喷射成形制造工艺

喷射成形是一种先进的材料制备技术,该技术具有近终形制造的特点,近年来已广泛应用于研究和开发多种高性能快速凝固材料.文中介绍了喷射成形工艺过程、特点,并回顾了喷射成形工艺的发展历程及现在所达到的技术水平.     

A participatory approach to the establishment of a baseline scenario for a reforestation Clean Development Mechanism project

This paper is part of a two-year study to investigate the feasibility of initiating a Clean Development Mechanism (CDM) project in an indigenous community of Eastern Panamá, Ipetí-Emberá. We use participatory mapping and matrices as well as household surveys to develop a land-use/land-cover baseline scenario and examine the role of local participation in assessing land-use change. In Ipetí, land-use change has not occurred in a linear way over the last decades, and our data unveils socio-economic factors as potential key drivers of change. The concordance that we observed between geographic information and individual and collective perceptions of land-use change substantiates the possibility of using local knowledge in the establishment of baseline data for CDM projects. Our calculations suggest that the total carbon (C) stocks in the Tierra Colectiva (TC) of Ipetí-Emberá in 2004 represents a 47% reduction from the estimated C stock at the onset of settlement in the early 1970’s. Results from the participatory assessments predict that, in 2024 and in absence of a CDM project, the C stocks will decline from 301,859 t C in 2004 to 155,730 t C, which constitutes a reduction of 52%. The scenario with CDM estimates C stocks of 305,853 t C for 2024, a value slightly superior to the 2004 value. In the TC there is ground to believe that cattle ranching is likely to become an ever more important activity as the population is young and growing and cannot easily move elsewhere. Forests tend to be cleared for cultivation while pastures are established on short fallows. Our baseline scenario underlines the potential for a CDM project to make a significant difference in the future C stocks of this landscape.     

一株硝基苯高效降解菌的筛选及其降解特性

自南京化工厂下水道底泥和废水处理系统曝气池活性污泥中驯化分离得到一株能快速降解硝基苯的菌株,初步鉴定其为不动杆菌属菌株。该菌株降解硝基苯的最适宜环境条件为温度25℃～35℃,pH7～8,振荡速率大于120r/m。在适宜环境条件下,该菌株能够在24h内全部降解初始浓度不超过400mg/L的硝基苯,该浓度范围内硝基苯的降解过程符合零级动力学特征;当硝基苯的初始浓度超过400mg/L时,降解菌的生长受到毒害作用,该浓度范围内硝基苯的降解在开始有一个明显的停滞期,降解过程不再符合零级或一级动力学特征。     

Societal Concerns about Pork and Pork Production and Their Relationships to the Production System

Pork producers in Western Europe moreand more encounter a variety of societalconcerns about pork and pork production. Sofar, however, producers predominantly focusedon low consumer prices, therewith addressingjust one concern. This resulted in an intensiveand large-scale production system, decreasinglyrelated to the area of farm land, andaccompanied with increasing concerns aboutsafety and healthiness of pork, animal welfare,environmental pollution, and others.An overview was given of possible concernsabout West-European pork production with theconsumers, citizens, and producers, and thoseconcerns are traced back to the pork productionsystem. The various kinds and qualities ofinformation about the pork production system onwhich possible concerns are based have beenworked out extensively in this paper. Knowledgeabout the aspects of pork production that cangive rise to concerns can be used in two ways.First, the communication about those aspectstowards consumers and citizens can be adjustedor extended to give them better possibilitiesto make food choices or to develop their ownopinions about pork production. Second,producers could change the pork productionsystem such that it better satisfies consumersand citizens. Such adaptations are wellpossible, as three pork quality schemes, whichhave been evaluated, illustrate. However, mostof these adaptations can only be carried out atthe cost of the present low consumer prices andwill not occur spontaneously on a large scale.Therefore, accounting for the type andrelevance of the concerns, legislation isnecessary to address societal concerns in abalanced way such that pork production systemsbecome acceptable for the majority of oursociety.     

工业生态系统及其建设

本文分析了工业生态系统的基本特征及核心内容、阐述了工业生态系统建设的基础，原则及其对策。     

Effect of Cross-Linking Waste Protein with Diepoxides on its Biodegradation under Anaerobic Conditions

Biodegradability testing was performed in an aqueous environment under anaerobic conditions after inoculation with digested sludge from municipal wastewater treatment plant. In cross-linking with 1,2:3,4-diepoxybutane in limits 0.8–9.1% weight, biodegradability degree decreased from 76.8 to 62.2%; when 1,2:7,8 diepoxyoctane in quantities 1.1–13.2% weight was used, biodegradability degree dropped more prominently – from 72.3 to 22.8%. There is obviously a direct connection between growing cross-link degree (assessed by so-called fixation index) and decreasing readiness to biodegradation, apparently owing to build-up of a network forming an obstacle to access of micro-organisms and enzymes.     

塔克拉玛干沙漠腹地沙尘暴特征--以塔中地区为例

塔克拉玛干沙漠是中国油气开发的重要区域，沙尘暴是该区域重要的灾害性天气，但以往相关的研究很少。为了了解塔克拉玛干沙漠腹地沙尘暴的发生规律，利用塔中气象站1997-2002年的气象资料，对塔中地区沙尘暴的强度、过程、类型和时间变化等特征进行了分析。研究结果表明：（1）塔中年平均沙尘暴日数为16．83d，较沙漠北缘的轮台和沙漠南缘的民丰、和田为多，体现出沙尘源对沙尘暴发生的影响；（2）沙尘暴发生之前出现明显的风速突然降低和风向转换；（3）同塔里木盆地其它区域一样，塔中沙尘暴也可分为5种类型，其主导类型为冷空气东灌型；（4）沙尘暴时间变化规律明显，且从20世纪90年代至21世纪初，塔中沙尘暴日数与持时明显下降，同全疆的变化趋势一致。     

The greening of brownfields in American cities

The redevelopment of brownfields has become a central component of government efforts to revitalize many US cities. While the focus of these efforts has concentrated on promoting industrial and commercial redevelopment, some cities have started to also consider converting brownfields into parks and open space as part of a more comprehensive renewal strategy. Based on a survey of 20 case studies, this paper identifies and discusses: (1) the primary issues involved in brownfield greening projects; (2) the benefits of such projects; and (3) the specific planning processes involved. The overall conclusion drawn from the survey is that numerous renewal‐oriented benefits can ensue from greening projects, if there is extensive stakeholder commitment devoted to deal with its financial and development‐oriented challenges.     

Food justice youth development: using Photovoice to study urban school food systems*

How do youth learn through participation in efforts to study and change the school food system? Through our participatory youth action research (YPAR) project, we move beyond the “youth as consumer” frame to a food justice youth development (FJYD) approach. We track how a group of youth learned about food and the public policy process through their efforts to transform their own school food systems by conducting a participatory evaluation of farm-to-school efforts in collaboration with university and community partners. We used the Photovoice research method, placing cameras in the hands of young people so that they themselves could document and discuss their concerns and perspectives. The research was designed to gain insight about youths’ knowledge of food, health, and community food systems. Drawing upon the youth group’s insights, we build a framework for building critical consciousness through FJYD.