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551.
地理信息系统(GIS)是处理资源、环境等多种信息的计算机数据管理系统。本文介绍了6IS技术在全国土壤污染状况调查工作中调查点位的布设、现场定位采样、调查数据存储等方面的应用,并探讨该技术在今后土壤污染防治工作中的应用。  相似文献   
552.
通过梳理国家示范高职院校等先期建设院校的经验,认为测评实施的策略选择是组建专门领导机构;先培训后测评;分批进行,稳步推进;以项目课程开发为依托;与教师下厂实践相结合;注重测评成果的应用等。  相似文献   
553.
ABSTRACT

Public schools are more than educational institutions; they are essential to creating liveable neighbourhoods. Despite their importance, public schools are being permanently closed across North America, and particularly in the Canadian province of Ontario. In 2015, one of Ontario's public school boards made the decision to permanently close the province's oldest public high school, located in the urban core of the historic midsized city of Kingston. While the school is not scheduled to close until late 2019, the established fate of this prominent public asset has important consequences for the liveability of Kingston's urban core. Accordingly, the objective of this study was to document residents’ perceived impacts of the decision to close to Kingston Collegiate Vocational Institute (KCVI) on liveability in the school's catchment area. We observed widespread dissatisfaction with the decision to close KCVI (85%), with large proportions of respondents (above 40%) anticipating KCVI's closure to negatively impact neighbourhood liveability in various ways in the future. Approximately one-quarter of respondents indicated that they have considered moving as a result of the decision, and among these, concerns about negative impacts to household-level well-being were particularly acute. Given the socio-demographic profile of respondents who have considered moving, these findings suggest that the closure of KCVI could have a destabilising effect on the neighbourhoods within the KCVI catchment area by driving families out of the city's urban core. Our findings suggest that policies to address concerns of under-enrolment are short-sighted and undermine efforts of other sectors to promote liveable communities.  相似文献   
554.
Abstract

Congestion causes many externalities for the society, including time delays, excessive fuel consumption, air pollution, noise and safety concerns. In Shanghai, various policy options have been explored, piloted or applied; however, not all of them may be understood and accepted by the public. A survey was conducted to investigate people’s attitudes towards several policy options. The main findings reveal that Shanghai residents are resistant to certain policies, such as congestion charges, higher parking charges in congested areas and car restrictions. Instead, they favor public transport provisions. The paper suggests that there is a case for promoting public transport and more efficient trips when the car ownership is still low, and for investing in a policy of educating the public on the ‘true’ costs and causes of congestion before embarking on an intensive policy of congestion charges or restrictions.  相似文献   
555.
Objective: Driver sleepiness contributes substantially to road crash incidents. Simulator and on-road studies clearly reveal an impairing effect from sleepiness on driving ability. However, the degree to which drivers appreciate the dangerousness of driving while sleepy is somewhat unclear. This study sought to determine drivers' on-road experiences of sleepiness, their prior sleep habits, and personal awareness of the signs of sleepiness.

Methods: Participants were a random selection of 92 drivers traveling on a major highway in the state of Queensland, Australia, who were stopped by police as part of routine drink driving operations. Participants completed a brief questionnaire that included demographic information, sleepy driving experiences (signs of sleepiness and on-road experiences of sleepiness), and prior sleep habits. A modified version of the Karolinska Sleepiness Scale (KSS) was used to assess subjective sleepiness in the 15 min prior to being stopped by police.

Results: Participants' ratings of subjective sleepiness were quite low, with 90% reporting being alert to extremely alert on the KSS. Participants were reasonably aware of the signs of sleepiness, with many signs of sleepiness associated with on-road experiences of sleepiness. Additionally, the number of hours spent driving was positively correlated with the drivers' level of sleep debt.

Conclusions: The results suggest that participants had moderate experiences of driving while sleepy and many were aware of the signs of sleepiness. The relationship between driving long distances and increased sleep debt is a concern for road safety. Increased education regarding the dangers of sleepy driving seems warranted.  相似文献   

556.
为分析驾驶人高速公路施工区合流选择意愿的影响因素,基于非集计理论构建多属性施工区驾驶人合流选择意愿模型。利用SP调查法自主设计调查问卷,获得328份有效施工区驾驶人合流选择数据;利用Pearson相关系数分析施工区合流选择意愿与驾驶人因素和道路交通环境因素的相关性;以上游过渡区、警告区Ⅰ和警告区Ⅱ 3个合流区域作为选择肢,从驾驶人和道路交通环境特征属性2个方面归纳出6个因素对施工区合流选择意愿的影响,应用分类变量处理方法将其定义为6种指标,并进行赋值。结合非集计理论,以328份有效问卷为建模数据,建立施工区合流选择意愿的MNL模型,并利用似然比、优度比和模型命中率3个指标判断模型的拟合程度。结果表明:模型拟合程度较好;驾龄、施工区类型、道路条件、交通控制标志、速度条件和限速策略对驾驶人施工区合流选择意愿有显著影响。  相似文献   
557.
558.
To explore the current situation and distribution of fish in the eight major estuaries of the Pearl River Estuary in China, acoustic detection and water quality monitoring were conducted in 2018. The results showed that almost living in eight major estuaries were juvenile, the proportion of strong echo was higher in winter, and Jiaomen and Modaomen Estuary were relatively rich in adult fish. In winter, the Humen, Jiaomen, and Yamen Estuary had a high density relatively, for 46.05 (± 50.30), 33.12 (± 93), and 32 (± 78) ind/103 m3, respectively. However, the fish densities of the Hengmen, Modaomen, and Hutiaomen estuaries were higher in summer at 55.72 (± 83.23), 37.52 (± 55) and 36 (± 99) ind/103 m3, respectively. Thus, fish are mainly concentrated in the flood tidal estuary in winter and in the ebb tidal estuary in summer. In addition, fish density was higher in flood tide than in ebb tide, and the strong echo proportion was lower. In winter, the key water quality factors affecting the biodiversity of estuary fish Shannon were chlorophyll a (P < 0.05), while what affected the fish density were turbidity and salinity (P < 0.05). This study showed that the Pearl River estuary was still the main habitat for juvenile fish. However, habitat variability is obvious; hence, it is important to flexibly carry out the delimitation of estuarine fish reserves and ecological restoration. © 2022 Authors. All rights reserved.  相似文献   
559.
Reducing greenhouse gases in the atmosphere is becoming a pressing issue for the global community. Afforestation and reforestation are promoted worldwide as an effective means of sequestering carbon. For its national interest and global concerns, China has made great efforts to protect its existing forests and develop programs of afforestation and reforestation. Based on two surveys recently conducted in Liping County, Guizhou province, this paper investigates the economic changes associated with the implementation of the "Grain For Green" policy. Based on the analytical framework of benefit cost analysis, this paper concludes that the implementation of the reforestation of sloping agricultural land policy would not be possible if there were no government subsidies for the peasants. The short term economic returns of land and labour from forestation are substantially lower than those generated from grain or cash crop production on the steep slope lands. The government subsidies provide great economic incentives for peasants to take part in the project. The subsidies in fact have elevated peasant income in rural Liping. The estimated potential economic returns of plantations over the long run indicate that the removal of the government financial subsidies would not create an economic crisis for the peasants if the current market conditions continue.  相似文献   
560.
自然资源综合科学考察是基础性科技工作,对于服务国民经济和社会发展具有重要的科技支撑作用。进入21世纪,我国自然资源综合科学考察工作从低谷中逐步复苏,但依然面临科考人才断档、经费支持不足、跨国考察组织艰难、重大成果产出不多等诸多挑战。本文从地域范围、队伍组成、技术手段、成果影响等角度总结了我国综合科学考察工作的最新进展,并展望新时代,提出了我国综合科学考察研究工作的六大发展趋势,包括:从综合科学考察向自然资源综合考察研究转变;考察国际化进程将加快;注重多学科综合考察与宏观微观结合调查;考察技术将更加多样化、智能化和精准化;考察信息数据共享平台支撑能力更加强大;科考人才的培养成为紧迫需求将得到加强。  相似文献   
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