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41.
Maria Quero-Pastor Carmen Garrido-Perez Asuncion Acevedo Merino Jose M. Quiroga Alonso 《臭氧:科学与工程》2016,38(6):425-433
This article presents the results of the degradation of clofibric acid by ozonation. Furthermore, results of the toxic effect of clofibric acid and its intermediate compound, 4-chlorophene generated during the oxidation process, to alga Selenastrum capricornium, are also discussed. The degradation and mineralization of the compound are studied according to the optimized operating conditions. These variables include pH, conductivity, hydraulic retention time and the use of a mixing maze. All the trials are conducted in a purpose-built pilot-scale reactor. Working under the optimal operating conditions (pH = 9, HRT = 12.5 min and ozone dose = 14 ± 2 gN/m3), a degradation value of 98% was obtained, although mineralization of the compound did not occur. Results show that clofibric acid and its intermediate are toxic during the first 10 min of treatment for concentrations equal to or greater than 1 mg/L. Under optimal conditions toxicity is not observed for any concentrations. 相似文献
42.
Since dysregulation of intracellular calcium (Ca2+) levels is a common occurrence in neurodegenerative diseases, including Alzheimer’s disease (AD), the study of proteins that can correct neuronal Ca2+ dysregulation is of great interest. In previous work, we have shown that plasma membrane Ca2+-ATPase (PMCA), a high-affinity Ca2+ pump, is functionally impaired in AD and is inhibited by amyloid-β peptide (Aβ) and tau, two key components of pathological AD hallmarks. On the other hand, sorcin is a Ca2+-binding protein highly expressed in the brain, although its mechanism of action is far from being clear. Sorcin has been shown to interact with the intracellular sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA), and other modulators of intracellular Ca2+ signaling, such as the ryanodine receptor or presenilin 2, which is closely associated with AD. The present work focuses on sorcin in search of new regulators of PMCA and antagonists of Aβ and tau toxicity. Results show sorcin as an activator of PMCA, which also prevents the inhibitory effects of Aβ and tau on the pump, and counteracts the neurotoxicity of Aβ and tau by interacting with them. 相似文献
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45.
Saez M González-Vázquez S González-Penedo M Barceló MA Pena-Seijo M Coll de Tuero G Pose-Reino A 《Computer methods and programs in biomedicine》2012,108(1):367-376
There are some evidence of the association between the calibre of the retinal blood vessels and hypertension. Computer-assisted procedures have been proposed to measure the calibre of retinal blood vessels from high-resolution photopraphs. Most of them are in fact semi-automatic. Our objective in this paper is twofold, to develop a totally automated system to classify retinal vessels into arteries and veins and to compare the measurements of the arteriolar-to-venular diameter ratio (AVR) computed from the system with those computed from observers. Our classification method consists of four steps. First, we obtain the vascular tree structure using a segmentation algorithm. Then, we extract the profiles. After that, we select the best feature vectors to distinguish between veins and arteries. Finally, we use a clustering algorithm to classify each detected vessel as an artery or a vein. Our results show that compared with an observer-based method, our method achieves high sensitivity and specificity in the automated detection of retinal arteries and veins. In addition the system is robust enough independently of the radii finally chosen, which makes it more trustworthy in its clinical application. We conclude that the system represents an automatic method of detecting arteries and veins to measure the calibre of retinal microcirculation across digital pictures of the eye fundus. 相似文献
46.
Yago Saez Pedro Isasi Javier Segovia Julio C. Hernandez 《New Generation Computing》2005,23(2):129-142
Evolutionary Computation encompasses computational models that follow a biological evolution metaphor. The success of these
techniques is based on the maintenance of the genetic diversity, for which it is necessary to work with large populations.
However, it is not always possible to deal with such large populations, for instance, when the adequacy values must be estimated
by a human being (Interactive Evolutionary Computation, IEC). This work introduces a new algorithm which is able to perform
very well with a very low number of individuals (micropopulations) which speeds up the convergence and it is solving problems
with complex evaluation functions. The new algorithm is compared with the canonical genetic algorithm in order to validate
its efficiency. Two experimental frameworks have been chosen: table and logotype designs. An objective evaluation measures
has been proposed to avoid user interaction in the experiments. In both cases the results show the efficiency of the new algorithm
in terms of quality of solutions and convergence speed, two key issues in decreasing user fatigue.
Yago Saez: He received the Computer Engineering degree from the Universidad Pontificia de Salamanca in 1999 Spain. He now is a Ph.D.
student and works as assistant professor at the EVANNAI Group at the Computer Science Department of CARLOS III, Madrid, Spain.
His main research areas encompasses the interactive evolutionary computation, the design applications and the optimization
problems.
Pedro Isasi, Ph.D.: He received Computer Science degree and Ph.D. degree from the Universidad Politécnica de Madrid (UPM), Spain in 1994. He
is now working as professor at the EVANNAI Group at the Computer Science Department of CARLOS III, Madrid, Spain. His main
research areas are Machine Learning, Evolutionary, Computation and Neural Networks and Applications to Optimization Problems.
Javier Segovia, Ph.D.: He is a receiving physicist, Ph.D. degree in Computer Science (with honours) from the Universidad Politécnica de Madrid
(UPM). Currently Dean of the UPM School of Computer Science, and is editor and/or author of more than 70 scientific publications
in the fields of genetic algorithms, data and web mining, artificial intelligence and intelligent interfaces.
Julio C. Hernandez, Ph.D.: He has received degree in Maths, Ph.D. degree in Computer Science. His main research area is the artificial intelligence
applied to criptography and net security. His unofficial hobbies are chess and go. Currently, he is working as invited researcher
at INRIA, France. 相似文献
47.
MC Lebrethon O Avallet Y Reznik F Archambeaud J Combes TB Usdin G Narboni J Mahoudeau JM Saez 《Canadian Metallurgical Quarterly》1998,83(12):4514-4519
In the present work, the presence of gastric inhibitory polypeptide (GIP) receptors and their functional role in the adrenal cells of three patients with food-dependent Cushing's syndrome were studied. RT-PCR and in situ hybridization studies demonstrated the presence of GIP receptor in the adrenals of the three patients. The presence of this receptor was also demonstrated in two human fetal adrenals, but not in two normal adult human adrenals or in the adrenals of one patient with nonfood-dependent Cushing's syndrome. Freshly isolated cells from patient adrenals responded in a dose-dependent manner to the steroidogenic action of both ACTH and GIP, whereas cells from normal adrenals responded only to ACTH. Treatment of cultured normal adrenal cells with ACTH, but not with GIP, increased the messenger ribonucleic acid (mRNA) levels of cholesterol side-chain cleavage cytochrome P-450, P450c17, and 3beta-hydroxysteroid dehydrogenase, whereas both hormones enhanced these mRNAs in patients' adrenal cells, although the effects of ACTH were greater than those of GIP. Moreover, pretreatment with ACTH enhanced the steroidogenic responsiveness of both normal and patient adrenal cells, whereas GIP caused homologous desensitization, and this was associated with a marked reduction of GIP receptor mRNA levels, as demonstrated by RT-PCR and in situ hybridization. Finally, both ACTH and GIP inhibited DNA synthesis in one patient's adrenal cells, whereas in normal adrenal cells only ACTH had this effect. In conclusion, the present data demonstrate that ectopic expression of functional GIP receptors is the main cause of food-dependent Cushing's syndrome. 相似文献
48.
Saez M Cadarso-Suárez C Figueiras A 《Computer methods and programs in biomedicine》2003,71(2):175-179
Calculating odds ratios (OR) and corresponding confidence intervals (CI) for exposures that have been measured using a continuous scale, presents important limitations in the traditional practice of epidemiology. Our objective is to describe an S-Plus function, that we called np.OR, that allows the computation of the pointwise estimates of the ORs as well as their corresponding CIs of continuous predictors introduced nonlinearly in a generalised model. The function can also be generalised to compute the pointwise estimates of categorical predictors that were introduced nonlinearly. To illustrate usage of the program we analyse the relationship between ambient temperature and total mortality in Barcelona for the period 1991-1995, while controlling for observed and unobserved confounders. 相似文献
49.
Lewis BJ Desormeaux M Green AR Bennett LG Butler A McCall M Vergara JC 《Radiation protection dosimetry》2004,111(2):151-171
A methodology is presented for collecting and analysing exposure measurements from galactic cosmic radiation using a portable equipment suite and encapsulating these data into a semi-empirical model/Predictive Code for Aircrew Radiation Exposure (PCAIRE) for the assessment of aircrew radiation exposure on any flight over the solar cycle. The PCAIRE code has been validated against integral route dose measurements at commercial aircraft altitudes during experimental flights made by various research groups over the past 5 y with code predictions typically within +/-20% of the measured data. An empirical correlation, based on ground-level neutron monitoring data, is detailed further for estimation of aircrew exposure from solar particle events. The semi-empirical models have been applied to predict the annual and career exposure of a flight crew member using actual flight roster data, accounting for contributions from galactic radiation and several solar energetic-particle events over the period 1973-2002. 相似文献
50.
The combinatorial clock-proxy auction is analyzed as a selling mechanism of a portion of the “digital dividend” in an European
country. We assumed bidders with bounded rationality making their bidding decisions based on a system of recommendation that
learns from the environment. The auction outcome when all bidders follow the proposed strategies was compared with the efficient
outcome of the auction. Although significant differences were found in the seller’s income, no significant variations were
found in the distribution of spectrum licenses among bidders. 相似文献