全文获取类型
收费全文 | 213篇 |
免费 | 8篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 44篇 |
金属工艺 | 6篇 |
机械仪表 | 4篇 |
建筑科学 | 3篇 |
矿业工程 | 1篇 |
能源动力 | 10篇 |
轻工业 | 8篇 |
无线电 | 48篇 |
一般工业技术 | 58篇 |
冶金工业 | 25篇 |
原子能技术 | 3篇 |
自动化技术 | 10篇 |
出版年
2023年 | 2篇 |
2022年 | 11篇 |
2021年 | 9篇 |
2020年 | 9篇 |
2019年 | 4篇 |
2018年 | 3篇 |
2017年 | 7篇 |
2016年 | 2篇 |
2015年 | 5篇 |
2014年 | 5篇 |
2013年 | 6篇 |
2012年 | 9篇 |
2011年 | 11篇 |
2010年 | 6篇 |
2009年 | 17篇 |
2008年 | 19篇 |
2007年 | 19篇 |
2006年 | 6篇 |
2005年 | 8篇 |
2004年 | 4篇 |
2003年 | 4篇 |
2002年 | 8篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 11篇 |
1997年 | 7篇 |
1996年 | 6篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1985年 | 2篇 |
1983年 | 1篇 |
1981年 | 3篇 |
1976年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有222条查询结果,搜索用时 15 毫秒
1.
Graziosi Fabio Ruggieri Marina Santucci Fortunato 《Wireless Personal Communications》2002,21(2):141-162
In this paper the performance of a packet mobile radio network is studied inthe presence of shadow fading outage intervals.Under quite general assumptions for the medium access protocol,the probability mass function of the sequence of packets that may be lostdue to an outage interval is derived. It is seen that long sequences of lostpackets are likely to occur for typical values of the mobile speed andshadowing correlation parameters.For delay constrained sources, e.g., voice, the analysis is mainly focused atderiving the probability function of the sequence of dropped packetsand the probability of dropping. For data sources, the delay statistic isalso derived. In the latter case, the effect of finite buffer length isaddressed. Simulation is used to verify the accuracy of approximations introduced in the analysis. 相似文献
2.
Experimental measurements and full-2D numerical simulations show that velocity saturation effects in polysilicon thin-film transistor (TFTs) cannot be neglected in order to obtain a precise modelling of output characteristics. Since full-2D numerical simulations are time consuming and unpractical for circuit simulations, we have developed a new quasi-2D model, that takes into account both velocity saturation effects and the presence of a longitudinal electric field in the Poisson's equation, and includes the effect of parasitic bipolar transistor (PBT) action to reproduce kink effect. The agreement of the quasi-2D model with experimental data from p-channel polysilicon TFTs is very satisfactory even for short channel device, and the presence of a velocity-saturated region with a nearly constant free carrier concentration is reproduced without introducing further assumptions. 相似文献
3.
Valletta A. Mariucci L. Fortunato G. Brotherton S.D. Ayres J.R. 《Electron Devices, IEEE Transactions on》2002,49(4):636-642
Hot-carrier injection is known to produce interface states and oxide trapped charge, which, depending upon their spatial distribution, can strongly influence the local electric fields as well as the current flow. In this work, we analyze the hot carrier-induced degradation of gate overlapped lightly doped drain (GOLDD) polysilicon thin film transistors (TFTs) and a new model, which correlates the interface state generation with the hot carrier injection current, is proposed. The defect generation rate has been assumed to depend upon the product of hot electron and hole currents Jeh, and the resulting interface state distribution has been evaluated self-consistently with the current density and carrier concentration distributions. By successive iterations, a complete spatial and time evolution of the interface state distribution has been determined, and the electrical characteristics, calculated with these interface state distributions are in good agreement with the experimental data 相似文献
4.
The interferometric correlation method can provide a simple and inexpensive solution for pollution imagery, especially in the case of a spatially localized gaseous cloud. We describe herein a general method for designing an interferometric correlator for the analysis of any pollutant gas that has regularly distributed absorption spectral lines. We also present a setup using a birefringent interferometer in front of a simplified camera formed by a plano-convex lens and a linear CCD sensor; this demonstrates the monitoring of SO(2) gas. Results from the laboratory simulation show the feasibility of this method. Outdoor measurements permit determination of the required conditions for on-site real-time measurement. 相似文献
5.
Mohammad Farhan Tanzim Nuno Fortunato Ilias Samathrakis Ruiwen Xie Ingo Opahle Oliver Gutfleisch Hongbin Zhang 《Advanced functional materials》2023,33(28):2214967
All-d Heuslers are a category of novel compounds combining versatile functionalities such as caloric responses and spintronics with enhanced mechanical properties. Despite the promising transport properties (anomalous Hall (AHC) and anomalous Nernst (ANC) conductivities) shown in the conventional Co2XY Heuslers with p-d hybridization, the all-d Heuslers with only d-d hybridization open a new horizon to search for new candidates with outstanding transport properties. In this work, the AHC and ANC are evaluated for thermodynamically stable ferro/ferri-magnetic all-d-metal regular Heusler compounds based on high-throughput first-principles calculations. It is observed that quite a few materials exhibit giant AHCs and ANCs, such as cubic Re2TaMn with an AHC of 2011 S cm-1, and tetragonal Pt2CrRh with an AHC of 1966 S cm-1 and an ANC of 7.50 A m-1K-1. Comprehensive analysis on the electronic structure reveals that the high AHC can be attributed to the occurrence of the Weyl nodes or gapped nodal lines in the neighborhood of the Fermi level. The correlations between such transport properties and the number of valence electrons are also thoroughly investigated, which provides a practical guidance to tailor AHC and ANC via chemical doping for transverse thermoelectric applications. 相似文献
6.
7.
Silicon - In this paper, the role of different high-k materials in enhancing the efficiency of a metal insulator semiconductor (MIS) solar cell is investigated in detail. In order to overcome the... 相似文献
8.
Davide Ciardiello Brigida Anna Maiorano Paola Parente Maria Grazia Rodriquenz Tiziana Pia Latiano Cinzia Chiarazzo Valerio Pazienza Luigi Pio Guerrera Brunella Amoruso Nicola Normanno Giulia Martini Fortunato Ciardiello Erika Martinelli Evaristo Maiello 《International journal of molecular sciences》2022,23(2)
Biliary tract cancers (BTC) represent a heterogeneous and aggressive group of tumors with dismal prognosis. For a long time, BTC has been considered an orphan disease with very limited therapeutic options. In recent years a better understanding of the complex molecular landscape of biology is rapidly changing the therapeutic armamentarium. However, while 40–50% of patients there are molecular drivers susceptible to target therapy, for the remaining population new therapeutic options represent an unsatisfied clinical need. The role of immunotherapy in the continuum of treatment of patients with BTC is still debated. Despite initial signs of antitumor-activity, single-agent immune checkpoint inhibitors (ICIs) demonstrated limited efficacy in an unselected population. Therefore, identifying the best partner to combine ICIs and predictive biomarkers represents a key challenge to optimize the efficacy of immunotherapy. This review provides a critical analysis of completed trials, with an eye on future perspectives and possible biomarkers of response. 相似文献
9.
Martina Casarin Tiago Moderno Fortunato Saima Imran Martina Todesco Deborah Sandrin Giulia Borile Ilaria Toniolo Massimo Marchesan Gino Gerosa Andrea Bagno Filippo Romanato Emanuele Luigi Carniel Alessandro Morlacco Fabrizio Dal Moro 《International journal of molecular sciences》2022,23(5)
Bladder cancer (BC) is among the most common malignancies in the world and a relevant cause of cancer mortality. BC is one of the most frequent causes for bladder removal through radical cystectomy, the gold-standard treatment for localized muscle-invasive and some cases of high-risk, non-muscle-invasive bladder cancer. In order to restore urinary functionality, an autologous intestinal segment has to be used to create a urinary diversion. However, several complications are associated with bowel-tract removal, affecting patients’ quality of life. The present study project aims to develop a bio-engineered material to simplify this surgical procedure, avoiding related surgical complications and improving patients’ quality of life. The main novelty of such a therapeutic approach is the decellularization of a porcine small intestinal submucosa (SIS) conduit to replace the autologous intestinal segment currently used as urinary diversion after radical cystectomy, while avoiding an immune rejection. Here, we performed a preliminary evaluation of this acellular product by developing a novel decellularization process based on an environmentally friendly, mild detergent, i.e., Tergitol, to replace the recently declared toxic Triton X-100. Treatment efficacy was evaluated through histology, DNA, hydroxyproline and elastin quantification, mechanical and insufflation tests, two-photon microscopy, FTIR analysis, and cytocompatibility tests. The optimized decellularization protocol is effective in removing cells, including DNA content, from the porcine SIS, while preserving the integrity of the extracellular matrix despite an increase in stiffness. An effective sterilization protocol was found, and cytocompatibility of treated SIS was demonstrated from day 1 to day 7, during which human fibroblasts were able to increase in number and strongly organize along tissue fibres. Taken together, this in vitro study suggests that SIS is a suitable candidate for use in urinary diversions in place of autologous intestinal segments, considering the optimal results of decellularization and cell proliferation. Further efforts should be undertaken in order to improve SIS conduit patency and impermeability to realize a future viable substitute. 相似文献
10.
The purpose of these field and lab studies undertaken during rehabilitation work being done on an ancient railway line was to characterize a layer of ballast fouled with soil found in the track substructure. The field studies included the characterization of the thickness, grain size distribution and void ratio of the fouled ballast layer, as well as a large number of plate load tests, both on the fouled ballast layer and on the subgrade. The resilient behaviour of the fouled ballast was evaluated in the lab by cyclic triaxial tests on large size reconstituted specimens with distinct fouling indexes (different grain size distribution) and distinct humidity states (dry or wet). The results obtained were used as support for the decision to maintain the fouled ballast layer under the new sub-ballast in a number of stretches of the renewed line. 相似文献