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391.
LB de Abreu 《Canadian Metallurgical Quarterly》1997,115(4):1495-1507
OBJECTIVE: Revision and questioning of orthodox principles regarding the conduction of nerve impulse. DESIGN: Retrospective study with clinical analysis of results. SITE: Hospital das Clinicas (HCFMSP), public university institution with research programs and tertiary attention to health. GROUP MEMBERS: Author and a team of residents and trainees. OPERATION: Direct suture of nervous stumps utilizing auxiliary technical procedures:- joint-flexion, nerve transposition, tendon transplants, bone shortening. MEASUREMENT: Clinical evaluation and objective tests for tactile and stereognostic function recovery (Weber Test). RESULTS: Variable, depending on preoperative conditions:- type of lesion, time elapsed since injury. CONCLUSIONS: Neurorrhaphy should be the procedure of choice even for long term lesions, although the expected results may be less favourable. Periodical evaluation from 24 hs. postoperative, checking for early undefined signals of nervous function recovery. Association of specific drugs for chemical biophysics of the nerve. 相似文献
392.
To assess the physiologic response to daily life stress in patients with craniomandibular disorders (CMD), office and ambulatory blood pressure and heart rate were studied in 25 female patients and 25 controls. Significant differences (p < 0.05) were found between the groups for heart rate before the clinical examination and that in the patient group when compared before and after the clinical examination. Higher values were found for mean daytime systolic and diastolic blood pressure in the control group compared with the patient group (p < 0.05). The mean number of systolic blood pressure > or = 140 mmHg during 24 h and daytime was significantly higher (p < 0.05) in the control group than in the patient group. In this study the CMD patients with muscular diagnosis were not more stressed than healthy subjects in the daily activities as evaluated by ambulatory blood pressure measurements. 相似文献
393.
Tarcisio E. AndradeJr Carlos Renato Rambo Heino Sieber Antonio E. Martinelli Dulce Maria A. Melo 《Journal of Materials Science》2007,42(14):5426-5430
Al2O3 fibers with a hollow morphology were produced by Al-vapor infiltration-reaction and subsequent oxidation from pyrolysed fibers
of natural sisal. Following pyrolysis, the bio-fiber template was reacted with gaseous Al at 1,400 °C–1,600 °C in vacuum to
form Al4C3. After an oxidation/sintering process at 1,550 °C, the biomorphic Al4C3 fibers were fully converted into Al2O3, maintaining the microstructural features of the native sisal. Phase and microstructural characterization during processing
were evaluated by high temperature X-ray diffractometry and scanning electron microscopy, respectively. Thermo-analyses were
performed in the Al4C3 samples in order to estimate the reactions and the weight change during the oxidation step. 相似文献
394.
Ana R. Almeida Roberto D. Dias Carlos J. P. Monteiro Artur R. Abreu Pedro M. P. Gois J. Carles Bayon Mariette M. Pereira 《Advanced Synthesis \u0026amp; Catalysis》2014,356(6):1223-1228
A new efficient multicatalytic process involving a single catalyst to promote tandem hydroformylation/arylation reactions is disclosed. The effect of the rhodium ligand was evaluated and the rhodium/triphenylphosphine catalytic system was selected to apply the methodology to different olefins and boronic acids. High yields (up to 89%) and good to excellent isomer ratios (up to 98:2) were achieved using aryl olefins as starting materials. This new methodology allows the preparation of secondary alcohols, from simple olefins, and paves the way for the synthesis of high‐value products, namely vinylindole and anethole derivatives.
395.
Ladislav Novotný Hamilton Ferreira Gomes de Abreu Jozef Zajac Miloslav Béreš 《Science & Technology of Welding & Joining》2018,23(2):148-157
Welded components contain certain geometrical imperfections which may affect buckling behaviour of the final product. However, geometrical perfect models are usually used in the finite element method simulation. When a simple weld model is used, the mode of the end-distortion is predictable. Imperfections are created in the same shape as predicted. This paper presents a novel numerical approach on how to generate geometrical imperfections in finite element models. In this approach, as first, a large temperature gradient for the weld seam elements is prescribed. Then a linear steady-state thermal analysis is conducted and is followed by a structural analysis to determine the initial stress stiffness matrix for an eigenvalue analysis. The mode shapes of eigenvalue analysis are finally used to generate the imperfections. The results obtained in the course of this work allowed to calculate resultant welding distortion more accurate. 相似文献
396.
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398.
Eduardo Abreu Ciro Díaz Juan Galvis Marcus Sarkis 《Computers & Mathematics with Applications》2018,75(6):1852-1867
We describe and analyze a volumetric and residual-based Lagrange multipliers saddle point reformulation of the standard high-order finite method, to impose conservation of mass constraints for simulating the pressure equation on two dimensional convex polygons, with sufficiently smooth solution and mobility phase. We establish high-order a priori error estimates with locally conservative fluxes and numerical results are presented that confirm the theoretical results. 相似文献
399.
Although the benefits of clustering for innovation have received much attention in the theoretical as well as empirical literature, analyses at the regional level often disregard the characteristics of local firms. We tackle both at the same time: agglomeration externalities (Marshall, Porter, Jacobs) from census microdata, and firm data from the Community Innovation Survey. Importantly, we allow for sectoral heterogeneity of agglomeration forces. We find that the firm characteristics, including those that proxy for ‘absorptive capacity’, have a much stronger relationship with the propensity to innovate than regular agglomeration externalities. The latter are only statistically significant for a few specific sectors, and even then only for some types of innovation. Sorting of innovation‐prone firms into specific locations might therefore be much more important to explain spatial patterns of innovation than agglomeration externalities. 相似文献
400.
Quantitative image analysis as a diagnostic tool for identifying structural changes during a revival process of anaerobic granular sludge 总被引:3,自引:0,他引:3
Due to unspecified operational problems, the specific acetoclastic activity (SAA) of the anaerobic granular sludge present in an industrial UASB reactor was considerably damaged (from 250 to less than 10mL CH(4)@STP/gVSS.d), significantly reducing the biogas production of that industrial unit. The hydrogenotrophic methanogenic activity exhibited a value of 600mL CH4@STP/gVSS.d, the settling velocity was 31.4+/-9.8m/h, the average equivalent diameter was 0.92+/-0.43mm, and about 70% of the VSS were structured in aggregates larger than 1mm. In order to study the recovery of the SAA, this sludge was collected and inoculated in a lab-scale expanded granular sludge blanket (EGSB) reactor. Ethanol was fed as the sole carbon source during a trial period of 106 days. Process monitoring included COD removal efficiency, methane production, and periodic determination of the specific methanogenic activity in the presence of acetate, propionate, butyrate, ethanol and H(2)/CO(2). Quantitative image analysis allowed for information to be obtained on granular fragmentation/erosion and filaments release. During the first operational period, biogas production was mainly due to the hydrogenotrophic activity. However, after 40 days, the SAA steadily increased achieving a maximum value of 183+/-13mL CH4@STP/gVSS.d. The onset of SAA recovery, granules breakdown and filaments release to the bulk occurred simultaneously. Further increase in SAA was accompanied by granular growth. In the last 25 days of operation, the size distribution was stable with more than 80% of projected area of aggregates corresponding to granules larger than 1mm (equivalent diameter). Confocal images from FISH hybridized sections of the granules showed that after SAA recovery, the granules developed an organized structure where an acidogenic/acetogenic external layer was apparent. Granular fragmentation and increase of filaments in the bulk, simultaneously with the increase in the acetoclastic activity are described for the first time and might represent a structural response of granular sludge to promote the optimal substrate uptake at minimal diffusion limitations. 相似文献