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排序方式: 共有657条查询结果,搜索用时 15 毫秒
1.
现行的政府单一主导、政府与开发
商合作的社区更新模式与业主的自主更新需
求产生了矛盾。针对现有研究对社区更新的
系统性缺乏关注的问题,本文从整体视角出
发,通过构建“参与主体—程序设计—法规
政策—资金调配”四维框架,分析现行社区
更新模式与业主自主更新需求产生冲突的内
在机制。在优化现有模式的基础上,提出三
种适应业主自主更新需求的理论模式。桂华
邨业主自主更新失败的实践案例证明了本文
所提出的四维框架的重要性。最后,从政府
视角对我国社区更新机制提出优化建议。 相似文献
2.
This paper considers thermochemical recuperation (TCR) of waste-heat using natural gas reforming by steam and combustion products. Combustion products contain steam (H2O), carbon dioxide (CO2), and ballast nitrogen (N2). Because endothermic chemical reactions take place, methane steam-dry reforming creates new synthetic fuel that contains valuable combustion components: hydrogen (H2), carbon monoxide (CO), and unreformed methane (CH4). There are several advantages to performing TCR in the industrial furnaces: high energy efficiency, high regeneration rate (rate of waste-heat recovery), and low emission of greenhouse gases (CO2, NOx). As will be shown, the use of TCR is significantly increasing the efficiency of industrial furnaces – it has been observed that TCR is capable of reducing fuel consumption by nearly 25%. Additionally, increased energy efficiency has a beneficial effect on the environment as it leads to a reduction in greenhouse gas emissions. 相似文献
3.
Exosomes, especially from mesenchymal stem cells, have attracted extensive attention in regeneration medicine. Mesenchymal stem cells derived exosomes (MSCs-exosomes) have shown anti-inflammatory, anti-oxidant, anti-apoptosis and tissue regeneration effects in a variety of tissue injury repair models. MSCs-exosomes hold many excellent properties such as low immunogenicity, biocompatibility, and targeting capability. With the in-depth study on the generation and function of exosomes, MSCs-exosomes are considered to be the bright stars in the field of regenerative medicine. However, there are still many obstacles to overcome in terms of exosomes isolation, clinical trials and safety evaluation. In this article, what we should focus on about MSCs-exosomes in regeneration medicine will be discussed. 相似文献
4.
Soot deposition effects and microwave regeneration modelling of diesel particulate filtration system
《能源学会志》2020,93(2):463-473
Regeneration of accumulated soot particles in the substrate walls of the diesel particulate filtration system is one of the major challenges faced by the automotive industry. This study investigated the conversion efficiency and filtration behaviour of the after treatment system comprising of diesel oxidation catalysis (DOC) and diesel particulate filtration (DPF) system. The average conversion efficiency of hydrocarbons was close to 54% and filtration efficiency of the particle number emissions was around 92%. Characterization of the DOC and DPF substrate were conducted using microscopic imaging, Fourier transform infrared spectroscopy (FTIR) and particle size analysis (PSA). The results of FTIR study indicated the presence of carcinogenic agents trapped in the porous walls of the filter substrate. A model for microwave based regeneration system is proposed in this article and CFD analysis were conducted to determine the temperature and electric field distribution in the DPF substrate for a regeneration time of 180 s. Results of simulation showed that the microwave radiations raise the temperature close to soot oxidation temperature (873 K), ensuring effective regeneration. 相似文献
5.
《International Journal of Hydrogen Energy》2020,45(46):24626-24635
In this paper, a series of alkaline earth metals oxides doped Ni/La2O3–Al2O3 catalysts were synthesized by the coprecipitation method combined with two step impregnation methods. n-decane reforming was used to investigate these catalysts, in order to develop an excellent catalyst with better hydrogen selectivity, activity, stability, as well as lower carbon deposition. Deactivation by carbon deposition, the catalyst regenerability and stability tests were also used to weigh the selected catalyst. These catalysts are characterized by N2 adsorption-desorption, XRD, NH3-TPD, Raman, and TEM. The introduction of alkaline earth metals modifiers enhances the activity, stability and anti-coking ability, meanwhile the SrO modified Ni/La2O3–Al2O3 shows the best catalytic activity. Moreover, the hydrogen selectivity and conversion over regenerative Ni/La2O3–Al2O3/SrO catalysts were quite close to the results of fresh ones. The enhancements of M oxides doped catalysts (especially Sr) can be due to the improved textural properties, basicity, metal-support interaction and anti-coking ability. As a consequence, loading different metals in different ways helps to gradually improve the stability, activity and coking inhibition of catalysts is an effective approach to obtain a multi-function catalyst. 相似文献
6.
《International Journal of Hydrogen Energy》2020,45(15):8507-8525
Dendritic fibrous type SBA-15 (DFSBA-15) was recently discovered with its outstanding catalytic performance and coke resistance as compared to the conventional SBA-15. The operating conditions for dry reforming of methane (DRM) over 10Ni/DFSAB-15 were optimized by using response surface methodology (RSM), followed by stability and regeneration study. Characterization results (TEM and FESEM) confirmed the homogenous distribution of NiO particles with no morphological change in spherical DFSBA-15 upon Ni addition. Process parameters, such as reaction temperature (X1, 700 °C–900 °C), gas hourly space velocity (X2, 15,000 mL/g.h ‒ 35,000 mL/g.h), and CH4/CO2 ratio (X3, 1–3) were studied over CO2 conversion (Y1), CH4 conversion (Y2), and H2/CO ratio (Y3). The optimal reaction conditions were found at X1 = 794.37 °C, X2 = 23,815.022 mL/g.h, and X3 = 1.199, with Y1 = 95.67%, Y2 = 93.48%, and Y3 = 0.983. The in-situ FTIR studies of adsorbed CH4, CO2, and CH4 + CO2 confirmed the formation of unidentate carbonate, bidentate carbonate, and linear carbonyl species as intermediate species. 10Ni/DFSBA-15 presented good reproducibility by using both regeneration medium (air and CO2/N2) with two-fold regeneration by air as compared to CO2/N2. It was proven that the synthesized 10Ni/DFSBA-15 was appreciably stable and prone to be regenerated by air for DRM under optimal conditions. 相似文献
7.
本文选择食堂废弃的地沟油为研究对象,通过控制水解条件,获得不同性质的地沟油改性捕收剂。分别探究温度、催化剂、乳化剂用量等因素对地沟油水解的影响规律,确定其最佳的改性条件。采用接触角测定表征地沟油的改性效果,通过比较地沟油改性捕收剂在固废浮选方面的应用效果。结果表明地沟油改性剂具有一定的捕收作用,在浮选分离领域,可替代传统脂肪酸类捕收剂及非极性烃类捕收剂的使用。 相似文献
8.
《International Journal of Hydrogen Energy》2022,47(62):26549-26573
Efficient hydrogen storing alternatives are now been pursued for decades. Solid storage systems are currently highly researched due to high volumetric densities at low temperatures and pressure. Still, no developed systems have satisfied even close to the targets given by The United States Department of Energy (DOE) 2020. Although various systems have reported good outputs at nearly room temperatures. The boron-based hydrides (BBHs) are the typical materials. They show a maximum of four reacting B–H bonds and hence have high volumetric densities of hydrogen. The majority of the research has been dealing with dehydrogenation through thermolysis and hydrolysis. This article critically reviews different BBHs for effective hydrogen storage. The first materials reviewed are ammonia borane, lithium borohydride, and sodium borohydride. However, their progress declined in the past few years due to incomplete reactions, elevated dehydrogenation temperature, and purity of hydrogen produced. To overcome these issues, new materials using suitable dopants have been developed since 2000. These materials display enhanced operations along with few drawbacks. Regenerability and numerous other stability factors have been intensively analyzed in this review. Also, different strategies for a system to operate at room conditions have been critically discussed. The findings suggest that BBHs are potential candidates in the field of hydrogen storage, but their applicability highly depends upon the regenerability and recyclability of byproducts. 相似文献
9.
通过分析鲁尔区工业棕地的整体更新策略,结合国内实际情况,从不同侧面、不同层次对比说明了鲁尔对于我国老工业基地变革的借鉴意义。 相似文献
10.
上个世纪50年代以后,英国中央和地方政府制定了不少城市复兴的政策和规划,在学术界也有许多的研究。英国从"以地产开发为导向的城市复兴策略"逐步转变为"以文化为导向的城市复兴策略"。历史老城的保护从1990年代中后期开始步入非单纯意义上的保护,而是引入了"复兴"的元素。本文通过对英国著名的"以历史遗产为导向的城市复兴"项目——纽卡斯尔格兰吉尔老城的分析,探讨了如何以城市复兴作为手段对历史老城进行保护,并总结一些对中国旧城保护和改造有借鉴意义的内容。 相似文献