Phytic acid-assisted fabrication of superhydrophilic Ru 3D electrode for electrocatalytic hydrogenation of p-Nitrophenol

A superhydrophilic Ru-based 3D electrode, denoted as Ru-PA/NF, was fabricated under the assistance of phytic acid (PA) for electrocatalytic hydrogenation of p-Nitrophenol. PA serves as a multifunctional modulator to facilitate the dispersion of active Ru species in porous nickel foam (NF), meanwhile enhance the surface wettability as well as adjust the micromorphology. In alkaline media, the Ru-PA/NF electrode shows the PNP conversion of 94.68% and the PAP selectivity of 99% after 9 h, accompanied by the faraday efficiency (FE) of 73.15%. Over the superhydrophilic Ru-PA/NF the rate constant of PNP conversion into PAP is 2.62-times higher than that over the hydrophobic Ru/NF prepared without the aid of PA, and FE of Ru-PA/NF is 1.28-times higher than Ru/NF. This can be ascribed to intriguing features of Ru-PA/NF involving higher Ru loading, more exposed sites, superior electrolyte wetting along with faster charge transfer rate.     

采前水杨酸处理对哈密瓜果实防御酶的诱导

采用1.0、2.0、3.0 mmol/L水杨酸分别在"蜜农9号"哈密瓜开花前1周、幼果期(花后2周)、果实迅速膨大期(花后3周)和网纹形成期(花后4周)对植株进行4次喷洒.依次在幼果期、膨大期、网纹形成期和成熟期进行取样.分析不同浓度水杨酸处理后果实体内3种防御性酶活性的变化.结果表明:采前1.0、2.0、3.0 mmol/L水杨酸处理均能有效地提高哈密瓜果实中过氧化物酶(POD)、多酚氧化酶(PPO)和苯丙氨酸解氨酶(PAL)活性,尤其以2.0 mmol/L水杨酸处理酶活性增加最为显著.     

微波合成对-香豆酸的工艺研究

采用微波辐射法,利用正交设计,以对-羟基苯甲醛和丙二酸为原料,甲苯、吡啶作为溶剂,苯胺作催化剂合成了对-香豆酸.最佳反应条件:在微波辐射下,反应物摩尔比为1:2(0.015mol:0.03mol),催化剂苯胺用量0.54g,辐射时间50min,产率达到72.76%.与传统法比较,微波辐射具有反应速度快、产率高的优点.     

降水及人类活动对阜平流域径流的影响

为了研究近年来气候变化和人类活动影响条件下的阜平流域径流的演变规律,采用5 a滑动平均法和线性回归法,对阜平流域径流量、变化趋势及影响因素进行了分析,并利用降水径流经验统计模型估算了降水变化和人类活动对流域年径流量的影响程度。结果表明:降水量与径流量有一致性的变化趋势,降水量下降的趋势不明显,而径流量呈显著减少的趋势;1969—1979年、1980—1989年、1990—1999年、2000—2005年,受人类活动影响所减少的年均径流量分别占径流总减少量的21.04%、46.05%、58.30%、54.93%,受降水变化影响所减少的年均径流量分别占径流总减少量的78.96%、53.95%、41.70%、45.07%;随着年代的推移,人类活动对径流的影响逐渐增大,而降水变化的影响逐渐减小,20世纪80年代以后,人类活动导致径流量减少的贡献率要大于降水因素。     

基于遗传算法的粗糙集属性约简算法

为了研究粗糙集理论中属性约简问题,给出了一种属性相对重要度定义,证明了其合理性,并将它应用到基于遗传算法的约简算法中,提出一种启发式遗传算法.算法采用修正策略保证群体进化收敛于最小约简,同时引入属性相对重要度作为启发信息,加快算法的收敛速度.对算法进行的时间复杂度和完备性分析以及数值实验表明,基于遗传算法的粗糙集属性约简算法具有完备、快速收敛等特点.     

网络教学平台在C++程序设计课程教学改革中的运用

随着信息化教育技术改革及基于Internet技术网络教学平台的运用,高校普遍意识到以课程教学改革思想构建网络教学平台的重要性。本文针对以往C++程序设计课程教学模式及不足,以网络教学平台为基础实施了3个方面的教改。同时以教改驱动模式构建了网络平台中的4大模块,并对各模块功能进行了详细的阐述。总结出今后C++程序设计课程教学模式,应当从以教为主向以学为主的转变,强化学生编程思维的培养和实际动手能力的提高。     

Hibernate框架下信息系统数据初始化问题的研究

由于对象关系映射(ORM)采用了一种完全不同的数据访问方式,为了使原有信息系统的数据迁移到采用了ORM框架的新系统后仍然保持数据的完整性和一致性,使用poi读取excel文件的结构化数据,使用java反射技术将读取的数据组装成对象。使用开源的ORM框架Hibernate将对象导入数据库中。结果表明该方案可以保证信息系统初始化后数据的完整性,从而解决了采用ORM框架的信息系统数据初始化问题。     

Detecting and resolving deadlocks in mobile agent systems

Mobile agents environment is a new application paradigm with unique features such as mobility and autonomy. Traditional deadlock detection algorithms in distributed computing systems do not work well in mobile agent systems due to the unique feature property of the mobile agent. Existing deadlock detection and resolution algorithms in mobile agent systems have limitations such as performance inefficiency and duplicate detection/resolution when multiple mobile agents simultaneously detect/resolve the same deadlock. To address these problems, we propose an improved deadlock detection and resolution algorithm that adopts priority-based technique and lazy reaction strategy. The priority-based technique aims to ensure that there is only one instance of deadlock detection and resolution, and it also helps reduce mobile agent movement and data traffic together with the lazy reaction strategy. The liveness and safety properties of the proposed algorithm are proved in this paper. Theoretical analysis and experimental results show that the proposed algorithm provides better performance in terms of agent movement, data traffic, and execution time.