全文获取类型
收费全文 | 229篇 |
免费 | 23篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 58篇 |
金属工艺 | 3篇 |
机械仪表 | 9篇 |
建筑科学 | 8篇 |
矿业工程 | 2篇 |
能源动力 | 4篇 |
轻工业 | 39篇 |
水利工程 | 1篇 |
石油天然气 | 2篇 |
无线电 | 5篇 |
一般工业技术 | 27篇 |
冶金工业 | 38篇 |
原子能技术 | 4篇 |
自动化技术 | 51篇 |
出版年
2023年 | 3篇 |
2022年 | 7篇 |
2021年 | 12篇 |
2020年 | 7篇 |
2019年 | 9篇 |
2018年 | 10篇 |
2017年 | 14篇 |
2016年 | 10篇 |
2015年 | 9篇 |
2014年 | 15篇 |
2013年 | 12篇 |
2012年 | 14篇 |
2011年 | 16篇 |
2010年 | 13篇 |
2009年 | 14篇 |
2008年 | 5篇 |
2007年 | 4篇 |
2006年 | 7篇 |
2005年 | 5篇 |
2004年 | 5篇 |
2003年 | 4篇 |
2002年 | 6篇 |
2001年 | 4篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1998年 | 11篇 |
1997年 | 9篇 |
1996年 | 8篇 |
1994年 | 2篇 |
1993年 | 6篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1986年 | 1篇 |
1976年 | 4篇 |
排序方式: 共有252条查询结果,搜索用时 31 毫秒
91.
A microscopic analysis of the effects of root surface scaling with different power parameters of er,cr:YSGG laser
下载免费PDF全文
![点击此处可从《Microscopy research and technique》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Guilherme José Pimentel Lopes de Oliveira Mariana Aline Cominotte Tamara PÁdua Pereira Beraldo José Eduardo Cezar Sampaio Rosemary Adriana Chiérici Marcantonio 《Microscopy research and technique》2015,78(6):529-535
The aim of this study was to evaluate the effects of different power parameters of an Erbium, Cromium: Yttrium, Scandium, Gallium, Garnet laser (Er,Cr:YSGG laser) on the morphology, attachment of blood components (ABC), roughness, and wear on irradiated root surfaces. Sixty‐five incisive bovine teeth were used in this study, 35 of which were used for the analysis of root surface morphology and ABC. The remaining 30 teeth were used for roughness and root wear analysis. The samples were randomly allocated into seven groups: G1: Er,Cr:YSGG laser, 0.5 W; G2: Er,Cr:YSGG laser, 1.0 W; G3: Er,Cr:YSGG laser, 1.5 W; G4: Er,Cr:YSGG laser, 2.0 W; G5: Er,Cr:YSGG laser, 2.5 W; G6: Er,Cr:YSGG laser, 3.0 W; G7: scaling and root planning (SRP) with manual curettes. The root surfaces irradiated by Er,Cr:YSGG at 1.0 W and scaling with manual curettes presented the highest degrees of ABC. The samples irradiated by the Er,Cr:YSGG laser were rougher than the samples treated by the manual curette, and increasing the laser power parameters caused more root wear and greater roughness on the root surface. The Er,Cr:YSGG laser is safe to use for periodontal treatment, but it is not appropriate to use irradiation greater than 1.0 W for this purpose. Microsc. Res. Tech. 78:529–535, 2015. © 2015 Wiley Periodicals, Inc. 相似文献
92.
Augusto Sampaio Sidney Nogueira Alexandre Mota Yoshinao Isobe 《Software Testing, Verification and Reliability》2014,24(4):289-319
This paper mechanises conformance verification in the setting of the CSP process algebra. The verification strategy is captured by a theorem stated as a process refinement expression, which can be verified by a model checker such as FDR. The conformance relation, cspio , distinguishes input and output events. The process algebraic framework of CSP is used to address compositional conformance verification by establishing compositionality properties for cspio with respect to the CSP operators. Although cspio has been defined in the standard CSP traces model, one can address quiescence situations using a special output event, in which case it is formally established that cspio is equivalent to Tretmans ioco . All the results have been mechanically proved using the CSP‐Prover. The proposed testing theory has been adopted in an industrial context involving collaboration with Motorola, on testing mobile applications. Several examples and a case study are presented to illustrate the overall approach. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
93.
MM De Oliveira MR Sampaio AB Noronha M Vicente S Vianna 《Canadian Metallurgical Quarterly》1993,76(309):213-221
Based on the fact that Chenopodium amaranticolor extracts showed inhibitory activity against tobacco mosaic virus (TMV) and Ehrlich tumour (EA), tests were carried out to investigate whether the antiviral and antitumoral activity were caused by the same compounds. When the extract was purified by CM Sephadex C-25 column, after precipitation with 90% ammonium sulphate, twenty active fractions against TMV and two pools of fractions active against EA were obtained. Only one fraction with high absorbance values at 260 and 280 nm was able to inhibit both TMV and EA. When the extract was purified by Bio Gel P-60 column two active fractions against TMV and EA were obtained, suggesting that they were contained in the 0.01 M fraction of the CM Sephadex column. It is suggested that C. amaranticolor leaf extract contained at least two protein-like substances manifesting antiviral and antitumoral activity. 相似文献
94.
S Boissinot Y Tan SK Shyue H Schneider I Sampaio K Neiswanger D Hewett-Emmett WH Li 《Canadian Metallurgical Quarterly》1998,95(23):13749-13754
It is known that the squirrel monkey, marmoset, and other related New World (NW) monkeys possess three high-frequency alleles at the single X-linked photopigment locus, and that the spectral sensitivity peaks of these alleles are within those delimited by the human red and green pigment genes. The three alleles in the squirrel monkey and marmoset have been sequenced previously. In this study, the three alleles were found and sequenced in the saki monkey, capuchin, and tamarin. Although the capuchin and tamarin belong to the same family as the squirrel monkey and marmoset, the saki monkey belongs to a different family and is one of the species that is most divergent from the squirrel monkey and marmoset, suggesting the presence of the triallelic system in many NW monkeys. The nucleotide sequences of these alleles from the five species studied indicate that gene conversion occurs frequently and has partially or completely homogenized intronic and exonic regions of the alleles in each species, making it appear that a triallelic system arose independently in each of the five species studied. Nevertheless, a detailed analysis suggests that the triallelic system arose only once in the NW monkey lineage, from a middle wavelength (green) opsin gene, and that the amino acid differences at functionally critical sites among alleles have been maintained by natural selection in NW monkeys for >20 million years. Moreover, the two X-linked opsin genes of howler monkeys (a NW monkey genus) were evidently derived from the incorporation of a middle (green) and a long wavelength (red) allele into one chromosome; these two genes together with the (autosomal) blue opsin gene would immediately enable even a male monkey to have trichromatic vision. 相似文献
95.
Adsorption of carotenes and phosphorus from palm oil onto acid activated bleaching earth: Equilibrium,kinetics and thermodynamics 总被引:2,自引:0,他引:2
Simone M. Silva Klicia A. Sampaio Roberta Ceriani Roland Verhé Christian Stevens Wim De Greyt Antonio J.A. Meirelles 《Journal of food engineering》2013
In this work, the adsorption of carotenes and phosphorus from crude palm oil onto acid activated bleaching earth was investigated under bleaching conditions, i.e. high temperature (90, 105 and 115 °C) and low pressure (less than 50 mbar). Bleaching earth was added to palm oil in a range of 0.5–3.0 wt%. Results presented in this work suggest that adsorption of β-carotene increases with temperature, while phosphorus adsorption was less affected. Both the pseudo-first-order and the pseudo-second-order kinetic model describe efficiently the β-carotene experimental data. Intra-particle diffusion is involved in β-carotene adsorption mechanism, although it is not the sole rate limiting step in the adsorption onto acid activated bleaching earth. Phosphorus adsorption was too fast resulting in a lack of kinetic data. The equilibrium data were described better by Langmuir and Freundlich models, for β-carotene and phosphorus, respectively. A multi-component Freundlich type isotherm was tested. Its competition coefficients were too low, and it assumed the same form as the monocomponent Freundlich. A thermodynamic study demonstrated that β-carotene and phosphorus adsorption is spontaneous, endothermic and an entropy-driven process. Isosteric heat values suggest that the interactions between adsorbate and adsorbent are heterogeneous. 相似文献
96.
97.
Decomposition rate and enzymatic activity of composted municipal waste and poultry manure in the soil in a biofuel crops field
下载免费PDF全文
![点击此处可从《Journal of the science of food and agriculture》网站下载免费的PDF全文](/ch/ext_images/free.gif)
98.
Joo Neves Miguel Sampaio Ana Sneca Susana Pereira Jos Pissarra Cludia Pereira 《International journal of molecular sciences》2021,22(19)
Adverse conditions caused by abiotic stress modulate plant development and growth by altering morphological and cellular mechanisms. Plants’ responses/adaptations to stress often involve changes in the distribution and sorting of specific proteins and molecules. Still, little attention has been given to the molecular mechanisms controlling these rearrangements. We tested the hypothesis that plants respond to stress by remodelling their endomembranes and adapting their trafficking pathways. We focused on the molecular machinery behind organelle biogenesis and protein trafficking under abiotic stress conditions, evaluating their effects at the subcellular level, by looking at ultrastructural changes and measuring the expression levels of genes involved in well-known intracellular routes. The results point to a differential response of the endomembrane system, showing that the genes involved in the pathway to the Protein Storage Vacuole and the exocyst-mediated routes are upregulated. In contrast, the ones involved in the route to the Lytic Vacuole are downregulated. These changes are accompanied by morphological alterations of endomembrane compartments. The data obtained demonstrate that plants’ response to abiotic stress involves the differential expression of genes related to protein trafficking machinery, which can be connected to the activation/deactivation of specific intracellular sorting pathways and lead to alterations in the cell ultrastructure. 相似文献
99.
Impact of Crude Oil Quality on the Refining Conditions and Composition of Nutraceuticals in Refined Palm Oil
下载免费PDF全文
![点击此处可从《Journal of food science》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Klicia A. Sampaio Jose Vila Ayala Vera Van Hoed Simone Monteiro Roberta Ceriani Roland Verhé Antonio J. A. Meirelles 《Journal of food science》2017,82(8):1842-1850
Palm oil is the major vegetable oil used worldwide due to its unique properties. The effect of crude palm oil acidity on the final free fatty acids (FFA) content, neutral oil loss (NOL), and nutraceutical compounds, such as carotenes, total tocols (tocopherols and tocotrienols), squalene, and phytosterols was investigated. A central composite design was employed to study the influence of the refining conditions: temperature (200 to 260 °C), steam percentage (0.5% to 3.5%), and initial FFA content (2.2% to 6.0%) on the quality of the refined product. The results revealed that initial palm oil acidity is a statistically important parameter to obtain commercially acceptable values for final FFA content. The increase of temperature presented the most important effect on the reduction of all nutraceutical compounds. The highest tocopherols (88%), phytosterols (98%), and squalene retention (84%) was obtained when applying the mildest temperature (200 °C). From the experimental results, 3 equations were generated enabling the prediction of the free fatty acids content, the tocols content, and the losses of neutral oil. Therefore, this work contributes to the understanding and optimization of the process for the production of palm oil with high nutraceutical quality and low free fatty acid contents. 相似文献
100.
Theoretical calculations of radiationless transition probabilities and energies for M-subshell vacancies in Zn, Cd, and Hg are tabulated using the Dirac–Fock method. Transition probabilities between an initial vacancy state and a final two-vacancies state are presented for each initial and final atomic angular momentum quantum number. Calculations were performed in the single configuration approach with the Breit interaction, self-energy and (Uehling) vacuum polarization corrections included in the self-consistent method. Higher-order retardation corrections and QED effects were also included as perturbations. 相似文献