全文获取类型
收费全文 | 141篇 |
免费 | 5篇 |
专业分类
电工技术 | 3篇 |
综合类 | 1篇 |
化学工业 | 21篇 |
金属工艺 | 2篇 |
机械仪表 | 2篇 |
建筑科学 | 2篇 |
能源动力 | 13篇 |
轻工业 | 9篇 |
水利工程 | 1篇 |
无线电 | 25篇 |
一般工业技术 | 23篇 |
冶金工业 | 18篇 |
原子能技术 | 1篇 |
自动化技术 | 25篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 7篇 |
2020年 | 1篇 |
2019年 | 4篇 |
2018年 | 2篇 |
2017年 | 6篇 |
2016年 | 2篇 |
2015年 | 6篇 |
2014年 | 4篇 |
2013年 | 10篇 |
2012年 | 6篇 |
2011年 | 10篇 |
2010年 | 5篇 |
2009年 | 6篇 |
2008年 | 5篇 |
2007年 | 5篇 |
2006年 | 5篇 |
2005年 | 2篇 |
2004年 | 7篇 |
2003年 | 3篇 |
2002年 | 1篇 |
2001年 | 1篇 |
1999年 | 2篇 |
1998年 | 10篇 |
1997年 | 5篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1992年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1972年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有146条查询结果,搜索用时 218 毫秒
31.
32.
Chelsea Schelly Jessica Price Aimee Delach Rupak Thapaliya Karen Leu 《The Electricity Journal》2019,32(10):106678
The Long Island Solar Roadmap Project involves a collaborative research approach with multiple organizational entities and actors engaged in a stakeholder driven process. Long Island is a space-constrained region with a steep urban to rural gradient, resulting in a complex suite of local governments, development priorities, and utility, planning, and development actors. This project is integrating technological, economic, and social data into a spatial planning output that allows decision makers to see where mid-to-large scale solar development (capacity of 250 kW and larger) is technically, economically, and socially feasible. This spatial output involves innovative methods of evaluating site suitability based on criteria developed by stakeholders. The project’s stakeholder and partnership driven approach allow the team to consider technological and economic feasibility across a wide variety of solar development forms and financial models. Social science data collected via a residential electric utility ratepayer survey is used to examine the perceptual barriers and opportunities for solar development as well as the sites and types of solar development that community members are most likely to support. The Long Island Solar Roadmap Project is an example of how research and community engagement can improve solar development policy and planning. 相似文献
33.
34.
Taoufiq GueddarVivek Dua 《Applied Energy》2012,89(1):117-126
The oil refining industry mainly uses linear programming (LP) modelling tools for refinery optimisation and planning purposes, on a daily basis. LPs are attractive from the computational time point of view; however these models have limitations such as the nonlinearity of the refinery processes is not taken into account. In addition, building the LP model can be an arduous task that requires collecting large amounts of data. The main aim of this work is to develop approximate models to replace the rigorous ones providing a good accuracy without compromising the computational time, for refinery optimisation. The data for deriving approximate models has been generated from rigorous process models from a commercial software, which is extensively used in the refining industry. In this work we present novel model reduction techniques based upon optimal configuration of artificial neural networks to derive approximate models and demonstrate how these models can be used for refinery-wide energy optimisation. 相似文献
35.
Healthcare is a fundamental part of every individual’s life. The healthcare industry is developing very rapidly with the help of advanced technologies. Many researchers are trying to build cloud-based healthcare applications that can be accessed by healthcare professionals from their premises, as well as by patients from their mobile devices through communication interfaces. These systems promote reliable and remote interactions between patients and healthcare professionals. However, there are several limitations to these innovative cloud computing-based systems, namely network availability, latency, battery life and resource availability. We propose a hybrid mobile cloud computing (HMCC) architecture to address these challenges. Furthermore, we also evaluate the performance of heuristic and dynamic machine learning based task scheduling and load balancing algorithms on our proposed architecture. We compare them, to identify the strengths and weaknesses of each algorithm; and provide their comparative results, to show latency and energy consumption performance. Challenging issues for cloud-based healthcare systems are discussed in detail. 相似文献
36.
Effects of applied electric field and microchannel wetted perimeter on electroosmotic velocity 总被引:1,自引:1,他引:0
Subhashish Dasgupta Ali Asgar S. Bhagat Marc Horner Ian Papautsky Rupak K. Banerjee 《Microfluidics and nanofluidics》2008,5(2):185-192
Parameters which affect electroosmotic flow (EOF) behavior need to be determined for characterizing flow in miniature biological
and chemical experimental processes. Several parameters like buffer pH, ionic concentration, applied electric field and channel
dimensions influence the magnitude of the electroosmotic flow. We conducted numerical and experimental investigations to determine
the impact of electric field strength and wetted microchannel perimeter on EOF in straight microchannels of rectangular cross-section.
Deviation from theoretical behavior was also investigated. In the numerical model, we solved the continuity and Navier–Stokes
equations for the fluid flow and the Gauss law equation for the electric field. Computational results were validated against
experimental data for PDMS-glass channels of different wetted perimeters over a range of applied electric fields. Results
show that increasing the applied electric field at constant wetted perimeter caused the electroosmotic mobility, the ratio
of electroosmotic velocity to applied electric field, to increase nonlinearly. It was also found that increasing the wetted
perimeter at constant applied electric field decreased the electroosmotic flow. These findings will be useful in determining
the optimum value of the electric field required to produce a desired electroosmotic flow rate in a channel of a particular
dimension. Alternately, these will also be useful in determining the optimum channel dimensions to provide a desired electroosmotic
flow rate at a specified value of the electric field. 相似文献
37.
HS Dua 《Canadian Metallurgical Quarterly》1998,82(12):1407-1411
BACKGROUND/AIMS: During the healing of corneal epithelial wounds with limbal involvement, conjunctival epithelium often migrates across the denuded limbus to cover the corneal surface. It is believed that, over a period of time, conjunctival epithelium covering the cornea assumes characteristics of corneal epithelium by a process referred to as conjunctival transdifferentiation. The purpose of this study was to examine, clinically, the fate of conjunctival epithelial cells covering the cornea and to assess the healing of corneal epithelial wounds when the conjunctival epithelium was removed or actively prevented from crossing the limbus and extending onto the cornea. METHODS: 10 patients with conjunctivalisation of the cornea were followed for an average of 7.5 months. Five patients in this group had their conjunctival epithelium removed from the corneal surface and allowed to heal from the remaining intact corneal epithelium. In another four patients with corneal epithelial defects, the conjunctival epithelium was actively prevented from crossing the limbus by mechanically scraping it off. RESULTS: The area of cornea covered by conjunctival epithelium appeared thin, irregular, attracted new vessels and was prone to recurrent erosions. Conjunctivalisation of the visual axis affected vision. Removal of conjunctival epithelium from the cornea allowed cells of corneal epithelial phenotype to cover the denuded area with alleviation of symptoms and improvement of vision. It was also established that migration of conjunctival epithelium onto corneal surface could be anticipated by close monitoring of the healing of corneal epithelial wounds, and prevented by scraping off conjunctival epithelium before it reached the limbus. CONCLUSION: This study shows that there is little clinical evidence to support the concept that conjunctival transdifferentiation per se, occurs in humans. "Replacement" of conjunctival epithelium by corneal epithelial cells may be an important mechanism by which conjunctival "transdifferentiation" may occur. In patients with partial stem cell deficiency this approach can be a useful and effective alternative to partial limbal transplantation, as is currently practised. 相似文献
38.
We show a new and constructive proof of the following language-theoretic result: for every context-free language L, there is a bounded context-free language L′⊆L which has the same Parikh (commutative) image as L. Bounded languages, introduced by Ginsburg and Spanier, are subsets of regular languages of the form w1*w2*?wm*w_{1}^{*}w_{2}^{*}\cdots w_{m}^{*} for some w
1,…,w
m
∈Σ
∗. In particular bounded context-free languages have nice structural and decidability properties. Our proof proceeds in two
parts. First, we give a new construction that shows that each context free language L has a subset L
N
that has the same Parikh image as L and that can be represented as a sequence of substitutions on a linear language. Second, we inductively construct a Parikh-equivalent
bounded context-free subset of L
N
. 相似文献
39.
Kimberly K. Richardson Wen Ling Kimberly Krager Qiang Fu Stephanie D. Byrum Rupak Pathak Nukhet Aykin-Burns Ha-Neui Kim 《International journal of molecular sciences》2022,23(2)
The damaging effects of ionizing radiation (IR) on bone mass are well-documented in mice and humans and are most likely due to increased osteoclast number and function. However, the mechanisms leading to inappropriate increases in osteoclastic bone resorption are only partially understood. Here, we show that exposure to multiple fractions of low-doses (10 fractions of 0.4 Gy total body irradiation [TBI]/week, i.e., fractionated exposure) and/or a single exposure to the same total dose of 4 Gy TBI causes a decrease in trabecular, but not cortical, bone mass in young adult male mice. This damaging effect was associated with highly activated bone resorption. Both osteoclast differentiation and maturation increased in cultures of bone marrow-derived macrophages from mice exposed to either fractionated or singular TBI. IR also increased the expression and enzymatic activity of mitochondrial deacetylase Sirtuin-3 (Sirt3)—an essential protein for osteoclast mitochondrial activity and bone resorption in the development of osteoporosis. Osteoclast progenitors lacking Sirt3 exposed to IR exhibited impaired resorptive activity. Taken together, targeting impairment of osteoclast mitochondrial activity could be a novel therapeutic strategy for IR-induced bone loss, and Sirt3 is likely a major mediator of this effect. 相似文献
40.
Body lipids of P. sarana of four different sizes were fractionated into phospholipids, neutral lipids, nonsaponifiables, total
fatty acids, polyunsaturated, monounsaturated and saturated fatty acid fractions. Percentage composition of each fraction
was determined. The triglyceride fatty acids were identified by thin layer and gas liquid chromatography. C8 to C23 fatty acids including both odd numbered and branched chain acids were detected. The major constituents were C14, C15, C16, C16:1, C18 C18:1, C18:2, C18:3; forty-three other acids were detected in lower proportions. Composition of each fatty acids and their variation with size
have been discussed.tP. sarana body lipids in general showed a behavior typical of fresh water fish by having a higher percentage
of saturated C16 and unsaturated C18 acids and a lower percentage of unsaturated C20 acid. 相似文献