川藏高海拔地区金冠苹果品质与气象因子的关系

【目的】研究川藏高海拔地区金冠苹果品质与气象因子的关系,为该区域金冠苹果的合理区划、优质生产提供理论依据。【方法】于2012-2013年随机取川藏高海拔地区四川茂县、小金、盐源、康定及西藏林芝5个重要产地的金冠苹果果实,测定其品质(单果质量、果形指数、果实硬度及花青苷、可溶性固形物、总糖、总酸、VC含量),同时收集5地2012和2013年金冠苹果果实发育主要时期各月(5-8月)及年主要气象资料(均温、平均昼夜温差、≥10℃积温、降雨量、日照时数),采用相关性分析及回归分析研究果实品质与气象因子的关系,确定优质金冠苹果生产需要的主要气象因子最适值。【结果】金冠苹果在5个产地品质差异显著,在小金表现较好;8月均温、5-8月及年均昼夜温差、年降雨量、6-8月及年日照时数是影响该地区金冠苹果品质的主要气象因子;8月均温19.1-21.3℃,5、6、7、8月及年均昼夜温差分别为10.6-12.3,11.0,9.7,11.7-13.3和12.8℃,7月≥10℃积温约636.5℃,6月及年降雨量分别为169.4和637.1-787.9mm,6、7、8月及年日照时数分别为154.3,174.6-200.8,153.5和2 405.6h是金冠苹果在川藏高海拔地区表现优良的适宜气象因子。【结论】确定了川藏高海拔地区金冠苹果优质生产的气象条件。     

水田激光平地机平地铲姿态测量系统的设计

水田激光平地机水平控制作为农田激光平地技术的重要组成部分,其研究过程中首先要解决平地铲实时倾角测量问题.为提高倾角测量精度,设计了平地铲姿态测量系统,采用MEMS传感器集成模块AD1S16300作为惯性测量单元,通过卡尔曼滤波实现传感器信息融合以计算平地铲倾角.分析了姿态测量系统的构成,阐述了两种传感器融合测量实时倾角的方法,基于ARM7 Cotex- M3微处理器设计了姿态测量系统硬件.采用AHRS500GA对该姿态测量系统性能进行了融合算法验证与ADIS16300测量平地铲倾角验证.测试结果表明,该姿态测量系统能在动态条件下准确地测定平地铲实时倾角,可以进一步应用于激光平地机的水平控制之中.     

Assessing rural peoples’ intention to adopt sustainable forest use and management practices in South Africa

This study examined rural peoples’ intention to adopt sustainability practices in communally managed forests in Vhembe district, South Africa, using the theory of planned behavior as a conceptual framework. A total of 155 respondents were surveyed. The data was analyzed using structural equation modeling (SEM). The results showed that rural people have a strong intention to adopt sustainable forest-use and management practices. Out of the three constructs comprising the theory of planned behavior, subjective norm (SN) and attitude to behavior (AB) positively correlated with intention, with SN having the strongest influence on intention. Perceived behavioral control (PBC), which is the third construct, negatively correlated with intention. The study indicates that respondents’ subjective belief about the approval or disapproval of sustainable forest management (SFM) practices by other relevant people mainly influenced their intention to adopt or not adopt such practices. Thus, strategies and policies to enhance the sustainable management of communally owned forests in South Africa need to consider local actor contexts and sociocultural norms and values. In this regard, the engagement of influential people at the community level, and the demonstration of the short- and long-term benefits of sustainable forest use and management practices offer promising entry points.     

洞庭湖周边居民对洞庭湖及其湿地依赖程度与态度研究

采用问卷调查方式,以户为单位调查洞庭湖周边社区居民对洞庭湖及其湿地的依赖情况与态度。结果显示:社区居民对洞庭湖及其湿地依赖方式主要有水产品捕捞,放牧打草,在滩涂种植杨树,芦苇等纸质原料产品,围湖造田种植水稻、蔬菜,水运,开展乡村旅游等,以依赖系数作为衡量社区居民对洞庭湖及其湿地依赖程度的指标,分析发现将近90%以上的居民对洞庭湖及其湿地或多或少存在依赖关系,其中33%的居民依赖系数超过0.8;同时调查发现38%的居民支持把洞庭湖及其湿地完全保护起来,62%的居民持反对态度,并用计量经济模型分析表明,居民对完全保护洞庭湖及其湿地持支持的态度与依赖洞庭湖资源的经济收入和所占有的耕地及滩涂面积呈负相关。     

惠阳金桔自然保护区社区参与动力机制分析

社区参与日益成为解决社区发展与自然资源保护之间矛盾的新方法。以TRA为理论视角,构建了居民社区参与概念模型。以金桔自然保护区为例,实证检验概念模型的可靠性。结果表明:主观规范通过社区参与行为意愿间接驱动社区参与;行为态度通过社区参与行为意愿间接驱动社区参与。     

Simulating integration of agroforestry into livestock farmers‘ projects in France

Drawing on almost one hundred contemporary farmers‘ experiences, within a French agroforestry experimental network, socio-economic and ecological approaches are combined to assess a set of agroforestry techniques. Among this network, twelve livestock farms were selected in contrasting bioclimatic regions and classified according to land use, stock number and family situation. Farmers were interviewed to define the primary objectives assigned to agroforestry and to build up several scenarios of agroforestry development on their farm. A dynamic resource model was used to predict the effects of agroforestry development on crop and timber production as well as on labour organisation and amenities. An example of simulation, comparing three agroforestry management projects, based on new plantations at wide spacing, farm forestry and silvopastoral thinnings, is developed for a farm in the Cévennes (southern France). The outputs of the model, related to labour requirements, stock number dynamics and landscape diversity are discussed in relation to farmer‘s perception of the role of trees in the farm operation, and the indirect economic benefits sought. This revised version was published online in June 2006 with corrections to the Cover Date.     

基于强化学习的采摘机器人采摘臂避碰设计

首先介绍了采摘机器人采摘臂避障问题和强化学习理论,并将强化学习方法应用到采摘臂避障问题中,构建了一平面3自由度的采摘机器人采摘臂的多Agent避碰系统。笔者研究目标是通过Agent感知采摘臂连杆与障碍物之间最小距离d和采摘臂姿态偏差角θ两方面信息,然后进行避障规划,在复杂未知环境中使其找到合适路径采摘目标。在NET平台上进行了基于强化学习的采摘臂避障系统平台的开发与仿真,对采摘臂避障系统的避障能力进行了测试分析。仿真实验表明:采摘臂避障避碰系统避障能力比较强,能够在复杂环境中采取避障措施,并准确达到指定位置。     

A survey of public attitudes towards barking dogs in New Zealand

AIMS: To investigate public attitudes towards barking dogs in New Zealand in order to quantify the extent to which people perceive barking dogs to be a problem, to compare tolerance of barking with that of other common suburban noises, to assess the level of public understanding about the function of barking, to determine risk factors for intolerance of barking and to assess knowledge of possible strategies for the investigation and management of problem barking.

METHODS: A 12-page questionnaire was sent to 2,000 people throughout New Zealand randomly selected from the electoral roll. Risk factors for being bothered by barking were examined using logistic regression analysis.

RESULTS: A total of 1,750 questionnaires were successfully delivered; of these, 727 (42%) were returned. Among respondents, 356/727 (49.0%) indicated that frequent barking during the day would bother them while 545/727 (75.0%) would be bothered by barking at night. Barking and howling were ranked above other suburban noises as a cause of annoyance. Risk factors for being bothered by daytime barking were not being home during the day, not owning a dog, and considering a dog bite to be a serious health risk. Risk factors for being bothered by night-time barking were not being home during the day, marital status, considering dog bites to pose a serious health risk, and having been frightened by a dog. Overall, 510/699 (73%) respondents understood that barking was a form of communication.

Action likely to be taken by 666 respondents hearing frequent barking included notifying and offering to help the owner (119; 17.8%), complaining to the owner (127; 19.1%) or the authorities (121; 18.2%), or doing nothing (299; 48%). Possible responses by 211 dog owners if they had a barking dog included seeking help from dog trainers (59; 28%) or behaviourists (54; 26%), buying an anti-barking device (33; 15%) or getting rid of the dog (20; 10%).

CONCLUSIONS: Barking was considered to be potentially disturbing by respondents to this survey. Attitudes towards barking were most influenced by age, dog ownership, past experience with dogs and attitude towards dog bites. Public understanding of the possible reasons for barking and appropriate methods of managing the behaviour when it becomes a problem could be improved by better education and the provision of information through veterinary clinics and social media.     

移动并联式六自由度转运调姿方法研究

针对大型航天相机长距离转运和快速精确自动调姿需求,提出一种基于全向移动平台和3-RPS并联调姿机构的移动并联式六自由度调姿方法。首先,测得相机当前姿态和目标姿态,推导二者位姿矩阵;通过运动学模型反解全向移动平台和并联调姿机构的各轴运动参数,将多轴耦合的空间六自由度完全解耦;建立全向移动平台和并联机构的运动学模型,实现上述运动参数的驱动;最后,进行了调姿算法试验,结果表明,调姿设备能够快速精准实现大型相机任意姿态向目标姿态的自动化柔性姿态调整,全向移动平台移动精度优于0.3mm,旋转精度优于0.05°,并联机构杆长精度优于0.5mm,验证了自动调姿的准确性。     

倾转三旋翼垂直起降无人机悬停姿态控制

针对一种倾转三旋翼垂直起降(VTOL)飞行器在悬停状态下的姿态控制问题,设计了一种基于STM32系列微控制器的飞行控制系统。采用十轴组合惯性导航模块实时采集载机平台姿态信息,并结合基于四元数的互补滤波算法进行姿态信息解算。针对无人机姿态控制实时性和精度要求高的特点,采用串级PID控制算法对载机进行悬停状态下的姿态控制。实验结果表明:串级PID控制算法在悬停状态下能够对倾转三旋翼垂直起降飞行器进行快速、稳定、准确的姿态控制,并具有一定的鲁棒性。在横滚角的内环采用PD控制(Kp为8.371,Kd为3.015),外环采用PD控制(Kp为5.1,Kd为1.15);俯仰角的内环采用PD控制(Kp为3.137,Kd为1.6),外环采用PID控制(Kp为3.43,Ki为0.003,Kd为3.97);偏航角采用PI控制(Kp为9.30,Ki为0.11)时,其悬停状态下具有最优姿态控制效果。研究结果对倾转三旋翼垂直起降飞行器飞行控制的后续研究具有指导作用。