全文获取类型
收费全文 | 776篇 |
免费 | 361篇 |
国内免费 | 18篇 |
专业分类
电工技术 | 2篇 |
综合类 | 9篇 |
化学工业 | 252篇 |
金属工艺 | 3篇 |
机械仪表 | 39篇 |
建筑科学 | 1篇 |
能源动力 | 10篇 |
轻工业 | 73篇 |
石油天然气 | 1篇 |
武器工业 | 1篇 |
无线电 | 159篇 |
一般工业技术 | 558篇 |
冶金工业 | 2篇 |
原子能技术 | 2篇 |
自动化技术 | 43篇 |
出版年
2024年 | 9篇 |
2023年 | 61篇 |
2022年 | 57篇 |
2021年 | 58篇 |
2020年 | 121篇 |
2019年 | 102篇 |
2018年 | 91篇 |
2017年 | 56篇 |
2016年 | 67篇 |
2015年 | 84篇 |
2014年 | 73篇 |
2013年 | 75篇 |
2012年 | 57篇 |
2011年 | 69篇 |
2010年 | 40篇 |
2009年 | 35篇 |
2008年 | 32篇 |
2007年 | 20篇 |
2006年 | 18篇 |
2005年 | 15篇 |
2004年 | 8篇 |
2003年 | 2篇 |
2002年 | 2篇 |
2001年 | 2篇 |
2000年 | 1篇 |
排序方式: 共有1155条查询结果,搜索用时 15 毫秒
11.
12.
Rope making is a millennia old technique to collectively assemble numerous weak filaments into flexible and high tensile strength bundles. However, delicate soft matter fibers lack the robustness to be twisted into bundles by means of mechanical rope making tools. Here, weak microfibers with tensile strengths of a few kilopascals are combined into ropes via microfluidic twisting. This is demonstrated for recently introduced fibers made of bicontinuous interfacially jammed emulsion gels (bijels). Bijels show promising applications in use as membranes, microreactors, energy and healthcare materials, but their low tensile strength make reinforcement strategies imperative. Hydrodynamic twisting allows to produce continuous bijel fiber bundles of controllable architecture. Modelling the fluid flow field reveals the bundle geometry dependence on a subtle force balance composed of rotational and translational shear stresses. Moreover, combining multiple bijel fibers of different compositions enables the introduction of polymeric support fibers to raise the tensile strength to tens of megapascals, while simultaneously preserving the liquid like properties of the bijel fibers for transport applications. Hydrodynamic twisting shows potentials to enable the combination of a wide range of materials resulting in composites with features greater than the sum of their parts. 相似文献
13.
Hybrid Paper–Plastic Microchip for Flexible and High‐Performance Point‐of‐Care Diagnostics 下载免费PDF全文
Mohamed Shehata Draz Maryam Moazeni Manasa Venkataramani Harini Lakshminarayanan Ecem Saygili Nivethitha Kota Lakshminaraasimulu Kamyar Mehrabi Kochehbyoki Manoj Kumar Kanakasabapathy Shirin Shabahang Anish Vasan Mohamad Ali Bijarchi Adnan Memic Hadi Shafiee 《Advanced functional materials》2018,28(26)
A low‐cost and easy‐to‐fabricate microchip remains a key challenge for the development of true point‐of‐care (POC) diagnostics. Cellulose paper and plastic are thin, light, flexible, and abundant raw materials, which make them excellent substrates for mass production of POC devices. Herein, a hybrid paper–plastic microchip (PPMC) is developed, which can be used for both single and multiplexed detection of different targets, providing flexibility in the design and fabrication of the microchip. The developed PPMC with printed electronics is evaluated for sensitive and reliable detection of a broad range of targets, such as liver and colon cancer protein biomarkers, intact Zika virus, and human papillomavirus nucleic acid amplicons. The presented approach allows a highly specific detection of the tested targets with detection limits as low as 102 ng mL?1 for protein biomarkers, 103 particle per milliliter for virus particles, and 102 copies per microliter for a target nucleic acid. This approach can potentially be considered for the development of inexpensive and stable POC microchip diagnostics and is suitable for the detection of a wide range of microbial infections and cancer biomarkers. 相似文献
14.
Energy Harvesting: Electric Field Assisted Microfluidic Platform for Generation of Tailorable Porous Microbeads as Cell Carriers for Tissue Engineering (Adv. Funct. Mater. 20/2018) 下载免费PDF全文
15.
Xiaocheng Wang Yunru Yu Chaoyu Yang Changmin Shao Keqing Shi Luoran Shang Fangfu Ye Yuanjin Zhao 《Advanced functional materials》2021,31(40):2105190
Tissue-engineered scaffolds have been extensively explored for treating bone defects; however, slow and insufficient vascularization throughout the scaffolds remains a key challenge for further application. Herein, a versatile microfluidic 3D printing strategy to fabricate black phosphorus (BP) incorporated fibrous scaffolds with photothermal responsive channels for improving vascularization and bone regeneration is proposed. The thermal channeled scaffolds display reversible shrinkage and swelling behavior controlled by near-infrared irradiation, which facilitates the penetration of suspended cells into the scaffold channels and promotes the prevascularization. Furthermore, the embedded BP nanosheets exhibit intrinsic properties for in situ biomineralization and improve in vitro cell proliferation and osteogenic differentiation. Following transplantation in vivo, these channels also promote host vessel infiltration deep into the scaffolds and effectively accelerate the healing process of bone defects. Thus, it is believed that these near-infrared responsive channeled scaffolds are promising candidates for tissue/vascular ingrowth in diverse tissue engineering applications. 相似文献
16.
A fluid diode that allows fluid flow in one direction but blocks fluid flow in the opposite direction has wide applications including oil recovery, drug delivery, and lab‐on‐a‐chip microfluidics. Many studies are conducted to facilitate directional liquid motion on the solid surface or across thin porous layers. However, the self‐driven one‐way flow inside porous systems still remains a significant challenge. Here, a novel all‐hydrophilic fluid diode (AHFD) made of porous materials with asymmetric pores is reported, which allows capillary flow in a chosen direction. The direction‐dependent flow process and the breakthrough pressure are experimentally and theoretically examined. The proposed AHFD can have many potential applications such as functional protective clothing, microfluidic valve, and oil–water separator, and the idea can be extended to develop other all lyophilic fluid diodes such as oleophilic diode. 相似文献
17.
在交流电渗流(ACEO)泵的研究中,一般忽略电极厚度的影响;而三维交流电渗流泵通过将电极厚度设计成台阶形式后,可以大大提高电渗流泵的流量。数值研究了电极台阶高度对三维交流电渗流泵流量的影响。研究发现:在驱动电压幅值不变的条件下,随着台阶高度的增加,三维交流电渗流泵流量也会增大;而当台阶高度增加到一定程度后,流量又会随着台阶高度的增加而减小。因此,在三维交流电渗流泵的设计制造中,需要优化电极的台阶高度,选择合适的台阶高度可以极大地提高电渗流泵的流量。通过和传统交流电渗流泵的比较,还研究了三维交流电渗流泵对流量的增强效果。结果表明:在相同模型尺寸参数下,优化台阶高度后的三维交流电渗流泵能极大提高流量。 相似文献
18.
标准化是微流控系统的发展趋势,很多器件需要精确的流量控制和传输。因此,准确地表征和测量芯片功能模块的流体阻力具有重要的应用价值。提出了一种类比于惠斯通电桥测量不同流阻大小的器件,该器件将一个芯片内的膜阀视为可变流阻器,与待测器件并联。通过施加不同的压力,控制膜阀的开口度,保持桥平衡,直接计算获得待测芯片的流阻大小。仿真计算发现,其测量范围达到4个数量级,误差控制在3%以内。结果表明,微流控惠斯通电桥是测量流阻的有效方法,可以根据不同的应用环境,设计不同的尺寸和结构,以满足特定需要。 相似文献
19.
Efficient,Selective, and Reversible SO2 Capture with Highly Crosslinked Ionic Microgels via a Selective Swelling Mechanism 下载免费PDF全文
Ling Xia Qing Cui Xian Suo Yuhui Li Xili Cui Qiwei Yang Jianhong Xu Yiwen Yang Huabin Xing 《Advanced functional materials》2018,28(13)
SO2 capture through physisorption is a promising environmental benign technology to eliminate the emission of SO2. However, designing an efficient adsorption material with high capacity and selectivity of SO2 as well as excellent reversibility remains challenging. Here, a class of highly crosslinked nonporous poly(ionic liquid)s (PILs) xerogels is prepared with high ionic density by photopolymerization of Gemini IL monomers and a microfluidic technology is further explored to prepare the corresponding monodisperse PIL microgels with uniform and controllable sizes at the diameter range from 43 to 250 µm. This kind of novel dense nonporous ionic xerogels/microgels completely exclude the adsorption of common gases (CO2, CH4, etc.), but exhibit very high SO2 adsorption capacity (498 mg g?1) via selective swelling mechanism. Unprecedented SO2/CO2 and SO2/CH4 uptake selectivities with the value up to 614 and 1992, respectively, are achieved. The selective swelling mechanism is validated by optical microscope and differential scanning calorimetry measurements. More importantly, these kinds of xerogels show excellent reversibility in adsorption–desorption cycles. Column breakthrough experiments confirm the excellent performance of these PIL xerogels in SO2 capture. This work demonstrates that designing a nonporous material that has specific swelling interactions with certain molecules can be an effective strategy for realizing extremely high selectivity. 相似文献
20.
Venkata Subba Rao Jampani Dirk J. Mulder Kevin Reguengo De Sousa Anne‐Hélène Gélébart Jan P. F. Lagerwall Albertus P. H. J. Schenning 《Advanced functional materials》2018,28(31)
Micrometer‐scale liquid crystal network (LCN) actuators have potential for application areas like biomedical systems, soft robotics, and microfluidics. To fully harness their power, a diversification in production methods is called for, targeting unconventional shapes and complex actuation modes. Crucial for controlling LCN actuation is the combination of macroscopic shape and molecular‐scale alignment in the ground state, the latter becoming particularly challenging when the desired shape is more complex than a flat sheet. Here, one‐step processing of an LCN precursor material in a glass capillary microfluidic set‐up to mold it into thin shells is used, which are stretched by osmosis to reach a diameter of a few hundred micrometers and thickness on the order of a micrometer, before they are UV crosslinked into an LCN. The shells exhibit radial alignment of the director field and the surface is porous, with pore size that is tunable via the osmosis time. The LCN shells actuate reversibly upon heating and cooling. The decrease in order parameter upon heating induces a reduction in thickness and expansion of surface area of the shells that triggers continuous buckling in multiple locations. Such buckling porous shells are interesting as soft cargo carriers with capacity for autonomous cargo release. 相似文献