全文获取类型
收费全文 | 3904篇 |
免费 | 224篇 |
国内免费 | 19篇 |
专业分类
电工技术 | 65篇 |
综合类 | 22篇 |
化学工业 | 999篇 |
金属工艺 | 94篇 |
机械仪表 | 60篇 |
建筑科学 | 175篇 |
矿业工程 | 7篇 |
能源动力 | 153篇 |
轻工业 | 230篇 |
水利工程 | 14篇 |
石油天然气 | 8篇 |
无线电 | 368篇 |
一般工业技术 | 781篇 |
冶金工业 | 438篇 |
原子能技术 | 38篇 |
自动化技术 | 695篇 |
出版年
2023年 | 74篇 |
2022年 | 133篇 |
2021年 | 186篇 |
2020年 | 119篇 |
2019年 | 121篇 |
2018年 | 124篇 |
2017年 | 131篇 |
2016年 | 155篇 |
2015年 | 124篇 |
2014年 | 179篇 |
2013年 | 221篇 |
2012年 | 240篇 |
2011年 | 281篇 |
2010年 | 182篇 |
2009年 | 182篇 |
2008年 | 178篇 |
2007年 | 135篇 |
2006年 | 120篇 |
2005年 | 66篇 |
2004年 | 76篇 |
2003年 | 70篇 |
2002年 | 58篇 |
2001年 | 46篇 |
2000年 | 38篇 |
1999年 | 44篇 |
1998年 | 142篇 |
1997年 | 79篇 |
1996年 | 43篇 |
1995年 | 48篇 |
1994年 | 33篇 |
1993年 | 40篇 |
1992年 | 24篇 |
1991年 | 37篇 |
1990年 | 38篇 |
1989年 | 20篇 |
1988年 | 19篇 |
1987年 | 18篇 |
1986年 | 21篇 |
1985年 | 20篇 |
1984年 | 31篇 |
1983年 | 24篇 |
1982年 | 16篇 |
1980年 | 19篇 |
1979年 | 12篇 |
1977年 | 12篇 |
1976年 | 31篇 |
1975年 | 22篇 |
1974年 | 15篇 |
1972年 | 13篇 |
1971年 | 11篇 |
排序方式: 共有4147条查询结果,搜索用时 15 毫秒
101.
102.
Priti Tagde Agnieszka Najda Kalpana Nagpal Giriraj T. Kulkarni Muddaser Shah Obaid Ullah Sebastian Balant Md. Habibur Rahman 《International journal of molecular sciences》2022,23(5)
Breast cancer is one of the most common types of cancer among women globally. It is caused by mutations in the estrogen/progesterone receptors and conventional treatment methods are commonly utilized. About 70–80 percent of individuals with the early-stage non-metastatic disease may be cured. Conventional treatment is far less than the optimal ratio, as demonstrated through the high mortality rate of women with this cancer. However, conventional treatment methods like surgery, radiotherapy, and chemotherapy are not as effective as expected and lead to concerns about low bioavailability, low cellular uptake, emerging resistance, and adverse toxicities. A nanomedicine-based approach is a promising alternative for breast cancer treatment. The present era is witnessing rapid advancements in nanomedicine as a platform for investigating novel therapeutic applications and modern intelligent healthcare management strategies. This paper focuses on nanomedicine-based therapeutic interventions that are becoming more widely accepted for improving treatment effectiveness and reducing undesired side effects in breast cancer patients. By evaluating the state-of-the-art tools and taking the challenges involved into consideration, various aspects of the proposed nano-enabled therapeutic approaches have been discussed in this review. 相似文献
103.
Adeel Nasir Peter Rolf Richter Aude Le Bail Viktor Daiker Julia Stoltze Binod Prasad Sebastian Michael Strauch Michael Lebert 《International journal of molecular sciences》2022,23(5)
Euglena gracilis is a photosynthetic flagellate. To acquire a suitable position in its surrounding aquatic environment, it exploits light and gravity primarily as environmental cues. Several physiological studies have indicated a fine-tuned relationship between gravity sensing (gravitaxis) and light sensing in E. gracilis. However, the underlying molecular mechanism is largely unknown. The photoreceptor photoactivated adenylyl cyclase (PAC) has been studied for over a decade. Nevertheless, no direct/indirect interaction partner (upstream/downstream) has been reported for PAC. It has been shown that a specific protein, kinase A (PKA), showed to be involved in phototaxis and gravitaxis. The current study reports the localization of the specific PKA and its relationship with PAC. 相似文献
104.
105.
106.
Sebastian Siwek Javane Oktaee Sven Grasselt-Gille André Wagenführ 《Holz als Roh- und Werkstoff》2018,76(2):499-507
This research investigated the effect of different fractions of commercial wood flour (Type c100 from JRS, Germany) on mechanical and physical properties of wood-polymer composites (WPC). The fractions were named regarding the mean lengths of their particles in µm; 80, 130, 255, 405 and 485. The composite samples were manufactured with 30 wt% of wood flour fractions of all five groups as well as the not fractionated flour, and 70 wt% of cellulose propionate (CP). The melt mass-flow rate (MFR) of the different granules, tensile strength, and modulus of elasticity, flexural strength, flexural modulus and the impact strength of the injection molded specimens as well as the water uptake were determined in this study. WPCs with the specific size range used in this investigation exhibited improved strength and modulus of elasticity in tensile and flexural tests, compared to pure CP. Using fraction 255, the mechanical properties increased the most. Tensile strength rose by 28 and 13% compared to CP and to WPC with the not fractioned wood powder, respectively. Fraction 255 increased flexural strength by 33 and 5% compared to CP and WPC with the not fractioned flour. The MFR (tested at 190 °C with 7.16 kg) of WPC_255 is the lowest with 2.3 g/10 min. Composites with the smallest particles showed the least water uptake. 相似文献
107.
Krzysztof Krawczyk Alicja Szabelska-Bersewicz Sebastian Wojciech Przemieniecki Mateusz Szymaczyk Aleksandra Obrpalska-Stplowska 《International journal of molecular sciences》2022,23(21)
Simple SummaryA new sources of plant growth-promoting (PGP) bacteria are needed to increase the agricultural crops without increasing the usage of chemicals. The aim of this study was to test the hypothesis that insect-gut bacteria promote tomato plant growth. The insect gut bacteria were screened for the presence of PGP traits. The plants treated with bacterial consortium showed a significant increase in fruit yield, in both number of fruits (+41%) and weight of fruits (+44%). Our results showed that: (i) D. virgifera gut’s bacteria significantly promote the growth of tomato plants, and (ii) bacteria other than plant-related can be considered as PGP. It must be underlined that even though the insect gut bacteria were proven to stimulate the plant’s growth, their practical usage must be preceded by an examination of their influence on ecological and biological safety.AbstractWe investigated gut bacteria from three insect species for the presence of plant growth properties (PGP). Out of 146 bacterial strains obtained from 20 adult specimens of Scolytidae sp., 50 specimens of Oulema melanopus, and 150 specimens of Diabrotica virgifera, we selected 11 strains displaying the following: PGP, phosphate solubility, production of cellulase, siderophore, lipase, protease, and hydrogen cyanide. The strains were tested for growth promotion ability on tomato (Lycopersicon esculentum) plants. Each strain was tested individually, and all strains were tested together as a bacterial consortium. Tomato fruit yield was compared with the negative control. The plants treated with bacterial consortium showed a significant increase in fruit yield, in both number of fruits (+41%) and weight of fruits (+44%). The second highest yield was obtained for treatment with Serratia liquefaciens Dv032 strain, where the number and weight of yielded fruits increased by 35% and 30%, respectively. All selected 11 strains were obtained from Western Corn Rootworm (WCR), Diabrotica virgifera. The consortium comprised: Ewingella americana, Lactococcus garvieae, L. lactis, Pseudomonas putida, Serratia liquefaciens, and S. plymuthica. To our knowledge, this is the first successful application of D. virgifera gut bacteria for tomato plant growth stimulation that has been described. 相似文献
108.
109.
Prof. Dr.-Ing. Michael Bortz Dr.-Ing. Kai Dadhe Prof. Dr.-Ing. Sebastian Engell Dr.-Ing. Vanessa Gepert Prof. Dr.-Ing. Norbert Kockmann Dr. rer nat Ralph Müller-Pfefferkorn Dr.-Ing. Thorsten Schindler Prof. Dr.-Ing. Leon Urbas 《化学,工程师,技术》2023,95(7):975-988
The chemical industry is one of the key industrial sectors in Germany and at the same time one of the largest consumers of energy and raw materials. A successful energy transition and the development of a circular economy can only succeed if they are actively supported and shaped by the chemical industry – through the redesign of existing production processes and the exploration and implementation of new process routes. The challenge is to realize this transformation within a very short time and for many production processes, whereby a much larger number of process routes must be explored. Digital technologies are key to master this transformation towards more sustainability, climate, and environmental protection. The KEEN project aims to explore and leverage artificial intelligence (AI) opportunities in process industry. The newly developed AI methods are tested wherever possible in real working environments and production plants to prove the economic benefit, applicability, and reliability of the methods and technologies. 相似文献
110.
Johannes Neukäufer Mohamed Adel Ashour Nadin Sarajlic Harald Klein Sebastian Rehfeldt Heiko Hallmann Sebastian Meinicke Jürgen Paschold Carsten Knösche Thomas Grützner 《American Institute of Chemical Engineers》2023,69(3):e17902
This publication presents a general approach for the enhancement of packings regarding scalability, separation efficiency, and fluid dynamic properties using three-dimensional (3D) printing. The methodology is used to develop miniaturized, scalable packings for process development, and scale-up applications. For this purpose, a 3D printable computer-aided design version of the Rombopak 9M industrial packing (RP9M-3D), which is known for its positive scalability properties, was created. An initial characterization by means of computational fluid dynamics simulations and mass transfer measurements reveals positive but also negative design properties. These findings are used to create a more advanced, miniaturized packing structure, the XW-Pak. The evolved structure is compared to the RP9M-3D. The simulation and experimental results show that the enhanced packing, which is still in the early stages of development, exhibits higher separation efficiencies with improved scalability properties at the same void fraction and surface area than the RP9M-3D. 相似文献