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221.
222.
Hervé Baumann Pierluigi Crescenzi Pierre Fraigniaud 《Journal of Parallel and Distributed Computing》2014
This paper addresses the flooding problem in dynamic graphs, where flooding is the basic mechanism in which every node becoming aware of a piece of information at step t forwards this information to all its neighbors at all forthcoming steps t′>t. We show that a technique developed in a previous paper, for analyzing flooding in a Markovian sequence of Erdös–Rényi graphs, is robust enough to be used also in different contexts. We establish this fact by analyzing flooding in a sequence of graphs drawn independently at random according to a model of random graphs with given expected degree sequence. In the prominent case of power-law degree distributions, we prove that flooding takes almost surely O(logn) steps even if, almost surely, none of the graphs in the sequence is connected. In the general case of graphs with an arbitrary degree sequence, we prove several upper bounds on the flooding time, which depend on specific properties of the degree sequence. 相似文献
223.
An edge-Markovian process with birth-rate p and death-rate q generates infinite sequences of graphs (G
0, G
1, G
2,…) with the same node set [n] such that G
t
is obtained from G
t-1 as follows: if e ? E(Gt-1){e\notin E(G_{t-1})} then e ? E(Gt){e\in E(G_{t})} with probability p, and if e ? E(Gt-1){e\in E(G_{t-1})} then e ? E(Gt){e\notin E(G_{t})} with probability q. In this paper, we establish tight bounds on the complexity of flooding in edge-Markovian graphs, where flooding is the basic
mechanism in which every node becoming aware of an information at step t forwards this information to all its neighbors at all forthcoming steps t′ > t. These bounds complete previous results obtained by Clementi et al. Moreover, we also show that flooding in dynamic graphs
can be implemented in a parsimonious manner, so that to save bandwidth, yet preserving efficiency in term of simplicity and
completion time. For a positive integer k, we say that the flooding protocol is k-active if each node forwards an information only during the k time steps immediately following the step at which the node receives that information for the first time. We define the reachability threshold for the flooding protocol as the smallest integer k such that, for any source s ? [n]{s\in [n]} , the k-active flooding protocol from s completes (i.e., reaches all nodes), and we establish tight bounds for this parameter. We show that, for a large spectrum
of parameters p and q, the reachability threshold is by several orders of magnitude smaller than the flooding time. In particular, we show that
it is even constant whenever the ratio p/(p + q) exceeds log n/n. Moreover, we also show that being active for a number of steps equal to the reachability threshold (up to a multiplicative
constant) allows the flooding protocol to complete in optimal time, i.e., in asymptotically the same number of steps as when being perpetually active. These results demonstrate that flooding
can be implemented in a practical and efficient manner in dynamic graphs. The main ingredient in the proofs of our results
is a reduction lemma enabling to overcome the time dependencies in edge-Markovian dynamic graphs. 相似文献
224.
Marcello Canova Shawn Midlam-Mohler Pierluigi Pisu Ahmed Soliman 《Control Engineering Practice》2010,18(11):1307-1317
The lean trap (LNT) is an aftertreatment device used to reduce nitrogen oxides emissions on Diesel engines. To operate the LNT with high conversion efficiency, an optimized regeneration schedule is required, together with closed-loop control of the air/fuel ratio during regeneration. Furthermore, to comply with emissions regulations, diagnostic schemes are needed to detect and isolate faults, typically related to aging, sulfur poisoning and thermal deactivation.The paper describes a step-by-step methodology for the design and validation of model-based fault diagnosis for a LNT aftertreatment system. The approach is based on a control-oriented model of the LNT validated with experimental data.The proposed diagnostic approach is based on the generation of residuals using system models, through the comparison of the predicted and measured values of selected output variables. The paper focuses on the detection and isolation of sensor faults and LNT parametric faults. Different diagnostic methodologies are presented in relation to the detection of specific faults.Starting from sulfur poisoning detection in a laboratory environment which represents a preliminary validation of the approach, the diagnostic scheme is extended to detect various faults under different plant configurations and operating conditions, with a final application to on-board fault detection and isolation. 相似文献
225.
Pierluigi Nuzzo Fernando De Bernardinis Alberto Sangiovanni Vincentelli 《Analog Integrated Circuits and Signal Processing》2006,49(3):343-358
We apply Platform-Based Design (PBD) to the power optimization of a 14 bit, 80 MS/s pipelined Analog-to-Digital Converter
(ADC) in a mixed signal formulation. A platform is a library of components and interconnects, each characterized with a set
of behavioral, performance and composition models, that is used to raise the level of abstraction to enable system-level design.
PBD is a meet-in-the-middle methodology that consists of two phases. The bottom-up phase generates a set of platform libraries
that are exploited in the system hierarchy. The top-down phase allows exploring feasible solutions within the platform libraries
and selecting the optimum implementation. To evaluate the cost of each implementation, the behavioral models available through
platform abstraction are used both for digital and analog components. We provide an example of the use of the methodology
and its features for analog circuits by modeling two amplifiers with different topologies as analog components, showing details
of the analog characterization process. Then, we create a mixed signal platform library as a combination of an analog and
a digital platform (bottom-up phase). The top-down phase performs optimization across the analog/digital boundary to minimize
power consumption constrained to given noise and linearity requirements. Simulation results show that interesting power saving
can be achieved, as much as 64% compared with an original hand-optimized ADC.
Pierluigi Nuzzo received the Laurea degree in electrical engineering from the University of Pisa, Italy, in 2003, and the Diploma from the
Scuola Superiore Sant’Anna, Pisa, in 2004, both with honors. Since 2004, he has been with the Department of Information Engineering,
University of Pisa, where he is currently working toward the Ph.D. degree in electrical engineering and computer science.
During summer 2002 he was with the Fermi National Accelerator Laboratory, Batavia, IL as a student intern working on ASIC
testing. From August 2004 to February 2005 he was with IMEC, Leuven, Belgium, as a visiting scholar, working on low power
A/D converter design for ultra-wide band applications. His research interests include high speed, low power analog and mixed-signal
circuits in CMOS technology, digital calibration of ADCs, system level mixed-signal design and design methodologies.
Mr. Nuzzo received first place in the operational category and best overall submission in the 2006 DAC/ISSCC student design
competition.
Fernando De Bernardinis received the Laurea degree in Electrical Engineering from the University of Pisa, Italy, in 1996 and the M.S. degree and
Ph.D. degree from the University of California at Berkeley in 2001 and 2005, respectively.
Between 1992 and 1996 he was at the Scuola Superiore S. Anna in Pisa. From 1997 to 1998 he collaborated with the PARADES research
center in Rome. During the summers 1999 and 2000 he was at the ST Berkeley labs, working on wireless embedded system design.
From 2000 to 2006 he was assistant professor at the Department of Information Engineering at the University of Pisa, Italy.
His research interests include mixed-signal design, analog CAD, system level analog design and design methodologies.
In 2006 he has joined Marvell Semiconductors, Pavia, Italy, where he works on mixed-signal and RF system design.
Alberto Sangiovanni Vincentelli holds the Edgar L. and Harold H. Buttner Chair of Electrical Engineering and Computer Sciences at the University of California
at Berkeley. He has been on the Faculty since 1976. He obtained an electrical engineering and computer science degree (“Dottore
in Ingegneria”) summa cum laude from the Politecnico di Milano, Milano, Italy in 1971. In 1980–1981, he spent a year as a Visiting Scientist at the Mathematical
Sciences Department of the IBM T.J. Watson Research Center. In 1987, he was Visiting Professor at MIT. He has held a number
of visiting professor positions at Italian Universities, including Politecnico di Torino, Universita’ di Roma La Sapienza,
Universita’ di Roma Tor Vergata, Universita’ di Pavia, Universita’ di Pisa, Scuola Sant’Anna.
He was a co-founder of Cadence and Synopsys, the two leading companies in the area of Electronic Design Automation. He is
the Chief Technology Adviser of Cadence. He is a member of the Board of Directors of Cadence and the Chair of the Technology
Committee, UPEK, a company he helped spinning off from ST Microelectronics, where he is the Chair of its Nominating and Governance
Committee and a member of the Audit Committee, Sonics, where he serves as the Chair of the Nominating and Governance Committee,
Gradient, where he is a member of the Compensation committee, Accent, an ST Microelectronics-Cadence joint venture he helped
founding, and Value Partners. He is the Technology Advisor to the President of the Abruzzo Region. He is a member of the HP
Strategic Technology Advisory Board, of the Science and Technology Advisory Board of General Motors and of the Scientific
Council of the Tronchetti Provera foundation. He consulted for many companies including Bell Labs, IBM, Intel, United Technology,
COMAU, Magneti Marelli, Pirelli, BMW, Daimler-Chrysler, Fujitsu, Kawasaki Steel, Sony, ST and Hitachi. He was an advisor to
the Singapore Government for microelectronics and new ventures. He has consulted as Technology Partner for Greylock Ventures
and for Vertex Investment. He served as witness in US Congressional investigations on competitiveness of the US economy. He
is the founder and Scientific Director of the Project on Advanced Research on Architectures and Design of Electronic Systems
(PARADES), a European Group of Economic Interest supported by Cadence, Magneti-Marelli and ST Microelectronics. He is a member
of the Advisory Board of the Lester Center for Innovation of the Haas School of Business and of the Center for Western European
Studies and a member of the Berkeley Roundtable of the International Economy (BRIE). He is a member of the High-Level Group
and of the Steering Committee of the EU Artemis Technology Platform.
In 1981, he received the Distinguished Teaching Award of the University of California. He received the worldwide 1995 Graduate
Teaching Award of the IEEE (a Technical Field award for “inspirational teaching of graduate students”). In 2002, he was the
recipient of the Aristotle Award of the Semiconductor Research Corporation. He has received numerous research awards including
the Guillemin-Cauer Award (1982–1983), the Darlington Award (1987–1988) of the IEEE for the best paper bridging theory and
applications, and two awards for the best paper published in the Transactions on CAS and CAD, three best paper awards and
one best presentation awards at the Design Automation Conference. In 2001, he was given the prestigious Kaufman Award of the
Electronic Design Automation Council for pioneering contributions to EDA.
He is an author of over 700 papers and 15 books in the area of design tools and methodologies, large-scale systems, embedded
controllers, hybrid systems and innovation.
Dr. Sangiovanni-Vincentelli has been a Fellow of the IEEE since 1982 and a Member of the National Academy of Engineering,
the highest honor bestowed upon a US engineer, since 1998. 相似文献
226.
227.
Characterization of monomeric and gemini cationic amphiphilic molecules by fluorescence intensity and anisotropy. Part 2 总被引:2,自引:1,他引:1
Nadia Barbero Pierluigi Quagliotto Claudia Barolo Emma Artuso Roberto Buscaino Guido Viscardi 《Dyes and Pigments》2009,83(3):396-402
Four fluorophores of different nature, structure and properties were employed as probes for the characterization of a series of alkanediyl-α,ω-bis(alkyldimethyl ammonium bromide) surfactants. Pyrene and 3-(2-Benzothiazolyl)-7-(diethylamino)coumarin (coumarin 6) fluorescence intensity as well as coumarin 6 and fluorescein sodium salt fluorescence anisotropy were used to determine cmc whilst coumarin 6, fluorescein sodium salt and perylene fluorescence anisotropy was exploited to provide information on micellar structure; cmc values were confirmed using conductivity measurements. Conductivity data were analysed by means of a method which reveals the formation of ion pairs or premicellar aggregates; this approach was useful to justify and confirm results obtained using fluorescence. 相似文献
228.
Mariela M Torres Pierluigi Pierantozzi María Eugenia Cáceres Paola Labombarda Giuseppe Fontanazza Damián M Maestri 《Journal of the science of food and agriculture》2009,89(3):523-530
BACKGROUND: Thirty‐eight accessions of olive (Olea europaea L.) originating from Córdoba province (Argentina) and preliminarily identified as belonging to the Arbequina variety were genotyped using AFLP (amplified fragment length polymorphism) DNA markers. Also, the oil chemical composition was studied during three consecutive crop years. The objectives of the work were (a) to investigate genetic intra‐cultivar diversity and (b) to evaluate the oil chemical composition and compare it with that of Arbequina oil produced in Spain. RESULTS: The 19 primer combinations employed to perform the AFLP analysis produced 98 polymorphic bands. A reduced genetic heterogeneity was obtained, confirming that (a) the selected accessions belong to the Arbequina variety and (b) the traditional vegetative propagation practice has caused low genetic erosion in this variety cultivated in Córdoba. The main features that characterise the Argentinian Arbequina oils studied are the lower content of oleic acid and higher levels of phenolics and high‐molecular‐weight volatile compounds compared with those found in Spanish Arbequina oils. CONCLUSION: In spite of the small proportion of intra‐cultivar variability, the Arbequina variety grown in Argentina produces oils with different chemical traits from those obtained in the original Spanish growing region. These differences can be attributed mainly to the particular environmental conditions of the olive‐growing areas in these countries. Copyright © 2008 Society of Chemical Industry 相似文献
229.
Corl BA Baumgard LH Griinari JM Delmonte P Morehouse KM Yurawecz MP Bauman DE 《Lipids》2002,37(7):681-688
Cis-9,trans-11 and trans-7,cis-9 CLA are the most prevalent CLA isomers in milkfat. The majority of cis-9,trans-11 CLA is synthesized endogenously by Δ9-desaturase. We tested the hypothesis that trans-7,cis-9 CLA originates from endogenous synthesis by inhibiting Δ9-desaturase with a source of cyclopropene FA (sterculic oil: SO) or with a trans-10,cis-12 CLA supplement. Experiment 1 (four cows; Latin square) involved four treatments: control, SO, partially hydrogenated vegetable
oil (PHVO), and PHVO+SO. Milk, plasma, and rumen fluid were collected. Experiment 2 treatments (four cows) were 0 or 14.0
g/d of 10,12 CLA supplement; milk and plasma were collected. Samples were analyzed by GC and Ag+-HPLC to determine FA. In Experiment 1, SO decreased milkfat content of trans-7,cis-9 CLA by 68 to 71% and cis-9,trans-11 CLA by 61 to 65%. In Experiment 2, the 10,12 CLA supplement decreased milkfat content of trans-7,cis-9 CLA and cis-9,trans-11 by 44 and 25%, respectively. Correcting for the extent of treatment-induced inhibition of Δ9-desaturase based on changes in myristic and myristoleic acids, endogenous synthesis of trans-7,cis-9 CLA represented 85 and 102% in Experiments 1 and 2, respectively. Similar corrected values were 77 and 58% for endogenous
synthesis of cis-9,trans-11 CLA. Thus, milkfat cis-9,trans-11 CLA was primarily from endogenous synthesis with a minor portion from rumen escape. In contrast, trans-7,cis-9 CLA was not present in rumen fluid in significant amounts. Results indicate this isomer in milkfat is derived almost exclusively
from endogenous synthesis via Δ9-desaturase. 相似文献
230.
Reschiglian P Zattoni A Roda B Casolari S Moon MH Lee J Jung J Rodmalm K Cenacchi G 《Analytical chemistry》2002,74(19):4895-4904
Sorting and quantification of deactivated bacteria is an important way of quality control for whole-cell bacterial vaccines. In general, surface features of deactivated bacteria used for whole-cell bacterial vaccines affect the immunoresponse to bacteria-associated antigens. Enumeration of bacteria is also an important process development parameter for these vaccines. Field-flow fractionation (FFF) was previously applied to the separation of bacteria. For the first time, FFF is used for sorting bacteria strains of the same species on the basis of differences in bacterial membrane characteristics. Two FFF techniques, gravitational FFF (GrFFF) and asymmetrical flow FFF (AsFIFFF), are shown to be able to fractionate, distinguish, and quantify different deactivated Escherichia coli strains used for vaccines. E. coli can differ in the presence of fimbriae on the bacterial membrane. Fimbriae affect E. coli pathology and thus the use of E. coli for vaccines. GrFFF and AsFIFFF are able to fractionate fimbriated/ nonfimbriated cells in mixtures of different strains. While GrFFF is characterized by low cost and simplicity, As-FIFFF shows a higher performance in size fractionation with a high-speed separation. Coupled, on-line UV/visible turbidimetry yields the relative numbers of fractionated cells and sample recovery. Scanning electron microscopy and quasi-elastic light scattering are employed as uncorrelated techniques for size and morphology analysis of the E. coli strains. 相似文献