关键词： hybrid nanogenerator   thermal energy   mechanical energy   self-powered   cathodic protection  

摘要： Metal corrosion occurs anytime and anywhere in nature and the corrosion prevention has a great significance everywhere in national economic development and daily life. Here, we demonstrate a flexible hybrid nanogenerator (NG) that is capable of simultaneously or individually harvesting ambient thermal and mechanical energies and used for a self powered cathodic protection (CP) system without using an external power source. Because of its double peculiarities of both pyroelectric and piezoelectric properties, a polarized poly(vinylidene fluoride) (PVDF) film-based NG was constructed to scavenge both thermal and mechanical energies. As a supplementary, a triboelectric NG was constructed below the pyro/piezoelectric NG to grab ambient mechanical energy. The output power of the fabricated hybrid NG can be directly used to protect the metal surface from the chemical corrosion. Our results not only verify the feasibility of self-powered CP-based NGs, but also expand potential self-powered applications.

关键词： Free energy   Dihedral angles   Binding analysis   Drug interactions   Crystal structure   Adenine   Molecular dynamics   Protein structure databases  

摘要： Examination of InhA mutants I16T, I21V, I47T, S94A, and I95P showed that direct and water mediated H-bond interactions between NADH and binding site residues reduced drastically. It allowed conformational flexibility to NADH, particularly at the pyrophosphate region, leading to weakening of its binding at dinucleotide binding site. The highly scattered distribution of pyrophosphate dihedral angles and chi1 side chain dihedral angles of corresponding active site residues therein confirmed weak bonding between InhA and NADH. The average direct and water mediated bridged H-bond interactions between NADH and mutants were observed weaker as compared to wild type. Further, estimated NADH binding free energy in mutants supported the observed weakening of InhA-NADH interactions. Similarly, per residue contribution to NADH binding was also found little less as compared to corresponding residues in wild type. This investigation clearly depicted and supported the effect of mutations on NADH binding and can be accounted for isoniazid resistance as suggested by previous biochemical and mutagenic studies. Further, structural analysis of InhA provided the crucial points to enhance the NADH binding affinity towards InhA mutants in the presence of direct InhA inhibitors to combat isoniazid drug resistance. This combination could be a potential alternative for treatment of drug resistant tuberculosis.

关键词： 热能动力机械   现状   发展走向  

摘要： 当热能转换成动力,并且应用在人们的生产生活中时,不仅改变了人们的生产与生活的方式,而且为资源能源的可持续利用、高效利用提供了空间。热能动力机械以其科学性和先进性亟待在人们的生产实践中有着更大范围内的应用。

关键词： 农业机械总动力   回归分析   吉林省  

摘要： 农业机械化是农业现代化的重要标志,吉林省作为粮食大省,农业机械化的发展至关重要。为此,运用吉林省1987-2012年的相关数据,对吉林省农业机械总动力及其影响因素进行多元线性回归分析,建立了回归模型。结果表明:在其他变量保持不变的情况下,农村居民家庭恩格尔系数每降低1%,农机总动力就增加0.5947%;农村劳动力转移率每增加1%,农机总动力就增加0.5155%;农民家庭年纯收入每增加1%,农机总动力就增加0.1248%;农业财政支出每增加1%,农机总动力就增加0.0936%;人均耕地面积每增加1%,农机总动力就增加0.0064%。未来吉林省要充分重视这5个主要因素,从提高农民对农机的内在需求和加强政府扶持等外部环境两大方面促进农业机械化的发展。另外,需要加强对新型职业农民的培育,以适应新时期农机发展对人才与科技的需求。

关键词： 机枪发射系统   发射动力学   联合仿真   枪口响应  

摘要： 利用ADAMS和MATLAB/Simulink,建立了机枪系统的发射动力学模型和控制系统模型,并进行了含控制环的连发发射响应控制联合仿真。对联合仿真结果进行分析,观察枪口响应曲线,进行响应分析,为物理样机的研制提供了具体分析方法和理论参考依据。

关键词： PRASEODYMIUM   NEODYMIUM   PROMETHIUM   SAMARIUM   METAL ions   WATER   QUANTUM mechanics/molecular mechanics  

摘要： QMCF-MD simulations have been carried out for Pr(III), Nd(III), Pm(III) and Sm(III) ions in aqueous environment, employing ab initio quantum mechanical treatment for ion, first and second hydration shell. Interchanging prismatic structures are found for all ions, the main coordination number being 9, in good agreement with EXAFS experimental data. The ligand dynamics are characterized by first-shell mean residence times in the range of 50 to similar to 200 ps and by force constants for the Ln(III)-O(water) bond between 75 and 100 Nm(-1). (C) 2015 Elsevier B.V. All rights reserved.

关键词： 闪锌矿   焙烧宏观动力学   机械活化   表观活化能   非等温动力学方程  

摘要： 研究机械活化对闪锌矿的物化性质以及焙烧宏观动力学的影响,采用X射线衍射仪、扫描电镜、激光粒度分析仪、比表面积测试仪、热重分析,分析活化前后闪锌矿的晶体结构、表观形貌、粒度和比表面积的变化规律。使用MDTA分析法研究未活化与机械活化闪锌矿在空气气氛下的氧化焙烧宏观动力学。结果表明:机械活化使闪锌矿的物化性质发生明显改变。在焙烧过程中,经过机械活化的闪锌矿氧化速率远大于未活化闪锌矿的。机械活化可显著提高闪锌矿的反应活性。经机械活化30、120 min后,闪锌矿在焙烧过程中的表观活化能由未活化时的239.78 kJ/mol分别降至171.25和57.17 kJ/mol。并计算出其相应的非等温氧化动力学方程。

关键词： 工程机械   法国巴黎   建筑机械   博览会   近距离  

摘要： 巴黎国际工程机械和建筑机械博览会（INTERMAT2015）已于2015年4月25日在法国巴黎圆满落幕,本人非常荣幸地代表公司参加了这次展会,通过这次参观学习,收获颇丰,近距离了解了许多国外的先进技术以及新的应用。

关键词： MCS gene   Laparoscopy   Cardiac Surgical Procedures   total artificial heart   Hemodynamics  

摘要： Background: Technologic advances and superior survival with mechanical circulatory support (MCS) have led to an expanding population that develops intraabdominal conditions requiring intervention. Whether laparoscopy can be performed without detrimental effects on hemodynamics and device function is not well described. Materials and Methods: Effects of laparoscopy performed on MCS were retrospectively assessed. Intraoperative hemodynamics and device function were compared with the same time interval 24 hours prior to surgery using intrapatient paired t tests. Outcomes included survival, transfusion, thromboembolic events, and infection. Results: Twelve patients with ventricular assist devices or total artificial hearts underwent laparoscopy from 2012 to 2014. Median follow-up was 116 days. Operations included cholecystectomy, diagnostic laparoscopy, gastrojejunostomy, and gastrostomy. There were no differences between preoperative and intraoperative mean arterial pressure, heart rate, and inotrope or vasopressor requirements (P>.05). Device fill volume, flow, rate, and power were unchanged (P>.05), whereas pulsatility index decreased by 0.2 (95% confidence interval, 0.03, 0.36) with laparoscopy (P=.03). All intraoperative fluctuations in hemodynamics and device function improved with reduction of pneumoperitoneum, adjusting device speed, or pharmacologic support. There were no operative mortalities. Thirty-day survival and survival to discharge were 75% and 50%, respectively. Despite antiplatelet therapy and preoperative international normalization ratio of 2.20.9, there were no re-operations for bleeding, and 50% did not require transfusion. Two patients with recent cardiac surgery had thromboembolic events: one stroke and one device thrombus. None had postoperative bacteremia or driveline infection. Conclusions: Laparoscopy can be performed on MCS with low morbidity and mortality and minimal perturbations in hemodynamics and device function.