竹浆Co-salen仿酶预处理TCF漂白的研究

研究了竹浆Co-salent仿酶预处理TCF漂白,结果表明,竹浆Co-salent仿酶处理方式以单独预处理为宜,适宜条件：Co-salen用量0.03％、吡啶与Co-saler摩尔1：1、NaOH用量3％、H2O2用量1.5％、氧压0.2MPa、浆浓5％、温度90℃、时间5h;竹浆经OCoEpPaP流程漂白后的白度为90.5％,比空白样提高了5.3个百分点。黏度为620mL／g,比空白样降低99mL／g;Co-salen仿酶预处理能在一定程度上提高TCF终漂纸浆物理性能,降低漂白废液COD、BOD、SS负荷,并减少后续P缓和暇漂剂用量40％以上。     

二次研究完全胸腔镜与正中开胸对二尖瓣置换术疗效的Meta分析

目的 系统评价完全胸腔镜与正中开胸对二尖瓣置换术疗效的有效性和安全性。方法 计算机检索The Cochrane Library(2016第5期)、PubMed、EMbase、CBM、CNKI、WanFang Data和VIP数据库,搜集有关完全胸腔镜与正中开胸二尖瓣置换术疗效的的随机对照试验(RCT)和队列研究,检索时限均为从建库至2016年10月。由2位评价者独立筛选文献、提取资料和评价纳入研究的偏倚风险后,采用RevMan 5.2软件进行Meta分析。结果 最终纳入了6个队列研究,总共608例患者,其中全胸腔镜组(试验组)有270例患者,正中开胸组(对照组)有338例患者。Meta分析结果显示：全胸腔镜组术后呼吸机辅助时间[MD=-1.82,95%CI(-3.38,-0.26),P=0.02]、住院天数[MD=-3.50,95%CI(-6.04,-0.95),P=0.007]明显短于开胸组,术后引流量[MD=-99.40,95%CI(-181.30,-17.50),P=0.02]明显少于开胸组,但其主动脉阻断时间[MD=16.05,95%CI(2.47,29.62),P=0.02]明显长于开胸组。结论 完全胸腔镜下二尖瓣置换术跟传统开胸正中切口二尖瓣置换术相比,可明显减少术后引流量,缩短术后呼吸机辅助时间、住院天数,但有延长主动脉阻断时间的风险。受纳入研究质量和数量所限,上述结论仍需开展更多高质量的研究加以验证。     

《化工原理》教学中学生学习积极性的培养

化工原理是化学化工类专业的一门技术基础课,文章从结合学生所学专业与课本理论知识、加强学生参与意识、灵活运用教学法等方面着手,就如何激发学生学习积极性,提高教学效果作了一些有益的探讨。     

纸浆绿色漂白技术新进展

回顾了国内外纸浆绿色漂白技术的现状,主要介绍了H₂O₂漂白、臭氧漂白、生物漂白、电化学漂白以及其他漂白技术的新进展。     

全封闭大功率永磁牵引电机的温度场数值计算

为研究全封闭大功率永磁牵引电机额定工况下的稳态温度场,以一台额定功率为815 kW的永磁同步牵引电机为研究对象,依据成型绕组槽部导热模型,建立了整机三维温度场共轭传热计算模型。考虑旋转磁化、冲压过程和磁密高阶谐波对定子铁耗的影响,以及水套-定子铁心间接触热阻抗对电机温升的影响,采用Fluent软件对电机额定工况下的稳态流场与温度场求解,使用电阻法和埋置检温计法（ETD）测得电机在额定工况下绕组的平均温升、铁心测点和绕组端部测点局部温升,绝对误差分别为-3.7 K、-0.3 K和7.6 K。进一步分析了电机水路和内风路流场分布特性、水套-定子铁心间接触间隙对绕组平均温升的影响以及槽内绕组附近的温升分布情况,最后提出了该类电机冷却系统设计优化方向。     

On splitting-based numerical methods for nonlinear models of European options

We present a large class of nonlinear models of European options as parabolic equations with quasi-linear diffusion and fully nonlinear hyperbolic part. The main idea of the operator splitting method (OSM) is to couple known difference schemes for nonlinear hyperbolic equations with other ones for quasi-linear parabolic equations. We use flux limiter techniques, explicit–implicit difference schemes, Richardson extrapolation, etc. Theoretical analysis for illiquid market model is given. The numerical experiments show second-order accuracy for the numerical solution (the price) and Greeks Delta and Gamma, positivity and monotonicity preserving properties of the approximations.     

Age-related positivity enhancement is not universal: Older Chinese look away from positive stimuli.

Socioemotional selectivity theory postulates that with age, people are motivated to derive emotional meaning from life, leading them to pay more attention to positive relative to negative/neutral stimuli. The authors argue that cultures that differ in what they consider to be emotionally meaningful may show this preference to different extents. Using eye-tracking techniques, the authors compared visual attention toward emotional (happy, fearful, sad, and angry) and neutral facial expressions among 46 younger and 57 older Hong Kong Chinese. In contrast to prior Western findings, older but not younger Chinese looked away from happy facial expressions, suggesting that they do not show attentional preferences toward positive stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Divergent trajectories in the aging mind: Changes in working memory for affective versus visual information with age.

Working memory mediates the short-term maintenance of information. Virtually all empirical research on working memory involves investigations of working memory for verbal and visual information. Whereas aging is typically associated with a deficit in working memory for these types of information, recent findings suggestive of relatively well-preserved long-term memory for emotional information in older adults raise questions about working memory for emotional material. This study examined age differences in working memory for emotional versus visual information. Findings demonstrate that, despite an age-related deficit for the latter, working memory for emotion was unimpaired. Further, older adults exhibited superior performance on positive relative to negative emotion trials, whereas their younger counterparts exhibited the opposite pattern. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

基于移动组的全序可靠多播协议的研究

丈章给出一种基于移动组的全序可靠多播协议-MGTOM(Mobile-group-based Totally Ordered Reliable Multicast)协议,借助于逻辑令牌环来实现.MGTOM协议实现了移动组多播的原子性和全序性,原子性用于保证多播消息能够最终传递到移动组内的所有移动Agent,全序性则保证任意一对多播消息都按照相同顺序被所有组内移动Agent传递.在多播算法中,为了保证原子性,所有收到多播消息的组成员必须回复,然后持有令牌的组成员作为Sequencer,对多播消息进行排序.