祁连山南麓高寒灌丛GPP变化特征及对生长季积温的响应

全球气候变化背景下气温逐渐升高,将会对陆地生态系统碳循环产生重要影响。研究利用2003?2016年的涡度相关系统观测资料,研究了祁连山南麓高寒灌丛生长季(5月?9月)总初级生产力(gross primary productivity,GPP)在不同时间尺度上对生长季有效积温(growing season degree days,GDD)的响应,对于研究气候变暖对高寒生态系统碳循环的影响有重要意义。结果表明:高寒灌丛生态系统在生长季的月GPP、GDD都表现为先增大后减小的单峰变化趋势,都在7月或8月达到峰值,在5月达到最小值。在整个生长季尺度上,GPP与GDD具有较高变异性,但整体上表现为逐渐增加的趋势(P<0.05)。2003?2016年整个生长季GPP与GDD的均值分别为507.11 g·m^?2和975.93℃。在月尺度和生长季尺度上,GPP与GDD都呈显著正相关关系(P<0.05)。但是,通过比较生长季每个月GPP与GDD的关系发现,5、9月的GPP与GDD没有显著相关性(P>0.05),而在7月相关性最为显著(P<0.01)。整体上看,高寒灌丛生态系统植被的总初级生产力与热量条件表现为正相关关系,由此说明在全球气候变暖的背景下,青藏高原高寒灌丛生态系统植被的光合生产能力将会提高。     

香葱连作障碍的成因及其修复试验

选取不同连作年限(0、2、4、6、10、15 a)的葱田土壤,测定土壤的养分、微量元素和重金属含量,发现不同连作年限土壤中的铁、硼、镁等微量元素含量丰富,但是连作葱田土壤的容重、有机质含量和铵态氮含量有不同程度降低,硝态氮含量显著提高。用5种土壤改良剂对连作年限为15 a的葱田进行土壤淋施处理,试验结果表明,奥普尔冲施肥使土壤中的硝态氮含量降低11.57%,铵态氮含量提高50.27%,香葱产量提高2.66%,是最佳的土壤改良剂。     

Effect of the Silicic Acid Polymerization Degree on the Coagulating Property of Polyalumium Silicate Chloride

Polyaluminum silicate is a new type of inorganic macromolecular flocculants, which is developed as a complex product in recent years on the base of polyalumium flocculant and polysilicic acid flocculant. Sodium silicate is diluted to the concentration of 3.0% SiO 2 with distilled water. The solution was adjusted to pH 4.5 with sulphate acid and kept at quiescency for different time to get polysilicic acid with different polymerization degrees. Using polysilicic acid prepared and aluminium chloride as materials, a series of polyaluminium silicate chlorides(PASC) with different basicities(B), Al/Si molar ratios and polymerization degree of silicic acid are prepared by copolymerization technique. The Al-Ferron timed complex colorimetric method is applied to characterize species distribution of PASC and to study its influence factors. The interaction between hydrolyzed aluminum species and polysilicic acid with different polymerization degrees in PASC is discussed.The flocculant prepared is applied to the treatment of commercial concrete wastewater. The turbidity removal of commercial concrete wastewater is up to 97% when a PASC, prepared with polysilicic acid of 145 min polymerization degree.     

Reasoning Method Based on Motorcycle Design

According to the needs of setting up a professional system based on motorcycle design,the CBR(case based reasoning) and RBR(rule based reasoning) methods are introduced.After discussing the difference between the two kinds of reasoning,a method of integrating them into the motorcycle design flow is put forward to realize the design reusable technology and improve the design efficiency,by using the CBR in the step of selecting the similar motorcycle and the RBR in project's modification according to correlative rules.     

Weighting Coefficient Optimization Unification of Lexicographic Method in Fuzzy Multi -objective Optimization Design

The Lexicographic method has subjective and empirical character,so a weighting coefficient is introduced by considering the importance and proportion of each individual object,the preferable result of every individual object can be confirmed by comparing the degree of similarity between the perfect one and the ecumenic one and the Fuzzy optimization will be perfect.The effectiveness of these methods is illustrated by a fuzzy optimal design of the three-bar truss.     

Application of Matter Element Analysis in Assessment of Ambient Air Quality

A new method for assessment of ambient air quality is proposed by using matter element analysis.This model is simple and reasonable in assessment.The practical example is given,and compared with other methods.     

移动机器人避障路径规划方法研究

以全自主移动机器人为研究平台，介绍了移动机器人的硬件体系结构、避障行为决策、避障运动控制等。提出一种足球机器人避障路径规划方法，该方法吸取了栅格法信息处理量小的优点，只对障碍物的威胁点进行检测，弥补了其在特征匹配方面的不足，同时无需考虑障碍物的运动状态和运动速度，提高了机器人避障的灵活性和鲁棒性。     

越野汽车机械自动变速器换挡规律的自适应控制

针对越野汽车载荷变化大、路况复杂而又要具有机动灵活的特点,利用自适应控制技术所建立的自适应控制器,对实际行车状况的油门、车速和冲击度进行在线估计。根据得到的实际的车辆负荷度,按照已经建立的最小和最大负荷度下的机械自动变速器换挡控制规律,通过线性插值法,建立适应实际行车状况的换挡规律,实现换挡规律的自适应控制。     

基于灰色关联度变权法的浅层地下水环境质量综合评价

引入指数型白化权函数对灰色关联度变权法中的白化权函数进行修正,使得能够对地下水更合理、客观、准确地评价。将晋江市浅层地下水看作一个灰色系统,在灰色关联度变权法模型基础上,对各水质监测点不同类别的隶属度和灰色关联度作对比分析判断其评价等级以及质量优劣次序,说明灰色关联度变权法对地下水环境质量综合评价方法适当。研究区内绝大多数地区水质状况良好,影响区域地下水质量的指标主要为TDS、锰、硝酸盐、亚硝酸盐、氨氮、氯化物,水质较差区主要分布于沿海工业分布较密集区及引污水灌溉农田地区,说明工农业发展、人类活动加剧及海水入侵是造成本区水质变化的主要原因之一。