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关键词： Hydrogen evolution   Carbon nitride   Acrylamide   Photocatalysis   Water splitting  

摘要： The high charge recombination efficiency and weak visible-light absorption of polymeric carbon nitride (CN) severely suppress its photocatalytic performance. To overcome these defects, oxygen/carbon codoped CN (OCN) was prepared firstly using acrylamide as the additive. OCN exhibits much enhanced visible light absorption, charge separation and transfer, and thus photoactivity in hydrogen production and environmental remediation. OCN exhibits a similar to 6-fold higher photocatalytic hydrogen production rate (similar to 2626 mu mol h(-1) g(-1)) than CN, comparable to most of nonmetal-doped CN, and an apparent quantum yield of similar to 16.3% (420 nm). OCN is also much better at producing singlet oxygen than CN. The significantly enhanced charge separation for OCN arises from the O/C codoping structure which forms an impurity level above the valence band edge in the bandgap, i.e., works as a hole-capture center. This work affords a simple and effective strategy to synthesize modified CN for photoactivity enhancement, clarifies the doping mechanism, and may guide research on other nonmetal doped organic semiconductor photocatalysts. (C) 2019 Elsevier Inc. All rights reserved.

关键词： Surface defects  

摘要： Two-dimensional (2D) ultrathin mesoporous anatase TiO2 nanosheets with engineered surface defects (SDUATNs) are prepared by evaporation-induced self-assembly, solvothermal and surface hydrogenation reduction strategies. The as-prepared SDUATNs possess a comparatively large specific surface area of 100.4 m(2) g(-1), a main pore size of 9.7 nm, and a pore volume of 0.36 cm(3) g(-1). After surface hydrogenation, the narrowed bandgap of 2.97 eV expands the photoresponse from the ultraviolet to the visible-light region as a result of efficient surface defect engineering. The SDUATNs exhibit excellent photocatalytic hydrogen production performance (3.73 mmol h(-1) g(-1)), which is about 3-fold higher than that of pristine ultrathin mesoporous anatase TiO2 nanosheets (1.31 mmol h(-1) g(-1)) under AM 1.5G irradiation. The improvement of the hydrogen evolution performance is attributed to the efficient engineered surface defects and the special 2D ultrathin structure reducing the bandgap, increasing sunlight utilization, providing adequate surface active sites, shortening the migration distance of charge carriers and thus favoring the spatial separation of photogenerated electron-hole pairs. The high stability also favors practical applications. This work presents new insight to enhance the photocatalytic performance and may provide valuable ideas to fabricate other high-performance 2D photocatalysts.

关键词： 制药工程   制药分离技术  

摘要： 近些年,随着社会经济的不断发展,科学技术也随之得到大幅度提升,为各个领域的飞速发展提供了技术支持,使它们获得良好成效。制药工程从学科沿革来看不是全新的是相近专业的延续,也是中国科学技术发展的产物。制药工程与制药行业密切相关,近几年世界药品经济增长飞速,制药技术也在不断提升。其中制药分离技术的合理应用有很大的经济研究价值,因此,本文对制药工程中的制药分离技术展开详细的分析和探讨,以供参考。

关键词： 膜分离技术   环境工程   水处理  

摘要： 经济的快速发展,使水质愈加复杂,处理难度也不断加大。传统的处理工艺难以达到更好的处理效果。为了进一步增强处理效果,将膜分离技术应用到处理过程中。因其所具有的可多次重复利用、处理后的水质良好、自动化控制便于运行等优点,使得膜分离技术在环境工程水处理领域广泛应用。膜分离技术主要包含微滤技术、超滤技术、纳滤技术以及反渗透技术等,它们利用膜的选择透过性,从而将水中的有毒有害物质进行去除,广泛应用于生活饮用水的处理以及苦咸水淡化等领域。

关键词： 膜分离技术   水处理   环境工程  

摘要： 随着科学技术的不断发展,膜分离技术在水处理环境工程中得到广泛的应用。如今,水资源匮乏,皮革业污水量比较大,提升水资源的应用效率十分必要。本文分析膜分离技术的原理,并结合膜分离技术的种类,将膜分离技术应用在水处理环境工程中。

关键词： 制药工程   制药分离   萃取技术  

摘要： 介绍了固液分离技术、双水相分离技术、超临界流体分离技术以及反胶团生物分离技术,分析不同方法的制药分离工作流程,明确工作的基本原理及技术的应用特点和操作注意事项。在保证技术人员具备专业的工作能力基础上,能够科学结合药物成分及制作要求,选择应用效果最好的技术方法。制药企业应不断结合经验,分析不同分离技术的应用优势及不足,拟定科学的技术优化方案,以便提高制药企业的工作质量,推动企业各项工作的可持续发展。

关键词： 膜分离技术   环境工程   具体应用  

摘要： 在我国环境工程建设的过程中,膜分离技术的应用对于保障环境工程项目的整体效果有着十分重要的作用。本文将结合膜分离技术的特点,对不同类型的膜分离技术在环境工程中的具体应用进行分析,以此为环境工程中对膜分离技术的准确应用提供相应的参考意见。

关键词： 制药工程   分离技术   应用分析   管理方式  

摘要： 制药分离是现代制药过程中十分重要的一项工作,主要是利用分离物质中的有效活性以及共存杂质之间存在的差异性,做出相应的分离,是现代制药工艺产品产业化发展的一个重要环节,制药工艺分离技术是治疗过程中不可或缺的一个重要环节,也是保障治疗成功与否的一项关键技术,而在现代治疗分离过程中,如果分离方式选择错误或者分离设备以及能量投入的方式有一定的差异,就会导致分离的纯度和耗能的大小,以及最终的分离结果受到影响。本轮中针对制药工艺中的分离技术做出了简单的论述,旨在为相关工作人员开展分离工作提供一定的参考。

关键词： Alzheimer disease   Binet test   FAST   judgement   MRI   retrogenesis  

摘要： Background Alzheimer disease (AD) patients demonstrate various clinical features reminiscent of children (the retrogenesis model). The Binet test is available for assessing mental development and deterioration. However, neuroimaging correlations remain to be clarified. Although AD patients also manifest social judgment disability, there are few cognitive tests, contrary to so many memory tests. Among the database, we noticed that the Binet test includes the subscale of social judgement using illogical sentences and pictures. The aim of this study is to clarify the neuroimaging correlations for the Binet test, especially for the illogical questions. Methods Forty participants were selected from the database of the Tajiri Project. The Tanaka-Binet test was used to evaluate the mental age and the basic age. The latter is the age level at which the patient can completely accomplish all questions at the immediately lower age level and is used for calculating the mental age. Using the subtests of illogical sentences/pictures, logical judgment abilities were assessed. Using magnetic resonance imaging, we performed four-grade visual evaluation for cortical atrophy. The cerebral metabolic rate for glucose (CMRglc) was measured using an autoradiographic method of F-18-fluoreodeoxyglucose - positron emission tomography (FDG-PET). Results There was a significant Spearman's correlation between the clinical stage and the basic age. Degree of frontal, temporal and hippocampal atrophy were correlated with the basic age. The entire grey matter and frontal and temporal CMRglc were associated with the basic age. The illogical sentences scores were correlated with the bilateral temporal, hippocampal and the left parieto-temporal CMRglc, whereas the illogical picture scores were correlated with the right parieto-temporal CMRglc. Conclusions We found that frontal and temporal atrophy as well as hypometabolism were associated with the basic age. Regarding the illogical judgment, the curre

关键词： 混合气体   分离工程   Aspen   HYSYS   教学方法  

摘要： 文章以混合气体的分离过程为例,介绍了Aspen HYSYS化工商用模拟软件在分离工程课程教学中的应用,同时针对两种不同的设定状态实施模拟,并对不同情况下流比例的差异进行了分析。教学结果表明,该软件的应用提高了学生的学习兴趣和积极性,加深了学生对课程内容的理解,获得了良好的教学效果。