液固两相射流冲击磨损的数值计算与实验研究

应用实验与数值模拟研究液固两相射流对不锈钢材料的冲蚀磨损行为,分析不同质量分数、粒径情况下样品的平均磨损率,并基于数值模拟预测不同射流速度工况下的冲刷磨损率,最终建立冲刷磨损率与射流速度的关系模型。研究结果表明:单相射流流场的数值模拟结果与实验结果吻合较好;在距离射流中心区域不同径向距离上,平均速度的变化趋势较一致;在近壁面处,射流轴向速度突然减小,造成雷诺切应力增大。在远离壁面处,其法向速度逐渐增大,脉动速度相应增大,雷诺切应力增大;当射流继续远离壁面时,雷诺切应力开始减小直到趋近于0;在喷嘴正下方,压力分布存在1个滞止区,此处压力高于四周压力;下游冲刷磨损率先升高再稍微下降,而上游冲刷磨损率明显下降;实验样品表面微观测试结果验证了不同区域冲刷磨损率分布的正确性。国家自然科学基金资助项目(51776225,51376153,51406235);;中国石油大学(北京)科学基金资助项目(C201602)~

中红外吸收光谱测量激波风洞自由流中NO浓度和温度

JF-10氢氧爆轰驱动激波风洞内的高焓自由来流气体中含有因电离和离解等非平衡过程产生的微量组分。利用可调谐二极管激光吸收光谱技术(TDLAS),对自由流中NO微量组分的浓度和温度进行测量,有助于定量理解气体电离和离解这一非平衡过程。本实验中,JF-10氢氧爆轰驱动激波风洞实验段内压力为百帕量级,在谱线加宽中多普勒加宽占据主导,多普勒半高宽可由分子平均热运动速度获得,其半高宽与温度的平方根成正比,因此选取一条吸收谱线并准确测定其多普勒半高宽即可得到温度和浓度。本实验中采用中红外量子级联激光器(Quantum Cascade Laser),选取1909.7cm-1附近6条吸收线作为吸收线,在2kH..

中红外激光吸收光谱诊断ADN基推力器实验研究

ADN基推进技术是下一代卫星推进技术的研究热点,在卫星和火箭姿态控制以及小卫星主推进系统有广泛的应用前景。ADN基推进技术兼具单组元推进结构简单、可靠性高和双组元推进性能的优点,同时其推进剂是一种绿色无毒推进剂,被认为是肼类推进剂的理想替代品。目前关于ADN基推力器的工作,国内已经成功研制了工程样机,但是对于发动机内部燃烧机理的研究还很欠缺,这部分的掣肘也极度影响对工程样机可靠性的验证。本实验利用中红外吸收光谱技术,利用QCL量子级联激光器对发动机燃烧中重要的特征组分:CO,NO,N2O进行诊断测量测量。CO,NO,N2O是ADN基发动机燃烧室催化分解和燃烧反应的重要产物,是燃烧完全程度的直接..

Plasma assisted stabilization of a premixed methane-air flame by nanosecond repetitively pulsed discharges

Nanosecond pulsed discharges were applied to an experimental study of the temporal response of a premixed methane-air Bunsen flame.A nanosecond-gated schlieren system was employed to explore the microstructure and the dynamic response of flame to the discharges.At the meantime,time-resolved optic..

黑果枸杞原花青素合成相关无色花色素还原酶基因和花青素还原酶基因的克隆及表达分析(英文)

原花青素是黑果枸杞中一类重要的植化产物,但其生物合成机制仍不清楚。本研究利用黑果枸杞EST数据库,克隆了无色花色素还原酶基因(LrLAR)和花青素还原酶基因(LrANR)。PCR结果表明,LrLAR和LrANR分别由333个氨基酸残基、338个氨基酸残基组成的蛋白编码。进化分析表明,相应蛋白LrLAR、LrANR分别聚类于LAR和ANR簇。实时定量PCR结果表明,从果实未成熟时期到变色期,LrLAR、LrANR的表达量均急剧上升,但在随后的发育时期中逐渐下降;与在果实中相比,在嫩叶、成熟叶、茎、根中,两基因的表达量极低。植化分析发现,果实中总原花青素含量高于嫩叶、成熟叶、茎、根中的含量,并且在果实成熟过程中呈现先增加后基本趋于稳定的趋势。本研究将为揭示黑果枸杞原花青素生物合成机制及促进其工程改良奠定基础

Genome size for six commercially important fishes in China

采用流式细胞术,以人(HOMO SAPIEnS)淋巴细胞dnA含量(7.00Pg/2C)为标准,以鱼的红血细胞为材料,测定中国6种重要经济鱼类条纹斑竹鲨(CHIlOSCyllIuM PlAgIOSuM)、斜带石斑鱼(EPInEPHEluS COIOIdES)、赤点石斑鱼(EPInEPHEluS AkAArA)、大黄鱼(PSEudOSCIAEnA CrOCEA)、中华乌塘鳢(bOSTrICHTHyS SInEnSIS)、大菱鲆(SCOPHTHAlMuS MAXIMuS)的基因组大小(C-值)。结果显示,这6种经济鱼类的单倍体dnA含量分别为:条纹斑竹鲨(4.91±0.24)Pg;斜带石斑鱼(1.25±0.04)Pg;赤点石斑鱼(1.23±0.11)Pg;大黄鱼(0.76±0.03)Pg;中华乌塘鳢(0.85±0.04)Pg;大菱鲆(0.65±0.01)Pg。研究结果可为这6种经济鱼类的种质鉴定提供依据。此外,根据本研究的实验结果并结合其他鱼类的基因组大小资料,对鱼类基因组大小与其染色体数目及进化地位之间的相关性进行了探讨,对比分析显示,鱼类进化地位越高则dnA含量越少,同时鱼类基因组的大小差异存在复杂性,并不完全与染色体数目相关。本研究还就鱼类基因组大小的测定方法等问题提出建议,认为应采用流式细胞术和人淋巴细胞作为规范的检测方法和对照标准。The study of the genome size is highly significant as it can not only help to instruct the hybridization and breeding program,but also aid to the whole-genome sequencing project of commercial fishes.Chiloscyllium plagiosum,Epinephelus coioides,E.akaara,Pseudosciaena crocea,Bostrichthys sinensis and Scophthalmus maximus,with high market value,are commercially important and popular fishes in China because of their delicious and nutritious meat.In China,E.coioides,P.crocea and S.maximus have been the key of the aquaculture industry over a large scale.Nevertheless,there are still limited data of the genome size despite of many corresponding researches on the heredity,evolution and breeding.In this paper,the genome size( C-value) of these fishes was determined using a flow cytometry technique,and Human( Homo sapiens)lymphocyte( 3.50 pg/C) was serving as an internal control.The results showed C-values are 4.91±0.24,1.25±0.04,1.23±0.11,0.76±0.03,0.85±0.04,and 0.65±0.01 for C.plagiosum,E.coioides,E.akaara,P.crocea,B.sinensis and S.maximus,respectively.The results showed that the genome size of the class Chondrichthyes was significantly larger than that of Osteichthyes,and the genome size was found significantly different among these fishes except for E.coioides and E.akaara,which are in the same genus and have an affinity relationship between them.The C-values may be used as a criterion for species identification among these fishes.Base on our results and other data from genome-size database which were measured using the same method and control,the relationship between C-values and evolution status and chromosome amount of the fishes was discussed.Most of the data showed that with the higher evolution status of the fish,the lower C-value is presented.To a certain extent,the result demonstrated that C-value prefers to be more condensed along with the evolution of the genome.However,there are many complex factors which can influence the genome size of the fish.The point of view that the genome size positively correlates to the amount of chromosome is not always correct according to the data.In the present study,the amount of chromosome of P.crocea and B.sinensis are 48 and 46 respectively,while their relative genome sizes are 0.76 pg and 0.85 pg.Furthermore,the result also shows that there is more diversity on the genome size among species existing in original order such as the Chondrichthyes and Acipenseriformes of the Osteichthyes,which may be due to an age long evolution history of this fish.Finally,in order to avoid the disadvantages of poor accuracy and low comparability,we consider that the use of the flow cytometry technique and human lymphocyte as a control should be a more appropriate criterion for genome size determination protocol.国家自然科学基金项目(40976094

可调谐二极管激光吸收光谱诊断技术:原理和应用

可调谐二极管激光吸收光谱技术是一种非接触的光谱诊断技术,已经广泛应用于高温气动研究中.文章对吸收光谱的发展和应用于高温反应环境温度和组分浓度的测量进行了回顾.对不同的吸收测量策略以及相应的系统组成进行了详细介绍,最后介绍了应用吸收光谱技术研究超声速燃烧火星再入以及空间推进系统的详细结果

中红外吸收光谱测量激波风洞自由流中NO 浓度和温度

针对JF-10 氢氧爆轰驱动激波风洞内的高焓来流，利用可调谐二极管吸收光谱技术（TDLAS），对自由流中一氧化氮浓度和温度进行测量。利用1909.782019 cm?1 吸收线，在2 kHz 的扫描频率下，采用直接吸收-波长扫描法进行温度和浓度测量

用于超燃诊断的吸收光谱二维诊断技术

可调谐二极管吸收光谱技术(TDLAS)可同时进行多组分、多参数测量,其极强的环境适应性使其适于应用在直连式超燃试验台中。然而TDLAS是沿光程的积分测量,为提高其空间分辨能力,结合层析成像术(CT),发展了基于TDLAS的二维断层成像术(TDLAT)。将TDLAT系统用于直连台燃烧室出口,获得了静温/水蒸气浓度的动态二维分布信息。测量系统采用8×8路正交光束,4个测量波长:7185.6cm-1、7444.3cm-1、6807.8cm-1和7466.3cm-1,测量频率2.5 k Hz,使用模拟退火算法(SA)进行数据重建。反演得到的展向温度和浓度分布,能够用于分析燃烧展向燃烧区域分布和释热特征..