Rheology of Cellulose/Alginic Acid Blends with 1-Allyl-3-Methylimidazolium Chloride as Solvent

In this study, cellulose/alginic acid blend solutions were prepared with 1-allyl-3-methylimidazolium chloride as solvent. The effect of cellulose/alginic acid blend ratios on the rheological properties was studied. It was found that the viscosity and dynamic modulus decreased with the increase of alginic acid ratio. And the calculated viscosity values, which were obtained from the log-additivity rule, are less than the experimental viscosity values. This may be caused by the hydrogen bonding interaction between cellulose and alginic acid, which is beneficial to the miscibility of the blends. In order to prove the rheological result, cellulose/calcium alginate films were prepared from the solution, the hydrogen bonding between cellulose and alginate were investigated, which was related to the good miscibility of the blend solutions. POLYM. ENG. SCI., 60: 243–249, 2019. © 2019 Society of Plastics Engineers     

全国病险水库除险加固一期项目绩效评估分析

1998年大洪水后,国家按轻重缓急的原则分期分批实施病险水库除险加固.在对13个省(市)的995个一期项目调查的基础上,分析项目实施前后防洪、灌溉、发电、供水等方面各效益指标的变化情况,据此对全国病险水库除险加固一期项目绩效进行评估分析.     

预处理对玉米秸秆纤维筛分及酶解性能的影响

分别采用热水和NaOH对玉米秸秆进行预处理,并对预处理后玉米秸秆进行筛分。研究了两种预处理方法对玉米秸秆不同筛分组分及其化学成分的影响,并对不同筛分组分的纤维素酶解性能进行了研究。结果表明,与热水预处理相比,NaOH预处理玉米秸秆的细小纤维含量和纤维素酶解转化率更高。不同筛分组分的化学成分和酶解性能有一定差异,细小纤维的纤维素酶解效率更高。     

基于深度学习的医学影像配准综述

图像配准是医学影像处理与智能分析领域中的重要环节和关键技术.传统的图像配准算法由于复杂性较高、计算代价较大等问题,无法实现配准的实时性要求.随着深度学习方法的发展,基于学习的图像配准方法也取得显著效果.文中系统总结基于深度学习的医学图像配准方法.具体地,将方法归为3类:监督学习,无监督学习和对偶监督/弱监督学习.在此基础上,分析和讨论各自优缺点.进一步,着重讨论近年来提出的正则化方法,特别是基于微分同胚表示的正则和基于多尺度的正则.最后,根据当前医学图像配准方法的发展趋势,展望基于深度学习的医学图像配准方法.     

PTA装置加氢反应器在碱环境中的应力腐蚀分析及防护

针对PTA装置加氢反应器在高温碱环境下发生应力腐蚀的问题,采用光学显微镜和EDS等仪器对构件的腐蚀形貌和腐蚀产物进行了分析,并通过ANSYS有限元软件得到了热应力大小及分布情况,得出了形成碱腐蚀的主要因素及相互作用,据此提出了相应的防护和改进措施。     

MiR-320-3p Regulates the Proliferation and Differentiation of Myogenic Progenitor Cells by Modulating Actin Remodeling

Skeletal myogenesis is essential for the maintenance of muscle quality and quantity, and impaired myogenesis is intimately associated with muscle wasting diseases. Although microRNA (miRNA) plays a crucial role in myogenesis and relates to muscle wasting in obesity, the molecular targets and roles of miRNAs modulated by saturated fatty acids (SFA) are largely unknown. In the present study, we investigated the role of miR-320-3p on the differentiation of myogenic progenitor cells. Palmitic acid (PA), the most abundant dietary SFA, suppressed myogenic factors expression and impaired differentiation in C2C12 myoblasts, and these effects were accompanied by CFL2 downregulation and miR-320-3p upregulation. In particular, miR-320-3p appeared to target CFL2 mRNA directly and suppress the expression of CFL2, an essential factor for filamentous actin (F-actin) depolymerization. Transfection of myoblasts with miR-320-3p mimic increased F-actin formation and nuclear translocation of Yes-associated protein 1 (YAP1), a key component of mechanotransduction. Furthermore, miR-320-3p mimic increased myoblast proliferation and markedly impeded the expression of MyoD and MyoG, consequently inhibiting myoblast differentiation. In conclusion, our current study highlights the role of miR-320-3p on CFL2 expression, YAP1 activation, and myoblast differentiation and suggests that PA-inducible miR-320-3p is a significant mediator of muscle wasting in obesity.     

被含均匀度及其仿真

均匀度是一个有限点集在一个多面体内分布均匀性的描述,已经证明被含均匀度CL渐近服从x2(2m)/2Vn(1)m分布,且有E(CL)=Г(n/2 1)/πn/2,用地理信息系统开发语言Avanue对均匀度和被含均匀度进行了摸拟,为均匀度的收敛性证明打下了基础.     

Beam and image experiment of beam deflection electron gun for distributed X-ray sources

Distributed X-ray sources comprise a single vacuum chamber containing multiple X-ray sources that are triggered and emit X-rays at a specific time and location. This process facilitates an application for innovative system concepts in X-ray and computer tomography. This paper proposes a novel electron beam focusing, shaping,and deflection electron gun for distributed X-ray sources.The electron gun uses a dispenser cathode as an electron emitter, a mesh grid to control emission current, and two electrostatic lenses for beam shaping, focusing, and deflection. Novel focusing and deflecting electrodes were designed to increase the number of focal spots in the distributed source. Two identical half-rectangle opening electrodes are controlled by adjusting the potential of the two electrodes to control the electron beam trajectory, and then, multifocal spots are obtained on the anode target. The electron gun can increase the spatial density of the distributed X-ray sources, thereby improving the image quality. The beam experimental results show that the focal spot sizes of the deflected(deflected amplitude 10.5 mm)and non-deflected electron beams at full width at half maximum are 0.80 mm 90.50 mm and 0.55 mm 90.40 mm, respectively(anode voltage 160 kV; beam current 30 mA). The imaging experimental results demonstrate the excellent spatial resolution and time resolution of an imaging system built with the sources, which has an excellent imaging effect on a field-programmable gate array chip and a rotating metal disk.     

冶炼工艺对管线钢洁净度的影响

研究了LD-LF-CC和LD-ANS-OB-CC两条工艺路线对管线钢洁净度的影响.通过合理的工业试验和金相、化学等分析手段,对冶炼过程钢水中氧、氮含量和夹杂物进行了定量分析.结果表明:钢水经过LF炉和ANS-OB两种精炼工艺处理后钢水洁净度是一致的,采用LD-AND-OB-CC工艺生产某些钢种可降低成本.提出了精炼过程中吹氩工艺是去除夹杂物的主要因素.精炼处理时间40 min,钢中氧、氮和夹杂物基本达到最好水平,继续延长精炼时间钢水中夹杂物没有变化.