Stabilization for Schrödinger Equation with Internal Damping and Boundary Disturbance

In this paper, the stabilization for Schrödinger equation subject to internal damping and boundary disturbance at the control end is investigated. Due to its immeasurability, the nonlinear observer system is designed to obtain the state information, and the existence of weak solution and its convergence for the nonlinear observer system are proved. The feedback control is realized by the backstepping transformation. In addition, the adaptive disturbance rejection control is applied to estimate the disturbance. According to the observer and disturbance estimation, the feedback control is finally designed to stabilize the system asymptotically.

     

Effect of microwave heating time on the gel properties of chicken myofibrillar proteins and their formation mechanism

The present work was conducted to illustrate the mechanism of gel formation of myofibrillar proteins (MPs) under different microwave heating times. The results showed that the denaturation enthalpy (ΔH) of the MPs significantly decreased when the heating time increased from 3 to 9 s and then completely disappeared as the heating time progressed, indicating that the MPs gradually denatured and subsequently aggregated with increasing heating time, which was further verified by the changes in the secondary structure, electrophoretic bands, and gel properties (e.g., water holding capacity and textural profiles) of the MPs. Microstructural images indicated that the MP gel formed under 12 s had the most compact network, indicating that extended microwave heating time could induce quality deterioration of MP gels. Moreover, the hydrophobic forces, electrostatic forces, and disulphide bonds of the MPs gradually intensified with increasing microwave heating time, suggesting that both non-covalent and covalent bonds could promote molecular denaturation and subsequent aggregation of MPs. In addition, correlation analysis revealed that the changes in the molecular conformation of MPs induced by different microwave heating times could effectively regulate the formation of MP gels and their related properties.     

E-voting scheme using secret sharing and K-anonymity

E-voting maybe replaces the traditional voting scheme in the future, however, the security threat must be paid enough attention. In this paper, a novel e-voting scheme is proposed using secret sharing and k-anonymity, which not only satisfies the basic security goals such as the non-cheating, the universal verifiability, the confidentiality, and the anonymity, but also achieves the addition properties including coercion-resistance and unconditional security since the security of the proposed scheme does not rely on any computational hard problem.

     

Functional chemical modification of a porcine acellular dermal matrix with a modified naturally derived polysaccharide crosslinker

Antibacterial and physicochemical properties are generally considered important features of the porcine acellular dermal matrix (pADM). Oxidized 2-hydroxypropyltrimethyl ammonium chloride chitosan (OHTCC) was applied to crosslink with pADM at dosages of 1, 2, 4, 8, and 16%. The properties of the crosslinked pADM (OHTCC-pADM) were evaluated. DSC and TG analysis suggested that crosslinking could promote the thermal stability, the highest T_d, and T_max of OHTCC-pADM (8%) was 80 °C and 325 °C, which has been improved by 15 °C and 13 °C, respectively. While FTIR and AFM tests indicated that the structure integrity of collagen could still be maintained. SEM tests demonstrated the sustained three-dimensional architecture of OHTCC-pADM with appropriate porosity. Moreover, OHTCC-pADM exhibited improved ability to resist collagenase degradation, the degradation rate of 4%-, 8%-OHTCC-pADM was <50%. The tensile strength of OHTCC-pADM proved to be superior compared to pADM. Furthermore, 8%-OHTCC-pADM exhibited nearly 90% antibacterial activity against Escherichia coli, and Staphylococcus aureus. In addition, the results of the 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazoliumbromide study showed that the cytocompatibility of OHTCC-pADM decreased with the increasing the amount of OHTCC, but all relative proliferation rates were above 80%. In conclusion, our study revealed that OHTCC stabilized and functionalized pADM while preserving good cytocompatibility. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47633.     

压水堆堆芯损伤评价系统研究与开发

堆芯损伤评价是反应堆事故后应急评价的重要组成部分。本文在国外文献基础上,结合国内的运行经验,对压水堆堆芯损伤评价进行研究,并开发了相应的软件程序。堆芯损伤评价包括基于堆芯裸露时间、在线监测仪表读数和取样分析数据三种方法。考虑应急实时要求、电厂实际情况与国际经验,本文采用了基于在线监测仪表读数的评价方法,该方法主要是基于堆芯热电偶读数与安全壳辐射监测仪表读数进行评价,其他监测仪表读数进行辅助合理性证实。     

Effects of community of inquiry,learning presence and mentor presence on K-12 online learning outcomes

This study extends the community of inquiry (CoI) framework and self-regulated learning (SRL) theory through an exploration of the structural relationships among existing CoI variables, learning presence (i.e., self-efficacy and online SRL strategy) and learning outcomes in the context of K-12 online learning. To help understand the influence of K-12 mentoring – which is unique to online learning in the U.S. – mentor presence is also included. Structural equation modelling of 696 online 8th through 12th graders' survey responses and final grades showed that adding learning presence to the CoI framework helped to explain how these learners translated their online-learning perceptions into cognitive and affective learning outcomes. We also found that mentor presence significantly and positively predicted online SRL strategy, one of the two components of learning presence. Lastly, we established a connection between the CoI model and various types of learning outcomes that are indicators of K-12 online learning success – though it should be noted that important differences existed between a model based on final grades and two other outcome models. It is hoped that the processes identified in this study will be useful and relevant to K-12 online-learning institutions and educators seeking to improve their offering via a wide range of approaches.     

系列催化剂同时脱硫脱硝性能

FCC烟气中的SO₂和NO是主要的大气污染物,选择性催化还原是一种很好的脱除方法。采用浸渍法制备了CuO不同负载量的CuO/γ-Al₂O₃系列催化剂,通过XRD和H₂-TPR对催化剂进行表征,使用常压固定床流动法微型催化反应装置考察催化剂在以CO为还原气时,同时脱硫脱硝的催化活性。结果表明,CuO作为活性组分很好地分散在γ-Al₂O₃载体上,不破坏其结构;不同CuO负载量的CuO/γ-Al₂O₃催化剂具有良好的脱硫脱硝活性,脱硝率超过95.00%,脱硫率最低也能达到80.00%,CuO负载质量分数为10%的CuO/γ-Al₂O₃催化剂有最佳的脱硫脱硝活性;以CO作还原剂,CuO/γ-Al₂O₃系列催化剂的活性温度较高,脱硝率在700 ℃达到最大,为97.90%,脱硫率在760 ℃达到最大,为93.34%。CuO负载质量分数为10%的CuO/γ-Al₂O₃催化剂可作为一种较好的高温脱硫脱硝催化剂。     

阻燃剂TPSP对棉布阻燃性能和力学性能的影响

用阻燃剂螺环磷酰四氢吡咯酯(TPSP)与水性聚丙烯酸酯胶黏剂复合制成阻燃涂层胶,对棉布进行阻燃整理。通过正交实验得到了较优的阻燃整理条件:阻燃剂与黏合剂聚丙烯酸酯的质量比(阻/胶)为1.5∶1,棉布与阻燃胶的质量比(布/阻+胶)为60∶40,焙烘温度为140℃,焙烘时间为1.5 min。在该条件下,棉布的LOI值由未阻燃的18.2%提高到28.9%,阻燃等级达到B1级,断裂强力由未阻燃的364 N(经向)和320 N(纬向)提高到917 N(经向)和472 N(纬向),说明阻燃剂TPSP不但提高了棉布的阻燃性,而且提高了棉布的断裂强力。对优化条件下整理的棉布进行热重分析,结果表明,棉布的初始分解温度由未阻燃的314.5℃降低到287.6℃,降低了26.9℃;600℃时的残留量由未阻燃的0.29%增加到38.87%,增加了38.58%,说明阻燃剂TPSP有效地提高了棉布的成炭性能。     

电控正流量挖掘机分工况功率匹配研究

针对目前电控正流量挖掘机系统研究较少、空载时能量损失大、发动机与主泵功率不匹配以及节能控制效果不佳的问题,搭建基于AMESim和Simulink的挖掘机电液系统联合仿真平台,提出一种双变量泵的发动机-泵恒功率控制方法。通过样机仿真实验以及分工况功率匹配研究,验证搭建的电控正流量挖掘机系统的正确性以及分工况功率匹配的有效性。仿真实验结果表明：设计的仿真模型以及功率匹配策略表现良好,在仿真和实验中,不同的工况模式下均可以保证泵的恒功率特性,可以实现对发动机的功率控制,发动机功率可以得到充分利用。     

陈慈黉故居的建筑石雕装饰艺术

陈慈黉故居是中国近代中西合璧型的大型华侨住宅,其建筑石雕继承潮汕建筑艺术的精髓,同时运用西洋的材料及装饰图纹,大胆创新,形成了自己独特的建筑石雕装饰符号。