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排序方式: 共有466条查询结果,搜索用时 15 毫秒
61.
Alaa Eisa Nora EL-Rashidy Mohammad Dahman Alshehri Hazem M. El-bakry Samir Abdelrazek 《计算机、材料和连续体(英文)》2022,71(2):2901-2921
At this current time, data stream classification plays a key role in big data analytics due to its enormous growth. Most of the existing classification methods used ensemble learning, which is trustworthy but these methods are not effective to face the issues of learning from imbalanced big data, it also supposes that all data are pre-classified. Another weakness of current methods is that it takes a long evaluation time when the target data stream contains a high number of features. The main objective of this research is to develop a new method for incremental learning based on the proposed ant lion fuzzy-generative adversarial network model. The proposed model is implemented in spark architecture. For each data stream, the class output is computed at slave nodes by training a generative adversarial network with the back propagation error based on fuzzy bound computation. This method overcomes the limitations of existing methods as it can classify data streams that are slightly or completely unlabeled data and providing high scalability and efficiency. The results show that the proposed model outperforms state-of-the-art performance in terms of accuracy (0.861) precision (0.9328) and minimal MSE (0.0416). 相似文献
62.
Marianna Rossetti Lorenzo Stella Judit Morlà-Folch Sara Bobone Ariadna Boloix Lorena Baranda Danila Moscone Mònica Roldán Jaume Veciana Miguel F. Segura Mariana Köber Nora Ventosa Alessandro Porchetta 《Advanced functional materials》2021,31(46):2103511
The development of artificial vesicles into responsive architectures capable of sensing the biological environment and simultaneously signaling the presence of a specific target molecule is a key challenge in a range of biomedical applications from drug delivery to diagnostic tools. Herein, the rational design of biomimetic DNA-grafted quatsome (QS) nanovesicles capable of translating the binding of a target molecule to amphiphilic DNA probes into an optical output is presented. QSs are synthetic lipid-based nanovesicles able to confine multiple organic dyes at the nanoscale, resulting in ultra-bright soft materials with attractiveness for sensing applications. Dye-loaded QS nanovesicles of different composition and surface charge are grafted with fluorescent amphiphilic nucleic acid-based probes to produce programmable FRET-active nanovesicles that operate as highly sensitive signal transducers. The photophysical properties of the DNA-grafted nanovesicles are characterized and the highly selective, ratiometric detection of clinically relevant microRNAs with sensitivity in the low nanomolar range are demonstrated. The potential applications of responsive QS nanovesicles for biosensing applications but also as functional nanodevices for targeted biomedical applications is envisaged. 相似文献
63.
Modeling of complex interfaces: Gadolinium‐doped ceria in contact with yttria‐stabilized zirconia 下载免费PDF全文
Xavier Aparicio‐Anglès Nora H. de Leeuw 《Journal of the American Ceramic Society》2017,100(7):3329-3339
Gadolinium‐doped ceria (GDC) and yttria‐stabilized zirconia (YSZ) are well‐known electrolyte materials in solid oxide fuel cells (SOFCs). Although they can be used independently, it is common to find them in combination in SOFCs, where they are used as protective layers against the formation of secondary phases or electron conduction blockers. Despite their different optimum operating temperatures, it appears that oxygen conduction is not affected by their interface. However, the intrinsic mechanisms of oxygen diffusion at these interfaces still remain unclear. One of the main difficulties when modeling the contact between different materials, or indeed different particles of the same material, is caused by the structural complexity of these systems. If we wish to evaluate the properties of the materials, we first need to obtain a model that includes the main features of the GDC/YSZ interface, such as large‐scale defects or cation interdiffusion in the contiguous phase. Since the generation of such a mixed system is complicated, we show here how the “amorphization and recrystallization” strategy can help us to obtain realistic systems. In this, the first of our papers on the structure and properties of layered GDC/YSZ materials, we discuss the structural features of the grain boundary between GDC and YSZ obtained by molecular dynamics simulations. 相似文献
64.
Computer modelling techniques were employed to investigate the effect of surface silanol groups on the strength of adhesion
of apatite thin films to silica surfaces. To this end, we have studied a series of silica surfaces with different silanol
densities and calculated their interaction with apatite thin films. Our findings indicate that apatite does not attach strongly
to surface hydroxy groups, but that apatite should deposit at dehydrated silica surfaces, especially when the surface silicon
and oxygen species rearrange to form O–Si–O links. Any dangling silicon and oxygen bonds at the silica surfaces are saturated
by coordination to oxygen and calcium atoms in the apatite layer, but the extra reactivity afforded by these under-coordinated
surface species does not necessarily lead to more favourable substrate/film interactions. The lowest energy silica/apatite
interfaces are those where an undistorted apatite layer can be deposited on a regular, stable substrate surface. Our simulations
support the suggestion, that in vivo surface hydroxy groups are first condensed to form O–Si–O bridges before deposition and
growth of apatite. 相似文献
65.
Quantifying the degree of disorder in micronized salbutamol sulfate using moisture sorption analysis
Gorny M Jakobs M Mykhaylova V Urbanetz NA 《Drug development and industrial pharmacy》2007,33(3):235-243
Salbutamol sulfate is often micronized for use in dry powder inhalers. Therefore, it is of high interest to quantify the amorphous amount. It was investigated whether moisture sorption is able to measure the amorphous content of salbutamol sulfate. Different mixtures of amorphous and crystalline salbutamol sulfate were analyzed by moisture sorption. The amorphous material was obtained by spray drying. The measurement results were used to plot a calibration curve, which was used to quantify the amorphous amount in micronized salbutamol sulfate. 相似文献
66.
In the present paper we analyzed the effect caused by different recovery diets enriched with n-3 polyunsaturated fatty acids (PUFA n-3) on thymus and serum lipid pattern. Severe depleted weanling Wistar rats (D) were divided in three groups that received during 10 days a 20% casein diet supplemented with EPA+DHA (group Cas), a 20% protein milk diet prepared using a commercial reduced-fat product enriched with linolenic and linoleic acids (group L) and a 20% casein diet as control group C. Cas and L gave each other 24 mg/day of PUFA n-3 being the ratio n-6/n-3 8.1/1 and 7.6/1, respectively. Thymus was removed and weighted and cell number were determined; blood was recollected and Total cholesterol, triacylglycerol, HDL and LDL-cholesterol fractions and myristic, palmitic, stearic, oleic, linoleic, linolenic, araquidonic, EPA and DHA fatty acid concentrations were measured in serum. Statistical analysis was performed using Anova test. Cell number were higher (p<0.01) in Cas (44.48+/-8.20) and in L (56.45+/-14.72) when compared to group D (1.80+/-0.70) and group C (23.70+/-4.04). L presented lower values of cholesterol, HDL and LDL-cholesterol (p<0.01) and higher values of triacylglycerol (p<0.05) when compared to Cas, being EPA (p<0.05) and DHA (p<0.01) higher in Cas. Being PUFA n-3 contribution the same in Cas and L, both diets were able to reverse the thymic athropy presenting a different hipolipemic behavior due to the different sources of PUFA n-3 used in the diets. 相似文献
67.
Both potassium and ammonium ferrierite (FK and FA, respectively) were impregnated with tungsten species using either tungstic
acid or ammonium metatungstate as precursors. The skeletal isomerization of 1-butene at 200–400°C, atmospheric pressure and
0.15 atm 1-butene partial pressure, was studied on samples with and without tungsten. Tungsten species on FK promote the isobutene
formation while those species on FA generate a synergetic effect over the isobutene production. The presence of tungsten species
improves the material stability and mainly, the isobutene yield. Starting the 1-butene feed over the catalytic bed at 200°C
and then increasing the reaction temperature to 400°C, makes it possible to avoid the low isobutene selectivity at short times-on-stream.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
68.
J. Liu J. J. Duruz V. de Nora J. A. Sekhar 《Clean Technologies and Environmental Policy》1999,1(3):180-186
After nearly 100 years of aluminum production with the Hall-Héroult cell, major innovations are being considered, mainly
in the materials of construction and the electrodes. This article presents a brief review of some of the innovations made
in anode materials. Such improvements lead to better cell efficiencies and environmental benefits; and open the door for improved
cell designs hithertofore not possible with available cell materials.
Received: 17 November 1998 / Accepted: 19 March 1999 相似文献
69.
Flexible power generation scenarios for biogas plants operated in Germany: impacts on economic viability and GHG emissions 下载免费PDF全文
Markus Lauer Martin Dotzauer Christiane Hennig Monique Lehmann Eva Nebel Jan Postel Nora Szarka Daniela Thrän 《国际能源研究杂志》2017,41(1):63-80
Biogas plants enable power to be generated in a flexible way so that variable, renewable energy sources can be integrated into the energy system. In Germany, the Renewable Energy Sources Act promotes flexible power generation in biogas plants. Two existing biogas plants in flexible operation were analyzed with respect to economic viability and greenhouse gas (GHG) emissions to assess the feasibility of flexible operation. To do this, a biogas technology simulation model was developed to reproduce the technical design of both biogas plants and to link this design with twelve flexibilization scenarios. The evaluation of the economic viability is based on a discounting method of investment appraisal. For assessing the level of GHG emissions, the life cycle assessment method has been applied. The results show that the profitability of flexibilization is contingent upon premium payments promoting flexibility and direct sales resulting from a higher electrical efficiency of new or additionally installed combined heat and power units. Overall, with respect to profitability, the results of the flexible power generation scenarios are dependent upon the properties of the technical plant, such as its power generation and gas storage capacities. Relative GHG emissions from flexible biogas plants show significantly lower values than for referenced fossil gas–steam power stations. Among the various scenarios, the results reveal that the level of GHG emissions especially depends on the number of operating hours of the additional combined heat and power unit(s). The results of the analyzed biogas plants showed no direct correlation between GHG emissions and the economic benefits. Overall, a flexible power generation of biogas plants may improve the economic viability as well as result in lower GHG emissions in comparison with a conventional base load operation. © 2016 The Authors. International Journal of Energy Research published by John Wiley & Sons Ltd. 相似文献
70.
Somayeh S. Tarighat Fei Fei Eun Ji Joo Hisham Abdel-Azim Lu Yang Huimin Geng Khuchtumur Bum-Erdene I. Darren Grice Mark von Itzstein Helen Blanchard Nora Heisterkamp 《International journal of molecular sciences》2021,22(22)
Environmentally-mediated drug resistance in B-cell precursor acute lymphoblastic leukemia (BCP-ALL) significantly contributes to relapse. Stromal cells in the bone marrow environment protect leukemia cells by secretion of chemokines as cues for BCP-ALL migration towards, and adhesion to, stroma. Stromal cells and BCP-ALL cells communicate through stromal galectin-3. Here, we investigated the significance of stromal galectin-3 to BCP-ALL cells. We used CRISPR/Cas9 genome editing to ablate galectin-3 in stromal cells and found that galectin-3 is dispensable for steady-state BCP-ALL proliferation and viability. However, efficient leukemia migration and adhesion to stromal cells are significantly dependent on stromal galectin-3. Importantly, the loss of stromal galectin-3 production sensitized BCP-ALL cells to conventional chemotherapy. We therefore tested novel carbohydrate-based small molecule compounds (Cpd14 and Cpd17) with high specificity for galectin-3. Consistent with results obtained using galectin-3-knockout stromal cells, treatment of stromal-BCP-ALL co-cultures inhibited BCP-ALL migration and adhesion. Moreover, these compounds induced anti-leukemic responses in BCP-ALL cells, including a dose-dependent reduction of viability and proliferation, the induction of apoptosis and, importantly, the inhibition of drug resistance. Collectively, these findings indicate galectin-3 regulates BCP-ALL cell responses to chemotherapy through the interactions between leukemia cells and the stroma, and show that a combination of galectin-3 inhibition with conventional drugs can sensitize the leukemia cells to chemotherapy. 相似文献