Experiment on flow field and thrust induced by plasma actuators

为了深入了解等离子体激励器流动控制原理,采用PIV技术获得了静止空气中的等离子体激励器上表面诱导气流及其末端引射气流流场的流速分布和流态,并对由此产生的诱导推力进行了测量实验;研究了等离子体激励器上表面诱导气流加速机理和尾部流场形态以及电极对数对诱导气流加速的影响,并与推力实验结果进行比较。研究结果表明,等离子体激励器上表面空气被诱导产生定向流动,并在多对平行电极的作用下被逐渐加速;诱导气流在激励器末端的引射作用形成射流,增加等离子体激励器电极对数可以增大该射流的流速;所产生的诱导推力也随诱导气流流速的加速相应增大。The velocity distribution and flow pattern of the induced flow on the surface and in the downstream of the plasma actuator were obtained by PIV technique in the still air and the induced thrust produced by the flow also was measured with an electronic balance.The mechanism of the induced flow on the actuator surface was investigated.The effect on accelerating the induced flow by the electrode number was compared with the induced thrust measured.The results show that the air flow induced on the plasma actuator is directional to form a jet in the downstream edge of the actuator and the flow is gradually accelerated by the electrodes parallel in both side of the actuator.Both the jet velocity and the induced thrust increase with adding electrode number.福建省自然科学基金(2010J01014

解决城市交通拥挤的道路收费理论及实践探索

城市交通拥挤及相关的环境污染问题,实际上是城市道路和环境资源无偿利用产生的负外部性。对城市道路进行合理收费,是缓解城市交通拥挤的一项最有效的措施。本文从经济学的角度阐述了道路收费的理论基础以及在国外的几种实施模式,并以此为背景,对我国实施道路收费进行了思考

STUDY ON EXPERIMENTS FOR SUPPRESSING WINGTIP VORTICES WITH PLASMA

该文对利用dbd等离子体注入能量抑制翼尖涡进行了风洞试验研究。通过采用PIV粒子成像测速技术测量了三种不同结构的等离子体激励器影响下的后掠翼下游的尾涡流场,并结合矩形机翼在等离子作用前后的气动力变化,来判断等离子体抑制翼尖涡的效果。试验结果表明:在机翼翼梢的上下表面处布置等离子体激励器,通过等离子体产生的定向诱导气流形成诱导涡对流场注入能量,可以有效地延缓翼梢上翼面流动分离,抑制翼尖涡,增加升力,提高升阻比。在翼尖处流动分离较小时,等离子体抑制翼尖涡强度的效果明显;在大攻角下仍具有一定的作用;其效果与等离子体发生器的结构有关。因此,通过优化等离子体激励器结构,选择合适的等离子体激励器在翼梢表面的安放位置,可以更好地提高抑制翼尖涡的效果。The wind tunnel experiment on suppressing wingtip vortices(WTV) through adding energy with DBD plasma has been conducted in the paper.The WTV flow field of a swept wing has been visualized by PIV and the aerodynamic forces of a rectangular wing have been measured,in the condition of using three different kinds of plasma actuators respectively.The results show that the WTV may be suppressed and the separation on the upper wingtip surface may be delayed because the energy of the vortex induced by the plasma(VIP) is added into the flow field,which increases the lift and the ratio of lift to drag at a small angle of attack(AOA) effectively.Even at large AOA,the effect of plasma still appears.The effects are related to the structures of the plasma actuators.It can be obtain better results to suppress the WTV through optimizing the design of the plasma actuators and choosing the appropriate placement to install the actuators on wingtip surface.福建省自然科学基金项目(A1010014

Study on the rheology of xanthan and synergistic interaction with konjac gum and other gum

研究前期筛选获得一株多糖胶质高产菌Xanthomonas axonopodis所产的黄原胶FJAT-10151-DTJZ的品质,为该黄原胶的开发应用提供基础数据及参考。通过分析浓度、剪切速率、p H、加热温度、时间、冻融处理等对FJAT-10151-DTJZ粘度的影响研究其流变性,并研究其与结冷胶、黄原胶、凝胶多糖、瓜尔豆胶、刺槐豆胶、魔芋胶、果胶和壳聚糖8种胶的协效性。实验结果表明,FJAT-10151-DTJZ溶液的粘度随浓度的升高而升高,且为非牛顿流体;当FJAT-10151-DTJZ的浓度为1%时,其粘度为343 m Pa·s;p H、冻融对FJAT-10151-DTJZ的粘度影响不大;FJAT-10151-DTJZ的最佳加热温度为75℃;粘度随加热时间先增大后减小,当加热温度为75℃,加热时间为150 min,1%浓度的FJAT-10151-DTJZ溶液的粘度为808 m Pa·s。FJAT-10151-DTJZ只与魔芋胶有强烈的协同增效作用,与壳聚糖、结冷胶、黄原胶、凝胶多糖、瓜尔豆胶、刺槐豆胶、果胶无协效性。A Xanthomonas axonopodis strain producing xanthan gum had been screened,and researched the quality of xanthan gum FJAT-10151-DTJZ in order to provide basic data and reference for development and application. The rheology properties of FJAT-10151-DTJZ were discussed according to the viscosity variation with different conditions including concentration,shearing,p H,heating temperature,heating time and freezingthawing. The synergistic interactions of FJAT-10151-DTJZ with chitosan,gellan gum,xanthan gum,curdlan,guar gum,locust bean gum and pectin were also investigated. The results showed that polysaccharide gum solution FJAT-10151-DTJZ was non-Newton fluid. It's viscosity rised with its concentration and reached to343 m Pa·s when the concentration was 1%. The p H change and freezing-thawing played negligible effects on its viscosity. Its viscosity was 808 m Pa·s when it was heated at 75 ℃ for 150 min. Besides,FJAT-10151-DTJZ had no synergistic interaction with chitosan,gellan gum,xanthan gum,curdlan,guar gum,locust bean gum and pectin except konjac gum.国家948项目(2014-Z48);; 福建省公益类科研院所专项(2015R1018-2);; 福建省农业科学院科技创新项目(2015CX-7

生物藕合技术的原理及其应用

生物藕合是指将两种或多种分子进行键合的过程,此过程形成一个新的联合体,该联合体拥有其所有组分所具有的各特性。生物藕合技术自产生以来其应用不断推广,几乎已经涉及到生命科学领域的各个方面,也极大地推动了生物、化学、医学、农业等学科的发展。本文结合生物藕合技术的原理、特点,探讨了其发展与应用的推广与问题

Cloning, prokaryotic expression and homology modeling analysis of midgut aminopeptidase gene PxAPN5 in Plutella xylostella (Lepidoptera:Plutellidae)

【目的】克隆和表达小菜蛾PluTEllA XylOSTEllA氨肽酶基因,并进行基因序列分析和同源建模分析。【方法】以小菜蛾中肠C dnA为模板克隆分析氨肽酶基因序列,原核表达氨肽酶蛋白并进行酶活性测定,应用配体印迹分析氨肽酶与Cry2Ab蛋白的结合,通过蛋白质建模对突变位点进行分析。【结果】从小菜蛾中肠C dnA扩增出氨肽酶基因,该基因全长2 853 bP,编码950个氨基酸,预测蛋白分子量为107.3871 k dA,等电点为5.24;进化树分析显示,克隆得到的氨肽酶基因属于APn家族5,将其命名为PX APn5(gEn bAnk登录号:kM034756)。PX APn5蛋白具有鳞翅目昆虫氨肽酶蛋白的保守性特征,即含有n-糖基化位点、O-糖基化位点和gPI锚定位点,具有“HEXXH“锌蛋白酶结构域和C端跨膜区域。在大肠杆菌ESCHErICHIA COlI中原核表达PX APn5,表达产物经SdS-PAgE电泳,在110 k dA附近出现特异性条带;酶活性测试显示菌体破碎上清液具有氨肽酶活性,比活力为1 047.2 u/g。配体印迹结果显示表达的PX APn5能与Cry2Ab蛋白特异性结合。多序列比对结果表明,与其他已报道的小菜蛾氨肽酶相比,PX APn5氨基酸序列有3个保守性位点发生了突变,并通过蛋白质建模的方式表征突变位点。【结论】本研究成功克隆和表达了具有氨肽酶活性的小菜蛾氨肽酶,并发现其能与Cry2Ab蛋白特异性结合;通过蛋白质建模对氨肽酶突变位点的特征及功能进行了预测。这些结果对小菜蛾氨肽酶的功能性研究提供了理论基础。【Aim】The aim of this study is to analyze the cloning,expression and homology modeling of midgut aminopeptidase gene Px APN5 in the diamondback moth,Plutella xylostella.【Methods 】 A aminopeptidase( APN) gene was cloned from the P.xylostella midgut,and bioinformatics analysis of the gene was performed.The APN protein was expressed using prokaryotic expression system,and its enzymatic activity was assayed.The interaction between APN and Cry2 Ab was determined by using ligand blot analysis.Homology modeling of APN gene was conducted for the prediction of characteristics and functions of mutation sites.【Results】The sequencing results showed that the cloned APN gene( NCBI accession no.: KM034756) is 2 853 bp in length and encodes 950 amino acids with the predicted molecular weight of 107.3871 k Da and isoelectric point of 5.24.Phylogenetic tree analysis indicated that this APN gene belongs to class 5 of APN family,and it was named as Px APN5.Px APN5 has the conservative features of the APN proteins in lepidopteran insects including N-glycosylation and Oglycosylation sites,GPI anchor point,C-transmembrane domains and zinc-metalloprotease domain(361HEXXH365).A 110 k Da specific protein band appeared when APN protein was inducibly expressed in Escherichia coli.Aminopeptidase activity assay showed that the supernatant of broken bacteria possessedaminopeptidase activity and its specific activity was 1 047.2 U / g.The ligand blot result indicated that Px APN5 could bind to Cry2 Ab specially.Multiple alignment of amino acid sequences demonstrated that there are three mutations in Px APN5 when compared to other known APN proteins from P.xylostella.【Conclusion】The Px APN5 protein with aminopeptidase activity was successfully cloned and expressed,and it could bind to Cry2 Ab.Prediction of characteristics and functions of mutation sites in Px APN5 was carried out by homology modeling.These results laid the foundation for the functional research of Px APN.国家自然科学基金项目(31371999;31370059

潜在血源传播患者梅毒血清学TRUST/TPPA与IgM抗体联合检测

目的为潜在血源传播患者筛选梅毒血清学传染病指标。方法采用回顾性研究,对2006年6月1日～2009年12月31日本院23720例潜在血源传播患者与门诊患者的TRUST/TPPA联合检测结果进行分析比较;分析不同年度潜在血源传播患者TRUST-/TPPA+的百分率变化;对其中118份TRUST-/TPPA+的潜在血源传播患者血清标本同时采用TPPA法和FTA-ABS法进行Tp-IgM抗体检测。结果潜在血源传播患者和门诊患者的梅毒抗体阳性率分别为8.62%和26.69%,二者差异有显著性;在梅毒抗体阳性标本中,TRUST-/TPPA+占有相当的比例,二者分别为3.12%和7.50%;潜在血源传播患者中TRUST-/TPPA+的百分率呈逐年上升趋势;118份TRUST-/TPPA+的潜在血源传播患者血清,经TPPA法和FTA-ABS法检出TP-IgM抗体阳性分别为13例和10例。结论潜在血源传播患者的梅毒传染性指标的监测应至少包含特异性抗体试验,如TPPA;TP-IgM检测有助于判断其传染性

慢性肾衰患者血浆ADM、BNP和TGF-β_1的浓度变化及相互关系探讨

目的:探讨肾上腺髓质素(AMD)、脑利钠肽(BNP)和转化生长因子-β1(TGF-β1)在慢性肾衰(CRF)时的水平变化及其相互关系。方法:检测30例正常人和31例慢性肾衰患者血浆ADM、BNP和TGF-β1的浓度,CRF患者根据血肌酐水平分为2组,分析三者在不同组间的变化及其相互关系。结果:(1)CRF患者血浆ADM和BNP水平显著升高,且与血肌酐水平呈正相关;(2)CRF患者在肾衰早期TGF-β1水平显著升高,但随着血肌酐水平的升高而有所下降,与血肌酐水平呈负相关。结论:血浆ADM、BNP和TGF-β1参与了慢性肾功能衰竭发生、发展的病理生理过程,ADM和BNP水平的升高,是对机体的有益保护;而TGF-β1在肾衰过程中的变化,反映了机体自我调节的作用