气候变化对中国近海捕捞渔业的影响——以太平洋年代际涛动为例

太平洋年代际涛动（Pacific Decadal Oscillation,PDO）是气候年代际变化的主要模态之一,不仅对欧亚及北美大陆气候有重要的调节作用,对海洋生态系统及渔业资源也产生重要影响。本文以影响中国近海环境最主要的气候年代际事件PDO为切入点,采用经验正交函数分解（EOF）、超前滞后相关、一元回归分析和经验模态分解（EMD）等方法,分析了1950—2018年中国近海4种主要经济鱼种（小黄鱼（Larimichthys polyactis）、带鱼（Trichiurus lepturus）、银鲳（Pampus argenteus）及蓝点马鲛（Scomberomorus niphonius））渔获量波动与PDO变化的关系。结果表明：①渤黄东海4种渔获量与PDO的关系变化一致,存在显著的同期负相关;而南海4种渔获量与其他海区不同,与PDO相关性较差。②PDO变化对渔获量的影响主要集中在年代际尺度,并且在PDO位相转换期间的影响更为显著。③PDO变化通过引起渤黄东海的海温和初级生产力（以叶绿素为表征）显著变化,对渔获量波动产生影响。具体表现为当PDO处于负位相时,中国近海会出现海水增暖、叶绿素增加现象,适宜海温和初级生产力提升,使得渔获量增加。本文结合中国海洋渔业发展现状和特点,对中国海洋渔业发展方面提出相应对策建议,以期为气候变化背景下中国渔业资源的开发利用提供理论指导。     

Testing a theory of organizational culture,climate and youth outcomes in child welfare systems: A United States national study

Theories of organizational culture and climate (OCC) applied to child welfare systems hypothesize that strategic dimensions of organizational culture influence organizational climate and that OCC explains system variance in youth outcomes. This study provides the first structural test of the direct and indirect effects of culture and climate on youth outcomes in a national sample of child welfare systems and isolates specific culture and climate dimensions most associated with youth outcomes. The study applies multilevel path analysis (ML-PA) to a U.S. nationwide sample of 2,380 youth in 73 child welfare systems participating in the second National Survey of Child and Adolescent Well-being. Youths were selected in a national, two-stage, stratified random sample design. Youths’ psychosocial functioning was assessed by caregivers’ responses to the Child Behavior Checklist at intake and at 18-month follow-up. OCC was assessed by front-line caseworkers’ (N = 1,740) aggregated responses to the Organizational Social Context measure. Comparison of the a priori and subsequent trimmed models confirmed a reduced model that excluded rigid organizational culture and explained 70% of the system variance in youth outcomes. Controlling for youth- and system-level covariates, systems with more proficient and less resistant organizational cultures exhibited more functional, more engaged, and less stressful climates. Systems with more proficient cultures and more engaged, more functional, and more stressful climates exhibited superior youth outcomes. Findings suggest child welfare administrators can support service effectiveness with interventions that improve specific dimensions of culture and climate.     

A model for developing and assessing youth-based environmental engagement programmes

In this paper, we argue that a fundamental cultural shift is needed to effectively address anthropogenic causes of climate change. Evidence suggests that youth are well positioned to create such transformation. While various studies have contributed empirical evidence to numerous youth-based non-formal environmental engagement programmes, what is missing in the environmental education literature is discussion of a systematic approach to the development and evaluation of these programs. In this paper, we draw on the youth civic engagement literature to propose a framework that can be used as a basis to guide further development of evidence-based practices. Five major components are described as follows: (1) the engagement activity; (2) the engagement process; (3) initiating and sustaining factors; (4) mediators and moderators; and (5) outcomes. This approach to youth engagement can inform both researchers trying to study effective ways of creating change and practitioners developing environmental programmes that aspire towards a culture of sustainability.     

土壤碳储量及其碳固定研究

土壤碳库是陆地生态系统中最大且周转时间最慢的碳库,全球碳储量的最低值为719Pg,最高值为2 946Pg,中国土壤总有机碳库最高值接近180Pg。在对现有资料整理的基础上,着重讨论了土壤碳储量及其估计方法,包括森林类型法、土壤类型法、生命带类型法、模型法和遥感影像法等,分析了影响农业土壤固碳主要有气候因素、土壤理化性质因素和农业耕作措施等因素,指出农田土壤的碳固定将成为今后研究的热点,研究土壤与大气、植被碳库之间的碳交换过程,成为我们下一步工作的重点。     

我国大学科技创新景气指数研究

综述大学科技创新测度的理论与方法,分析现有基于创新能力和绩效的大学创新指数存在的缺乏时序性和动态性、无预警功能、不能反映大学科技创新景气波动状态、对科技创新政策指导性、时效性较弱等缺点。在创新周期理论基础上,基于景气状态视角,将景气分析方法与大学科技创新指标评价体系结合,构建大学科技创新景气指数及预警信号系统,以反映创新景气状态、波动程度及循环周期,并通过分析景气测度结果,为大学科技创新政策的制定和调整提供决策参考依据。     

南方丘陵山地带NDVI时空变化及其驱动因子分析

本文利用MODIS归一化植被指数(Normailized Difference Vegetation Index,NDVI)数据对南方丘陵山地带2000-2010年间植被覆盖的年际动态、季相变化和空间差异进行研究,并结合气象因子和土地利用/覆被数据分析植被覆盖变化的原因。研究表明:南方丘陵山地带植被NDVI值较高,属高植被覆盖区。2000-2010年间植被NDVI整体呈上升趋势,但并不显著(p=0.45)。从不同植被类型的季相变化来看,草地的变化幅度最大,其次为灌丛,森林植被变化幅度最小,生长峰值主要出现在8、9月份。植被覆盖变化存在显著的空间差异,封山育林、退耕还林还草生态恢复区和石漠化综合治理区的植被覆盖度显著提高,城镇化迅速发展区植被明显退化。植被覆盖变化是气候和人类活动共同作用的结果。植被覆盖年际变化与气候因子年际变化的相关系数区域分异比较明显。降水量对植被覆盖的影响主要表现在对植被生长年内变动的控制,大部分植被生长对降水存在1个月滞后现象。农业生产的提高、城市化进程的加速及生态建设的重视等人类活动是影响植被覆盖变化空间差异的另一重要因素。     

The Psychometric Properties of the Perceived Motivational Climate in Exercise Questionnaire

The current study aims to test the reliability and validity of the Leader–Member Exchange (LMX 7) scale with regard to coach–player relationships in sports settings. A total of 330 professional soccer players from the Turkish Super League as well as from the First and Second Leagues participated in this study. Factor analyses were performed to test the construct validity of the LMX 7. Exploratory factor analysis revealed a one-factor solution for the LMX 7. Confirmatory factor analysis showed acceptable fit indices (χ²₍₁₄₎ = 31.36; p = .001; χ²/df = 2.24; GFI = .95; CFI = .97; SRMR = .05). Cronbach`s alpha (α = .84) and construct reliability (CR = .85) indicated that the reliability of the LMX 7 was quite good. Factorial Invariance (Δχ²_diff = 4.49; p > .05) across samples provided cross-validation using Multi-Group Confirmatory Analysis (MGCFA). The MGCFA supported the model of league invariance. Evidence of cross validation and configural, metric, and scalar invariance tests suggested that the LMX 7 scale preserves its factor structure, factor loadings, factor variances, and item uniqueness equally well. Chi-square difference tests revealed full invariance (Δχ²₍₆₎ = 11.45; p > .05) and partial scalar invariance (Δχ²₍₆₎ = 9.46; p > .05). Overall, these results show that the LMX 7 scale is reliable and valid for examining coach–player relationships.     

Providing students with voice and choice: lessons from intervention research on autonomy-supportive climates in physical education

This article examines the latest thinking about autonomy-supportive climates within physical education. The basis for the inclusion of these climates are self-determination and achievement goal theories which suggest that a teacher's motivating style towards students can be conceptualised along a continuum that ranges from highly controlling to highly autonomy supportive. In general, autonomy-supportive teachers facilitate, whereas controlling teachers interfere with, the congruence between students' self-determined inner motives and their classroom activity. Drawing upon research involving interventions at pre-school, primary and secondary school levels, the paper examines how 27 studies that demonstrate providing pupils with opportunities to become self-directed leads to higher levels skill attainment, physical activity and perceived competence. Implications for curriculum, pedagogy and assessment are addressed and directions for future research are noted.     

Goal orientations,motivational climate,and prosocial and antisocial behaviour in youth football: Exploring their temporal stability and reciprocal relationships

Abstract

In this study, we examined the temporal stability and reciprocal relationships among task and ego orientation, task- and ego-involving climates, and prosocial and antisocial behaviour in youth football. Male (n = 156) and female (n = 24) footballers (mean age 14.1 years, s = 1.8) completed questionnaires towards the beginning and end of a regular season. Questionnaires measured goal orientation, perceived motivational climate, and frequency of prosocial and antisocial behaviours. Structural equation modelling indicated moderate covariance stability between the beginning and end of the season. Subsequent analyses revealed a significant decrease only in perceptions of task-involving climate. In the cross-lagged analyses, prosocial behaviour at the beginning of the season positively predicted task-involving climate at the end of the season. Antisocial behaviour at the beginning of the season positively predicted both ego orientation and ego-involving climate at the end of the season and a reciprocal relationship was revealed whereby ego orientation at the beginning of the season positively predicted antisocial behaviour at the end of the season. Task orientation at the beginning of the season negatively predicted ego-involving climate at the end of the season. All cross-lagged relationships were weak. This exploratory study offers limited support for bi-directional relationships between personal, environmental, and behavioural variables but provides useful insight into the covariance stability, change, and interrelationships between motivational and moral constructs over a competitive season.     

The role of self-determined motivation in the understanding of exercise-related behaviours,cognitions and physical self-evaluations

Abstract

In this study, we investigated the adjustments to posture, kinematic and temporal characteristics of performance made by lower limb amputees during the last few strides in preparation for long jump take-off. Six male unilateral trans-femoral and seven male unilateral trans-tibial amputees competing in a World Championships final were filmed in the sagittal plane using a 100-Hz digital video camera positioned so that the last three strides to take-off were visible. After digitizing using a nine-segment model, a range of kinematic variables were computed to define technique characteristics. Both the trans-femoral and trans-tibial athletes appeared to achieve their reduction in centre of mass during the flight phase between strides, and did so mainly by extending the flight time by increasing stride length, achieved by a greater flexion of the hip joint of the touch-down leg. The trans-tibial athletes appeared to adopt a technique similar to that previously reported for able-bodied athletes. They lowered their centre of mass most on their second last stride (?1.6% of body height compared with ?1.4% on the last stride) and used a flexed knee at take-off on the last stride, but they were less able to control their downward velocity at touch-down (?0.4 m · s^?1). Both this and their restricted approach speed (8.9 m · s^?1 at touch-down), rather than technique limitations, influenced their jump performance. The trans-femoral athletes lowered their centre of mass most on the last stride (?2.3% of body height compared with ?1.6% on the second last stride) and, as they were unable to flex their prosthetic knee sufficiently, achieved this by abducting their prosthetic leg during the support phase, which led to a large downward velocity at touch-down (?0.6 m · s^?1). This, combined with their slower approach velocity (7.1 m · s^?1 at touch-down), restricted their performance.