载体对甲烷催化部分氧化制合成气的影响

运用固定床流动反应装置、ＴＰＲ和ＸＲＤ等手段考察了载体的晶相组成、比表面和孔结构等性质对Ｎｉ基催化剂在甲烷部分氧化制合成气中反应性能的影响。结果表明，热稳定性好、导热好的惰性材料如（Ｃａ）ＭｇＡｌ２Ｏ４等是甲烷部分氧化制合成气理想的催化剂载体。载体必须具有适当的比表面和孔结构，以利于反应物分子在催化剂表面吸附并与活性中心充分接触，同时也有利于产物分子脱附并离开催化剂表面，防止副反应（积碳反应和燃烧反应）的发生，及时把反应热移走，避免热点产生使催化剂失活。另外还发现，具有不同比表面和孔结构的催化剂具有不同的最佳空

内蒙古“十一五”规划对水资源的影响评价

水资源是内蒙古自治区经济社会发展的刚性约束资源。从水资源供需平衡角度评价了内蒙古自治区"十一五"国民经济和社会发展规划的目标及方案是否在水资源供给能力之内。采用情景分析法和承压法评价了内蒙古"十一五"规划的水资源供需平衡以及未来对水资源的影响。结果表明,按照"十五"期间的节水力度(情景1),到2010年内蒙古需水总量为2.52×10~(10)m~3,按"十一五"规划的节水力度(情景2),则需水总量为2.06×10~(10)m~3,预计可供水量为2.29×10~(10)m~3。在情景1时水资源缺口达2.36×10~9 m~3,在情景2时,水资源盈余2.2×10~9m~3。从总体来看,只要加大节水力度,内蒙古"十一五"规划目标完全在水资源的供给能力之内。但由于水资源区域分布差异大,中西部地区在情景2时仍然处于缺水状态,因此,中西部地区需要调整规划的农业灌溉面积和局部工业发展规模

Study on Expense Stickiness of the Central Enterprises:A Perspective of Performance Evaluation

本文以2001~2006年上市公司年度财务数据为样本,研究了在《中央企业负责人经营业绩考核暂行办法》出台前后我国中央企业上市公司费用“粘性“的情况,结果发现:(1)央企上市公司的费用“粘性“存在;(2)在央企负责人第一个任期的2004~2006年考核期间,费用“粘性“程度有所降低;(3)央企不同行业的上市公司之间不存在费用“粘性“差异,考核办法出台前后不存在费用“粘性“差异。本文的研究结论是:费用“粘性“在央企中普遍存在,但是绩效评价制度对其会产生正向的影响。With the analysis of accounting data during 2001 to 2006 from Chinese listed companies which controlled by Stated-owned Assets Supervision and Administration Commission of the State Council (central enterprises),we studied on the expense stickiness.We find:(1) there was expense stickiness in central enterprises indeed.(2) the expense stickiness level decreased during the period of the first performance evaluation to the top management team in the listed companies controlled by Stated-owned Assets Supervision and Administration Commission of the State Council.(3)there isn't difference across industry of the central enterprises.Our conclusion is:the expense stickiness exists in general,but the performance evaluation system can give positive effect to it

Effect of pressure on joint cascade of kinetic energy and helicity in compressible helical turbulence

Direct numerical simulations of three-dimensional compressible helical turbulence are carried out at a grid resolution of 1024(3) to investigate the effect of pressure, which is important for the joint cascade of kinetic energy and helicity in compressible helical turbulence. The principal finding is that the pressure term of the helicity equation [defined as Phi(H) = p partial derivative(i)(omega(i)/rho)] has a smaller effect on the helicity cascade in the aspect of amplitude and a smaller effective range, which leads to a longer inertial subrange of the helicity cascade, in contrast to a kinetic energy cascade. In addition, we also find that the effective range of Phi(H) is concentrated only in large scales statistically, which is similar to the effect of the pressure term of the kinetic energy equation (defined as Phi(E) = p partial derivative(i)u(i)). From the overall sense of the effect of Phi(E) and Phi(H) on the kinetic energy and the helicity, respectively, both of them play a role of dissipation especially in the compression region. We propose that high enough helicity can affect the process of energy transformation between kinetic energy and internal energy, which means that the absolute local helicity hinders the process of kinetic energy transferring to internal energy, and promotes internal energy transferring to kinetic energy. In addition,Phi(H) plays a source role both for positive and negative helicity. We also study the mechanism of cancellations between compression and rarefaction regions, and we find that the impact of a shocklet on the helicity cascade can be ignored statistically.</p