不同桩芯微型桩抗弯承载力试验研究∗

为研究不同桩芯微型桩在隧道洞口不良地质边坡中的治理效果,拟对钢筋-混凝土、工字钢-混凝土、钢管-钢筋-混凝土、钢管-工字钢-混凝土微型桩开展抗弯极限承载力试验。研究表明,工字钢-混凝土微型桩相比钢筋-混凝土微型桩极限抗弯承载力不仅大幅度提升,其抵抗位移变形的能力也有所增加。钢筋-混凝土微型桩和工字钢-混凝土微型桩桩径由140 mm变化到203 mm,韧性分别提高25%、50%,抗弯承载力分别提高89%、91%。钢管微型桩的韧度、极限抗弯承载力都明显强于裸露混凝土桩,即使变形已非常显著,仍能继续受力。钢管-钢筋-混凝土微型桩、钢管-工字钢-混凝土微型桩桩径由140 mm变化到203 mm,抗弯承载力分别提高近256%、265%。     

芳香族化合物的生物降解途径

分析了以苯、甲苯、萘和联苯为代表的芳香族化合物的生物降解途径,发现其共同点都是经过两步加氧酶作用生成二醇,最后再开环;介绍了苯、甲苯、萘和联苯这几种芳香族化合物分解酶的组分、相对分子质量及其辅基。     

稀土湿法冶炼废水处理与资源化研究

对某稀土湿法冶炼工艺进行了以清洁生产为核心的技改方案研究,在清洁工艺设计的基础上,通过工艺原理分析和试验,说明其革新工艺的经济有效性;从酸浸废液中年回收硫酸亚铁３０００ｔ,从碱转废液中年回收硫酸钠３０００ｔ;从废水回收冰晶石,氟回收８６％;     

对中国排污收费制度改革的思考

排污收费制度是中国环境政策中一个核心的管理手段。它是我国为强化环境管理，运用经济手段，促进工业企业污染防治的一个独特的制度。在新的市场经济体制下和环境目标下，这项制度已不能适应社会主义市场经济发展的需要，因而在必要进行改革以适应新形势下环境保护工作的需要。在分析现行排污收费制度基础上，对我国现行的收费制度、政策和标准等的改革提出见解。     

Context-dependent crypsis: a prey’s perspective of a color polymorphic predator

Many animals use body coloration as a strategy to communicate with conspecifics, prey, and predators. Color is a trade-off for some species, since they should be visible to conspecifics but cryptic to predators and prey. Some flower-dwelling predators, such as crab spiders, are capable of choosing the color of flowers where they ambush flower visitors and pollinators. In order to avoid being captured, visitors evaluate flowers visually before landing. The crab spider Mecaphesa dubia is a polymorphic species (white/purple color morphs), which inhabits the flower heads of a dune plant, Palafoxia lindenii. Using full-spectrum photography of spiders and flowers, we evaluated how honeybees perceived the spiders at different distances. Using visual modeling, we obtained the chromatic and achromatic contrasts of the spiders on flower heads as perceived by honeybees. Purple morphs were found mainly on the receptacle area and white morphs were equally likely to be found in the flowers and receptacle. According to theoretical modeling, white morphs were visible to honeybees from a distance of 10 cm in receptacle area but appeared to be cryptic in the flower area. Purple morphs were cryptic on the receptacle and less so when they were on the flowers. Spiders on flower heads are predicted to be more easily detected by honeybees using chromatic contrast. Our study shows that the conspicuousness of flower dwelling spiders to honeybees depends on the color morph, the distance of observation, and the position of spider on the flower head.