首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   85篇
  免费   10篇
  国内免费   8篇
电工技术   1篇
综合类   4篇
化学工业   29篇
金属工艺   5篇
机械仪表   1篇
建筑科学   9篇
矿业工程   3篇
能源动力   6篇
轻工业   5篇
水利工程   2篇
石油天然气   3篇
武器工业   1篇
无线电   7篇
一般工业技术   20篇
冶金工业   7篇
  2024年   1篇
  2023年   6篇
  2022年   5篇
  2021年   3篇
  2020年   4篇
  2019年   3篇
  2018年   3篇
  2017年   5篇
  2016年   5篇
  2015年   2篇
  2014年   3篇
  2013年   1篇
  2012年   10篇
  2011年   4篇
  2010年   3篇
  2009年   3篇
  2008年   6篇
  2007年   6篇
  2006年   2篇
  2005年   2篇
  2004年   4篇
  2003年   5篇
  2002年   4篇
  2001年   1篇
  2000年   5篇
  1999年   3篇
  1998年   2篇
  1995年   1篇
  1990年   1篇
排序方式: 共有103条查询结果,搜索用时 0 毫秒
1.
Moisture-enabled electricity generation (MEG) is highly promising in next-generation energy conversion. However, the practical applications of existing MEG devices are limited due to their low current and voltage outputs, strong dependence on high moisture, and inflexible nature. Herein, an efficient MEG integrated with flexible, all-weather, and scalable fabrication characteristics based on the rational combination of carbonized polymer dots (CPDs) and liquid metal (LM) active electrodes is developed for the first time. Remarkably, the fabricated MEG device can produce a stable voltage output of 800 mV and a record high current density of 1640 µA cm−2. Even at a low air humidity of 15%, the MEG device can provide a high voltage output of 0.65 V and a considerable current density of 12 µA cm−2. The prompted diffusion of hydrogen ions in CPDs and the additional metal ions ionized from the LM electrode contribute synergistically to the high electricity generation. Additionally, the device can be easily integrated on various flexible substrates and generate an ultrahigh voltage of 210 V to power commercial electronics, showing great potential in large-scale fabrication and application.  相似文献   
2.
3.
Carbon dots with long‐wavelength emissions, high quantum yield (QY) and good biocompatibility are highly desirable for biomedical applications. Herein, a green, facile hydrothermal synthesis of highly efficient red emissive nitrogen‐doped carbonized polymer dots (CPDs) with optimal emission at around 630 nm are reported. The red emissive CPDs possess a variety of superior properties including excellent water dispersibility, good biocompatibility, narrow bandwidth emission, an excitation‐independent emission, and high QY (10.83% (in water) and 31.54% (in ethanol)). Further studies prove that such strong red fluorescence is ascribed to the efficient conjugated aromatic π systems and hydrogen bonds of CPDs. And the fluorescence properties of CPDs can be regulated by adjusting the dosage of HNO3 before the reaction. Additionally, the as‐prepared CPDs are successfully used as a fluorescent probe for bioimaging, both in vitro and in vivo. More importantly, biodistribution results demonstrate that most CPDs and their metabolites are not only excreted in urine but also excreted by hepatobiliary system in a rapid manner. Besides, the CPDs could easily cross the blood brain barrier, which may provide a valuable strategy for the theranostics of some brain diseases through real‐time tracking.  相似文献   
4.
对石灰颗粒,单个煤球的碳化过程,以新观点解释了煤球碳化机理,研究了成型压力与煤球质量、碳化速率及预干燥的关系。提出低压成型,高料层低温碳化及后补强期的新工艺。  相似文献   
5.
以高氯酸铵(AP)和碳化细菌纤维素(CBC)为原料,并以聚甲基氢基硅氧烷(PMHS)、十二氟庚基丙基三甲氧基硅烷(FAS)和甲基三乙氧基硅烷(MTES)为表面改性剂,采用溶液分散-冷冻干燥法制备疏水AP/CBC纳米结构材料。通过场发射扫描电子显微镜、红外光谱仪、X射线衍射仪、恒温恒湿箱、激光粒度分析仪、接触角测试仪等分别表征了AP/CBC纳米结构材料的微观形貌、分子结构、吸湿性能。结果表明,与纯AP相比,AP/CBC纳米结构材料的形貌变化较大,AP均匀分布在三维网络孔洞中,并且改性后的AP/CBC纳米结构材料表面被改性剂均匀包覆,这有助于疏水表面的形成。经过PMHS、FAS、MTES改性后的AP/CBC纳米结构材料的接触角分别为(109±2)°、(56±2)°、(55±2)°,与纯AP相比有很大的提高。经过改性处理的AP/CBC纳米结构材料吸湿性均小于纯AP,且经过PMHS改性的AP/CBC纳米结构材料的吸湿性最低,仅为0.31%。  相似文献   
6.
柴油车尾气微粒捕集器技术研究现状及发展趋势   总被引:2,自引:0,他引:2  
柴油车微粒排放物严重地污染环境并危害人类健康,其净化技术一直是人们研究的热点问题.微粒捕集器(DPF)技术是满足未来车用柴油机严格排放法规的重要措施.本文首先介绍了DPF净化机理及其常用的过滤体材料;然后综述了DPF再生技术的研究现状,对各种再生技术进行了分析;最后展望了微粒捕集器再生技术的发展趋势,提出微米木长纤维碳化木DPF过滤效率高,排气背压小,使用寿命长,可为柴油机尾气净化开辟一个新的方向.  相似文献   
7.
高任清  陈建兵 《混凝土》2007,(5):80-82,85
通过试验和实际工程中应用,找出了泵送混凝土碳化的影响因素,确定了施工抑制措施,总结出了不同龄期泵送混凝土的合理碳化深度值,对保证泵送混凝土的耐久性和建筑物的合理使用寿命有长远的经济效益和社会效益.  相似文献   
8.
Recent advances in three‐dimensional (3D) printing have enabled the fabrication of interesting structures which are not achievable using traditional fabrication approaches. The 3D printing of carbon microtube composite inks allows fabrication of conductive structures for practical applications in soft robotics and tissue engineering. However, it is challenging to achieve 3D printed structures from solution‐based composite inks, which requires an additional process to solidify the ink. Here, we introduce a wet 3D printing technique which uses a coagulation bath to fabricate carbon microtube composite structures. We show that through a facile nanogrooving approach which introduces cavitation and channels on carbon microtubes, enhanced interfacial interactions with a chitosan polymer matrix are achieved. Consequently, the mechanical properties of the 3D printed composites improve when nanogrooved carbon microtubes are used, compared to untreated microtubes. We show that by carefully controlling the coagulation bath, extrusion pressure, printing distance and printed line distance, we can 3D print composite lattices which are composed of well‐defined and separated printed lines. The conductive composite 3D structures with highly customised design presented in this work provide a suitable platform for applications ranging from soft robotics to smart tissue engineering scaffolds. © 2019 Society of Chemical Industry  相似文献   
9.
10.
介绍一种微波炉用连续波磁控管钍钨阴极的碳化工艺过程及碳化的方法,利用新的碳化工艺方法来控制碳化层厚度,选择合适的碳化层厚度,得到了长寿命高可靠的阴极。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号