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排序方式: 共有113条查询结果,搜索用时 15 毫秒
91.
Rodrigo Prado Martins Maria Cristina da Silva Valéria Dutra Luciano Nakazato Domingos da Silva Leite 《Meat science》2013
In the current study we screened Escherichia coli from intestine of pigs slaughtered in Mato Grosso, Brazil, for virulence-markers related to human disease. Furthermore, we employed for the first time a phylogenetic assay to explore the association between phylogeny and virulence genotype in E. coli from finished swine. A low prevalence (7.8%) of E. coli harbouring virulence genes was observed. Among the positive isolates, 3.3% could be classified as atypical EPEC, 2.2% as STEC and 2.2% as CDT harbouring E. coli. Virulence genes were not found to co-occur in a strain. Phylogenetic determination of isolates revealed a low prevalence of E. coli lineages related to disease. Therefore, preliminary sampling of 74 pigs indicated that slaughter swine may not be major reservoirs of E. coli capable of causing human disease. In light of the significant association between phylogeny and virulence genotype, we also underscored the phylogenetic grouping of strains as a valuable tool for E. coli surveillance programmes in slaughterhouses. 相似文献
92.
Csar Lúcio Lopes de Faria Jr. Tnia Keli Resende de Oliveira Vera Lúcia dos Santos Carlos Augusto Rosa Jos Domingos Ardisson Waldemar Augusto de Almeida Macêdo Armindo Santos 《Microporous and mesoporous materials》2009,120(3):228-238
In this work, we have developed a chemical process to agglomerate activated-gamma alumina microparticles. It is based on the sol–gel process. The process which was developed preserves the characteristics of porosity of the alumina microparticles. It allows us to obtain dried spheres with or without the introduction of a biomass type MDF (medium density fiberboard) with the following characteristics: medium diameter between 2.5 and 3.3 mm; narrow diameter range; high sphericity (0.90); high mechanical resistance (0.04 kg f/sphere); high specific surface area (257 m2/g); a network of micropores, mesopores and macropores which connects the surface and the core of the adsorbent sphere. It also allows us to obtain adsorbent alumina spheres with displaced core from the shallowest layers or even completely hollow. The possibility to add increasingly higher adsorbents biomass contents makes this process cheaper to fabricate adsorbent spheres. Besides that preliminary tests of adsorption show that dried spheres with and without MDF reach, respectively, an efficiency of removing Cd/Cu/Zn/As of 30.9%/13.5%/59.9%/43.9% and 71.3%/24.9%/48.4%/43.7%. All of these described characteristics suggest that the present method produces a good adsorbent for heavy metals and arsenic. 相似文献
93.
R. Schirru A. S. Martinez C. M. N. A. Pereira R. P. Domingos M. D. Machado L. Machado 《Progress in Nuclear Energy》1999,35(3-4)
Nuclear reactor design and operation often involve important human cognition and decisions. Design optimization, transient diagnosis and core reload optimization, are examples of complex tasks faced during a nuclear reactor design or operation. In order to handle such kind of tasks expert knowledge is required. Due to the complexity involved in the cognition and decisions to be taken, computerized systems have been intensely explored in order to aid design and operation. Following hardware advances, soft computing has been improved and, nowadays, intelligent technologies, such as evolutionary programming, neural networks, expert systems and fuzzy systems are being used to support design and operation. This work presents applications of intelligent Soft Computing (ISC) to three important cognition problems which are: the nuclear reactor design, the core reload optimization and transient diagnosis. 相似文献
94.
Fabricio F.T. Domingos Ralph G. Thomé Patrícia M. Martinelli Yoshimi Sato Nilo Bazzoli Elizete Rizzo 《Microscopy research and technique》2013,76(4):350-356
This study investigated the relationship among heat shock protein 70 (HSP70), proliferating cell nuclear antigen (PCNA), and testicular apoptosis during a breeding cycle of Prochilodus argenteus, a neotropical migratory characiform fish of importance in commercial fishery from the São Francisco River basin. A total of 48 (12 fish/sampling) adult males were caught using casting and drifting nets in four samplings from June 2008 to March 2009. Immunohistochemistry, Western blotting, terminal transferase‐mediated dUTP nick‐end labeling (TUNEL), enzyme‐linked immunosorbent assay (ELISA), and caspase‐3 colorimetric assay were assessed in different phases of spermatogenesis. Labeling for HSP70 occurred in spermatogonia (SPGA 18.0±1.5 and SPGB 27.9±1.0 in 100 mm2, respectively) and Sertoli cells in all sampling periods, with higher values in June (resting period) while spermatocytes were labeled in September (maturation period) and December (ripe period). For PCNA, immunoreaction was predominant in spermatogonia in June and September, while primary spermatocytes were labeled mainly in December (18.7±2.0). TUNEL‐positive reaction occurred throughout the sampling periods, and labeling was detected in the nucleus of germ cells in all developmental phases, except spermatozoa. By ELISA, total HSP70 in testis increased significantly from June to December, and decreased in March (regression period), P<0.05. Caspase‐3 activity decreased from June to December and increased in March. Taken together, our results suggest that HSP70 may protect the germ cells from caspase‐3‐dependent apoptosis during testicular activity and, reduction of HSP70 and increase of apoptosis contribute for testicular remodeling after the breeding season in wild populations of P. argenteus in the São Francisco River. Microsc. Res. Tech. 76:350–356, 2013. © 2013 Wiley Periodicals, Inc. 相似文献
95.
The objective of this study was to analyze the serum sample levels of selenium and copper in healthy volunteers living in the city Rio de Janeiro. Thirty individuals were submitted for nutritional assessment, electrocardiogram, echocardiogram, and serum selenium and copper analysis through hydride generation and flame atomic absorption spectrometry, respectively. The accuracy and precision of these methods were evaluated using certified reference materials. None of the studied individuals was undernourished; 53% were overweight and 13.3% were slightly obese. The mean serum selenium level was 73.18+/-9.9 microg/l (56.50-94.50 microg/l). Among women it was 76.28+/-8.7 microg/l and in men 72.23+/-10.24 microg/l (P=0.35). Among non-white individuals the mean was 73.12+/-12.57 microg/l and in the white individuals it was 73.20+/-9.11 microg/l (P=0.98). The mean serum level of copper was 1.09+/-0.39 mg/l (0.56-1.80 mg/l). The mean found in women was 0.99+/-0.22 mg/l and in the men 1.13+/-0.43 mg/l (P=0.42). In non-white individuals it was 1.36+/-0.48 mg/l and in white individuals was 1.00+/-0.31 mg/l (P=0.02). The authors concluded that selenium and copper serum levels observed in this study were similar to those found in other cities. 相似文献
96.
Fedro Domingos 《Artificial Intelligence Review》1997,11(1-5):227-253
High sensitivity to irrelevant features is arguably the main shortcoming of simple lazy learners. In response to it, many feature selection methods have been proposed, including forward sequential selection (FSS) and backward sequential selection (BSS). Although they often produce substantial improvements in accuracy, these methods select the same set of relevant features everywhere in the instance space, and thus represent only a partial solution to the problem. In general, some features will be relevant only in some parts of the space; deleting them may hurt accuracy in those parts, but selecting them will have the same effect in parts where they are irrelevant. This article introduces RC, a new feature selection algorithm that uses a clustering-like approach to select sets of locally relevant features (i.e., the features it selects may vary from one instance to another). Experiments in a large number of domains from the UCI repository show that RC almost always improves accuracy with respect to FSS and BSS, often with high significance. A study using artificial domains confirms the hypothesis that this difference in performance is due to RC's context sensitivity, and also suggests conditions where this sensitivity will and will not be an advantage. Another feature of RC is that it is faster than FSS and BSS, often by an order of magnitude or more. 相似文献
97.
Yasmine Mendes Pupo Paulo Vitor Farago Milton Domingos Michél Jessica Mendes Nadal Luis Antônio Esmerino Carlos Mauricio Lepienski 《The Journal of Adhesion》2015,91(5):356-368
The objective of this study was to assess the in vitro effect of a quaternary ammonium methacrylate polymer (QAMP) incorporated into a self-etching adhesive system on inhibiting caries by evaluating the mechanical properties of the adhesive interface. Twenty-four human third molars were distributed into: Clearfil? SE Bond containing 5% QAMP (experimental group), Clearfil? Protect Bond (positive control), and Clearfil? SE Bond (negative control). Teeth of each group were divided according to the method for producing artificial caries lesions: pH-cycling or microbiological assay. All samples were sectioned and polished in order to obtain hardness (H) and Young's modulus (E) values by nanoindentation test in the hybrid layer and dentin. Data were analyzed by ANOVA and Games Howell's post hoc test (α = 0.05). Regarding the hybrid layer, Clearfil? SE Bond containing QAMP demonstrated H and E values statistically higher than Clearfil? SE Bond in both pH-cycling and microbiological experiments. Considering dentin, Clearfil? SE Bond containing QAMP showed H and E values statistically higher than Clearfil? Protect Bond and Clearfil? SE Bond in the pH-cycling method and then Clearfil? SE Bond concerning the microbiological method. In general, Clearfil? SE Bond containing QAMP provided better mechanical properties for the resin–dentin interface after cariogenic challenges. 相似文献
98.
Poly(lactic acid) fibers obtained by solution blow spinning: Effect of a greener solvent on the fiber diameter 下载免费PDF全文
Delne Domingos da Silva Parize Juliano Elvis de Oliveira Milene Mitsuyuki Foschini José Manoel Marconcini Luiz Henrique Capparelli Mattoso 《应用聚合物科学杂志》2016,133(18)
Poly(lactic acid) (PLA) fibers has been obtained by solution blow spinning (SBS) using different solvents, however most of them are toxic and can be dangerous to human health or cause harm to the environment. Therefore, this work aimed to evaluate the use of dimethyl carbonate (DMC), a greener solvent, on the production of PLA fibers by SBS using surface response analysis to evaluate and compare the influence of three solvents (chloroform, DMC, and 1,1,1,3,3,3‐hexafluoro‐2‐propanol, HFP) in the average fiber diameter. Scanning electron microscopy (SEM) was used to analyze the fiber morphology and different ranges of fiber diameter was observed when varying the solvents (chloroform: 260–970 nm; DMC: 240–650 nm; and HFP: 220–470 nm). Regression analysis showed the polymer concentration was significant for all solvents and the air pressure was significant when using chloroform and HFP. Regardless of the air pressure, increasing the PLA concentration increased the average fiber diameters for all solvents. Chloroform and HFP indicated a tendency of reduction on the average fiber diameter when the air pressure was decreased, however this behavior was not observed for DMC. It was also observed that the standard deviation indicated to be more affected by the polymer concentration than by the air pressure. The results also indicated that lower surface tension and viscosity can reduce fiber thickness. All solvents showed to be feasible to produce PLA fibers by SBS and DMC can be used to produce PLA fibers with an affordable price using a greener process. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43379. 相似文献
99.
Engineering Behavior of a Sand Reinforced with Plastic Waste 总被引:7,自引:0,他引:7
Nilo Cesar Consoli Júlio Portella Montardo Pedro Domingos Marques Prietto Giovana Savitri Pasa 《Canadian Metallurgical Quarterly》2002,128(6):462-472
Unconfined compression tests, splitting tensile tests, and saturated drained triaxial compression tests with local strain measurement were carried out to evaluate the benefit of utilizing randomly distributed polyethylene terephthalate fiber, obtained from recycling waste plastic bottles, alone or combined with rapid hardening Portland cement to improve the engineering behavior of a uniform fine sand. The separate and the joint effects of fiber content (up to 0.9 wt?%), fiber length (up to 36 mm), cement content (from 0 to 7 wt?%), and initial mean effective stress (20, 60, and 100 kN/m2) on the deformation and strength characteristics of the soil were investigated using design of experiments and multiple regression analysis. The results show that the polyethylene terephthalate fiber reinforcement improved the peak and ultimate strength of both cemented and uncemented soil and somewhat reduced the brittleness of the cemented sand. In addition, the initial stiffness was not significantly changed by the inclusion of fibers. 相似文献
100.
Structured machine learning: the next ten years 总被引:4,自引:1,他引:3
Thomas G. Dietterich Pedro Domingos Lise Getoor Stephen Muggleton Prasad Tadepalli 《Machine Learning》2008,73(1):3-23
The field of inductive logic programming (ILP) has made steady progress, since the first ILP workshop in 1991, based on a
balance of developments in theory, implementations and applications. More recently there has been an increased emphasis on
Probabilistic ILP and the related fields of Statistical Relational Learning (SRL) and Structured Prediction. The goal of the
current paper is to consider these emerging trends and chart out the strategic directions and open problems for the broader
area of structured machine learning for the next 10 years. 相似文献