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991.
992.
Hegedus C Flóra-Nagy E Martos R Juhász A Fülöp I Pomaházi S Nagy IP Tóth Z Márton I Keszthelyi G 《Computer methods and programs in biomedicine》2000,63(2):77-84
The aim of this study was to examine the accuracy of the computerized 3D surface analyzing and volume measuring method in dentistry. Two different types of test objects were used in the first part of the measurements. Each sample of the two groups was cross-sectioned using a hard tissue microtome. The sections were photographed on both sides and were projected on a graphical tablet and analyzed using a computer program. The measured and calculated parameters were compared. In the second part, 200 microm thick horizontal sections were prepared from 11 human incisor roots using the hard tissue microtome. This way, five sections were prepared from the apical 2 mm of each root. The effects of section thickness and number were modeled by decreasing the inclusion rate of the obtained number of sections from 10 to 2 and its influence on the calculated results was determined. This method was suitable for the approximation and analysis of 3D parameters. The results indicated that using 200-300 microm section thickness, the measured values were approximately 8-21% lower than the real parameters. 相似文献
993.
Skowronek M Roterman Konieczny L Stopa B Rybarska J Piekarska B Górecki A Król M 《Computers & chemistry》2000,24(3-4):429-450
The structures of the closely related bis-azo dyes Evans blue, Trypan blue and Congo red, which appeared to have different self-assembly properties and correspondingly different abilities to form complexes with amyloids and some other proteins, were compared in this work. Ab initio and semi-empirical methods were used to find the optimal structures and partial charge distributions of the dyes. The optimal structures were searched using different widely used programs. The structures of Congo red and evans blue were found to be planar, except for the torsion on the central diphenyl bond connecting the two halves of the dye. Both symmetrical parts of the molecules appeared very close to planarity. However, Trypan blue exhibits non planarity on the di-azo bonds, as well as on the central bond between the symmetrical parts of the dye. In a consequence, the non planarity of this molecule is higher than in the case of its isomer, Evans blue and Congo red as well. The extra rotation around the azo bonds extorted by the close proximity of the sulfonic groups may be the direct cause of its poor self-assembling and complexation properties versus Evans blue. 相似文献
994.
Hernando ME Gómez EJ Corcoy R del Pozo F 《Computer methods and programs in biomedicine》2000,62(3):235-248
DIABNET is a knowledge-based system designed to aid doctors with therapy planning in gestational diabetes. The system core is a qualitative model, implemented by a Causal Probabilistic Network, that is able to detect the insulin effectiveness on a daily basis. DIABNET analyses monitoring data and proposes quantitative changes in insulin therapy and qualitative diet modifications. This paper proposes an evaluation methodology to assess the system performance when working in a real scenario. The methodology manages the absence of a gold standard and includes: a subjective analysis based on questionnaires and an objective analysis based on a quantitative comparison of the system's and experts' proposals. The paper also shows the results of two experiments in which expert diabetologists evaluated the therapeutical advice provided by DIABNET during the follow up of 9 patients with gestational diabetes. DIABNET detected the need of a therapy modification in 92% of the cases showing its appropriateness for automatic alarm generation. Around 80% of the proposals were accepted by experts. The evaluation results are encouraging and allow characterisation of the system's performance when proposing therapy modifications. Evaluation in its turn helps to refine the knowledge managed by DIABNET and enables us to look towards the further clinical use of DIABNET as a decision tool in gestational diabetes integrated in a telemedicine service. 相似文献
995.
S. S. M. Tavares J. R. Teodósio J. M. Neto M. R. Da Silva 《Journal of Materials Science》1999,34(18):4545-4550
A Fe-20Mo-5Ni-0.075C (wt%) alloy for magnets was prepared by induction melting under vacuum. The material was hot rolled, solution treated and aged at 610°C for different periods of time. The magnetic properties (Hc, Br, Bs and (BH)max) were measured and compared with some commercial alloys containing cobalt. The precipitation of Mo-rich phases and the decrease of the ferrite lattice parameter during ageing were detected by X-ray diffraction. The thermomagnetic analysis (TMA) was carried out in the solution treated samples and aged samples. The behaviour of TMA curves was explained with the help of X-ray analysis. 相似文献
996.
A study was carried out to determine the fat and cholesterol contents of several commercial pork cuts as function of sex. Fat and cholesterol content ranged from 2.7% and 57 mg/100 g in loin to 30.3% and 116 mg/100 g in dewlap. The higher the fat content the higher was the cholesterol content. Sex did not influence fat content and the fat/cholesterol ratio, but cholesterol content was higher in females than in males. 相似文献
997.
De Andraca I Salas MI López C Cayazzo MS Icaza G 《Archivos latinoamericanos de nutrición》1999,49(3):223-231
This study evaluates the participation of psychosocial variables in the relation between breast feeding (BF) and psychomotor development (PMD) in dyads with different BF duration. We assessed 138 mother-infant dyads, divided in two groups: 86 received BF as unique source of milk feeding for at least 6 months (prolonged BF group) and 52 were weaned before 45 days of age (early weaning group). General information about pregnancy, delivery and feeding was collected in a non experimental prospective design. At 6-7 months of age a milk feeding situation was observed at home, and mother-infant interactional patterns were recorded through a specially designed scale. At 12 months of age the PMD was assessed (Bayley Scales of Infant Development). Infant temperament, home stimulation, mother depression and family stress were also measured. Similar family characteristics were observed in both study groups. Early bonding and first feeding experiences were different, both reported as better in the prolonged BF group. Moreover, dyads of this group showed a higher variety and quality of mother-infant interactional patterns during feeding, with a higher synchrony and reciprocity in the relationship. Mean Mental Development Index (MDI) and Psychomotor Developmental Index (PDI) were similar in both groups. Explicatory variables for MDI and PDI are different in both study groups. Dyads who attained prolonged BF conform from a psychosocial perspective--a different group than the early weaned. 相似文献
998.
Arrangements are described for the recording of volume holograms with two sections that, when stacked together, work as uniaxial centered lenses and allow one to solve the problem of angular selectivity in the imaging of wide objects. The performance of such systems is examined qualitatively, and suggestions aimed at improving these designs are proposed. 相似文献
999.
A first inversion of the backscatter profile and extinction-to-backscatter ratio from pulsed elastic-backscatter lidar returns is treated by means of an extended Kalman filter (EKF). The EKF approach enables one to overcome the intrinsic limitations of standard straightforward nonmemory procedures such as the slope method, exponential curve fitting, and the backward inversion algorithm. Whereas those procedures are inherently not adaptable because independent inversions are performed for each return signal and neither the statistics of the signals nor a priori uncertainties (e.g., boundary calibrations) are taken into account, in the case of the Kalman filter the filter updates itself because it is weighted by the imbalance between the a priori estimates of the optical parameters (i.e., past inversions) and the new estimates based on a minimum-variance criterion, as long as there are different lidar returns. Calibration errors and initialization uncertainties can be assimilated also. The study begins with the formulation of the inversion problem and an appropriate atmospheric stochastic model. Based on extensive simulation and realistic conditions, it is shown that the EKF approach enables one to retrieve the optical parameters as time-range-dependent functions and hence to track the atmospheric evolution; the performance of this approach is limited only by the quality and availability of the a priori information and the accuracy of the atmospheric model used. The study ends with an encouraging practical inversion of a live scene measured at the Nd:YAG elastic-backscatter lidar station at our premises at the Polytechnic University of Catalonia, Barcelona. 相似文献
1000.
Summary Empirical evidence is given on how membership in a consolidated, well-established research team provides researchers with
some competitive advantage as compared to their colleagues in non-consolidated teams. Data were obtained from a survey of
researchers ascribed to the 'Biology and Biomedicine' area of the Spanish Council for Scientific Research, as well as from
their curricula vitae. One quarter of the scientists work as members of teams in the process of consolidation. Our findings
illustrate the importance, for the development and consolidation of research teams, of the availability of a minimum number
of researchers with a permanent position and of a minimum number of support staff and non-staff personnel (mainly post-doctoral
fellows). Consolidation of research teams has a clear influence on the more academic-oriented quantitative indicators of the
scientific activity of individuals. Researchers belonging to consolidated teams perform quantitatively better than their colleagues
in terms of the number of articles published in journals covered in the Journal Citation Reports, but not in terms of the impact of these publications. Consolidation favours publication, but not patenting, and it also
has a positive effect on the academic prestige of scientists and on their capacity to train new researchers. It does not significantly
foster participation in funded R&D projects, nor does it influence the establishment of international collaborations. Impact
is influenced to a remarkable degree by seniority and professional background, and is significantly greater for young scientists
who have spent time abroad at prestigious research laboratories. 相似文献