Selection of risk response actions with consideration of secondary risks

Secondary risk in project risk management refers to the risk that arises as a direct result of implementing a risk response action (RRA). It is important for project managers (PMs) to consider the effects caused by the secondary risks in the process of RRA selection. The purpose of this paper is to propose an optimization method to address the problem of selecting risk response actions (RRAs) with consideration of secondary risk which is seldom considered in the existing studies. The optimization model aims to minimize the total risk costs with time constraint being placed on the project makespan. By solving the model, an optimal set of RRAs along with the earliest start time for each activity can both be obtained. The results show that secondary risk plays an important role in the process of RRA selection. Project managers should allocate more budget for responding the project risk when the secondary risk is considered, and consider all factors relating to both time and cost so as to select appropriate RRAs to mitigate primary risk and secondary risk.     

次生生物甲烷与生物降解作用的判识——以准噶尔盆地腹部陆梁油气田为例

“次生生物气”是指原油遭受生物降解后生成的天然气，由于其成分几乎全部为甲烷，因此又称为“次生生物甲烷”。以准噶尔盆地陆梁油气田为例，基于天然气组分和稳定碳同位素组成，结合伴生原油的轻烃地球化学特征，系统研究了次生生物甲烷和生物降解作用的判识方法。研究表明：当热成因天然气与次生生物甲烷混合时，甲烷碳同位素组成变轻，天然气组分变干。同时，此类天然气通常与埋深(地温)和生物降解油藏密切相关。通过原油的轻烃化合物特征可以有效判别油藏是否遭受生物降解。次生生物甲烷的生成常常还伴随着原生热成因气中重烃气组分的选择性降解，造成天然气干燥系数变大，重烃气碳同位素组成富集¹³C，甚至发生倒转。目前使用的各类天然气成因判识图版只适用于原生热成因气，使用时必须充分考虑是否存在各类次生改造作用的影响。     

A method for evaluating paleo hydrocarbon pools and predicting secondary reservoirs: a case study of the Sangonghe Formation in the Mosuowan area, Junggar Basin

Taking the Jurassic Sangonghe Formation in the Mosuowan-Mobei area of the Junggar Basin as an example, this paper provides a method that evaluates paleo hydrocarbon pools and predicts secondary reservoirs. Through Quantitative Grain Fluorescence (QGF) experiments, well-tie seismic correlation, and paleo structure analysis, the scale and distribution of paleo hydrocarbon pools in the study area are outlined. Combining current structural features and fault characteristics, the re-migration pathways of paleo oil and gas are depicted. Based on barrier conditions on the oil re-migration pathways and current reservoir distribution, we recognize three types of secondary reservoirs. By analyzing structural evolution and sand body-fault distribution, the major control factors of secondary reservoirs are specified and, consequently, favorable zones for secondary reservoirs are predicted. The results are mainly as follows. (1) In the primary accumulation period in the Cretaceous, paleo hydrocarbon pools were formed in the Sangonghe Formation of the Mosuowan uplift and their size and distribution were extensive and the exploration potential for secondary reservoirs should not be ignored. Besides, paleo reservoirs were also formed in the Mobei uplift, but just small scale. (2) In the adjustment period in the Neogene, traps were reshaped or destroyed and so were the paleo reservoirs, resulting in oil release. The released oil migrated linearly northward along the structural highs of the Mobei uplift and the Qianshao low-relief uplift and then formed secondary reservoirs when it met new traps. In this process, a structural ridge cooperated with sand bodies and faults, applying unobstructed pathways for oil and gas re-migration. (3) The secondary hydrocarbon pools are classified into three types: low-relief anticlinal type, lithologic pinch-out type and fault block type. The distribution of the first type is controlled by a residual low uplift in the north flank of the paleo-anticline. The second type is distributed in the lithologic pinch-out zones on the periphery of the inherited paleo uplift. The third type is controlled by fault zones of which the strikes are perpendicular to the hydrocarbon re-migration pathways. (4) Four favorable zones for secondary reservoirs are predicted: the low-relief structural zone of the north flank of the Mosuowan paleo-anticline, the fault barrier zone on the western flank of the Mobei uplift, the Qianshao low-relief uplift and the north area of the Mobei uplift that parallels the fault zone. The study above effectively supports the exploration of the Qianshao low-relief uplift, with commercial oil discovered in the Qianshao1 well. Besides, the research process in this paper can also be applied to other basins to explore for secondary reservoirs.     

螯合树脂塔智能化控制的优化

介绍了螯合树脂塔的工作流程,分析了原控制系统存在的问题,提出了智能化改造方案,达到了预期效果。     

Teacher regulation of multiple computer-supported collaborating groups

Teachers regulating groups of students during computer-supported collaborative learning (CSCL) face the challenge of orchestrating their guidance at student, group, and class level. During CSCL, teachers can monitor all student activity and interact with multiple groups at the same time. Not much is known about the way teachers diagnose student progress and decide upon appropriate interventions when they regulate multiple groups synchronously. This explorative study describes the strategies and experiences related to regulating the activities of seven groups of students, as reported by two teachers, and aimed to widen the framework for describing teacher regulation of CSCL settings that are characterized by synchronicity. Recurring themes included the high amount of information load teachers experienced while diagnosing students’ needs, the focus and level of regulation, and the way the teachers used prior knowledge of students to decide on an intervention after diagnosis. Both teachers valued the ability to monitor student progress online, and mentioned the necessity of students being able to follow the teacher’s activity as well. Theoretical implications are described in terms of understanding teacher regulation, synchronicity, and information load. Practical implications are described for lowering information load.     

Secondary school educators' perceptions and practices in handling cyberbullying among adolescents: A cluster analysis

School educators play an important role in cyberbullying management. Since scarce earlier research indicated low perceived competence of school educators in handling cyberbullying, more insight is needed in what determines their actions and how to improve these practices. This study assessed school educator practices, their perceptions and context factors from a behavior change theoretical framework, and investigated educator clusters related to this. An online survey was conducted among 451 secondary school educators (teachers, principals, school counselors). School educators mostly used recommended actions (i.e. conversations with pupils, enlisting professionals for support, parental involvement, providing supportive victim advice). Four educator clusters were identified: ‘referrers’ (65%), ‘disengaged’ educators (14%), ‘concerned’ educators (12%) and ‘use all means’ educators (9%). The first two clusters were less adept at handling cyberbullying and comprised mostly teachers, particularly indicating a need for training teachers. Our findings show a need for tailored educator training, e.g. by job position, gender, school size and grade. The behavior change theoretical framework can help target educators' particular needs.     

不同折流板结构螺旋折流板换热器传热性能的比较(英文)

Numerical simulations were performed on flow and heat transfer performances of heat exchangers having six helical baffles of different baffle shapes and assembly configurations, i.e., two trisection baffle schemes, two quadrant baffle schemes, and two continuous helical baffle schemes. The temperature contour or the pressure contour and velocity contour plots with superimposed velocity vectors on meridian, transverse and unfolded concentric hexagonal slices are presented to obtain a full angular view. For the six helix baffled heat exchangers, the different patterns of the single vortex secondary flow and the shortcut leakage flow were depicted as wel as the heat transfer properties were compared. The results show that the optimum scheme among the six configurations is a circumferential overlap trisection helix baffled heat exchanger with a baffle incline angle of 20° (20°TCO) scheme with an anti-shortcut baffle structure, which exhibits the second highest pressure dropΔpo, the highest overal heat transfer coefficient K, shel-side heat transfer coefficient ho and shel-side average comprehensive index ho/Δpo.     

Complexities of digital technology use and the teaching and learning of function

Many argue that digital technologies have the potential to enhance the teaching and learning of mathematics. However, the availability of technology is not sufficient to realise this potential. The study reported takes a detailed approach to investigate the utility of the particular offerings of the available technologies in the teaching and learning of a specific area of mathematics, functions. Sixteen affordances identified in the data are described. The complexity of the process involved in resolving a situation where particular affordances would be useful so as they are perceived and enacted is detailed. Finally, a grounded theory framework arising from the data analysis from this study that can be used to explain, predict and guide action in other digital environments is presented.     

山地河谷型村落的更新与活化 ——以浙江德清东沈村为例

江南地区山地纵横、水网密布， 地貌丰富多样，村落呈现出不同的类型及特 征，山地河谷村落数量众多。但现阶段乡建 同质化严重，不同类型村落的适宜性政策被 忽略。本文以浙江德清东沈村为例，分析山 地河谷村落特征，以地形地貌为出发点，从 山、水、村落三方面，提出基于山水特质的村 落更新与活化策略，促进乡村经济、社会、文 化的永续发展。