全文获取类型
收费全文 | 336篇 |
免费 | 16篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 82篇 |
金属工艺 | 2篇 |
机械仪表 | 3篇 |
建筑科学 | 16篇 |
矿业工程 | 2篇 |
能源动力 | 10篇 |
轻工业 | 55篇 |
水利工程 | 3篇 |
石油天然气 | 2篇 |
无线电 | 10篇 |
一般工业技术 | 34篇 |
冶金工业 | 55篇 |
自动化技术 | 76篇 |
出版年
2023年 | 3篇 |
2022年 | 8篇 |
2021年 | 10篇 |
2020年 | 6篇 |
2019年 | 4篇 |
2018年 | 9篇 |
2017年 | 3篇 |
2016年 | 11篇 |
2015年 | 6篇 |
2014年 | 8篇 |
2013年 | 17篇 |
2012年 | 14篇 |
2011年 | 22篇 |
2010年 | 19篇 |
2009年 | 15篇 |
2008年 | 18篇 |
2007年 | 19篇 |
2006年 | 14篇 |
2005年 | 16篇 |
2004年 | 6篇 |
2003年 | 7篇 |
2002年 | 11篇 |
2001年 | 5篇 |
2000年 | 7篇 |
1999年 | 9篇 |
1998年 | 19篇 |
1997年 | 15篇 |
1996年 | 16篇 |
1995年 | 11篇 |
1994年 | 5篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1985年 | 1篇 |
1982年 | 1篇 |
1980年 | 2篇 |
1977年 | 1篇 |
1976年 | 2篇 |
排序方式: 共有352条查询结果,搜索用时 9 毫秒
111.
Alvaro Sierra‐Altamiranda Hadi Charkhgard 《International Transactions in Operational Research》2020,27(2):945-957
We present OOESAlgorithm.jl , a package for optimizing a linear function over the efficient set of biobjective mixed integer linear programs. The proposed package extends our recent study (see Sierra‐Altamiranda and Charkhgard [INFORMS Journal on Computing, https://doi.org/10.1287/ijoc.2018.0851]) by adding two main features: (a) in addition to CPLEX, the package allows employing any single‐objective solver supported by MathProgBase.jl , for example, GLPK, CPLEX, and SCIP; (b) the package supports execution on multiple processors and is compatible with the JuMP modeling language. An extensive computational study shows the efficacy of the package and its features. 相似文献
112.
This paper describes the grammatical approach, an approach to the specification of XML processing tasks based on attribute grammars. This approach describes how to provide task-specific context-free grammars for XML documents, as well as how to decompose complex processing tasks into simpler ones with attribute-grammar fragments. The result is a high-level, syntax-directed declarative specification for the processing of XML documents, which facilitates the development and maintenance of complex XML processing applications while preserving the flexibility of general-purpose XML processing models. The grammatical approach is illustrated using Chasqui, an e-learning platform for building educational digital libraries of learning objects. 相似文献
113.
Cristian S. de Oliveira Luis T. Quispe Cristiani C. Plá Cid Jelver A. Sierra Silvio de Barros A. Mello 《The Journal of Adhesion》2018,94(6):473-485
We have studied the influence of the organic molecule DL-Dithiothreitol on the properties of isotropic conductive adhesives for application in microelectronics. The Ag fillers were prepared from commercial micro flakes or submicron particles from waste jewelry. The results show that coating of the Ag recycled fillers with thiol avoided the agglomeration of the particles improving the dispersion and the electrical and mechanical properties. By comparing the samples, the better properties were obtained from adhesives with recycled Ag particles relative to the ones formulated with commercial Ag flakes and improvement can be attributed to the absence of the lubricant layer and smaller size of the particles produced from recycled silver. 相似文献
114.
Andrew Thoesen Sierra Ramirez Hamid Marvi 《American Institute of Chemical Engineers》2019,65(3):894-903
This study presents an experimental, computational, and analytical comparison of a submerged, double-helix Archimedes screw generating propulsive force against a bed of glass beads. Three screws of different pitch lengths were studied. Each screw was tested at six speeds in approximately 10 trials for a total of 180 experimental trials. These experiments were then replicated in EDEM, a discrete element method (DEM) software program. DEM simulation results for thrust forces in the 30–120 rpm regime had a 5%–20% inflation of forces compared to experimental results. These simulations were then compared with resistive force theory (RFT) plate approximation of the screw geometries. We analyze a superposition-based partition approach to the full-length screws as well as force generation in shortened, one- and two-blade screws. We find that the force generation is dependent on the flow patterns and cannot be reduced to partitioned approximations as with simple intruders. © 2018 American Institute of Chemical Engineers AIChE J, 65: 894–903, 2019 相似文献
115.
Violeta Morcuende-Ventura Sonia Hermoso-Durn Natalia Abian-Franco Roberto Pazo-Cid Jorge L. Ojeda Sonia Vega Oscar Sanchez-Gracia Adrian Velazquez-Campoy Teresa Sierra Olga Abian 《International journal of molecular sciences》2021,22(12)
(1) Background: Biophysical techniques applied to serum samples characterization could promote the development of new diagnostic tools. Fluorescence spectroscopy has been previously applied to biological samples from cancer patients and differences from healthy individuals were observed. Dendronized hyperbranched polymers (DHP) based on bis(hydroxymethyl)propionic acid (bis-MPA) were developed in our group and their potential biomedical applications explored. (2) Methods: A total of 94 serum samples from diagnosed cancer patients and healthy individuals were studied (20 pancreatic ductal adenocarcinoma, 25 blood donor, 24 ovarian cancer, and 25 benign ovarian cyst samples). (3) Results: Fluorescence spectra of serum samples (fluorescence liquid biopsy, FLB) in the presence and the absence of DHP-bMPA were recorded and two parameters from the signal curves obtained. A secondary parameter, the fluorescence spectrum score (FSscore), was calculated, and the diagnostic model assessed. For pancreatic ductal adenocarcinoma (PDAC) and ovarian cancer, the classification performance was improved when including DHP-bMPA, achieving high values of statistical sensitivity and specificity (over 85% for both pathologies). (4) Conclusions: We have applied FLB as a quick, simple, and minimally invasive promising technique in cancer diagnosis. The classification performance of the diagnostic method was further improved by using DHP-bMPA, which interacted differentially with serum samples from healthy and diseased subjects. These preliminary results set the basis for a larger study and move FLB closer to its clinical application, providing useful information for the oncologist during patient diagnosis. 相似文献
116.
Dr. Tyler J. Doyon Prasanth Kumar Sierra Thein Maeve Kim Abigail Stitgen Abbigail M. Grieger Cormac Madigan Prof. Patrick H. Willoughby Prof. Andrew R. Buller 《Chembiochem : a European journal of chemical biology》2022,23(2):e202100577
Enzymes from secondary metabolic pathways possess broad potential for the selective synthesis of complex bioactive molecules. However, the practical application of these enzymes for organic synthesis is dependent on the development of efficient, economical, operationally simple, and well-characterized systems for preparative scale reactions. We sought to bridge this knowledge gap for the selective biocatalytic synthesis of β-hydroxy-α-amino acids, which are important synthetic building blocks. To achieve this goal, we demonstrated the ability of ObiH, an l -threonine transaldolase, to achieve selective milligram-scale synthesis of a diverse array of non-standard amino acids (nsAAs) using a scalable whole cell platform. We show how the initial selectivity of the catalyst is high and how the diastereomeric ratio of products decreases at high conversion due to product re-entry into the catalytic cycle. ObiH-catalyzed reactions with a variety of aromatic, aliphatic and heterocyclic aldehydes selectively generated a panel of β-hydroxy-α-amino acids possessing broad functional-group diversity. Furthermore, we demonstrated that ObiH-generated β-hydroxy-α-amino acids could be modified through additional transformations to access important motifs, such as β-chloro-α-amino acids and substituted α-keto acids. 相似文献
117.
The 30-base pair (bp) deletion of the cytoplasmic carboxy-terminal domain of the latent membrane protein 1 (LMP-1) gene was analyzed in 37 frozen tissues from patients with Epstein-Barr virus (EBV)-related gastric cancer and 18 throat washings from healthy adults in southern Japan. The 30-bp deletion was identified in 33 (91.7%) of 36 specimens of EBV-related gastric cancers and in 15 (83.3%) of 18 throat washings from healthy adults. In one case of gastric cancer, an additional 9-bp deletion was identified downstream of the 30-bp deletion. From the last transmembrane domain to the end of the carboxy terminal of LMP-1, mutations were examined in 37 cases of gastric cancers and in three cases of throat washings. Twenty-eight nonsilent mutations were identified in this region of EBV-related gastric cancer and throat washings. Five nonsilent mutations at positions 168,755, 168,746, 168,687, 168,357, and 168,355 were identified in all 30-bp-deleted cases of EBV-related gastric cancers and throat washings. However, these nonsilent mutations were not identified in three patients without the 30-bp deletion. Although the deletion and single-base mutations of the LMP-1 gene in gastric cancers and throat washings were similar to those of nasopharyngeal carcinoma in Taiwan and China, more single-base mutations were found in southern Japan. These data indicate that high prevalence of the 30-bp deletion of the LMP-1 gene in gastric cancers may reflect the prevalence of the deletion variant in the normal population in southern Japan. 相似文献
118.
Germán Sierra Gallego Catherine Batiot-Dupeyrat Joël Barrault Elizabeth Florez Fanor Mondragón 《Applied Catalysis A: General》2008,334(1-2):251-258
Perovskites LaNiO3, LaNi1−xMgxO3−δ and LaNi1−xCoxO3−δ were synthesized by auto combustion method. TPR analysis reveled that Mg or Co substituted perovskites were more difficult to reduce. The perovskites were evaluated as catalyst precursors in the dry reforming of methane. Catalysts obtained by reduction of LaNiO3 and LaNi1−xMgxO3−δ perovskite had the highest catalytic activity for CO2 reforming of CH4 at 700 °C using drastic reaction conditions (10 mg of catalyst, a mixture of CH4/CO2 without dilution gas). Methane and carbon dioxide conversions were 57% and 67%, respectively, with a H2/CO ratio equal to 0.47.The presence of cobalt leads to a decrease of the catalytic activity. This decreasing of activity may be attributed to the Co–Ni alloy formation. Computational calculations revealed that Ni atom cleaves the C–H atom while Co is not able to activate the CH4 molecule. The interaction energy of CH4 with the Ni and CO atom was 18 kcal/mol and 0.7 kcal/mol, respectively.The catalysts were characterized by TPR, TEM and in situ XRD. 相似文献
119.
Sierra Didier Cubillos‑Varela Alfonso Franco Carlos 《Clean Technologies and Environmental Policy》2022,24(10):3317-3317
Clean Technologies and Environmental Policy - 相似文献
120.
As part of the formulation studies of policosanol, a new hypocholesterolemic drug, a physico-mechanical characterization was developed. Thermal analysis, using differential scanning calorimetry was used to evaluate the purity of policosanol from batch to batch and, also, the particle size distribution. The degree of wettability of policosanol was studied by measuring the contact angle and solubility in different solvents. The compressibility and cohesion of particles were evaluated using a profile of compression forces, ranging between 6.5 kN and 39.0 kN. Also, other properties such as flow properties, true density, and tapped and bulk density were measured. The industrial batches of policosanol that were studied show an adequate purity and a uniform distribution of the particle sizes. Policosanol shows good flow properties, compressibility, and cohesion as well as a low solubility in the majority of the solvents used in the pharmaceutical industry, and its solubility in water or in aqueous solutions was, mainly, null. The wettability of policosanol in the different solvents shows the following order: methylene chloride > ethanol > acetone > water. 相似文献