广东清远市再生有色金属产业集群成长动力机制     

金利霞  李郇*  张虹鸥 《热带地理》2013,(3):314-323

从资源、市场、政策、产业转移等角度,结合区位熵、半结构式企业访谈和案例分析等定量与定性研究方法,探讨清远市再生有色金属产业集群的发展历程、现状、存在问题及其成长机制,提出在产业集群的演化过程中,其成长的动力机制随着经济和社会环境的变化也在不断地演变。在产业集群的形成初期,除了传统要素外,历史偶然性和市场自发性为集群的产生提供了可能性;而在中后期,政府作为制度的提供者在集群的发展和演变中扮演着重要角色。具体而言,巨大的有色金属再生资源蓄积量和庞大的劳动力资源等内生资源优势,加上政府对再生资源产业和集群的政策扶持、跨区域产业转移的制度安排、有意识地引进和培育龙头企业等外生制度优势,内源和外源动力共同促成高端要素的集聚发展、产业集群转型升级、集群化生产网络和专业化分工的形成。这种欠发达地区经济崛起的内生性推动力,能为其他城市发展再生资源产业提供重要的经验借鉴。  相似文献   

Adsorption–Reduction Behavior of Co(NH3) on Activated Carbon     

Yan‐Peng Mao  Yu Chen  Jing‐Yi Cheng  Hai‐Song Zhu  Xiang‐Li Long  Wei‐Kang Yuan 《洁净——土壤、空气、水》2012,40(2):117-122

A novel method has been put forward to retrofit the wet ammonia desulfurization process to realize the combined removal of sulfur dioxide and nitric oxide by introducing soluble cobalt(II) salt into aqueous ammonia solution. The active constituent of scrubbing NO from the flue gases is the produced by ammonia coordinating with Co²⁺. The regeneration of can be realized under the catalysis of activated carbon so as to sustain a high NO removal efficiency for a long time. In this paper, the adsorption–reduction behavior of on activated carbon has been researched using scanning electron microscopy, X‐ray diffraction, and X‐ray photoelectron spectroscopy. A conclusion can be drawn from the results that cobalt ions in the aqueous solution are adsorbed by activated carbon and most of them are reduced to Co²⁺ ions, and some of the Co²⁺ ions are further reduced into metallic cobalt. The results also demonstrate that the functional groups on the surface of carbon take part in this redox reaction. The C? H groups on the carbon surface are oxidized into C? OH, and then some of the hydroxyl groups are further oxidized into carbonyl or carboxyl groups.  相似文献   

Empowerment of an Aging Population and Rural Women Farmers: a Small Business Model-A Japanese Case Study     

QIU Zhenmian  CHEN Bixia 《资源与生态学报(英文版)》2016,7(6):486-494

Using the combined approach of questionnaire and semi-structured interview, this study aims to examine the characteristics of a small agricultural business, and benefits perceived by the participants, and challenges. The “multi-industrial system” regional initiative for creating new high-value-added businesses project encourages rural residents to commercialize their surplus agricultural and forestry products, such as pickled or dried wild and cultivated plants. Knowledgeable older people, women farmers in particular, are motivated to market their vegetables directly to the urban market, and their home-processed wild plants to local restaurants and hotels. It found that the older people involved in the business considered that their health and economic situation had been improved through participating in vegetable cultivation and sales. Some lessons from this case study can be identified: the empowerment of older people and women farmers, through active interaction with the market and learning new technologies, including internet-based information search strategies.  相似文献   

不同温度下罗非鱼人工感染海豚链球菌后血液生化指标及组织病理   总被引：1，自引：0，他引：1  

柒壮林  祝璟琳  杨弘  邹芝英  乐贻荣  李大宇  肖炜  单航宇  韩珏 《广东海洋大学学报》2012,(4):34-41

在28℃、33℃两种温度下,用海豚链球菌人工感染尼罗罗非鱼后,测定尼罗罗非鱼血液生化指标。结果显示:两个温度水平病鱼的血清总蛋白(TP)随时间延长都呈现升高趋势;谷丙转氨酶(ALT)、谷草转氨酶(AST)活性随时间延长先升高后降低再升高,33℃实验组ALT、AST活性比28℃实验组达峰值时间短,并显著高于对照组(p<0.05);尿素、钾(K+)含量随时间延长逐渐升高后降低,钠(Na+)含量先升高后降低再升高,肌酐含量呈上升趋势;血清碱性磷酸酶(AKP)活性28℃实验组呈先升高后降低趋势,33℃实验组呈升高趋势;超氧化歧化酶(SOD)活性随时间延长先升高后降低再升高,33℃实验组各个时间点基本高于28℃实验组;球蛋白(GLO)随感染后时间延长呈现升高趋势,至120 h,显著高于对照组(p<0.05),但温度组间各时间点没有显著差异(p>0.05)。组织病理学观察发现,33℃实验组肝细胞、肾小管上皮细胞水肿变性;28℃实验组肝细胞出现嗜酸性小体;肾小管上皮细胞出现嗜酸性的红色小体,颗粒变性。表明感染海豚链球菌的尼罗罗非鱼肝脏、肾脏均有损伤,造成功能障碍,高温时损伤更严重。  相似文献   

城市再生视野下的棚户区改造实践问题     

董丽晶  张平宇 《地域研究与开发》2008,27(3):44-48

棚户区改造的目的是为了改善城市面貌和居民居住环境,提高城市品位和居民生活质量.目前,我国城市开展了大规模棚户区改造工程,然而大多数改造工作重心仍以拆建房屋为主,对棚户区的系统改建不足.针对这一问题,从棚户区改造与城市再生的关系入手,结合国内外大量棚户区改造的经验与教训,强调棚户区的改造不仅是单纯意义上的物质再生,更是涵盖经济复兴、社区重构、文化重建的社会再生.以辽宁省阜新市棚户区改造作为实证案例进行分析,指出当前棚户区改造中存在的诸多问题.在棚户区改造中,需要将建筑、就业、环境、文化、社会等因素融合一起,以促进城市再生与可持续发展.  相似文献   

Further records of Craspedacusta sowerbyi lankester in north island lakes (note)   总被引：1，自引：1，他引：0  

G. R. Fish 《新西兰海洋与淡水研究杂志》2013,47(4):573-574

Collections of mature medusae from Lake Rotoiti proved all to be male and provide further evidence that the origin of the species in New Zealand was from a very limited introduction.  相似文献   

Morphogenesis during sexual and asexual reproduction in Amphipolydora vestalis (Polychaeta: Spionidae)     

Glenys D. Gibson  Ian G. Paterson 《新西兰海洋与淡水研究杂志》2013,47(4):741-752

  相似文献   

塔里木盆地塔中地区下古生界二次生烃的类型及其特征   总被引：10，自引：0，他引：10  

解启来周中毅  施继锡朱毅秀 《地质论评》2004,50(4):377-383

塔中地区下古生界碳酸盐岩烃源岩中的干酪根、吸附有机质、包裹体有机质和晶包有机质,可以成为二次生烃的物质来源。该地区存在两类二次生烃——构造运动二次生烃和碳酸盐岩深埋二次生烃,二者所形成的包裹体在类型、数量、大小、气液比、荧光颜色及强度等方面均有明显不同。通过对塔中地区多口探井和人工井的埋藏史和生烃史研究,表明塔中北斜坡下古生界碳酸盐岩可以二次生烃,面积约9000km^2,生烃时代主要为中新生代。此外,还利用逐级升温爆破—气相色谱方法,测定了高过成熟碳酸盐岩烃源岩中吸附有机质、包裹体有机质以及晶包有机质的数量和释放过程,以评价高过成熟碳酸盐岩烃源岩的生烃能力。研究塔中地区的二次生烃,对深部油气勘探有着重要的现实意义。  相似文献   

福建省永安市西洋镇2.5a生人促阔叶林与伐前林分的对比评价     

张晓红  黄清麟  张超 《山地学报》2010,28(1)

福建省永安市西洋镇2.5 a生人促阔叶林分平均胸径、树高、密度、单位面积蓄积量和平均年生长量分别为2.0 cm、1.8 m、19 533 株/hm2 、7.0 m~3/hm~2和2.80 m~3/(hm~2·a),乔木层物种丰富度R、多样性指数SW、均匀度E和生态优势度ED分别为33、2.93、0.62和0.21,林分相对直径分布范围0.25-3.00,直径分布为反J型,表现为异龄林特征.35 a生的伐前林分平均胸径、树高、密度、单位面积蓄积量和平均年生长量分别为13.6 cm、10.5 m、1 185 株/hm2 、101.3 m~3/hm~2和2.89 m~3/(hm~2·a),乔木层物种丰富度R、多样性指数SW、均匀度E和生态优势度ED分别为24、3.72、0.81和0.10,林分相对直径分布范围0.44-2.50,直径分布为反J型,表现为异龄林特征.  相似文献   

The effect of a tidal cycle on the dynamics of nutrients in a tidal estuary in the Seto Inland Sea, Japan   总被引：4，自引：0，他引：4  

Shigeru Montani  Paolo Magni  Megumi Shimamoto  Nao Abe  Koichi Okutani 《Journal of Oceanography》1998,54(1):65-76

A 24 hour time series survey was carried out during a spring tide (tidal range ca.2 m) of May 1995 on a tidal estuary in the Seto Inland Sea, Japan, in the context of an integrated program planned to quantify the dynamics of biophilic elements (carbon, nitrogen and phosphorus) and the roles played by the macrobenthos on the processes. Three stations were set along a transect line of about 1.4 km, which linked the river to the rear to the innermost part of the subtidal zone. Every hour, at each station, measurements were made of surface water temperature, salinity and dissolved oxygen concentration, and surface water was collected for the determination of nutrients [NH₄ ⁺−N, (NO₃ ⁻+NO₂ ⁻)−N, PO₄ ³⁻−P and Si (OH)₄−Si]. During the ebb flow, riverine input of silicate and nitrate+nitrite significantly increased the concentrations of both the intertidal and the subtidal stations. Conversely, during the high tide, river nutrient concentrations were lowered by the mixing of fresh water with sea water. As a result, best (inverse) correlations were found at the river station for salinity against silicate (y=-2.9 Sal.+110.7,r ²=0.879) and nitrate+nitrite (y=-1.3 Sal.+48.4,r ²=0.796). In contrast, ammonium nitrogen concentrations were higher at intermediate salinities. Indeed, no significant correlation was found between salinity and ammonium. The effect of the macrobenthos, which is abundant on the intertidal flat, is discussed as a biological component that influences the processes of nutrient regeneration within the estuary. The effect of the tidal amplitude is an important one in determining the extent of the variations in nutrient concentrations at all three stations, which were stronger between the lower low tide and the higher high tide.  相似文献