Topology and Stability of Trivalent Polyhedral Clusters

An algorithm to generate the molecular graphs of the trivalent clusters is presented. All the polyhedral trivalent cages with 4-16 vertices are enumerated, with particular attention being given to their symmetry, spectra and stability. The relative stability of isomers is not decided solely by their symmetry. A new kind of spectral phenomenon is reported. This is the occurrence of graphs having the same HOMO-LUMO gap, the same E and the same even-order moments. We refer to it as 'pseudo-isospectrality'.     

多级脉冲深穿透射孔技术

目前国内较先进的射孔工艺是增效射孔和三相流射孔,这2种射孔工艺均存在射孔深度和造缝深度浅的问题,尤其是对低渗油藏和纵向渗透率远大于横向渗透率的油藏,此造缝深度并不能满足油田生产的需要.介绍了一种新型的射孔技术,它是一种能进行深度射孔造缝的多级射孔技术,利用三级推进剂燃爆时产生峰值不连续的高温、高压气流,形成多级脉冲,多次冲击射孔孔眼前沿的裂缝,使其有效延伸至地层深处,从而较单独的射孔更能有效地增加油气产量.通过地面水泥靶的试验,证明了该射孔器的延缝功能和安全性;通过塘32等井的现场试验,证明该射孔技术对污染地层解堵有显著效果,可明显地降低地层破裂压力.     

A Novel Athermal 40-Channel DWDM Multi/Demultiplexer Based on the Combination of AWGs and Interleaver

An athermal 40-channel dense wavelength-division-multiplexing multi/demultiplexer using a novel combination technology is proposed. It consists of one 1times4 100- to 400-GHz spacing interleaver filter and four sub-arrayed-waveguide gratings (AWGs). The temperature-dependent wavelength shift of the combined device is successfully suppressed to 0.058 nm in the -20degC to 70degC temperature range. Moreover, the combined device's adjacent crosstalk (typically -35 dB) is much better than conventional AWGs (typically -25 dB).     

Emergy account for biomass resource exploitation by agriculture in China

On the basis of Odum's ecological economic measure of emergy as embodied solar energy, a system account of biomass resource exploitation by agriculture in China 2004 is developed in this paper, which supplements a former study on corresponding long-term historical trends during 1978 to 2000 (Chen et al., 2006. Emergy-based analysis of the Chinese agriculture. Agriculture, Ecosystems and Environment 115, 161–173). The aggregate fluxes and indicators for biomass resource exploitation in China 2004 are calculated and illustrated when compared with those for 2000 to elucidate the latest status of the Chinese agriculture as the exploitation sector for biomass resource. Data sources and algorithm are presented in detail as basic references for related analysis involving the ecological economy of biomass exploitation in agriculture.     

新疆重质混合原油研制高等级道路沥青

对利用新疆重质混合原油生产的减压渣油作为基质沥青制备高等级道路沥青进行了研究。考察了低硫石蜡基原油（A）和含硫环烷-中间基原油（B）的掺炼比对基质沥青四组分组成的影响，减压渣油软化点与基质沥青四组分组成的关系，以及添加剂对改进沥青性质的作用。由此得出原油（B）的合适掺炼量，减压渣油软化点的控制范围和优化的生产工艺条件，调合出了符合GB／T18150—2000和JTGF40—2004要求的高等级道路沥青。     

镁法海绵钛生产工艺中大型无隔板镁电解槽的节能实践

以镁法海绵钛生产工艺中大型无隔板镁电解槽的实际节能情况为例，探讨了在镁电解生产中的非生产耗电、生产耗电、漏电等因素造成的能量浪费，阐述了生产中粗镁直流电耗、电流效率、工作电压3者之间的关系，指出了影响电解槽工作电压的有关因素及降低电解槽工作电压的途径。     

常减压蒸馏装置阻垢剂进料管腐蚀与防护

通过对常减压蒸馏装置阻垢剂进料管的材质、性能、工作条件及腐蚀形貌、腐蚀产物的全面分析,找出了使进料管发生大面积腐蚀的腐蚀介质为环烷酸.并提出了减缓阻垢剂进料管环烷酸腐蚀的措施,主要包括选用更耐蚀的316或316 L材质以及改进三通结构等.     

开发井低渗透储层中长期产能预测

研究表明，某些低渗透储层具有启动压力梯度影响，即实际生产压差只有大于某个数值时，储层流体才能流动。针对此问题，从低速非达西渗流理论入手，给出了考虑启动压力影响的低速非达西储层的产能预测方法，并在F160-126等开发评价井上进行了应用，达到了准确评价低渗透非达西储层中长期产能、指导开发井生产的目的。     

一种制备磁性粉末的新技术--均匀颗粒成型法

采用均匀颗粒成型法（Uniform Dropler Spray-UDS）制备Fe基合金粉末，该方法制备的颗粒粒度分布均匀，性能一致，大大优于传统的粉末制备方法（如破碎法、气雾化），具有广阔的应用前景。本文分析了粉末制备过程中颗粒尺寸的影响因素，结果表明：颗粒的大小主要取决于坩埚底部小孔、坩埚内外气体压强差以及振荡频率三个独立变量。     

基于遗传算法的水轮机最优工况参数计算

利用遗传算法计算水轮机的最优工况参数，给出遗传算法的具体实现步骤，并结合某电站的实际运行参数进行计算，结果表明，利用遗传算法计算水轮机的最优工况是可行的，而且寻优效率高，结果可靠。表2个。