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991.
Antisense (AS) and hairpin (HP) RNA interference (RNAi) targeted gene suppression technologies have been used to modify seed
oil composition. Larger numbers of AS transgenics have to be screened to achieve a targeted level of suppression compared
to RNAi. We hypothesized combining AS with RNAi might result in enhanced gene suppression compared to either method individually.
AS and HP-RNAi were combined as hairpin antisense (HPAS) constructs containing ~125 bp sense and antisense portions of an
untranslated region of the target gene separated by an intron containing an antisense copy of a portion of the target coding
region. The Δ12-desaturase FAD2, the ω3-desaturase FAD3 and β-ketoacyl-ACP synthase (KAS) II were targeted in Arabidopsis to evaluate changes in oil composition with AS, HP and HPAS constructs driven by the phaseolin promoter. Modest but statistically
significant enhancements in oilseed phenotypes were observed with HPAS relative to AS and HP-RNAi. Phenotypes for HPAS suppression
of FAD2 and FAD3 were indistinguishable from their strongest mutant alleles. Our data suggest that HPAS may be useful for:
(1) achieving levels of suppression comparable to those of gene knockouts in a tissue specific manner. (2) Maximizing suppression
of suboptimal RNAi constructs and (3) minimizing the screening of transgenics to achieve desired oilseed composition. 相似文献
992.
993.
Kwan Lau Wang S.H. Lixin Xu Lu C. Tam H.Y. Wai P. 《Photonics Technology Letters, IEEE》2008,20(20):1730-1732
We demonstrate an all-optical multicast switch with the capability to select five reconfigurable channel groups with six output multicast channels using three control wavelengths at 10 Gb/s using Raman-assisted four-wave mixing in dispersion-shifted fiber. All the output channels comply with the 100 GHz (i.e., 0.8 nm) spaced International Telecommunication Union (ITU) grid. 相似文献
994.
995.
Péter Biró Tamás Fleiner Robert W. Irving David F. Manlove 《Theoretical computer science》2010,411(34-36):3136-3153
We study two generalised stable matching problems motivated by the current matching scheme used in the higher education sector in Hungary. The first problem is an extension of the College Admissions problem in which the colleges have lower quotas as well as the normal upper quotas. Here, we show that a stable matching may not exist and we prove that the problem of determining whether one does is NP-complete in general. The second problem is a different extension in which, as usual, individual colleges have upper quotas, but, in addition, certain bounded subsets of colleges have common quotas smaller than the sum of their individual quotas. Again, we show that a stable matching may not exist and the related decision problem is NP-complete. On the other hand, we prove that, when the bounded sets form a nested set system, a stable matching can be found by generalising, in non-trivial ways, both the applicant-oriented and college-oriented versions of the classical Gale–Shapley algorithm. Finally, we present an alternative view of this nested case using the concept of choice functions, and with the aid of a matroid model we establish some interesting structural results for this case. 相似文献
996.
Protein content determination in Brassica oleracea species using FT‐NIR technique and PLS regression
Tamás Szigedi József Lénárt Mihály Dernovics Sándor Turza Marietta Fodor 《International Journal of Food Science & Technology》2012,47(2):436-440
Six fresh and one frozen vegetable cultivar groups possessing remarkably different morphology from the same Brassica oleracea species, including broccoli, Brussels sprouts, curly cabbage, white cabbage, red cabbage, cauliflower and white kohlrabi, were chosen to set up a Fourier transform near‐infrared spectroscopy (FT‐NIR)‐based method for the quantification of protein content. Sample preparation was based on lyophilisation and homogenisation. Calibration was set up with the help of the Kjeldahl method for the quantification of protein content in the range of 12.9–32.5 m/m%. Calibration model was developed using the spectral regions 1136–1334 and 1639–1836 nm, with partial least squares regression. This model was checked by cross‐validation. The performance of the final FT‐NIR estimation model was evaluated by root mean square of cross‐validation, root‐mean‐square error of estimation and the determination coefficient (R2). The final estimation function for the protein determination was characterised with the predictive error of 0.76 m/m% and R2 value of 98.81. 相似文献
997.
998.
A. Akbarnezhad K.C.G. Ong M.H. Zhang C.T. Tam T.W.J. Foo 《Construction and Building Materials》2011,25(8):3469-3479
The presence of mortar has been reported as the main factor causing the lower quality of recycled concrete aggregates (RCA) when compared to natural aggregates (NA). A novel microwave-assisted technique to increase the quality of RCA by partially removing the mortar adhering to RCA particles and breaking up the lumps of mortar present in RCA is introduced in this paper. The technique takes advantage of the difference in the electromagnetic properties of the adhering mortar and natural aggregates to generate high thermal stresses within the mortar, especially at the interface with the embedded natural aggregates, to cause delamination. The stresses generated also result in the breaking up of the lumps of mortar into smaller pieces. The results of an experimental study conducted to investigate the capability of the microwave-assisted RCA beneficiation technique and to compare its efficiency with other beneficiation methods proposed in available literature are presented. Moreover, the effects of incorporating various amounts of un-treated and microwave-treated coarse RCA on the mechanical properties of concrete are investigated. The temperature distribution and stresses developed in RCA when subjected to microwave heating during the beneficiation process are numerically calculated for a better understanding of the processes involved. 相似文献
999.
The effect of contact torques on porosity of cohesive powders 总被引:1,自引:0,他引:1
Guido Bartels Tamás Unger Dirk Kadau Dietrich E. Wolf János Kertész 《Granular Matter》2005,7(2-3):139-143
The porosity of uniaxially compacted cohesive powders depends on the applied stress (including gravity). The case, where these stresses are weak, is considered. The compaction results in a porosity which is a function of sliding, rolling and torsion friction. By contact dynamics simulations it is shown that the influences of contact torques (static rolling and torsion friction) on the porosity are significant and approximately additive. The relevance for nano-powder pressure sintering is discussed. 相似文献
1000.
Chung-Hung Tam Shih-Chin Lee Shih-Hsien Chang Tzu-Piao Tang Hsin-Hung Ho Hui-Yun Bor 《Ceramics International》2009,35(2):565-570
Commercial as-hp (hot pressing) treated Cr–Si targets are used throughout this study, with three different compositions: Cr20–Si80, Cr35–Si65 and Cr50–Si50. To evaluate the effects of microstructure and properties of as-hp treated Cr–Si targets by hot isostatic pressing (HIP) SEM, XRD and porosity inspections were performed. The experimental results showed that the 1373 K, 1750 MPa, 4 h HIP treated with three different Cr–Si targets had suppressed porosities successfully. The most efficient was Cr50–Si50 target subjected to HIP treatment. Porosity decreased about 60% after HIP treatment, and both the nitrogen and oxygen concentrations of the targets were slightly increased after HIP treatment. This was especially true for the single silicon in Cr–Si targets such as Cr20–Si80 and Cr35–Si65. The aim of this paper is to discuss these methods and finding suitable temperatures for the HIP for Cr–Si targets. 相似文献