锆改性沸石活性覆盖控制重污染河道底泥氮磷释放研究

通过实验考察了锆改性沸石对水中磷酸盐和铵的吸附去除作用,并考察了锆改性沸石活性覆盖控制底泥溶解性磷酸盐和铵释放的效率。锆改性沸石对水中磷酸盐的吸附能力随pH值的增加而降低：当pH值由4增加到5时,锆改性沸石对水中铵的吸附能力增加;当pH值5-8时,对铵的吸附能力较高;当pH值由8增加到10时,对铵的吸附能力下降。锆改性沸石对水中磷酸盐和铵的吸附动力学满足准二级动力学模型,并且对磷酸盐和铵的吸附速率比较快。Langmuir和Freundlich等温吸附模型可以用于描述锆改性沸石对水中磷酸盐和铵的吸附平衡数据,根据Langmuir模型计算得到的锆改性沸石对水中磷酸盐和铵的最大吸附量分别为7．75mg·g-1和9．59mg·g-1（pH7和25℃）。锆改性沸石对水中磷酸盐和铵的去除率随锆改性沸石投加量的增加而增加,其吸附水中磷酸盐的主要机制是配位体交换,吸附水中铵的主要机制是阳离子交换。被锆改性沸石所吸附的磷酸盐大部分（82．5％）以较为稳定形态磷（NaOH—P）存在,低溶解氧条件下不容易重新被释放出来。吸附磷酸盐后锆改性沸石中水溶性磷（WSP）、易解吸磷（RDP）和NaHCO,可提取态磷（Olsen—P）含量非常低,藻类可利用磷（AAP）含量仅占总磷含量的29％左右。低溶解氧条件下,重污染河道底泥会释放出大量的溶解性磷酸盐和铵,锆改性沸石活性覆盖则不仅可以使上覆水中的溶解性磷酸盐浓度控制到很低的水平,而且可以明显降低铵由底泥向上覆水迁移的速率。上述实验结果表明,锆改性沸石适合作为一种活性覆盖材料用于控制底泥溶解性磷酸盐和铵的释放。     

江苏省农村居民点用地整理的分区与时序

影响江苏省农村居民点整理的因素南北差异巨大,开展全省范围内农村居民点整理分区和整理时序研究,对于指导农村居民点整理决策具有重要意义。该文构建了自然、经济、社会、土地和建筑5大因素17个指标的评价体系,采用因子分析方法提取了5个公共因子,计算了65个评价单元的综合分值,按评价值划定了5个分区并确定了整理时序。研究表明：采用因子分析方法划定农村居民点整理分区并确定整理时序结果可信;地区经济发展水平、人口结构和农村居民点用地集约利用度对整理的影响最大;5个分区的总体分布趋势是苏南向苏北逐渐过渡;整理时序靠前的分区区位相对优越、经济发达,但整理成本较高,时序靠后的分区经济欠发达,但整理成本较低。该研究可为制定土地整治规划、确定土地整理项目提供决策依据。     

RANGELAND DEGRADATION ON THE QINGHAI‐TIBET PLATEAU: IMPLICATIONS FOR REHABILITATION

With ever intensifying land use, land degradation is becoming an increasingly important issue around the world, especially in China. This paper evaluates the extent and underlying causes of rangeland degradation on the Qinghai‐Tibet Plateau in China through a comprehensive review of the literature. Diverse forms and differing intensities of rangeland degradation have been reported in several regions of the Plateau. Rangeland degradation is particularly severe in South Qinghai, North Tibet and the Qaidam Basin. Anthropogenic activities, especially changing land use practices, are identified as the primary force driving rangeland degradation. Dissimilar to climate change‐induced degradation, such anthropogenic degradation is a rather short‐term process altering the abiotic properties of the underlying soil. On the basis of these findings, we assessed the prospects of rehabilitating degraded rangeland to productive uses. Different measures are proposed to rehabilitate rangelands that have been degraded by different mechanisms. Reduction in grazing intensity is prescribed to rehabilitate reversibly degraded rangelands. Targeted human intervention in the forms of selective planting of grasses and artificial seeding, in conjunction with ecological and biological control of the plateau rodent population, is recommended to rehabilitate ‘irreversibly’ degraded rangelands. Our studies suggest it is very difficult or even impossible to rehabilitate new assemblage of species which appear as a result of climate change. Copyright © 2011 John Wiley & Sons, Ltd.     

Clarification of the etiology of peach bacteria leaf shot hole caused by Pantoea spp. in Henan Province,China, based on morphological characteristics and multi-locus sequences analysis

European Journal of Plant Pathology - Peach bacteria leaf shot hole is a commonly occurring foliar disease of economic importance, which severely affects the host photosynthesis and contributes to...     

辣椒新品种晋椒401的选育

晋椒401是以母本M4627、父本F4352配制的杂交辣椒新品种,适宜干制。晚熟,植株生长势强,株型直立,株高70 cm左右,开展度54 cm×56 cm左右。叶色绿,始花节位10节;果实羊角形,顺直,果面微皱,青熟果绿色,老熟果红色;果纵径18.4 cm,果横径1.1 cm,单果质量8 g左右;果皮薄,易干制,辣味浓。较抗疫病,耐病毒病和疮痂病,抗倒伏,适应性广。一般每667 m2产鲜椒2300kg。     

PVP-碘对南美白对虾无节幼体的急性毒性试验

采用静水试验法，用PVP-碘对南美白对虾无节幼体进行了急性毒性试验。试验结果表明：PVP-碘对南美白对虾无节幼体的24h及40h半致死浓度分别为8.737mg/L及6.512mg/L，其安全浓度为0.65mg/L。     

花椒枝屑栽培金针菇的研究

以落叶灌木树种花椒树的枝屑作为栽培原料进行金针菇栽培试验。结果表明：花椒枝屑占比为45% 的原料配方适
宜于金针菇栽培,金针菇子实体产量、生物学效率与对照（以棉籽壳为主料的常用栽培配方）相近,略低于对照;金针菇中
Ca、Fe 含量较高,与对照差异达极显著水平,但Mg、Cu、Zn 含量、蛋白质等营养成分与对照间差异不显著;金针菇中氨
基酸总量、必需氨基酸总量高于对照;以花椒枝屑作金针菇栽培原料可降低成本,投入产出比较高。     

通径分析与灰色关联分析的比较

利用两组试验数据对通径分析与灰色关联度分析进行了比较。结果表明：通径分析是在考虑自变数间相互关系的基础上进行的，而灰色关联分析未考虑自变数间的关系。采用两种方法分析同一数据得出的自变量相对重要性位次不同，但关联度位序与相关系灵敏绝对值的位次基本一致。     

海坛岛木麻黄防护林生态经济效益研究

采用直接计算法和替代工程法,对海坛岛木麻黄防护林的生态经济效益进行了评估,重点计算了涵养水源、防风增产、土壤保育、固碳制氧这4个主要的生态经济效益。结果表明：海坛岛木麻黄防护林具有较大的生态经济效益,具体为：涵养水源效益6980．81万元·a-1,防风增产效益987．71万元·a-1,固碳制氧效益344．99万元·a-1,土壤保育效益173．63万元·a-1。研究结果可作为建立海坛岛木麻黄防护林生态补偿机制的依据。     

Parameter Optimization Analysis of Viscous Dampers for Dissipation Structure

The design method of parameter optimization of nonlinear viscous dampers for dissipation structure was analyzed based on response surface methods. The method included experimental design, finite element analysis, fitting the response surface function and parameter optimization. Taking a reinforced concrete frame structure for an instance, the mathematical model of parameter optimization of viscous dampers for dissipation structure was established by taking the minimum all damping force as objective function and taking the interlayer maximum displacement less than limits as constraints, and then the damper parameters were optimized using the method of nonlinear programming optimization. The results show that the method of parameter optimization of viscous dampers based on response surface method can ensure the structural displacement is less than limit and the construction cost can be reduced.