首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   52篇
  免费   1篇
电工技术   2篇
化学工业   19篇
金属工艺   1篇
建筑科学   2篇
能源动力   5篇
轻工业   2篇
无线电   1篇
一般工业技术   6篇
冶金工业   2篇
自动化技术   13篇
  2022年   5篇
  2021年   9篇
  2020年   1篇
  2019年   2篇
  2018年   1篇
  2017年   4篇
  2016年   1篇
  2013年   5篇
  2012年   2篇
  2011年   1篇
  2010年   7篇
  2009年   1篇
  2008年   2篇
  2007年   4篇
  2005年   1篇
  2004年   1篇
  2002年   1篇
  1999年   1篇
  1998年   1篇
  1997年   1篇
  1995年   1篇
  1979年   1篇
排序方式: 共有53条查询结果,搜索用时 31 毫秒
31.
In recent years, fiber-reinforced polymer (FRP) wrapping effectiveness has been clearly confirmed especially with reference to concrete structures. Despite evident advantages of FRP based confinement on members subjected to compressive overloads due to static or seismic actions, the use of such technique in the field of masonry has not been fully explored. Thus, to assess the potential of confinement of masonry columns, the present paper shows the results of an experimental program dealing with 18 square cross sections (listed faced tuff or clay brick) masonry scaled columns subjected to uniaxial compression load. In particular, three different confinement solutions have been experimentally analyzed in order to evaluate and compare the effectiveness of uniaxial glass FRP, carbon FRP, and basalt FRP laminates wrapping. The main experimental outcomes are presented and discussed in the paper considering mechanical behavior of specimens, axial stress-axial strain relationships, and effective strains at failure on the reinforcement. Test results have showed that the investigated confining systems are able to provide significant gains both in terms of compressive strength and ductility of masonry columns. Results of the presented experimental activity along with data available in the literature have been finally used to assess the reliability of the main existing analytical models; refined equations have been then proposed to minimize the scattering between theoretical predictions and experimental available data.  相似文献   
32.
Various mesoporous silica supported Pd materials were prepared by different methodologies in order to control and optimize the metal nanoparticle sizes for catalytic applications. The catalytic activities (conversion, mol% and selectivity to methyl-cinnamate) of the supported palladium catalysts were investigated in the Heck reaction under microwave irradiation using various haloarenes. Pd materials prepared by co-precipitation exhibited a very poor activity in the Heck reaction compared to that of Pd impregnated samples. Impregnated materials prepared without the use of a specific reducing agent had comparable activities to those of APTS-NaBH4 reduced Pd materials, validating the simplicity of the methodology. High selectivities to methylcinnamate were obtained for all materials.  相似文献   
33.
The Sulfur–Iodine (S_I) cycle, driven by nuclear power, seems to be one of the main candidates to produce hydrogen on a large scale. A new S_I process flowsheet is proposed, set up at CEA and simulated by ProSim code and, based on that, data and results on the coupling of the thermochemical plant with a Very High Temperature Nuclear Reactor (VHTR) are presented. The scale up to industrial level, the conceptual design and cost estimation of the plant are then presented and discussed. In order to support a high temperature aggressive environment, well established chemical engineering methods as well as non traditional materials, devices and technologies have been selected. The influence of the adopted technology on the H2 cost has also been investigated and is widely discussed, comparing two different cases. An economic sensitivity analysis carried out by varying the hydrogen production level is presented, showing that an optimum H2 production exists and, due to relevant heat recovery processes, the minimum cost is not achieved for the maximum allowable H2 production rate. Finally an optimized layout for the minimum cost plant, set up adopting the pinch technique, is presented leading to a further reduction of H2 production costs.  相似文献   
34.
Drug-induced liver injury (DILI) is a challenging clinical event in medicine, particularly because of its ability to present with a variety of phenotypes including that of autoimmune hepatitis or other immune mediated liver injuries. Limited diagnostic and therapeutic tools are available, mostly because its pathogenesis has remained poorly understood for decades. The recent scientific and technological advancements in genomics and immunology are paving the way for a better understanding of the molecular aspects of DILI. This review provides an updated overview of the genetic predisposition and immunological mechanisms behind the pathogenesis of DILI and presents the state-of-the-art experimental models to study DILI at the pre-clinical level.  相似文献   
35.
In this paper, the use of a method for online detection of positive- and negative-sequence components of three-phase quantities, named the delayed signal cancellation (DSC) method, is investigated. Problems that arise in practical implementation of the DSC method in computer-controlled systems are investigated. Expressions of the detection error due to nonideal discretization are derived and calculations are verified experimentally. Two methods for reducing the detection error are presented and verified. It is also shown that the given expressions and proposed methods for reducing the detection errors can also be applied to the case of grid frequency variations  相似文献   
36.
A detailed analysis has been carried out to assess the thermodynamic and economic performance of Diabatic Compressed Air Energy Storage (D‐CAES) systems equipped with above‐ground artificial storage. D‐CAES plant arrangements based on both Steam Turbine (ST) and Gas Turbine (GT) technologies are taken into consideration. The influence of key design quantities (ie, storage pressure, turbine inlet pressure, turbine inlet temperature) on efficiency, capital and operating costs is analysed in detail and widely discussed. Finally, D‐CAES design solutions are compared with Battery Energy Storage (BES) systems on the basis of the Levelized Cost of Storage (LCOS) method. Results show that the adoption of D‐CAES can lead to better economic performance with respect to mature and emerging BES technologies. D‐CAES ST based solutions can achieve a LCOS of 28 €cent/kWh, really close to that evaluated for the better performing BES system. Interesting LCOS values of 20 €cent/kWh have been attained by adopting D‐CAES plant solutions based on GT technology.  相似文献   
37.
This research was aimed at testing whether the partial substitution of NaCl with KCl (50 or 75% relative substitution) in the fermenting brine of green table Nocellara del Belice olives debittered using two used method (Spanish and Castelvetrano) affected the presence of nutritionally relevant molecules (tocopherols, carotenoids, squalene, phenolic compounds) or the organoleptic characteristics of the table‐ready product. Results support the effectiveness of NaCl partial substitution by potassium chloride for olive processing, with the advantage of a significant decrease in the amount of sodium in the end product. The presence of the main bioactive molecules remained substantially unchanged, but KCl was associated with an increase in bitterness in both debittering methods. However, bitter properties (bitter, persistence and aftertaste) of olives obtained through the modification of Castelvetrano method still remained below those debittered with the classic Spanish method preserving, for such olives, the characteristic of ‘sweet olives’.  相似文献   
38.
The Philadelphia-negative myeloproliferative neoplasms (MPNs) are malignancies of the hematopoietic stem cell (HSC) arising as a consequence of clonal proliferation driven by somatically acquired driver mutations in discrete genes (JAK2, CALR, MPL). In recent years, along with the advances in molecular characterization, the role of immune dysregulation has been achieving increasing relevance in the pathogenesis and evolution of MPNs. In particular, a growing number of studies have shown that MPNs are often associated with detrimental cytokine milieu, expansion of the monocyte/macrophage compartment and myeloid-derived suppressor cells, as well as altered functions of T cells, dendritic cells and NK cells. Moreover, akin to solid tumors and other hematological malignancies, MPNs are able to evade T cell immune surveillance by engaging the PD-1/PD-L1 axis, whose pharmacological blockade with checkpoint inhibitors can successfully restore effective antitumor responses. A further interesting cue is provided by the recent discovery of the high immunogenic potential of JAK2V617F and CALR exon 9 mutations, that could be harnessed as intriguing targets for innovative adoptive immunotherapies. This review focuses on the recent insights in the immunological dysfunctions contributing to the pathogenesis of MPNs and outlines the potential impact of related immunotherapeutic approaches.  相似文献   
39.
Current manufacturing systems have a very structured production model, expecially when high complexity and precision is required, as in semiconductor devices manufacturing. In addition, rapid changes in both production and market requirements may occur, hence great flexibility is essential. This goals, together with the capability of adding new features as well as removing some model limitations, often impose to re-engineer periodically existing models, reducing as much as possible the time-to-market of a new product. Updating a model generally also requires to improve existing applications, both re-writing software components as well as adding new features to existing components. Here the model currently used inside STMicroelectronics facilities to define production flow (the sequence of operations to be performed in order to make products) is considered. First, the model is described highlighting its limitations, then an enhanced object-oriented model is introduced, in order to provide both a better management of all entites through aggregational and constitutional hierarchies and a significant time reduction of production flow definitions through a flexible inheritance mechanism. In addition, required improvements on existing applications are considered, introducing an enhanced environment capable of supporting the enhanced model while preserving both technical and economic investments thus avoiding radical changes in existing environment.  相似文献   
40.
This work is aimed at fabricating nanocomposites based on zinc oxide (ZnO) nanostructures and nanocellulose dispersed in a UV-cured acrylic matrix (EC) for application as functional coatings for self-powered applications. Morphological, thermal, and dynamic mechanical properties of the nanocomposites were characterized by X-Ray diffractometry (XRD), scanning electron microscopy, and differential scanning calorimetry. The piezoelectric behavior was evaluated in terms of root mean square (RMS) open circuit voltage, at different accelerations applied to cantilever beams. The generated voltage was correlated with ZnO nanostructures morphology, aluminum nitride film integration on the beam and proof mass insertion at the tip. Nitride layer increased the RMS voltage from 1 to 2.4 mV up to 3.9 mV (using ZnO nanoflowers). As confirmed by XRD analyses, the incorporation of ZnO nanostructures into the acrylic matrix favored an ordered structural arrangement of the deposited AlN layer, hence improving the piezoelectric response of the resulting nanocomposites. With proof mass insertion, the output voltage was further increased, reaching 4.5 mV for the AlN-coated system containing ZnO nanoflowers.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号