基于地表-地下水文过程模拟的农业灌溉开采量估算

通过发展新安江模型中非饱和带、饱和含水层水量平衡计算及入渗补给、潜水蒸发、河流-地下水水量交换动态模拟功能,在对作物灌溉需水量的估算基础上,利用河流流量和地下水埋深观测资料进行模型反演,实现对灌溉开采量的估算。在淮北平原沙颖河流域井灌区应用表明,该方法不仅较好地模拟河川径流和地下水埋深动态变化,而且较好地估算出灌溉开采量动态变化过程及其对地下水埋深的影响。地下水开采量估算及地下水位动态变化对地下水控制管理具有重要价值。     

五元联系数在长江下游生态航道评价中的应用

针对生态航道评价中存在的模糊、不确定性问题,基于集对分析理论和层次分析法,建立了五元联系数模型,根据生态航道评价指标体系各指标与等级标准的联系程度,构造联系度公式,结合层次分析法计算各评价指标的权重,运用该模型开展了长江下游南京-浏河口段生态航道评价,结果表明,南京-浏河口段生态航道等级为Ⅲ级,其中航运功能、自净功能和景观娱乐功能为Ⅰ级,生态功能为Ⅳ级,需要结合该河段实际情况加强生态环境保护工作。敏感性分析表明,功能层权重的小幅度波动不会对评价结果造成较大影响,说明对该河段的评价结果比较稳定。     

岗南水库上游流域大气氮干湿沉降研究

以岗南水库上游流域为研究对象,在岗南水库及其控制流域设置5个采样点位,分析2015年7月至2016年6月流域大气氮素干、湿沉降通量时空分布特征。结果表明,岗南水库流域总氮干、湿沉降通量范围分别为17.7～134.7kg/(km~2·月)和9.9～386.8kg/(km~2·月)。大气干沉降以硝态氮和有机氮为主,春、夏季较高;湿沉降中氮素形态以氨态氮和硝态氮为主,夏季最高,春季次高,秋冬季较低。空间分布上,呈现出由西北向东南不断增加的趋势。利用大气氮素总沉降量、流域面积以及水库水面面积计算得到全流域大气总氮沉降入河负荷量为3 674t/a,直接沉降入库负荷量为105.16t/a。     

单级泵站不同机组流量分配的优化研究

调水工程中泵站建成后,在不同的时期承担不同的调水任务,为了完成各种调水任务,往往使水泵在不同的工况点运行。基于离散的单级泵站运行工况点,对泵站的流量分配进行了优化研究;在满足水泵流量、扬程和各种水力学条件的约束下,以泵站整体效率最高为目标函数,基于一些工况进行了不同机组流量分配的对比研究,建立了流量优化分配数学模型,得出了各个工况点下泵站内机组流量分配的最优组合。     

Platinum impregnated zeolite β as a reforming catalyst

It is shown that Pt impregnated w5075750j9124112/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0"> zeolite has a high reforming capability for naphthenic feeds such as methylcyclopentane and methylcyclohexane, which are transformed in aromatic and cyclic saturated multibranched molecules with higher octane numbers. The temperature plays a major role in these reactions. The cycloolefinic intermediates produced by the dehydrogenation of the feed molecules are alkylated with the carbonium ions produced by the ring opening of other feed molecules. The disproportionation of the alkylated compounds is suggested to be responsible for the enlargement of the feed molecules. This disproportionation, the isomerization of the cycloolefinic intermediates, and some cracking particularly for methylcyclohexane, are proposed to be responsible for the product distribution under the present conditions.     

Chemical effects in commercial and laboratory mixtures of ‘reactive’ phosphate rock and acidulated fertilisers

The chemical analyses of different size fractions of a variety of commerical and laboratory prepared samples of partially acidulated phophate rocks and mixtures of w80481/xxlarge8216.gif" alt="lsquo" align="BASELINE" BORDER="0">reactivew80481/xxlarge8217.gif" alt="rsquo" align="BASELINE" BORDER="0"> phosphate rock and single superphosphate (called LONGLIFE in New Zealand) have been studied. Whereas only minor chemical segregation effects have been observed for partially acidulated products quite a large bias has been established for LONGLIFE materials, and more especially commercial samples, where larger proportions of phosphate rock were found in the lower size fractions. This inhomogeneity was considered to arise from poor mixing of components and subsequent inconsistent granulation; more stringent rejection criteria for undersize material would greatly assist in improving the product quality. Chemical w80481/xxlarge8216.gif" alt="lsquo" align="BASELINE" BORDER="0">deactivationw80481/xxlarge8217.gif" alt="rsquo" align="BASELINE" BORDER="0"> of the phosphate rock residue in LONGLIFE materials was also observed; this can be partially explained by a selective reaction of the w80481/xxlarge8216.gif" alt="lsquo" align="BASELINE" BORDER="0">reactivew80481/xxlarge8217.gif" alt="rsquo" align="BASELINE" BORDER="0"> phosphate rock component with acid still present at the time of mixing with the single superphosphate component.     

Himachalol andβ-himachalene: Insecticidal principles of himalayan cedarwood oil

Chromatographic fractions of Himalayan cedarwood oil (Cedrus deodara) were bioassayed against the pulse beetle (Callosobruchus analis F.) and the housefly (Musca domestica L.). Almost all fractions showed insecticidal activity against both test species. Fractions I and V led to the highest mortality and also produced a quick knockdown effect. Fractions I and V, after rechromatography and purification, yielded himachalol (3%) and w46424105q/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-himachalene (31%), based on essential oil weight, respectively. Further evaluation of these two naturally occurring sesquiterpenes indicated 97.5% mortality at 0.56 w46424105q/xxlarge956.gif" alt="mgr" align="MIDDLE" BORDER="0">mol/insect against the pulse beetle. These biologically active natural products of plant origin may serve as a suitable prototypes for development of commercial insecticides.CIMAP Publication No. 598.     

Porous Properties of γ-Alumina/Potassium Aluminosilicate Gel Composites Prepared by Selective Leaching and Precipitation Method

Composites of mesoporous w150750451024q/xxlarge947.gif" alt="gamma" align="MIDDLE" BORDER="0">-alumina and potassium aluminosilicate (KAS) gel were prepared by selective leaching of calcined kaolinite using KOH solution followed by neutralization of the solution at pH 5.5 with nitric acid. The porous properties of the composites were characterized by N₂ gas adsorption and their microtextures were observed by electron microscope. The resultant composites have specific surface areas of about 290 m²/g, pore sizes of about 1.85 nm in radius and pore volumes of about 0.5 ml/g. The porous properties of the composites are compared with those of w150750451024q/xxlarge947.gif" alt="gamma" align="MIDDLE" BORDER="0">-alumina and KAS gel.     

Solid-liquid phase equilibria of (α-methylnaphthalene + β-methylnaphthalene) and (chlorobenzene + bromobenzene) systems under high Pressures

Solid-liquid phase equilibria of the (w21317/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-methylnaphthalene + w21317/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-methylnaphthalene) and the (chlorobenzene + bromobenzene) systems have been investigated at temperatures from 278 to 343 K and pressures up to 500 MPa using a high-pressure optical vessel. The uncertainties of the measurements of temperature, pressure, and composition were within ±0.1 K, ±0.5 MPa, and ±0.001 mole fraction, respectively. In both systems, the freezing and melting pressures at a constant composition increase almost linearly with increasing temperatures. In the former system, where the two components can form a solid solution with one another to a limit extent, the eutectic point shifts to a higher temperature and to a w21317/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-methylnaphthalene-rich composition with increasing pressures. In the latter system, where the two components are completely soluble in each other in the solid phase, the freezing points of all mixtures lie between those of the pure components at each pressure. It is found that the coexistence curves obtained can be expressed by a quadratic equation in pressure.     

SiC(w)-ZrO2改性MoSi2复相陶瓷的组织与性能

通过热压烧结制备SiC(W)-ZrO2-MoSi2复相陶瓷,利用X射线衍射仪、图像分析仪、透射电镜对复相陶瓷试样组织结构进行了研究,探讨了SiC(W)-ZrO2协同作用对MoSi2陶瓷性能的影响.结果表明:纳米ZrO2颗粒的加入对材料的细化作用较SiC晶须明显,复相协同作用细化效果更好.SiC(W)-ZrO2协同作用的综合机制有利于提高复相陶瓷的抗弯强度和断裂韧性,ZrO2量的增加对提高复相陶瓷断裂韧性的作用更明显;ZrO2粒子钉扎位错,导致可动位错绕过,强化材料基体.弥散分布的SiC晶须阻碍位错运动,使位错缠结、交割,阻碍晶界迁移;粒子周围出现孪晶以及SiC晶须引起的层错,阻碍其晶粒长大.