’s post hoc test (n = 10, α = 0.05), the highest enclosed mold shear bond strength (EM-SBS) value was observed in Group 5 (20.5 MPa ± 8.0 MPa) at the end of 4 months. Experimental silane primer containing a blend of 1.0 vol.% ACPS and 0.5 vol.% BTSE with infused single-walled CNTs might significantly enhance resin cement adhesion to silica-coated ZrO2. 相似文献
105.
Rashid Masood Khan Waseem Iqbal Muhammad Faisal Amjad Haider Abbas Hammad Afzal Abdul Rauf Maruf Pasha 《The Journal of supercomputing》2018,74(10):5060-5081
Recent years have seen tremendous increase in crime and terrorism all over the world which has necessitated continuous surveillance of public spaces, commercial entities and residential areas. CCTV cameras are an integral part of any modern surveillance system and have evolved significantly. They are a vital part of any investigation that follows a criminal or terrorism incident by providing invaluable evidence. In this paper, we show that the Advance Systems Format (ASF) file used in most IP cameras, which is also the main file containing metadata about the streaming packets, is vulnerable to forgery. This file is stored in plain text and any technically savvy person can forge it; therefore, a mechanism is needed to prevent it. To that end, we have gathered critical artifacts from an ASF file of IP cameras and carried out their forensic analysis. The analysis performed during this study demonstrates successful detection of forgery/tampering of evidence in IP cameras. 相似文献
106.
107.
108.
Anish Khan Abdullah M. Asiri Aftab Aslam Parwaz Khan Sirajuddin Vikas Gupta 《Polymer Composites》2016,37(8):2460-2466
An advanced nanocomposite, polyaniline tungstophosphate (PANI‐WP) cation exchanger, was synthesized by simple solution method and treated with silver nitrate resulting silver embedded PANI‐WP (PANI‐WP/Ag). Spectroscopic characterization of PANI‐WP/Ag was carried out by scanning electron microscopy, fourier transform infrared spectroscopy, UV‐Visible spectroscopy, and X‐ray diffraction. Electrical conductivity measurements and thermal effect on conductivity of PANI‐WP/Ag was studied after acid treatment. The dc electrical conductivity was found 3.06 × 10−3 S cm−1 for HCl doped, measured by 4‐in line‐probe dc electrical conductivity measuring technique. Thermal conductivity is stable with all temperatures in isothermal studies showing excellent stability of PANI‐WP/Ag material. Hybrid showed better linear Arrhenius electric conducting response for semiconductors, stable upto 120°C. It was observed that conductivity is at the border of metallic and semiconductor region. POLYM. COMPOS., 37:2460–2466, 2016. © 2015 Society of Plastics Engineers 相似文献
109.
Metal/Polymer Based Stretchable Antenna for Constant Frequency Far‐Field Communication in Wearable Electronics 下载免费PDF全文
Aftab M. Hussain Farhan A. Ghaffar Sung I. Park John A. Rogers Atif Shamim Muhammad M. Hussain 《Advanced functional materials》2015,25(42):6565-6575
Body integrated wearable electronics can be used for advanced health monitoring, security, and wellness. Due to the complex, asymmetric surface of human body and atypical motion such as stretching in elbow, finger joints, wrist, knee, ankle, etc. electronics integrated to body need to be physically flexible, conforming, and stretchable. In that context, state‐of‐the‐art electronics are unusable due to their bulky, rigid, and brittle framework. Therefore, it is critical to develop stretchable electronics which can physically stretch to absorb the strain associated with body movements. While research in stretchable electronics has started to gain momentum, a stretchable antenna which can perform far‐field communications and can operate at constant frequency, such that physical shape modulation will not compromise its functionality, is yet to be realized. Here, a stretchable antenna is shown, using a low‐cost metal (copper) on flexible polymeric platform, which functions at constant frequency of 2.45 GHz, for far‐field applications. While mounted on a stretchable fabric worn by a human subject, the fabricated antenna communicated at a distance of 80 m with 1.25 mW transmitted power. This work shows an integration strategy from compact antenna design to its practical experimentation for enhanced data communication capability in future generation wearable electronics. 相似文献
110.
Wearable Electronics: Metal/Polymer Based Stretchable Antenna for Constant Frequency Far‐Field Communication in Wearable Electronics (Adv. Funct. Mater. 42/2015) 下载免费PDF全文