浅议科技期刊专栏的设置

科技期刊的专栏设置体现了科技期刊的办刊宗旨和方针,是体现科技期刊内容的"科技"特色的具体手段.本文就科技期刊的专栏设计的原则、特点、方法以及注意的问题进行分析,并对其进行了阐述.     

A BASIS FOR ASSESSING DIFFERENTIAL PARTICIPATION IN WATER-BASED RECREATION1

ABSTRACT: Participation in water-based recreation activities does not arise in random fashion nor simply as a result of having a water resource immediately available. Neither do individuals and groups engage in the same activities or a specific activity in the same way. The purpose of the present paper is to describe an alternative framework whereby differences among recreation users can be identified. Prior to this time, research directed toward understanding participation patterns at a recreational site have emphasized the activities while ignoring the human behavior factors which determine how participation arises. People consider recreation sites to be leisure settings in which the definition of such places has a broader socio-cultural meaning than that the site was designed. These definitions are reflected within the context of the social group and can be observed in the subsequent orientation to leisure and play. When activities are considered in the context of a human group, differences in participation patterns can be discovered.     

Evaluating the effects of alternative forest management plans under various physiographic settings using historical records as a reference

Using historical General Land Office record as a reference, this study employed a landscape-scale disturbance and succession model to estimate the future cumulative effects of six alternative management plans on the tree species composition for various physiographic settings for the Mark Twain National Forest in Missouri. The results indicate that over a 200-year horizon, the relative abundance of black oak and pine species groups will decrease and the relative abundance of the white oak species group will increase, regardless of management strategy. General Land Office witness tree records provide a measure of tree species composition in the period from 1800 to 1850, prior to the large-scale influx of European settlers. Compared to the tree species composition described in the General Land Office records, the six contemporary management alternatives considered all would lead to a lower abundance of pine species, a higher abundance of red/black oak species, and a slightly higher abundance of white oak species after 200 years. Impacts of management on tree species composition varied with physiographic settings. The projected relative abundance of pine differed significantly across the five physiographic classes over the first 40 years of the simulation. In the medium term (simulation years 41-100) the projected relative pine abundance differed significantly among only four physiographic classes. In the long term (simulation years 100-200) the projected relative pine abundance differed for only one physiographic class. In contrast, differences among physiographic classes in the relative abundance of black oaks and white oaks increased over time. In general, the expected long-term differences in relative tree species abundance among six proposed alternative management plans are small compared to shifts in tree species composition that have occurred from 1850 to the present.     

基于反距离加权插值法评价海域水质类别空间分布

空间插值技术可以对污染物分布状况进行面状连续表征,是对点位法评价的有效补充。笔者根据现行海水水质评价方法,类比给出近岸海域水质类别空间分布评价的流程:单指标空间插值-单指标水质分类-多指标水质类别判定。研究了反距离加权插值参数的选取方法,并以点位密度不同的全国近岸海域(开放型)和渤海海域(近封闭型)为例进行了插值实验。 结果表明:对目前的点位分布情况而言,全国近岸海域参数设为p=3,N=4, C=200m较为适宜；渤海海域参数为p=2,N=5,C=200m较为适宜。反距离加权插值法在开放海域的拟合效果要优于近封闭海域。     

我国主要城市的大气质量的反演、重建与分析

该文收集有关城市的1959~1979年逐年的晴天太阳辐射资料,根据辐射传输方程扣除水汽和CO₂的吸收效应,利用各地区污染物浓度垂直分布和混合层高度规律,再同已有的TSP监测资料分区分析,可得到有关地区的大气TSP质量的逐年反演值。      

上海市中心城区地表温度与绿地覆盖率相关性研究

利用卫星遥感提取的外环线以内绿地信息和由热红外波段资料反演的地表温度。对绿地覆盖率和中心城区地表温度进行相关分析。结果表明：在上海市外环线以内的大范围内。在有损估计的条件下。地表温度(T）和绿地覆盖率(S)之间满足线性关系；T=33.2132-4.6915S(r^2=1.000),即对整个外环线范围地区。绿地覆盖率每增加1％。地表平均温度将下降0．047℃；绿地对热岛效应的减缓作用。在斑块水平上体现明显，在绿地斑块水平上，地表温度(T)和绿地覆盖率(S)之间满足非线性关系：T=32.733 0.0121S-0.0011S^2 0.0000074S^2 (r^2=0.985)。用延安中路绿地作为检验表明,绿地建成后,地表平均温度降低了0．87～1．29℃。     

Investigating the impact of Glyoxal retrieval from MAX-DOAS observations during haze and non-haze conditions in Beijing

This study presents the Multi Axis Differential Optical Absorption Spectroscopy(MAXDOAS) measurements for Glyoxal(CHOCHO) in Beijing, China(39.95°N, 116.32°E). CHOCHO is the smallest compound of di-carbonyl group. As a primary sink of CHOCHO, its photolysis with NOx(oxides of nitrogen) results in the production of tropospheric ozone. Therefore,the focus of CHOCHO DOAS measurements is increasing in trend. We did the measurements from 09 May 2017 to 09 September 2017. The study was conducted to compare different retrieval settings in order to reveal best DOAS fit settings for CHOCHO;furthermore, effect of haze and non-haze days on CHOCHO concentration was examined.The root mean square of residual and Differential Slant Column density(dSCD) error was reduced when measurements were done with lower wavelength limit around 432–438 nm and upper intervals around 455–460 nm. Thus, lower wavelength intervals around432–438 nm and upper intervals around 457–460 nm were best for the retrieval of dSCDs for CHOCHO. Meteorological conditions like haze or non-haze days did not have significant effect on DOAS fit parameters. The CHOCHO vertical column densities range from 1.33 E +14 to 9.77 E + 14 molecules/cm2 during the study period with average of 6.16 E +14 molecules/cm2. The results indicated that during haze days CHOCHO concentration was higher because of lower rate of photolysis and atmospheric oxidation potential. Our results did not show any significant weekend effect on CHOCHO atmospheric concentration.     

Natural area visitors' place meaning and place attachment ascribed to a marine setting

Investigations of place have often focused on either place meaning (utilizing interpretive designs) or place attachment (using quantitative measures). Rarely have researchers explored the association between place meaning and place attachment. Hence, this investigation was designed to explore how individuals' attachment to a natural environment is reflected in their depictions of why the resource is meaningful.     

Antecedents of injury among youth in agricultural settings: a longitudinal examination of safety consciousness,dangerous risk taking,and safety knowledge

PROBLEM: Injuries are the leading cause of death for adolescents in the United States. METHODS: This study longitudinally examined three psychological mediators of injury among 3,081 youths in agricultural settings: (a) safety consciousness, (b) dangerous risk taking, and (c) safety knowledge. These variables are examined within a nomological network of contextual variables. RESULTS: Cross-sectional results revealed that safety consciousness and dangerous risk taking were the strongest predictors of reported injury at Time 1 and Time 2. Safety knowledge had an unexpected negative association with injury, albeit weak. As predicted, participating in safety activities was positively associated with safety consciousness, and time spent working was strongly associated with safety knowledge. Furthermore, self-esteem had both positive and negative safety outcomes, suggesting a more complex functioning. Males exhibited fewer safety cognitions than females as predicted. Longitudinal data also revealed that injury at Time 1 and dangerous risk taking were the strongest predictors of Time 2 injury. IMPACT ON INDUSTRY: Results from this study emphasize the importance of assessing dangerous risk-taking perceptions when attempting to predict future injuries.     

Reconciling reintegration: the complexity of economic and social reintegration of ex‐combatants in Burundi

The extent to which disarmament, demobilisation and reintegration (DDR) programmes initiated by state or multilateral agencies can realise the reintegration of ex‐combatants remains debated. While some consider that DDR should have the ambition to result in long‐term reintegration, others argue that DDR should focus on short‐term goals. This paper explores experiences with the reintegration of ex‐combatants in Burundi. It shows the interconnectedness of economic and social reintegration processes, and demonstrates that the reintegration of ex‐combatants cannot be seen in isolation from the wider recovery and development context in which DDR is taking place. Moreover, the case demonstrates that reconciliation and social reintegration are deeply interconnected, to the extent that social reintegration may fail if reconciliation is not taken into account. Rather than a debate between long‐ and short‐term goals, the focus should therefore be on increasing the understanding of reintegration processes and finding ways in which programmes can contribute to those.