Methane hydrate dissociation experiment in a middle-sized quiescent reactor using thermal method

Dissociation kinetic behavior of methane hydrate was studied at 268.15 K using thermal method in a closed quiescent middle-sized reactor of 10 L, which with a multi-deck cell-type vessel as the internals and coiled copper tubes placed inside assuring hydrate form or dissociate in all cells of the vessel simultaneously to reduce or eliminate the scale-up effect. A dramatically reduced dissociation rate phenomenon - “buffered dissociation” due to the ice melting was observed. The influences of the water temperature, the heating rate, the quantity of hydrate, and the dissociation pressure upon the dissociation rate and the extent of the buffering effect were investigated experimentally to reveal the gas production mechanism from hydrate below the ice point. The experimental results indicate that the rate of heat transfer and the thermodynamic driving force were the key rate-limiting factors for hydrate dissociation in the closed reactor. The buffering effect of gas production can be eliminated and the dissociation rate can be increased by increasing the temperature of the heating water and lowering the dissociation pressure. However, the temperature buffering behavior cannot be eliminated.     

Trace metals and organochlorines in the bamboo shark Chiloscyllium plagiosum from the southern waters of Hong Kong, China

The bamboo shark Chiloscyllium plagiosum is an abundant benthic species along the shallow continental shelf of Southeast Asia. It is commonly taken by fishermen in China, India, Taiwan and Thailand for human consumption. This study measured trace metal and organochlorine concentrations in C. plagiosum collected from the southern waters of Hong Kong, China. Metals (Ag, Cd, Cr, Cu, Mn, Ni, Pb and Zn) were measured in three different tissues: dorsal muscle, spleen and liver. Polychlorinated biphenyls (PCBs) and chlorinated pesticides in the dorsal muscle were identified and quantified using gas chromatography. Metal concentrations varied among the three different tissues, with liver having higher levels of Ag and Cd, and spleen possessing higher levels of Cu and Mn. Both Ni and Pb in all tissues were below the detection limit. Tissue concentrations of Cr, Cu, Mn and Zn generally decreased with increasing body weight whilst no significant concentration-size relationship was found for other metals. In muscle tissues, total PCBs ranged from 1.056-4.771 ng/g (wet wt.) with a median of 1.801 ng/g, while total DDTs ranged from 0.602-23.55 ng/g with a median of 1.109 ng/g, in which p,p'-DDE was the predominant metabolite. Levels of total hexachlorohexanes and cyclodienes were low. The pesticide p,p'-DDT was the only compound found to be positively correlated with body weight, indicating temporal bioaccumulation of this compound. Zn concentrations in the muscle of C. plagiosum were comparatively higher than recorded in other shark species, however, concentrations of other metals and organochlorines were relatively low. C. plagiosum feeds primarily on polychaetes, shrimps and small fishes, and thus is unlikely to contain levels of contaminants of human health concern.     

利用地形图生成DOM数据的研究

作为地理信息系统数据库的基本数据层,数字正射影像数据还可以满足各类用户的信息需求,如:空间定位及矢量数据的质量控制、城市规划、环境分析、三维景观显示以及流域管理和防汛调度、水资源利用、水环境保护等,提出了一种用三维地形图生产DOM数据的一般流程。     

气相色谱法研究超声波对变压器油的影响

应用气相色谱法研究了超声波对变压器油的影响,并与振荡法测定结果进行了对比。实验结果表明,超声波可使变压器油发生分解,生成H2,CO,CH4,CO2,C2H4,C2H6,C2H2等可溶于变压器油的气体,且溶解于变压器油中的这些气体的含量随超声功率及超声时间的不同而不同;在50℃、超声功率210 W左右、超声时间30 min的优化超声条件下,变压器油样中各种溶解气的含量达到最大,即H2 1.540×103μL/L、CO 6.128×102μL/L、CH44.834×102μL/L、CO2 2.541×102μL/L、C2H4 1.550×103μL/L、C2H2 4.709×102μL/L、C2H6 2.182×102μL/L。与振荡法相比,变压器油经超声波处理后,溶解气中这7种气体的含量增加了100～3 350倍。超声波对被超声物具有分解作用,变电站附近不应安放超声装置,用超声波处理试样时应考虑它对试样的不利影响。     

柴油催化燃烧添加剂制备研究

通过对添加剂的组成及配比的研究 ,得到一种新型高效柴油催化燃烧添加剂。测定了添加剂的理化性质。对添加剂的节油率及烟度降低率进行了综合测试和评价     

气体钻井的录井监测方法

由于气体钻井循环系统的流体介质改变——由常规的液态变为气态,致使传统的录井方法无法适应,表现为:①粉尘状岩屑采集困难且样品质量很难满足要求;②因出口样气中粉尘掺混,易产生管路堵塞,影响气测分析结果的精度;③综合录井仪原有的密度、电导率等参数无法监测,切断了地层流体信息识别和井下工况异常的及时报警。针对这些难题,通过现场调研和探索,分别研制出"岩屑自动取样装置"、"气体净化装置"和"气体钻井实时监测系统",实现了气体钻井连续、自动录取岩屑,提高了钻井地质剖面的符合率;实现了样品气的连续、干燥、无尘获取,确保了气测分析精度的需要;在出口管线的适当位置加装湿度和硫化氢等集成传感器,实现了气体钻井出口参数的实时监测和工程、地质异常的预警,为安全钻井施工方案的制订提供了依据。该方法与技术经现场多口井应用与推广,取得了良好的效果,获得了2项实用新型专利并申请了1项软件著作权登记。     

灰色补偿神经网络及其应用研究

本文给出了灰色系统与神经网络的一种新的结合方式—灰色补偿神经网络。该网络利用神经网络建立残差与数据间的映射关系,并采用其预测结果补偿灰色系统模型的预测值。仿真结果表明本方法优于其它灰色神经网络。     

Fuzzy combination of fuzzy and switching state-feedback controllers for nonlinear systems subject to parameter uncertainties.

This paper presents a fuzzy controller, which involves a fuzzy combination of local fuzzy and global switching state-feedback controllers, for nonlinear systems subject to parameter uncertainties with known bounds. The nonlinear system is represented by a fuzzy combined Takagi-Sugeno-Kang model, which is a fuzzy combination of the global and local fuzzy plant models. By combining the local fuzzy and global switching state-feedback controllers using fuzzy logic techniques, the advantages of both controllers can be retained and the undesirable chattering effect introduced by the global switching state-feedback controller can be eliminated. The steady-state error introduced by the global switching state-feedback controller when a saturation function is used can also be removed. Stability conditions, which are related to the system matrices of the local and global closed-loop systems, are derived to guarantee the closed-loop system stability. An application example will be given to demonstrate the merits of the proposed approach.     

高效阳离子聚合物絮凝剂的制备及性能研究

通过反相乳液法合成了不同阳离子度的丙烯酰胺（AM）与二甲基二烯丙基氯化铵（DADMAC）二元共聚物及AM与DADMAC和甲基丙烯酰氧乙基三甲基氯化铵（DMC）三元阳离子共聚物。分别考察了二元单体质量比和三元单体摩尔比对共聚物性能的影响,结果表明,二元共聚物中DADMAC单体反应不完全;三元共聚物中随着DMC含量的增加,共聚物阳离子度和特性粘数也随之增加。考察了共聚物阳离子度对絮凝效果的影响,结果表明,当共聚物阳离子度达65％～68％时,处理膨润土悬浮体系的效果较佳。     

WZ12-1油田南块涠四段油层有效厚度研究

针对WZ12-1油田南块涠四段低孔、低渗、低电阻率油层有效厚度划分中存在的问题,提出了油层有效厚度划分的图版参数。利用目的层段测井、地质和试油资料的统计分析和综合归纳,建立起储层岩性、电阻率、孔隙度、泥质质量分数、渗透率及含油饱和度的有效厚度下限标准。从而,在该区低电阻率、低孔、低渗、高水饱油层有效厚度评价中精细地反映储层岩性、物性和含油性特征,有效地剔除了钙质及泥质夹层、致密层、干砂层和不够标准的差油层,确定了各井油层的有效厚度,提高了测井解释和储层研究精度,为该区低孔低渗油田增储上产提供了有利目标。