全文获取类型
收费全文 | 463篇 |
免费 | 23篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 7篇 |
化学工业 | 108篇 |
金属工艺 | 4篇 |
机械仪表 | 14篇 |
建筑科学 | 11篇 |
能源动力 | 36篇 |
轻工业 | 49篇 |
水利工程 | 1篇 |
石油天然气 | 17篇 |
无线电 | 53篇 |
一般工业技术 | 94篇 |
冶金工业 | 57篇 |
原子能技术 | 4篇 |
自动化技术 | 34篇 |
出版年
2023年 | 10篇 |
2022年 | 27篇 |
2021年 | 29篇 |
2020年 | 19篇 |
2019年 | 20篇 |
2018年 | 13篇 |
2017年 | 21篇 |
2016年 | 23篇 |
2015年 | 15篇 |
2014年 | 17篇 |
2013年 | 39篇 |
2012年 | 15篇 |
2011年 | 22篇 |
2010年 | 17篇 |
2009年 | 11篇 |
2008年 | 11篇 |
2007年 | 16篇 |
2006年 | 3篇 |
2005年 | 4篇 |
2004年 | 6篇 |
2003年 | 8篇 |
2002年 | 4篇 |
2001年 | 6篇 |
2000年 | 8篇 |
1999年 | 6篇 |
1998年 | 25篇 |
1997年 | 17篇 |
1996年 | 11篇 |
1995年 | 3篇 |
1994年 | 11篇 |
1993年 | 2篇 |
1992年 | 4篇 |
1991年 | 8篇 |
1989年 | 4篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1983年 | 2篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1977年 | 1篇 |
1976年 | 4篇 |
1975年 | 3篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1966年 | 2篇 |
1954年 | 1篇 |
排序方式: 共有489条查询结果,搜索用时 15 毫秒
481.
Pandey Swarnima Siddiqui Mohd Adnan Azim Afzal Sinha Neeraj 《Magma (New York, N.Y.)》2023,36(4):659-669
Magnetic Resonance Materials in Physics, Biology and Medicine - An early metabolic signature associated with the responsiveness to treatment can be useful in the better management of septic shock... 相似文献
482.
Shahida Anusha Siddiqui Anjelina Sundarsingh Nur Alim Bahmid Nilesh Nirmal Joeri F. M. Denayer Keikhosro Karimi 《Comprehensive Reviews in Food Science and Food Safety》2023,22(5):4147-4185
The development of biodegradable packaging is a challenge, as conventional plastics have many advantages in terms of high flexibility, transparency, low cost, strong mechanical characteristics, and high resistance to heat compared with most biodegradable plastics. The quality of biodegradable materials and the research needed for their improvement for meat packaging were critically evaluated in this study. In terms of sustainability, biodegradable packagings are more sustainable than conventional plastics; however, most of them contain unsustainable chemical additives. Cellulose showed a high potential for meat preservation due to high moisture control. Polyhydroxyalkanoates and polylactic acid (PLA) are renewable materials that have been recently introduced to the market, but their application in meat products is still limited. To be classified as an edible film, the mechanical properties and acceptable control over gas and moisture exchange need to be improved. PLA and cellulose-based films possess the advantage of protection against oxygen and water permeation; however, the addition of functional substances plays an important role in their effects on the foods. Furthermore, the use of packaging materials is increasing due to consumer demand for natural high-quality food packaging that serves functions such as extended shelf-life and contamination protection. To support the importance moving toward biodegradable packaging for meat, this review presented novel perspectives regarding ecological impacts, commercial status, and consumer perspectives. Those aspects are then evaluated with the specific consideration of regulations and perspective in the European Union (EU) for employing renewable and ecological meat packaging materials. This review also helps to highlight the situation regarding biodegradable food packaging for meat in the EU specifically. 相似文献
483.
Mehwish Shaikh Isma Farah Siddiqui Qasim Arain Jahwan Koo Mukhtiar Ali Unar Nawab Muhammad Faseeh Qureshi 《计算机系统科学与工程》2023,46(1):287-302
Pneumonia is a dangerous respiratory disease due to which breathing becomes incredibly difficult and painful; thus, catching it early is crucial. Medical physicians’ time is limited in outdoor situations due to many patients; therefore, automated systems can be a rescue. The input images from the X-ray equipment are also highly unpredictable due to variances in radiologists’ experience. Therefore, radiologists require an automated system that can swiftly and accurately detect pneumonic lungs from chest x-rays. In medical classifications, deep convolution neural networks are commonly used. This research aims to use deep pre-trained transfer learning models to accurately categorize CXR images into binary classes, i.e., Normal and Pneumonia. The MDEV is a proposed novel ensemble approach that concatenates four heterogeneous transfer learning models: MobileNet, DenseNet-201, EfficientNet-B0, and VGG-16, which have been finetuned and trained on 5,856 CXR images. The evaluation matrices used in this research to contrast different deep transfer learning architectures include precision, accuracy, recall, AUC-roc, and f1-score. The model effectively decreases training loss while increasing accuracy. The findings conclude that the proposed MDEV model outperformed cutting-edge deep transfer learning models and obtains an overall precision of 92.26%, an accuracy of 92.15%, a recall of 90.90%, an auc-roc score of 90.9%, and f-score of 91.49% with minimal data pre-processing, data augmentation, finetuning and hyperparameter adjustment in classifying Normal and Pneumonia chests. 相似文献
484.
Asgar Ali Aiman S. Mansol Ayesha Ashraf Khan Kasturi Muthoosamy Yasmeen Siddiqui 《Comprehensive Reviews in Food Science and Food Safety》2023,22(3):2408-2432
Postharvest diseases and quality degradation are the major factors causing food losses in the fresh produce supply chain. Hence, detecting diseases and quality deterioration at the asymptomatic stage of produce enables growers to treat the diseases earlier, maintain quality and reduce postharvest food losses. With the emergence of numerous technologies to detect diseases early and monitor the quality of fresh produce, such as polymerase chain reaction, gas chromatography-mass spectrophotometry, and near-infrared spectroscopy, electronic nose (EN) has also gained acknowledgement and popularity in the past decade as a robust and non-invasive analysis tool to detect odor profile and establish volatile biomarkers for metabolomics databases. However, literature reviewing the EN research on the early detection of diseases in produce after harvest is scarce. The fundamental concept of EN working principles (odor sampling, gas detection, and data acquisition method), as well as the application of EN as a whole, are covered in the first section of the review. An in-depth discussion of the application of EN analysis in the early identification of postharvest diseases and quality monitoring is provided in the subsequent sections, which is the key objective of this comprehensive review. The prospect, limitations, and likely future developments of EN in the postharvest sector are further highlighted in the last section. 相似文献
485.
Saiqua Siddiqui Divyanshu Singh Priyanka Singh Brajendra Singh 《Journal of the American Ceramic Society》2023,106(11):6732-6742
Optimization of energy storage performance in dielectric ceramics has been a focus in recent decades due to the benefits of high energy storage density, efficiency, and exceptional temperature stability. In this work, we report huge dielectric constant in La0.55Li0.35TiO3-δ and sharp decrease in its value with the substitution of Sr and Cu at Ti position. These samples La0.55Li0.35TiO3-δ (LLTO), La0.55Li0.35Ti0.9Cu0.1O3-δ (LLTCO) and La0.55Li0.35Sr0.1Ti0.9O3-δ (LLSTO) were prepared by solid state reaction method. The interfacial polarization of lithium ion aggregation close to the grain boundaries and the dipoles of Li ions in the sample are suggested to be the source of the enormous dielectric values. Parent composition (LLTO) shows highest dielectric constant value (6.29 × 105 at frequency 10 Hz, 7.30×104 at 1 kHz) recorded at room temperature while the lowest dielectric loss value (0.124) was observed for LLSTO at frequency 1 kHz. Structural characterization has been done using X-ray diffraction (XRD) technique to investigate the crystal structure of the prepared compositions. The XRD patterns show the similar crystal structure for all the compositions with the parent composition LLTO. The optical band gap is calculated by Kulbeka Munk function and Tauc plot using UV–visible diffuse reflectance spectroscopy technique. The maximum band gap value (3.32 eV) is obtained for parent composition while doping of Cu and Sr at Ti site in La0.55Li0.35TiO3-δ decreases the band gap value. Optical microscopy shows the micron size grains in these samples. Doping of Sr and Cu in perovskite structure of LLTO brings tunability in dielectric and optical properties. 相似文献
486.
Bashir MD Yasir Raushan Mohd. Adil Ahmad Shameem Siddiqui Mohammed Jawaid 《SILICON》2022,14(6):2851-2862
Silicon - In this paper, we propose dual material gate with dual-k dielectric gate oxide double gate junctionless transistor ‘DMG-DK-JLT’ for significant enhancement of performance. We... 相似文献
487.
Herbin H. Basalius Aravind M. Amalanathan M. Mary M. Sony Michael Lenin M. Maria Parvathiraja C. Siddiqui Masoom Raza Wabaidur Saikh Mohammad Islam Md Ataul 《Journal of Inorganic and Organometallic Polymers and Materials》2022,32(3):1103-1115
Journal of Inorganic and Organometallic Polymers and Materials - In this study, green synthesis of silver nanoparticles, an aqueous Syzygium malaccense fruit extract, was employed... 相似文献
488.
Al-Wasidi Asma S. Abouelreash Yasmeen G. AlReshaidan Salwa Naglah Ahmed M. 《Journal of Inorganic and Organometallic Polymers and Materials》2022,32(3):1142-1158
Journal of Inorganic and Organometallic Polymers and Materials - In this paper, chitosan/Fe3O4/graphene oxide hydrogel was synthesized then modified with 2,6-pyridinedicarbonyl dichloride to obtain... 相似文献
489.
Journal of Computational Electronics - In the present work, eight donor–bridge–acceptor (D-b-A) moieties with one- and two-electron donor species with different electron acceptor... 相似文献