Dependence of magnetic field just inside the magnetopause on subsolar standoff distance: Global MHD results

The subsolar magnetopause is the boundary between the solar wind and the Earth’s magnetosphere,where reduced solar wind dynamic pressure is equal to the magnetic pressure of the Earth’s outer magnetosphere.We use a global magnetohydrodynamic (MHD)model to estimate the ratio f of the compressed magnetic field just inside the subsolar magnetopause to the purely dipolar magnetic field.We also compare our numerical results to a similar work by Shue,which used Time History of Events and Macroscale Interactions during Substorms(THEMIS)data.Our results show that the ratio f is linearly proportional to the subsolar magnetopause standoff distance(r0)for both the northward and southward interplanetary magnetic field,properties consistent with Shue but with a smaller proportionality constant.However,previous theoretical studies show that f is nearly independent of the subsolar standoff distance.The global model results also show that f is smaller for the southward Interplanetary Magnetic Field(IMF)under the same r0,and that the proportionality constant for the southward IMF is larger than that for the northward IMF.Both conclusions agree with statistical results from observations by Shue.     

浅谈如何加强工程项目建设资金管理

文章对加强工程项目建设资金管理的必要性进行了分析,并对如何加强项目资金管理和运用的办法进行了分析和探讨。     

人工挖孔桩施工实践与体会

文章结合工程实例,针对人工挖孔桩在成孔过程中遇到的问题,并根据自身的实践与体会,对施工中的质量控制和特殊问题的处理方法进行了探讨.     

改性粉煤灰对空气中甲醛的吸附研究

以粉煤灰为主要材料,使用3种方法分别对粉煤灰进行改性,研究不同条件下改性粉煤灰对空气中甲醛的吸附特性和去除效果,并探讨粉煤灰对甲醛的吸附和脱附机理.研究结果表明3种改性粉煤灰对甲醛的吸附能力由高到低为:ZnCl2改性粉煤灰,热处理粉煤灰,水洗粉煤灰；在甲醛初始质量浓度为0.41 mg/m3,改性粉煤灰用量为1.0 g,温度为25℃的情况下,ZnCl2改性粉煤灰对甲醛最大去除率达70.48％,去除效果与煤基活性炭的相当(最大去除率为68.96％),远超过了未改性的粉煤灰的最大去除率(30.71％); ZnCl2改性的粉煤灰重新活化后,可重复使用,5次再生实验后的吸附率仍达60.02％.     

Estimation of net surface shortwave radiation from land surface temperature in regional scale

The method to estimate NSSR (net surface shortwave radiation) from LST (land surface temperature) in regional scale is discussed. First, an elliptical model between the time series of normalized LST and NSSR was developed using the daily evolution of LST and NSSR. Second, time series of LST and NSSR were simulated by common land model (CoLM) and were proved to be of high accuracy. On the basis of these, a non-linear least square ellipse fitting using the genetic algorithm method was used to fit the normalized LST and NSSR. Finally, LST was inverted using MODIS (moderate resolution imaging spectroradiometer) data with the split-window algorithm, and the regional NSSR was then estimated with LST and an elliptical model. The validation result shows that the derived average NSSR of 50×50 pixels of MODIS data was quite close to the observed data, and the distribution was reasonable, which indicates that the proposed method was capable of estimating NSSR on a regional scale.     

漯河市外来林业有害生物防控技术研究

开展漯河市外来有害生物调查,较为全面地掌握漯河市外来林业有害生物的种类、数量、分布、危害及生态习性,有针对性地采取综合措施治理与推广,可较好地控制主要外来有害生物发生,对保护漯河市生态环境,巩固绿化造林成果具有重要意义。     

肉桂醛臭氧化反应吸收过程的研究

实验表明，将肉桂醛臭氧化的反应器串联后，臭氧利用率可达９０％以上，文章对反应选择性及工艺条件进行了分析。     

CuMn-ZSM-5在NH_3选择催化还原NO反应中的催化活性

采用浸渍法制备CuMn-ZSM-5催化剂,在微型气固相反应装置上考察其在NH3选择催化还原NO反应中的催化活性,与ZSM-5空白样以及负载单金属氧化物进行比较,并考察反应温度、铜锰物质的量比和金属负载量对催化活性的影响,同时对催化剂进行XRD和SEM分析表征实验。研究结果表明:空白Na-ZSM-5催化剂活性很低,以Cu对其进行改性能有效提高其低温活性,但当温度高于350℃时其活性很低;以Mn对ZSM-5改性则能提高其高温活性,但低温活性很低;CuMn-ZSM-5整合了Cu-ZSM-5和Mn-ZSM-5的优点;活性金属负载量为4.5 mmol/g,铜和锰物质的量比为2:1的CuMn-ZSM-5,在250～500℃时NO去除率维持在80%以上。     

基于云模型的软件构件可复用性量化评价

构件的可复用性是构件性能最重要的评价指标之一,对构件可复用性的评价越接近实际,说明评价结果越可信.通过云模型对构件可复用性进行量化评价来提高评价的可信度.仿真实验表明,基于云模型的构件可复用性量化评价比常规方法的评价结果更接近实际,说明基于云模型的软件构件可复用性量化评价结果具有更高可信度.