Can video games change attitudes towards history? Results from a laboratory experiment measuring short- and long-term effects

This study investigates a video game's effects on implicit and explicit attitudes towards depicted historical events in the short- and long-term on a sample of 148 young adults. We used, as an intervention tool, a serious game Czechoslovakia 38–89: Borderlands that deals with the expulsion of the Sudeten Germans from the former Czechoslovakia after the WWII. Results showed more negative pretest-posttest explicit attitude changes towards the expulsion on a general level (d = −0.34) and a specific level (d = −0.53) compared to the control group. Over the long-term, group differences in attitude change remained significant for the specific level (d = −0.44), but not for general one (d = −0.16). Exploratory analysis on the item level indicated that especially attitudes towards the expulsion's (un)fairness were affected by the game. However, no significant changes were found in implicit attitudes in the experimental group. This study is the first of such scale to empirically investigate video games' effects on a society's historical awareness.     

An efficient approach for the S‐shaped penalty function

Interval goal programming (IGP) with a marginal penalty function (PF) was first proposed by Charnes and Collomb in 1972, and further improved by Kvanli and other researchers. Recently, Lu and Chen proposed an efficient logarithmic method to formulate IGP with an S‐shaped PF. However, their method requires adding many binary variables when the problem size becomes large, which increases the computational burden in the solution process. This study proposes an efficient approach for the S‐shaped PF. The arbitrary PF frequently appears in the fields of business and industry. However, none of the previous approaches have addressed arbitrary PFs without adding binary variables. The proposed approach can be easily extended to formulate an arbitrary PF in which binary variables are no longer required, regardless of the number of break points. The proposed method can improve the efficiency of IGP for solving large size management and decision problems in considering PFs. In order to demonstrate the correctness, usefulness of the proposed model, illustrative examples are provided.     

Analytical estimation of energy dissipations: Viscous,Joulian, and Darcy of viscoelastic fluid flow phenomena over a deformable surface

In this paper, analytical estimation of energy dissipations, such as viscous, Joulian, and Darcy dissipation of viscoelastic flow phenomena over a deformable surface has been presented. This supplement to the study of many transport processes, which occur in nature, and various experimental setups that are driven or modified by the composition of the various flow characteristics and material or phase constitution. These processes are very important and have received considerable attention in the literature. The estimation of dissipative energy in the process of transport energy is an important phenomenon to investigate. The present analysis is carried out on steady MHD viscoelastic liquid due to deformable domains. Moreover, the impact of internal heat sources and prescribed thermal conditions, such as surface temperature and heat flux, are carefully studied. Analytical solutions to governing equations are obtained with the help of Kummer's function. The solutions are presented graphically as well as in tables to estimate the energy losses and their effects on transport processes, which serve as the salient features of the current analysis. The outcomes serve as a guideline due to the process of transport properties as per the design requirements. Looking into the current scenario, dissipative heat energies have several applications in industries and technological processes, such as electric heaters, fuses, food processing, and several others.     

2011～2020年华北平原气溶胶光学厚度时空分布特征及潜在源分析

随着经济高速增长和城市化进程不断加快,华北平原区域性空气污染问题愈演愈烈。针对该区域开展长时序气溶胶光学厚度时空分布特征和潜在源分析研究,对华北平原大气污染治理具有重要意义。基于长时序MODIS/Terra C6.1 MOD04_L2气溶胶光学厚度产品,分析华北平原气溶胶光学厚度的时空分布特征,并利用后向轨迹聚类分析讨论华北平原7个重点城市气团输送的季节变化,并以污染较为严重的河北石家庄为例进行潜在源分析和浓度权重分析,探究影响其大气质量的污染物潜在源区。结果表明:2011～2020年华北平原气溶胶光学厚度月均值呈显著的周期性变化,以年为周期,每个周期内峰值一般出现在6月至8月; 气溶胶光学厚度月际年内呈单峰分布,峰值出现在6月(0.75),最小值出现在12月(0.37); 气溶胶光学厚度季均值从大到小依次为夏季(0.67)、春季(0.59)、冬季(0.49)、秋季(0.46); 10年间气溶胶光学厚度呈下降趋势,整体下降幅度达36.84%,其中2011年最高(0.72),2018年最低(0.45); 华北平原7个重点城市春、夏、秋、冬四季主要受短距离气团输送影响较大,长距离气团输送影响较小; 2014～2020年河北石家庄的空气质量优良天数占比相对较小,空气质量状况差,影响其空气质量的污染物多为本地生成,同时也受周边省市近距离输送的影响。     

Investigation on standard entropy change of metal hydrides and work function of metals

We focused on the work function of metals as an index of ion binding property between metals and hydrogen and analyzed the relation between the standard entropy change of metal hydrides and the work function of metals (alloys). The standard entropy change of saline hydrides and metallic hydrides roughly increased with the work function. It was indicated that hydrogen storage alloys consist of metal elements A and B whose work functions are small and large, respectively. The standard entropy changes of alloy-based metal hydrides with different composition ratio ΔS⁰ linearly increased with the work functions of the alloys W_c. W_c also linearly increased with the bulk modulus B_c. Then, it was found that ΔS⁰ was proportional to the standard heat of formation ΔH⁰ because dW_c/dB_c, dΔS⁰/dW_c and dΔH⁰/dB_c are constant.     

Fuzzy approximation-based adaptive control of nonstrict feedback stochastic nonlinear systems with time-varying state constraints

This article develops an approximation-based fuzzy control scheme for nonstrict feedback stochastic nonlinear systems (NFSNS) with time-varying state constraints. The difficulty in constructing controller is how to conquer the algebraic loop problem caused by nonstrict feedback structure, as well as prevent the state constraints from violating. To dispose the time-varying state constraints, time-varying barrier Lyapunov function is incorporated into the backstepping design framework. The lumped uncertainties of NFSNS are approximated by the fuzzy logic systems. By virtue of fuzzy basis function, the algebraic loop problem is effectively handled. Theoretical analysis shows that the predefined state constraints are not violated and all signals of the closed-loop systems are bounded. Finally, simulation results substantiate the validity of the devised method.     

多约束下距离加权最优滑模末制导律

为解决多约束下制导炮弹的精确制导问题,采用带有相对距离权函数的最优滑模末制导律,将权函数引入到最优制导律中,通过改变制导炮弹的运动轨迹、运动时间,进而增强制导精度。针对单权函数难以同时满足制导精度与导引头视线角、过载等约束的问题,采用不同权函数的分段加权方法解决加权最优末制导引起的制导问题。结合滑模变结构控制理论,设计分段加权最优滑模末制导律,增强制导系统的抗干扰能力。仿真验证结果表明,该末制导律既能解决过载、导引头视线角、落角等多约束情况下的精确制导问题,同时又具有一定的鲁棒性。     

限制失真的网格参数化方法

针对当前网格参数化效率较低、映射失真较严重的问题，提出一种限制失真的网格参数化方法。首先，预处理原始网格模型。输入原3D网格模型，采用Half-Edge数据结构来重新组织网格并切割网格模型产生相应的切缝；构建Tutte映射把3D网格映射到一个2D凸多边形域，即构建2D网格模型。然后，进行限制失真的网格参数化计算。将Tutte映射后的2D网格模型作为限制失真计算的初始数据，建立相对于原3D模型网格的失真度量函数；求得该度量函数的最小值点，即为映射后的网格坐标集合；将映射后的网格作为限制失真映射的输入网格，设定迭代终止条件，循环迭代直至迭代结束，得到收敛的最优网格坐标；在计算映射失真度时，针对等距映射失真采用Dirichlet能量函数度量，针对共形映射失真采用尽可能等距（MIPS）能量函数度量；在求解映射失真度量函数的最小值点时采用代理函数法结合组合牛顿法的最优解方法。最终，实现了该方法并开发了一个原型系统。在原型系统中，分别设计了限制等距失真和限制共形失真的网格参数化实验，对程序执行时间和失真能量下降情况进行了统计和对比，提供了相应的纹理映射效果展示。实验数据表明，所提出的方法执行效率高、映射失真能量下降快，最优值收敛质量稳定；纹理映射时纹理着色均匀、布局紧致、线条均匀，符合实际应用的标准。     

顺苯磺酸阿曲库铵不抑制患者接受术中血液回收后肌肉及呼吸功能的恢复:单中心前瞻性研究

目的术中血液回收技术(intraoperative blood salvage,IBS)是临床常用的一种血液保护技术,但术后自体血液回输存在肌松药物残留问题。顺苯磺酸阿曲库铵(cis-atracurium besilate,Cisa)是一种新型肌松药物,本研究观察Cisa应用于接受IBS患者的临床安全性。方法前瞻性分析比较2017年3月至6月在北京积水潭医院脊柱科接受全身麻醉下腰椎减压内固定手术的50例腰椎间盘突出患者。患者顺序纳入,前25例进入试验组,后25例进入对照组。全身麻醉后应用Cisa作为肌松药,采用IBS技术于术中采集手术视野自体血并洗涤。术后入恢复室,常规监测4个成串刺激(train-of-four stimulation,TOF)以评估肌肉恢复情况,拔除气管插管后每隔5 min记录TOF值,共观察40 min。试验组患者于拔除气管插管后一次性输入术中收集的自体血,对照组于40 min观察结束后回输自体血。分析并比较两组患者术前及观察结束时的动脉血氧分压(arterial partial pressure of oxygen,PaO_2)和二氧化碳分压(partial pressure of carbon dioxide in artery,PaCO_2),用于评估呼吸功能恢复情况。结果所有患者完成全部观察内容,其中男女比例1∶1,年龄(55. 1±11. 1)岁,体重(72. 7±9. 8) kg,两组基线资料均衡,TOF值随时间推迟呈上升趋势,但两组患者在40 min观察点上TOF增加值无统计学差异[(9. 6±7. 3)%比(9. 5±8. 1)%,P=0. 963]。两组患者在观察结束时均出现一定程度的呼吸功能不全,但组间PaCO_(2-incr)[4. 4(2. 0,8. 0) mm Hg比4. 8 (0,7. 1) mm Hg,P=0. 312)(1 mm Hg=0. 133 kPa)和PaO_(2-decr)[3. 2 (-2. 4,7. 9) mm Hg比7. 2(-1. 6,13. 0) mm Hg,P=0. 133]并无统计学差异。结论全身麻醉下接受IBS的患者使用Cisa作为肌松药物是安全的。