全文获取类型
| 收费全文 | 438篇 |
| 免费 | 13篇 |
| 国内免费 | 2篇 |
专业分类
| 技术理论 | 1篇 |
| 综合类 | 47篇 |
| 化学工业 | 103篇 |
| 金属工艺 | 13篇 |
| 机械仪表 | 7篇 |
| 建筑科学 | 3篇 |
| 矿业工程 | 4篇 |
| 能源动力 | 25篇 |
| 轻工业 | 87篇 |
| 石油天然气 | 5篇 |
| 无线电 | 19篇 |
| 一般工业技术 | 81篇 |
| 冶金工业 | 1篇 |
| 原子能技术 | 1篇 |
| 自动化技术 | 56篇 |
出版年
| 2024年 | 15篇 |
| 2023年 | 16篇 |
| 2022年 | 3篇 |
| 2021年 | 19篇 |
| 2020年 | 33篇 |
| 2019年 | 19篇 |
| 2018年 | 15篇 |
| 2017年 | 15篇 |
| 2016年 | 23篇 |
| 2015年 | 40篇 |
| 2014年 | 26篇 |
| 2013年 | 60篇 |
| 2012年 | 40篇 |
| 2011年 | 25篇 |
| 2010年 | 23篇 |
| 2009年 | 22篇 |
| 2008年 | 6篇 |
| 2007年 | 8篇 |
| 2006年 | 6篇 |
| 2005年 | 5篇 |
| 2003年 | 1篇 |
| 2002年 | 3篇 |
| 2001年 | 3篇 |
| 2000年 | 2篇 |
| 1999年 | 2篇 |
| 1998年 | 1篇 |
| 1995年 | 1篇 |
| 1994年 | 2篇 |
| 1993年 | 1篇 |
| 1991年 | 3篇 |
| 1990年 | 1篇 |
| 1987年 | 5篇 |
| 1986年 | 4篇 |
| 1983年 | 1篇 |
| 1972年 | 1篇 |
| 1967年 | 1篇 |
| 1966年 | 2篇 |
排序方式： 共有453条查询结果，搜索用时 0 毫秒
421.
The current study focused on fabrication and mechanical evaluation of intra/interply hybrid laminates – reinforced high‐density flexible foam composites. The effects of composite thickness and expansion factor on the tensile and compressive characterization of the hybrid ‐ laminated composites were experimentally investigated. Double face sheets were made of high‐strength intra/interply hybrid laminates containing recycled Kevlar nonwovens and glass woven fabric. The results revealed that the hybrid laminates face sheet apparently promoted the tensile strength and tear resistance of the high ‐ density flexible polyurethane foam. Tearing resistance in perpendicular direction exceeded more than twice the value in parallel direction. In terms of dynamic cushioning properties, cushioning force increased with the increase in composite thickness and the decrease in expansion factor , whereas the cushioning capacity loss, however, showed a different trend with the variation of the parameters. Most samples buffered more than 95% incident force under dynamic loading. Composite thickness and expansion factor exhibited significant influence on compression and indentation properties, including hardness, initial hardness factor , and indentation modulus. Except the composites with 10 mm thickness, the intra/interply hybrid laminated composites exhibited hysteresis loss of indentation force deflection ranging from approximately 30 to 38%, which was due to the fiber and thermal bonding point failure of hybrid laminates as unrecoverable damage. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41438. 相似文献
422.
The chemical modification of soy protein isolate (SPI) with various amounts of oxidized sucrose was performed in this study. The poor mechanical properties and lack of hydrolysis resistance of SPI have limited its applications in various fields. Although chemical modification proved to be an effective method to enhance the properties of SPI films, current SPI modifiers are either expensive, toxic, or do not impart the satisfiable properties to the modified materials. In this research, the possibility of modification of SPI films using oxidized sucrose to improve their strength and stability was examined. At optimal conditions, oxidized sucrose‐modified SPI films showed about 50% higher wet strength than the control films. The melting temperature of modified SPI film was 26°C higher than the unmodified control. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41473. 相似文献
423.
Shin‐Cheng Jang Yao‐Chi Shu Fu‐Sheng Chuang Wen‐Chin Tsen Jing‐Dong Chow Chien‐Chung Chen 《应用聚合物科学杂志》2012,124(6):4645-4654
Two series of blends, O‐PP15 and O‐PP35, were prepared by mixing polypropylene (PP), luminescent powders (SrAl2O4: Eu2+, Dy3+) of 15 and 35 μm average particle diameter, and hydrophobic dispersant at about 190°C in the Brabender mixer. The effect of amounts and diameter of luminescent powders on the physical properties of PP material were discussed herein. The luminescence and afterglow time tests indicated that the initial luminescence of all blends increased with the luminescent powders amounts. O‐PP35 blends showed lower afterglow luminance than O‐PP15 blends at low luminescent powder amounts. The melting and crystallization temperatures of the blends appeared at 152–168°C and 87–103°C, respectively. The blends displayed peaks attributable to a α crystal structure at 2θ = 18°–19°. The β crystal structure was only evident from its characteristic 2θ peak at 15°–16° in the WAXD pattern of the O‐PP35 blends with high luminescent powder amounts. All of the blends had lower tensile strengths. However, the improvement in the luminescent powder distribution was evident from the SEM images after adding hydrophobic dispersant. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
424.
Poly(lactic acid) or poly(lactide) (PLA) is a biodegradable and biocompatible thermoplastic polymer, being derived from renewable resources such as corn and sugar cane. The building block of PLA, lactic acid is chiral and the polymerization of lactic acids (or lactides) leads to isotatic, syndiotatic and atactic/heterotactic PLA primary structures. The stereoselective interaction between two complementary enantiomeric PLLA and PDLA has led to enhanced physical properties such as mechanical properties, thermal resistance and hydrolytic stability compared with the parent polymers. Progress in controlled and/or living polymerization techniques combined with other new synthetic methodologies has facilitated the preparation of PLA-based copolymers with complex architectures such as diblock, triblock, multiblock, star-shape block, comb-shape block and various PLA-grafted structures. The utilization of stereocomplexation strategy to these newly developed copolymers has opened avenues to access a variety of new materials with unique characteristics, including novel chemical functionalities, bioactivities, and smart (responsive to external stimulus) properties tailored for specific applications. This review presents recent advancements in the synthesis of PLA-based block/graft copolymers having complex architectures, with emphasis on the enhanced material performances induced by PLA stereocomplex formation. The origin of the enhanced thermal mechanical property observed in PLA stereocomplex is first discussed. The strong interaction resulted from stereocomplexation in PLA based copolymers could be exploited not only for fabrication of advanced therapeutic delivery carriers and tissue engineering devices, but also for stabilizing colloidal systems in microparticles, micelles and hydrogels, that further broaden the applications of PLA that could not have been attained with single PLLA or its copolymers. The stereocomplexation could also be used to tailor the interface interactions between fillers and PLA matrix that lead to higher strength and toughness of PLA. 相似文献
425.
《Plastics, Additives and Compounding》1999,1(5):30-34
Resorcinol-based polymers are proving to be ideal as gas barrier materials in packaging for highly oxygen-sensitive foods and beverages. Dr. Raj Durairaj discusses the work undertaken to date and opportunities for the future. 相似文献
426.
The syntheses and structures of the series of metal complexes, namely [CuCl2(L)2·H2O)]n (L = 4-amino-1,2,4-triazole), 1; {[Cu(L)4][ClO4]2.H2O}n, 2; and [Cd2Cl4(L)2.2H2O]n, 3 are reported. These were prepared by the self-assembly of Cu(II) and Cd(II) salts with L in MeOH/H2O system. All these complexes have been characterized by elemental analysis, IR spectrum, and single crystal X-ray diffraction. Complexes 1–2 show 1-D polymeric infinite chains, while complex 3 shows 2D pleated net. The anions Cl− in complexes 1 and 3 act as bridging or terminal ligands to the metal atoms while the ClO4− anions in 2 are not coordinated to the metal centers. 相似文献
427.
In this study, flame‐retarding property of PU foam was realized by compounding with flame‐retarding nonwovens in order to stop flame burning and spread. Followed with global warming, thermal‐insulating materials are also used inside of building for energy conservation. This article presents preparation technique and property evaluation of PU composite board composed of composite nonwovens and PU foam by integrating foaming process. By optimization of composite nonwoven, effects of foam density and nonwoven composition on flame‐retarding and thermal‐insulating properties were discussed. Puncture resistance property of composite board was also investigated for resisting against sharp‐object impacts. The resultant composite board would be applied as partition materials in future building decoration. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40463. 相似文献
428.
Reactive dye fixation and color yield of a dyed cellulosic fiber significantly depend on the dye diffusion into the fiber polymer system. In case of pad‐dyeing processes, dye diffusion exerts a more significant influence on dye fixation and hence color yield. This article proposes a new method for determining the extent of diffusion of reactive dyes into the fiber in pad dyeings using Kubelka–Munk equation. The K/S values are used as in an equation, %D (extent of dye diffusion) = 100 ? [(K/Sdiffusion index)/ (K/Sreference) × 100]. The article introduces and explains how to determine the new K/S variables used in this equation. The new method is simple, nondestructive, relatively faster, and applicable to industrial dyehouses, and was validated by a microscopic analysis of dyed fiber cross‐section carried out in this work and to the dye manufacturer's recommendations for dyebath‐ingredient concentrations. © 2012 Wiley Periodicals, Inc. Col Res Appl, 39, 63–69, 2014 相似文献
429.
Dimensional changes of Caribbean pine and Rose gum (eucalyptus) were continuously measured during mild pyrolysis (heat treatment) with a dynamic mechanical analyzer (DMA) in creep mode with a negligible force. Mass loss was measured on matched samples by thermo-gravimetric analysis (TGA). All experiments were carried out at 220 °C (air and nitrogen), 250 and 280 °C (nitrogen) with a residence time up to 10 h. Eucalyptus exhibits a greater shrinkage and mass loss than pine. By normalizing the shrinkage (heat treatment shrinkage divided by total hygroscopic shrinkage), one single master curve is obtained per species, whatever the heat treatment conditions (temperature, nature of gas) and material direction. For each species, a unique expression is proposed to predict the dimensional changes due to mild pyrolysis as a function of mass loss and total hygroscopic shrinkage. The ability to predict heat treatment shrinkage is useful from industrial perspective (density prediction, change in bed thickness, modeling tools). 相似文献
430.
通过收集和整理至今在贵州等少数民族地区仍被广泛应用的苗绣、侗绣等手工刺绣品,将其归类为单针法和双针法锁绣两大类,分析其工艺技法,并阐述现代技术下的锁绣设计的变化,探究其在现代设计中的价值. 相似文献