针对城市历史文化问题的研究,文章采用数字可视化软件(CiteSpace),以“历史街区”“保护”为主题,对CNKI数据库与Web of Science数据库近30年发表的相关论文的研究机构、作者、关键词等知识图谱进行可视化分析。更加直观地呈现出历史文...针对城市历史文化问题的研究,文章采用数字可视化软件(CiteSpace),以“历史街区”“保护”为主题,对CNKI数据库与Web of Science数据库近30年发表的相关论文的研究机构、作者、关键词等知识图谱进行可视化分析。更加直观地呈现出历史文化街区保护的整体信息全景,系统地梳理该领域的研究现状、研究前沿和研究热点。归纳总结出,国内外历史文化街区保护研究主要涵盖了历史街区的概念与评定标准、保护原则与手段、量化技术在街区保护中的应用和多元视角下街区保护等内容。探寻了我国关于历史街区保护的研究脉络和演变规律。研究表明,我国30年历史文化街区保护的相关研究逐步走向成熟和完善,但在整体联动性、研究的深度和广度,以及经济和社会治理层面的研究还有待进一步提升,后续研究将在大数据、人工智能技术和智慧城市背景下更加科学和全面地展开。展开更多
This study investigated the integrated bioremediation techniques for a shrimp culture system to reduce unconsumed feed and the contents of suspended solids（SS）, nutrients and organic pollutants using barracuda,clamw...This study investigated the integrated bioremediation techniques for a shrimp culture system to reduce unconsumed feed and the contents of suspended solids（SS）, nutrients and organic pollutants using barracuda,clamworm, scallop, large algae and a biofilter. A multi-pool internal circulation system was designed to test the effectiveness of the techniques in the laboratory. The experimental result has shown that Argopecten irradians,Gracilaria lemaneiformis and the biofilter efficiently reduced the contents of SS, dissolved inorganic carbon（DIC）and dissolved organic carbon（DOC） in the breeding wastewater. The amount of unconsumed feed was significantly reduced by barracuda and clamworm, but there was an increase in the contents of SS, DIC and DOC in the water due to disturbance by the barracuda and clamworm. The capacity of macroalgae to extract inorganic nitrogen was insufficient. However, the balance of the nitrogen fixation rate of macroalgae and the biological exhaust nitrogen rate within the system should be fully considered. The use of the biofilter alone was not optimal for the remediation of organic matter in shrimp effluent so that auxiliary foam separation technology is needed to improve the ability of the system to remove macromolecules. This study provides a basis for the further development of remediation techniques to reduce the environmental impact of shrimp aquaculture.展开更多
文摘针对城市历史文化问题的研究,文章采用数字可视化软件(CiteSpace),以“历史街区”“保护”为主题,对CNKI数据库与Web of Science数据库近30年发表的相关论文的研究机构、作者、关键词等知识图谱进行可视化分析。更加直观地呈现出历史文化街区保护的整体信息全景,系统地梳理该领域的研究现状、研究前沿和研究热点。归纳总结出,国内外历史文化街区保护研究主要涵盖了历史街区的概念与评定标准、保护原则与手段、量化技术在街区保护中的应用和多元视角下街区保护等内容。探寻了我国关于历史街区保护的研究脉络和演变规律。研究表明,我国30年历史文化街区保护的相关研究逐步走向成熟和完善,但在整体联动性、研究的深度和广度,以及经济和社会治理层面的研究还有待进一步提升,后续研究将在大数据、人工智能技术和智慧城市背景下更加科学和全面地展开。
基金The National Natural Science Foundation of China under contract No.2006AA10Z415the Public Science and Technology Research Funds Projects of Ocean under contract No.201305005
文摘This study investigated the integrated bioremediation techniques for a shrimp culture system to reduce unconsumed feed and the contents of suspended solids（SS）, nutrients and organic pollutants using barracuda,clamworm, scallop, large algae and a biofilter. A multi-pool internal circulation system was designed to test the effectiveness of the techniques in the laboratory. The experimental result has shown that Argopecten irradians,Gracilaria lemaneiformis and the biofilter efficiently reduced the contents of SS, dissolved inorganic carbon（DIC）and dissolved organic carbon（DOC） in the breeding wastewater. The amount of unconsumed feed was significantly reduced by barracuda and clamworm, but there was an increase in the contents of SS, DIC and DOC in the water due to disturbance by the barracuda and clamworm. The capacity of macroalgae to extract inorganic nitrogen was insufficient. However, the balance of the nitrogen fixation rate of macroalgae and the biological exhaust nitrogen rate within the system should be fully considered. The use of the biofilter alone was not optimal for the remediation of organic matter in shrimp effluent so that auxiliary foam separation technology is needed to improve the ability of the system to remove macromolecules. This study provides a basis for the further development of remediation techniques to reduce the environmental impact of shrimp aquaculture.
