全文获取类型
收费全文 | 537篇 |
免费 | 40篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 37篇 |
综合类 | 3篇 |
化学工业 | 113篇 |
金属工艺 | 9篇 |
机械仪表 | 19篇 |
建筑科学 | 33篇 |
矿业工程 | 2篇 |
能源动力 | 41篇 |
轻工业 | 52篇 |
水利工程 | 11篇 |
石油天然气 | 12篇 |
无线电 | 48篇 |
一般工业技术 | 73篇 |
冶金工业 | 44篇 |
原子能技术 | 3篇 |
自动化技术 | 80篇 |
出版年
2023年 | 6篇 |
2022年 | 15篇 |
2021年 | 33篇 |
2020年 | 31篇 |
2019年 | 39篇 |
2018年 | 42篇 |
2017年 | 40篇 |
2016年 | 45篇 |
2015年 | 17篇 |
2014年 | 42篇 |
2013年 | 54篇 |
2012年 | 42篇 |
2011年 | 26篇 |
2010年 | 26篇 |
2009年 | 20篇 |
2008年 | 17篇 |
2007年 | 8篇 |
2006年 | 9篇 |
2005年 | 6篇 |
2004年 | 4篇 |
2003年 | 7篇 |
2002年 | 3篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 16篇 |
1997年 | 7篇 |
1996年 | 4篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1980年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有580条查询结果,搜索用时 31 毫秒
571.
The inhibitory effect of lactic acid bacteria on aflatoxin production and expression of aflR gene in Aspergillus parasiticus
下载免费PDF全文
![点击此处可从《Journal of Food Safety》网站下载免费的PDF全文](/ch/ext_images/free.gif)
572.
Sedigheh Sadegh Hassani Leila Samiee Ebrahim Ghasemy Alimorad Rashidi Mohammad Reza Ganjali Saeedeh Tasharrofi 《International Journal of Hydrogen Energy》2018,43(33):15941-15951
In the work presented here, a facile approach for the preparation of nitrogen-doped porous graphene was applied for the first time using ammonium acetate as a nitrogen rich precursor via pyrolysis at 900 °C for 2 h.The physicochemical properties of the prepared samples were determined using Field Emission Scanning Electron Microscopy (FE-SEM), Energy-dispersive X-ray spectroscopy (EDS) mapping, Raman spectroscopy and X–ray photoelectron spectroscopy (XPS). The prepared samples were further applied for the oxygen reduction reaction (ORR) in alkaline solution, and the electrochemical performance was investigated and compared with porous graphene and Pt/C 20 wt.%. The results revealed that introducing nitrogen to the graphene structure leads to improvement in catalytic activity, enhanced catalytic current as well as more positive potential. Furthermore, N-doped graphene prepared using ammonium acetate exhibited excellent methanol tolerance and long-term stability. Finally, it was shown that the optimal pyrolysis temperature was obtained at 900 °C. Therefore, it is concluded that ammonium acetate could be used as an effective precursor for the ORR. 相似文献
573.
Saeideh Fayyazi Mohammad Ebrahim Bahrololoom Mahdi Kasraei 《Transactions of the Indian Institute of Metals》2018,71(12):3045-3062
High-velocity oxy-fuel (HVOF) thermal spraying is one of the best methods for depositing conventional WC–Co cermets. The aim of the present work was to optimize the WC–17Co coating deposited using HVOF spraying process. Taguchi fractional factorial experimental design (L18) and ANOVA were used to optimize the process parameters. Seven factors (spray distance, oxygen flow rate, carrier gas flow rate, powder feed rate, coating thickness, substrate preheat temperature and grit type) were selected. Grit type had two levels, and the others had three levels. The coating properties measured were wear resistance, microhardness and roughness. Pin-on-disk wear tests were used for measuring wear. Scanning electron micrographs were used to investigate the cross sections of the coatings and the morphology of the as-sprayed coatings, and their relationship between the process parameters and energy-dispersive X-ray was used to analyze the coatings. In Taguchi method, “lower the better” quality was used for optimizing roughness and “higher the better” quality was used for optimizing wear resistance and microhardness. The most influential factor on increasing wear resistance and microhardness was powder feed rate and on reducing the roughness was oxygen flow rate. In addition, the influence of grit type on wear resistance and microhardness and the influences of grit type and substrate preheat temperature on the coating roughness were negligible. 相似文献
574.
Rushikesh Battulwar Masoud Zare-Naghadehi Ebrahim Emami Javad Sattarvand 《岩石力学与岩土工程学报(英文版)》2021,13(4):920-936
In the last two decades, significant research has been conducted in the field of automated extraction of rock mass discontinuity characteristics from three-dimensional (3D) models. This provides several methodologies for acquiring discontinuity measurements from 3D models, such as point clouds generated using laser scanning or photogrammetry. However, even with numerous automated and semi-automated methods presented in the literature, there is not one single method that can automatically characterize discontinuities accurately in a minimum of time. In this paper, we critically review all the existing methods proposed in the literature for the extraction of discontinuity characteristics such as joint sets and orientations, persistence, joint spacing, roughness and block size using point clouds, digital elevation maps, or meshes. As a result of this review, we identify the strengths and drawbacks of each method used for extracting those characteristics. We found that the approaches based on voxels and region growing are superior in extracting joint planes from 3D point clouds. Normal tensor voting with trace growth algorithm is a robust method for measuring joint trace length from 3D meshes. Spacing is estimated by calculating the perpendicular distance between joint planes. Several independent roughness indices are presented to quantify roughness from 3D surface models, but there is a need to incorporate these indices into automated methodologies. There is a lack of efficient algorithms for direct computation of block size from 3D rock mass surface models. 相似文献
575.
Unsteady cavitation causes noise,damage,and performance decline in the marine engineering and fluid machinery systems.Therefore,finding a method to control the ... 相似文献
576.
Anjana Soorajkumar Ebrahim Alakraf Mohammed Uddin Stefan S. Du Plessis Alawi Alsheikh-Ali Richard K. Kandasamy 《International journal of molecular sciences》2022,23(15)
Short linear motifs (SLiMs) are short linear sequences that can mediate protein–protein interaction. Mimicking eukaryotic SLiMs to compete with extra- or intracellular binding partners, or to sequester host proteins is the crucial strategy of viruses to pervert the host system. Evolved proteins in viruses facilitate minimal protein–protein interactions that significantly affect intracellular signaling networks. Unfortunately, very little information about SARS-CoV-2 SLiMs is known, especially across SARS-CoV-2 variants. Through the ELM database-based sequence analysis of spike proteins from all the major SARS-CoV-2 variants, we identified four overriding SLiMs in the SARS-CoV-2 Omicron variant, namely, LIG_TRFH_1, LIG_REV1ctd_RIR_1, LIG_CaM_NSCaTE_8, and MOD_LATS_1. These SLiMs are highly likely to interfere with various immune functions, interact with host intracellular proteins, regulate cellular pathways, and lubricate viral infection and transmission. These cellular interactions possibly serve as potential therapeutic targets for these variants, and this approach can be further exploited to combat emerging SARS-CoV-2 variants. 相似文献
577.
Nesrine Ebrahim Hajir A. Al Saihati Ola Mostafa Amira Hassouna Sameh Abdulsamea Eman Abd El Aziz M. El Gebaly Nashwa Hassan Abo-Rayah Dina Sabry Mohamed El-Sherbiny Abdelmonem G. Madboly Noha Ibrahim Hussien Raja El Hasnaoui Saadani Hasnaa Ali Ebrahim Omnia A. M. Badr Nehal M. Elsherbiny Rabab F. Salim 《International journal of molecular sciences》2022,23(11)
578.
Mostaanzadeh Hossein Shahmohammadi Mohammad Ehsani Ali Moharramnejad Mojtaba Honarmand Ebrahim 《Journal of Materials Science: Materials in Electronics》2021,32(22):26539-26547
Journal of Materials Science: Materials in Electronics - In the present study, we introduce a simple chemical method to synthesize Zn-based MOF (Zn-BTC). The structural morphology and... 相似文献
579.
In this study, buckling of rectangular orthotropic plates resting on a Pasternak elastic foundation under biaxial in-plane loading by the power series method (the method of Frobenius) was analyzed. Similar to many studies, two opposite edges of loading are simply supported and two other edges are assumed clamped. In order to extract the characteristic equations of orthotropic rectangular plate under in-plane loading resting on a Pasternak elastic foundation, the classical plate theory, by considering the interaction between plate and foundation, is used. The results showed that in the aspect ratio of less than 2, the existing Pasternak foundation caused the buckling load to increase severely, but by increasing the aspect ratio, the effect of the foundation is negligible. Applying the in-plane load in the y-direction caused the buckling load to decrease, but by increasing the aspect ratios the effect of the load is negligible. 相似文献
580.
Menas Ebrahim Eissa Mohamed Abdel Azim Mohamed Maher Ata 《International Journal of Communication Systems》2023,36(13):e5517
The number of internet users and connected devices has dramatically expanded due to the recent technological boom and the benefits that the internet of things offers to ease our lives. Network scheduling, quality of service, resource allocation, and security issues are now being addressed via software-defined networking (SDN). SDN has several benefits over traditional networks, including global centralized control, managing network traffic, and separating the forwarding and control plane. The work done in this paper aims to design and implement a traffic-aware routing framework based on routing optimization presented as an integer linear programming (ILP) to improve heterogeneous traffic flows' quality of service (QoS) in a simulated SDN environment. With the knowledge that the routing problem is a nondeterministic polynomial-time-hard problem, the proposed scheme aims to decrease the computational routing time to make the ILP-based routing system more suitable for real-time processing. The simulation results illustrate that the proposed framework reduces the computational time by 23% and 49% for Abilene and Goodnet topology, respectively. Additionally, with 1000 flows in the network, the suggested scheme reduces the number of network flows that violate the QoS by 9% and 22% (with Abilene topology) and 16% and 51% (with Goodnet topology) as compared to the existing shortest path delay and sway methods, respectively. 相似文献