全文获取类型
| 收费全文 | 716篇 |
| 免费 | 19篇 |
| 国内免费 | 4篇 |
专业分类
| 电工技术 | 19篇 |
| 综合类 | 1篇 |
| 化学工业 | 137篇 |
| 金属工艺 | 4篇 |
| 机械仪表 | 28篇 |
| 建筑科学 | 33篇 |
| 能源动力 | 35篇 |
| 轻工业 | 35篇 |
| 水利工程 | 4篇 |
| 石油天然气 | 4篇 |
| 武器工业 | 1篇 |
| 无线电 | 72篇 |
| 一般工业技术 | 111篇 |
| 冶金工业 | 112篇 |
| 原子能技术 | 1篇 |
| 自动化技术 | 142篇 |
出版年
| 2024年 | 10篇 |
| 2023年 | 16篇 |
| 2022年 | 19篇 |
| 2021年 | 39篇 |
| 2020年 | 32篇 |
| 2019年 | 35篇 |
| 2018年 | 30篇 |
| 2017年 | 23篇 |
| 2016年 | 37篇 |
| 2015年 | 22篇 |
| 2014年 | 31篇 |
| 2013年 | 43篇 |
| 2012年 | 40篇 |
| 2011年 | 47篇 |
| 2010年 | 33篇 |
| 2009年 | 29篇 |
| 2008年 | 35篇 |
| 2007年 | 28篇 |
| 2006年 | 22篇 |
| 2005年 | 17篇 |
| 2004年 | 20篇 |
| 2003年 | 15篇 |
| 2002年 | 16篇 |
| 2001年 | 17篇 |
| 2000年 | 12篇 |
| 1999年 | 14篇 |
| 1998年 | 2篇 |
| 1997年 | 4篇 |
| 1996年 | 5篇 |
| 1995年 | 2篇 |
| 1994年 | 5篇 |
| 1993年 | 4篇 |
| 1992年 | 3篇 |
| 1991年 | 2篇 |
| 1990年 | 2篇 |
| 1988年 | 3篇 |
| 1986年 | 2篇 |
| 1985年 | 2篇 |
| 1984年 | 1篇 |
| 1982年 | 3篇 |
| 1981年 | 1篇 |
| 1980年 | 2篇 |
| 1977年 | 1篇 |
| 1976年 | 1篇 |
| 1975年 | 3篇 |
| 1974年 | 2篇 |
| 1973年 | 1篇 |
| 1970年 | 2篇 |
| 1969年 | 1篇 |
| 1966年 | 1篇 |
排序方式： 共有739条查询结果，搜索用时 15 毫秒
61.
Delong Li Youning Gong Yuexing Chen Jiamei Lin Qasim Khan Yupeng Zhang Yu Li Han Zhang Heping Xie 《纳微快报(英文)》2020,(3):77-116
Thermoelectric generators have attracted a wide research interest owing to their ability to directly convert heat into electrical power.Moreover,the thermoelectric properties of traditional inorganic and organic materials have been significantly improved over the past few decades.Among these compounds,layered two-dimensional(2D)materials,such as graphene,black phosphorus,transition metal dichalcogenides,IVA–VIA compounds,and MXenes,have generated a large research attention as a group of potentially high-performance thermoelectric materials.Due to their unique electronic,mechanical,thermal,and optoelectronic properties,thermoelectric devices based on such materials can be applied in a variety of applications.Herein,a comprehensive review on the development of 2D materials for thermoelectric applications,as well as theoretical simulations and experimental preparation,is presented.In addition,nanodevice and new applications of 2D thermoelectric materials are also introduced.At last,current challenges are discussed and several prospects in this field are proposed. 相似文献
62.
Zhifeng Xu Yushuang Du Na Li Hongmin Geng Qasim Ali Xinbo Li Yajun Gao Yan Wang Ronghui Xing Jie Wu Fangjie Cui Chengzhang Wang Xiaoyan Zhu Yalei Cui Defeng Li Yinghua Shi 《Food Science & Nutrition》2022,10(8):2601-2610
Alfalfa (Medicago sativa L.) is abundant in dietary fiber, alfalfa saponins, and other active ingredients. However, the application of alfalfa is scarce in food. Meatball is one of the most popular meat products in daily life, but eating too many meatballs could result in obesity, hyperlipidemia, and other diseases. With increasing attention to healthy diet, how to keep the original color, aroma, taste, and shape of food with low fat and nutrition has become an urgent problem to be solved. In this study, different amounts of alfalfa meal or extruded alfalfa meal were added to pork meatballs to explore the optimal adding ratio of two kinds of alfalfa meal in pork meatballs. Further animal experiments were conducted for two weeks to prove the efficacy of two kinds of alfalfa balls in lowering blood lipid and body weight. The results showed that 0.5% alfalfa meal and 1% extruded alfalfa meal could improve the quality of prepared pork meatballs. Animal experiments demonstrated that two kinds of alfalfa meal pork meatballs had a good effect of reducing blood lipid, and the alfalfa meal pork meatballs had a better effect on reducing serum cholesterol and average daily weight gain of mice. This study provided a theoretical basis for making healthy and nutritious pork meatballs, which could provide more delicious food for people, especially people who are obese and the elderly. 相似文献
63.
Ali Ikram Syed Qasim Raza Farhan Saeed Muhammad Afzaal Haroon Munir Aftab Ahmed Muhammad Babar Bin Zahid Faqir Muhammad Anjum 《Food Science & Nutrition》2021,9(1):480-488
This study was planned to investigate the effect of replacing milk fat with aloe vera gel addition on yogurt quality. Purposely, yogurt was prepared with different concentration of aloe vera gel and coded as AGY0, = Control (3.5% fat and no AG), AGY1 = (1% fat and 1% AG), AGY2 = (1% fat and 2% AG), AGY3 = (1% fat and 3% AG), AGY4 = (2% fat and 1% AG), AGY5 = (2% fat and 2% AG), and AGY6 = (2% fat and 3% AG). Aloe vera gel yogurt was analyzed for physicochemical, microbial, and sensory characteristics with defined interval (0, 7th, 14th, and 21st) days. All attributes of the yogurt were significantly (0.05) affected by the addition of aloe vera gel. Results showed that the pH (4.6–4.05), viscosity (46.4–4.3), WHC (32.8%–26.1%), fat (0.9%–3.48%), protein (3.14%–3.36%), lactose (4.07%–4.23%), ash (0.48%–0.63%), total solids (11.08%–17.18%), SNF (7.69-l5.21%), and TPC (2.36 × 107 to 1.02 × 107 CFU/ml) values of yogurt samples decreased with storage time. However, acidity and syneresis of yogurt increased with the passage of time ranging from 1.12%–1.67% and 0.9–5 ml, respectively. In conclusion, aloe vera improved the texture of the yogurt which leads to higher consumer acceptability. Addition of 3% aloe vera to 1% fat (AGY3) containing buffalo milk yogurt was found to best for physicochemical as well as organoleptic characteristics as well as organoleptic characteristics. 相似文献
64.
Tarek O. Abdul Fattah;Janet Jacobs;Vladimir P. Markevich;Nikolay V. Abrosimov;Ian D. Hawkins;Matthew P. Halsall;Iain F. Crowe;Anthony R. Peaker; 《Solar RRL》2024,8(4):2300956
Increasing the understanding of the electronic properties of gallium (Ga) in silicon (Si) used nowadays to manufacture p-type Si solar cells is of key technological importance. In this contribution, the results of the effect of Ga concentration on the low-temperature photoluminescence (PL) spectra in crystalline Si are reported. The Ga-doped Si samples studied have negligible boron concentrations, which can complicate spectral analysis of the bound exciton (BE) lines. The split Ga BE ground state at T = 10 K is analyzed and the PL intensity ratios for the BE to free exciton peaks are compared. By comparing these to known Ga concentrations, derived from capacitance–voltage measurements, an all-optical (PL) calibration curve for the quantification of Ga concentration in Si is established. The effects of both temperature and excitation power on the PL intensity ratios are also studied. By combining the temperature-induced changes in the PL intensity ratios with the calibration curve at 10 K, a calibration function has been determined. It is found that the decay rates of the PL intensity ratios as a function of excitation power are independent of the chosen (split) BE peak. The major benefits of this method and its limitations are discussed. 相似文献
65.
Kate Doubleday Faeza Hafiz Andrew Parker Tarek Elgindy Anthony Florita Gregor Henze Graziano Salvalai Shanti Pless Bri‐Mathias Hodge 《Wiley Interdisciplinary Reviews: Energy and Environment》2019,8(5)
Recent efforts to reduce energy consumption and greenhouse gas emissions have resulted in the development of sustainable, smart districts with highly energy efficient buildings, renewable distributed energy resources (DERs), and support for alternative modes of transportation. However, there is typically little if any coordination between the district developers and the local utility. Most attention is paid to the district's annual net load and generation without considering their instantaneous imbalance or the connecting network's state. This presents an opportunity to learn lessons from the design of distribution feeders for districts characterized by low loads and high penetrations of DERs that can be applied to the distribution grid at large. The aim of this overview is to summarize current practices in sustainable district planning as well as advances in modeling and design tools for incorporating the power distribution system into the district planning process. Recent developments in the modeling and optimization of district power systems, including their coordination with multi‐energy systems and the impact of high penetration levels of renewable energy, are introduced. Sustainable districts in England and Japan are reviewed as case studies to illustrate the extent to which distribution system planning has been considered in practice. Finally, newly developed building‐to‐grid modeling tools that can facilitate coordinated district and power system design with utility involvement are introduced, along with suggestions for future research directions. This article is categorized under:
- Wind Power > Systems and Infrastructure
- Energy Policy and Planning > Systems and Infrastructure
- Energy Efficiency > Systems and Infrastructure
66.
Shaimaa M. Aboukhatwa Dr. Thomas W. Hanigan Taha Y. Taha Dr. Jayaprakash Neerasa Dr. Rajeev Ranjan Dr. Eman E. El-Bastawissy Dr. Mohamed A. Elkersh Prof. Dr. Tarek F. El-Moselhy Prof. Dr. Jonna Frasor Prof. Dr. Nadim Mahmud Prof. Dr. Alan McLachlan Prof. Dr. Pavel A. Petukhov 《ChemMedChem》2019,14(11):1096-1107
Histone deacetylase (HDAC) activity is modulated in vivo by post-translational modifications and formation of multiprotein complexes. Novel chemical tools to study how these factors affect engagement of HDAC isoforms by HDAC inhibitors (HDACi) in cells and tissues are needed. In this study, a synthetic strategy to access chemically diverse photoreactive probes (PRPs) was developed and used to prepare seven novel HDAC PRPs 9 – 15 . The class I HDAC isoform engagement by PRPs was determined in biochemical assays and photolabeling experiments in live SET-2, HepG2, HuH7, and HEK293T cell lines and in mouse liver tissue. Unlike the HDAC protein abundance and biochemical activity against recombinant HDACs, the chemotype of the PRPs and the type of cells were key in defining the engagement of HDAC isoforms in live cells. Our findings suggest that engagement of HDAC isoforms by HDACi in vivo may be substantially modulated in a cell- and tissue-type-dependent manner. 相似文献
67.
Mahmoud MOUSTAFA Saad ALAMRI Hoida ZAKI Naglaa LOUTFY Tarek TAHA Ali SHATI Mohamed ALKAHTANI Sajda SIDDIQI 《Biocell》2019,43(2):81-88
The present research reports of quick and marked changes induced by plant extract of Euryops arabicus in thegene expression of 49-kDa apyrases, cytoskeletal proteins, ATPases, ADPase and amount of amino acid of pea (Pisumsativum L. var. Alaska). Pellets of cytoskeletals proteins (27000 xg) were probed with anti-apyrase antibody, biotinylatedanti-rat, actin and alpha and beta-tubulin for Western blotting. ATPase and ADPase activities were determined basedon the hydrolytic efficacy of adenine triphosphate and adenine diphosphate. By 72 hours, the abundance of apyrases,cytoskeletal proteins and amount of amino acid in pellets of 27000 xg of germinated pea seeds in E. arabicus extractswere sharply increased than those sown in distilled water. All the samples exhibited that the stems had more amountfrom apyrases, cytoskeletal proteins, amino acids and ATPase and ADPase activities than primary leaves and primaryroots that were germinated either on E. arabicus water extract or in distilled water. Based on the enzyme’s capability tohydrolyse nucleotide triphosphate and nucleotide diphosphate as well as the direct association between expression of49-kDa apyrase and cytoskeletal proteins, E. arabicus water extract had an important effect on plant germinations. 相似文献
68.
Minh‐Duc Hua Jochen Trumpf Tarek Hamel Robert Mahony Pascal Morin 《Asian journal of control》2019,21(4):1443-1458
This paper presents a new algorithm for online estimation of a sequence of homographies applicable to image sequences obtained from robotic vehicles equipped with vision sensors. The approach taken exploits the underlying Special Linear group structure of the set of homographies along with gyroscope measurements and direct point‐feature correspondences between images to develop temporal filter for the homography estimate. Theoretical analysis and experimental results are provided to demonstrate the robustness of the proposed algorithm. The experimental results show excellent performance and robustness even in the case of very fast camera motions (relative to frame rate) and severe occlusions. 相似文献
69.
70.
Youcef Djebloun Mabrouk Hecini Tarek Djoudi Belhi Guerira 《Journal of Natural Fibers》2019,16(3):357-367
The present study is an attempt to valorize local vegetable fibers by evaluating thire effectiveness as a new composite biomaterial. Our aim was to determine the mechanical characteristics, namely the elastic modulus and Poisson’s coefficient, of a fiber, locally called “Lif,” that is a natural material extracted from different date palm tree varieties in Biskra, a region situated in southeastern Algeria. This study compares the mechanical characteristcs of the Lif date palm tree fiber with other synthetic and plant fibers studied previously. 相似文献