五个杨树品种生长、光合生理及根尖离子流速特性比较分析

通过比较不同品种杨树(Populus)的生长、光合生理及根尖离子流速特性差异,为速生适应性强品种的早期选育提供参考。以渤丰3号杨(P.×euramericana‘Bofeng 3’)、渤丰1号杨(P.×euramericana‘Bofeng 1’)、西雄1号杨(P.×euramericana‘Xixiong 1’)、中雄7号杨(P.×euramericana‘Zhongxiong 7’)和中雄4号杨(P.deltoides×P.suaveolens cl.‘Zhongxiong 4’)5个杨树品种1年生苗为研究对象,于正常培养条件下的试验开始和试验结束(30 d)时分别测定株高、地径等生长指标,并于10、20、30 d时分别测定幼苗的叶片数量、单叶面积、叶长、叶宽、瞬时净光合速率(P_(n))、胞间CO_(2)摩尔浓度(C_(i))、气孔导度(G_(s))、蒸腾速率(T_(r))、叶绿素相对含量以及根尖K^(+)、Ca^(2+)、H^(+)流速等指标,经过30 d的正常管理,5个品种的株高生长量之间的差异达到显著水平,由高到低依次为中雄4号杨、西雄1号杨、渤丰3号杨、中雄7号杨、渤丰1号杨;其中光合特性指标和蒸腾速率渤丰1号杨均表现为最大,中雄4号杨均表现为最小,但是中雄4号杨的单叶面积((57.49±2.37)cm^(2))、总叶面积((1721.10±28.59)cm^(2))、单株净光合速率((17863.10±910.21)μmol·m-2·s-1)和水分利用率((3.15±0.06)μmol·mmol^(-1))均表现为最大,且K^(+)外排流速最慢,为(62.68±0.45)pmol·cm^(-2)·g^(-1),Ca^(2+)内流流速最快,为(-74.24±1.29)pmol·cm^(-2)·g^(-1),而渤丰1号的单株净光合速率((8539.70±164.64)μmol·m-2·s-1)和水分利用率((2.64±0.07)μmol·mmol^(-1))最小,且K^(+)外排流速((130.81±1.71)pmol·cm^(-2)·g^(-1))最快,Ca^(2+)内流流速((-34.43±0.84)pmol·cm^(-2)·g^(-1))最慢。综上所述,5个杨树品种中,中雄4号杨总叶面积、单株净光合速率、水分利用率最高,蒸腾速率最小,根尖K^(+)外排流速最慢,Ca^(2+)内流流速最快,植物体内K^(+)、Ca^(2+)离子含量最多,H^(+)最活跃,株高生长表现最好,可能具有潜在的较强环境适应能力,适宜种植的范围更广。

盐碱胁迫对紫花苜蓿根系Na^+、K^+离子流速的影响

中国盐碱地形成,大部分与土壤中碳酸盐的累计有关,因而碱化度普遍较高。在盐碱地再利用过程中,简单说,可以分为轻盐碱地、中度盐碱地和重盐碱地。利用Na Cl、Na2SO4、Na HCO3、Na2CO34种盐,按不同比例配比,人工模拟盐碱地中轻盐碱地盐碱度、中度盐碱地盐碱度和重盐碱地盐碱度。选用耐盐苜蓿品种金皇后、中度耐盐苜蓿品种阿尔冈金、敏感苜蓿品种敖汉,分别进行盐碱胁迫实验;通过非损伤微测技术检测苜蓿根系Na+、K+离子流变化,比较轻盐碱度、中度盐碱度和重盐碱度胁迫下3个耐盐苜蓿品种的离子流速差异。结果显示:在盐碱胁迫下,耐盐碱品种金皇后Na+离子流速外流速度比中度耐盐品种阿尔冈金要高,且均表现为外流;敏感品种敖汉在中度盐碱环境下由外流转变为内流,并出现萎蔫迹象。3个苜蓿品种的K+离子流速都发生变化,表现为外流,但流速变化各不相同且无明显的规律性。所以,在盐碱抗逆性中紫花苜蓿可以通过Na+离子流速控制来适应盐碱环境。

重茬胁迫下苹果不同砧木幼苗生长及根系吸收的差异

【目的】选择合适砧木是防治苹果重茬障碍最有前途的方法之一。本研究比较了三种苹果砧木的幼苗在重茬胁迫下的生长及根系吸收的差异,探讨重茬胁迫对K+、Ca2+吸收的影响,为筛选抗重茬砧木材料和培育抗重茬砧木品种提供理论依据。【方法】以平邑甜茶(Malus hupehensis Rehd.)、新疆野苹果[Malus sieversii(Ledeb.)Roem.]和富平楸子[Malus prunifolia(Willd.)Borkh.]一年生实生苗为试材,取自泰安市道朗镇玄家庄20年红富士/八棱海棠老果园原树穴深0—40 cm的根际土作为试验用土,于2012年4月25日取砧木幼苗并分为两组,一组利用非损伤微创技术测定根际K+、Ca2+离子流,根系固定于平衡液中,平衡半小时后测定重茬胁迫前的根际离子流速,然后将其在重茬土提取液中浸泡半小时,测定重茬胁迫后的根际离子流速;另一组移栽至直径为25cm、深30cm的苗盆中,7 9月分别测定植株株高、径粗、叶绿素含量和光合速率;生长季结束后扫描根系结构,分别称量幼苗根系、枝条、叶片的鲜重和干重。【结果】三种砧木幼苗受到重茬胁迫后,地上部生长受到不同程度抑制。重茬胁迫前后平邑甜茶株高差异不显著,新疆野苹果和富平楸子株高胁迫后均显著降低;新疆野苹果光合速率重茬土显著低于正茬土,其它两种砧木光合速率在胁迫前后无显著差异;叶绿素含量均表现为重茬土显著低于正茬土;径粗在胁迫前后无显著差异。重茬土中新疆野苹果根系干物质积累下降明显,根/冠比增大;三种砧木的根系生长量显著增大,根系总长度分别是正茬土中根系总长度的1.45倍、2.22倍、1.71倍;三种砧木幼苗在重茬土中的根系活力均低于正茬,但胁迫前后平邑甜茶根系活力下降幅度最小。重茬胁迫后,三种砧木的根际K+离子流均由内流转变为外排,胁迫前后平邑甜茶的根际K+离子平均流速变化较小,说明对其影响小,新疆野苹果根际K+离子平均流速变化最为明显,其吸收K+能力最弱;平邑甜茶根际Ca2+流动方向在胁迫前后未发生变化,均为内流,而另外两种砧木根际Ca2+离子流均由内流转变为外排,且新疆野苹果根际Ca2+离子平均流速变化最为明显。【结论】苹果砧木在重茬胁迫下地上部生长受到显著性抑制,根系总量增大,K+、Ca2+的吸收受到不同程度的影响;重茬使抗性较差的砧木新疆野苹果的物质积累受到较严重的阻碍,根冠比显著增加,K+、Ca2+的吸收受到严重影响;较耐重茬的砧木平邑甜茶的根冠比相对稳定,K+、Ca2+的吸收受到的影响也最小;富平楸子的表现介于两者之间。

‘泡桐1201’幼苗对钠盐胁迫的生理响应

探讨‘泡桐1201’幼苗对盐胁迫的应答机制,为选育耐盐碱性作物,大力推广该树种提供科学依据。以30 d ‘泡桐1201’幼苗为材料,设置5组不同浓度梯度的盐胁迫处理,分析幼苗生理状况,通过测定幼苗的株高和主根长,植株根、茎、叶的鲜质量和干质量,叶片的叶绿素质量分数,叶和根的超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性、丙二醛(MDA)质量摩尔浓度、过氧化氢酶(CAT)活性以及根系Na^+、K^+、H^+和Ca^(2+)的流速等指标,分析其生理方面、抗氧化系统以及离子流方面对盐胁迫的响应。结果表明,随着盐胁迫浓度增加,‘泡桐1201’幼苗生长受到的抑制增强,根长、株高、鲜质量和干质量均逐渐下降,地上部和地下部生物量均呈下降趋势。SOD活性、POD活性和CAT活性均先升高后降低,SOD活性和CAT活性变化趋势一致,均在100 mmol·L^(-1)时达到最大值;叶绿素质量分数呈现逐渐减少趋势。随着盐胁迫浓度的增大,根系Na^+外排速率先增大后减小,在100 mmol·L^(-1)达到最大值,以此来维持植物细胞的离子平衡,降低盐胁迫对植物的危害。K^+流速均表现为外排,外排速率随着盐胁迫浓度增加而增大。H^+主要表现为内流,并且随着盐胁迫浓度的增加,内流速率先增加后减小。Ca^(2+)流速均表现为内流,并且随着盐胁迫浓度增大流速增大。盐胁迫导致‘泡桐1201’幼苗株高、主根长、根茎叶的干质量和鲜质量受到抑制;‘泡桐1201’幼苗在盐浓度为0～50 mmol·L^(-1)胁迫下能够正常生长,在200 mmol·L^(-1)甚至出现致死的情况。

外源亚精胺对高温胁迫下生菜氮代谢的影响

【目的】在高温季节种植的生菜产量和营养品质不佳,而与生菜产量最密切的营养元素是氮。研究外源亚精胺(Spd)在生菜抗高温胁迫中的氮代谢调控机理,为降低高温对生菜产生的危害提供保护措施。【方法】试验材料为散叶生菜‘北散生3号’,试验处理设置常温对照(昼/夜温度:22℃/17℃,CK)、高温胁迫处理(昼/夜温度:35℃/30℃,H)、高温喷施Spd处理(HS)。观察3个不同处理生菜的生长形态变化,研究生菜根系离子流速、含氮化合物(总氮、氨态氮、硝态氮)含量、氮代谢关键酶活性及基因相对表达水平的变化。此外,分析CK、H和HS处理对生菜叶片游离氨基酸含量的影响。【结果】与对照CK相比,生菜生长在H处理受到抑制;与H处理相比,HS处理的生菜总鲜重、总干重、叶长、叶宽、根长、根系体积和根系表面积均有所增加,分别增加了24.00%、24.62%、14.97%、11.83%、23.24%、29.47%和36.98%。CK、H和HS处理的生菜总氮含量变化与生菜的生长趋势一致。CK、H和HS处理的生菜根系NO3-净吸收量远小于NH4+,即生菜根系主要以吸收NH4+为主;H处理使根系NO3-外排而HS处理促进根系NO3-内流。HS处理有效抑制高温导致的叶片和根系氨态氮含量的积累。同时,与H处理相比,HS处理增加了叶片和根系的硝酸还原酶(NR)、谷氨酰胺合酶(GS)、谷氨酸合酶(GOGAT)、谷氨酸脱氢酶(GDH)的活性及上调LsNR、LsGS、LsGOGAT1、LsGDH的相对表达水平。与CK相比,H处理的总游离氨基酸(TAA)含量显著减少(P<0.05);HS处理缓解了高温导致的TAA含量减少。处理CK、H和HS之间的鲜味氨基酸(UAA)、甜味氨基酸(SAA)和苦味氨基酸(BAA)的变化趋势与TAA一致,与其呈相反趋势的是芳香族氨基酸(AAA)。处理CK、H和HS之间的天冬氨酸(Asp)、苏氨酸(Thr)、谷氨酸(Glu)、甘氨酸(Gly)、缬氨酸(Val)、赖氨酸(Lys)、组氨酸(His)、精氨酸(Arg)和脯氨酸(Pro)这9种氨基酸与TAA的变化趋势一致。其中,检测的游离氨基酸中变异系数最大的是Arg。【结论】高温喷施Spd处理抑制了高温导致的生菜生物量积累的降低。与高温处理相比,高温喷施Spd处理缓解了高温胁迫导致的氮代谢紊乱,增加了叶片总游离氨基酸含量和呈味氨基酸中的甜味氨基酸、鲜味氨基酸、苦味氨基酸含量,有效地改善了生菜的耐高温能力,提升了高温胁迫下生菜的营养品质。

基于ANSYS的双丝间接电弧的数值模拟

双丝间接电弧焊(TWIAW)是一种新研发的具有理论研究价值和应用前景的焊接工艺。本文根据磁流体动力学理论,建立了双丝间接电弧的数学模型,运用ANSYS软件,对双丝间接电弧等离子体温度场、电流密度和等离子体流速分布等参数进行了数值模拟,数值模拟结果与焊接实际情况比较符合,为双丝间接电弧的进一步研究及该焊接工艺的推广应用提供了重要数据。

单组分胰岛素的制备及质量分析

单峰胰岛素经DEAE 琼脂糖快流速离子交换层析后用醋酸锌结晶,得到结晶单组分胰岛素.层析和结晶的胰岛素回收率分别为93.8%±1.0%(n=3)和94.7%±1.5%(n=3).产品经PAGE分析为单带,HPLC检测高分子量杂蛋白和脱酰胺胰岛素的含量分别为0.42%±0.06%(n=3)和1.29%±0.06%(n=3),锌的残留量为0.187%±0.006%(n=3),产品效价为27.13±0.40U/mg(n=3).所有指标均达到USP24的质量标准.该工艺具有回收率高、产品质量好的特点.

凝血因子 Ⅸ复合物制备工艺的优化及性质研究

目的 用国产凝胶制备高质量的凝血因子 复合物。方法 以新鲜冰冻血浆为原料 ,经过国产DEAE-琼脂糖快流速阴离子交换层析及 Ca3(PO4 ) 2 吸附法制备凝血因子 复合物。对制备获得的凝血因子 复合物进行凝血活性测定 ,高分子量杂蛋白定量检测以及 SDS- PAGE、免疫电泳 (IE)、交叉免疫电泳 (CIE)等性质分析 ,并且与用进口 DEAE- Sepharose CL- 6 B制备获得的凝血因子 复合物相比较。结果 两步的活性回收率分别为93.6 7± 2 .5 6 % (n=6 )和 88.71± 2 .39% (n=6 )。凝血因子 (F ) :C比活为 7.36± 0 .96 U/ mg(n=6 )。性质分析结果显示 ,本工艺制备的凝血因子 复合物不仅充分保留了有效成分 ,而且制品的纯度和血栓安全性有明显提高。结论 国产凝胶完全能取代进口凝胶用于制备高质量、低成本的凝血因子

Electrophoresis of poly(dT)_(20) through α-hemolysin nanopore in high concentration potassium chloride solution

Experiments of poly（dT）20 electrophoresis throughα-hemolysin nanopores were performed to unveil the electrophoretic transport mechanism of DNA through nanopores in high concentration potassium chloride solution. It is found that there are two obvious current blockades induced by poly（dT）20 translocation and collision events. Both blockade currents increase linearly with the applied bias voltage. However, the normalized blockade currents are almost kept the same although variable bias voltages are applied. The collision time of poly（dT）20 in the luminal site of the pore remains constant for different voltages. The translocation speed of poly（dT）20through the nanopore decreases with the increase of bias voltage. It is because as the potential increases, the drag force on the homopolymer helps it to crumple into a cluster much easier due to the poor stacking of thymine residues compared with homopolymers consisting of other nucleotides. Molecular dynamics simulations further confirm the experimental results. Increasing the applied bias voltage can slowdown the translocation velocity of the flexible poly（dT）20, which favors increasing the precision of single molecule detection by using nanopores.

EXPERIMENTAL INVESTIGATION ON INDUCED FLOW VELOCITY OF PLASMA AERODYNAMIC ACTUATION

Plasma flow control is an active flow control technology that based on the plasma aerodynamic actuation. It can be used to enhance the aerodynamic characteristics of aircraft and propulsion systems. To study the phenomena occurring in plasma aerodynamic actuation and the mechanism of plasma flow control, the induced flow velocity of the plasma aerodynamic actuator is experimentally investigated under a variety of parameter conditions. The results indicate that plasma aerodynamic actuation accelerates the near surface air at velocities of a few meters per second, and there is an angle about 5° between the mainstream and the actuator wall and a spiral vortex is formed when the induced flow is moving along the wall. Besides, with the fixed frequency, the induced flow velocity increases linearly with the applied voltage, but it is insensitive to the frequency when the applied voltage is fixed. And the configuration is an effective factor for the performance of the plasma aerodynamic actuator.

Research on the Critical Conditions for Clay Particle Release During Saline Aquifer Freshening Process

Water sensitivity phenomenon occurs during saline aquifer freshening process in seawater intrusion area, and clay particles released in the phenomenon can damage the infiltration capacity of the aquifer. In order to find out the factors and mechanisms for clay particle release, laboratory column infiltration experiments simulating saline aquifer freshening process were designed to measure the critical conditions(critical flow velocity, critical salt concentration and critical ionic strength) and force analysis for clay particle according to DLVO electric double layer theory was employed to illustrate the mechanisms for particle release. The research results showed that critical flow velocity for clay particle release is influenced by salt concentration of injecting solution. When salt concentration of injecting solution is very high, clay particles are not released, indicating that there does not exist a critical flow velocity in this situation. As salt concentration of injecting solution decreases, particles start to be released. The critical salt concentration for clay particle release is 0.052 mol L-1 in our work, which was determined by a constant-flux experiment for stepwise displacement of high concentration Na Cl solution. The critical ionic strength for clay particle release decreases as Ca2+ molar content percentage of the mixed solution of Na Cl and Ca Cl2 increases following the first-order exponential decay equation y = 0.0391e-0.266 x + 0.0015.

Numerical simulation of the pulsing air separation field based on CFD

The flow field of pulsing air separation is normally in an unsteady turbulence state.With the application of the basic principles of multiphase turbulent flows,we established the dynamical computational model,which shows a remarkable variation of the unstable pulsing air flow field.CFD(computational fluid dynamics) was used to conduct the numerical simulation of the actual geometric model of the classifier.The inside velocity of the flowing fields was analyzed later.The simulation results indicate that the designed structure of the active pulsing air classifier provided a favorable environment for the separation of the particles with different physical characters by density.We shot the movement behaviors of the typical tracer grains in the active pulsing flow field using a high speed dynamic camera.The displacement and velocity curves of the particles in the continuous impulse periods were then analyzed.The experimental results indicate that the effective separation by density of the particles with the same settling velocity and different ranges of the density and particle size can be achieved in the active pulsing airflow field.The experimental results provide an agreement with the simulation results.

Combustion characteristics of supersonic strut-cavity combustor under plasma jet-assisted combustion

Plasma jet has been widely used in supersonic combustor as an effective ignition and combustion assisted method,but currently it is mostly combined with the traditional wall fuel injection method,while the application combined with the central fuel injection method is less.In order to expand the combustion range,the plasma jet was introduced into a strut-cavity combustor with an alternating-wedge.The effects of total pressure of strut fuel injection,total pressure of cavity fuel injection,total pressure of plasma jet injection and plasma jet media on the combustion characteristics were analyzed in supersonic flow by numerical calculations in a three-dimensional domain.The combustion field structure,wall pressure distribution,combustion efficiency and distribution of H2O at the exit of the combustor with different injection conditions were analyzed.The results show that the combustion efficiency decreases with the increase of the strut fuel injection total pressure.However,the combustion area downstream increases when the total pressure of the strut fuel injection increases within the proper range.The combustion range is expanded and the combustion efficiency is improved when the cavity fuel injection total pressure is increased within the range of 0.5−2.0 MPa,but a sharp drop in combustion efficiency can be found due to limited fuel mixing when the total injection pressure of the cavity fuel is excessively increased.With the increased total injection pressure of the plasma jet,the height of the cavity shear layer is raised and the equivalence ratio of the gas mixture in the cavity is improved.When the total pressure of the plasma jet is 1.25 MPa,the combustion efficiency reaches a maximum of 82.1%.The combustion-assisted effect of different plasma jet media is significantly different.When the medium of the plasma jet is O2,the combustion-assisted effect on the combustor is most significant.

Ozonation of Sulfur Dioxide in Sulphuric Acid Solution

In this study, the oxidation rates of sulfur dioxide （SO2） in sulphuric acid solution by ozone and oxygen were compared, and the oxidation mechanism of ozone on SO2 was investigated. The results showed that the oxidation-reduction potential of the acidic solution was enhanced, the transformation rate of sulfuric acid to sulphuric acid was increased and the absorption driving force was improved in the presence of ozone. By comparing the amount of sulfate ions measured in the experiments and the theoretical amount of sulfate ions calculated from the amount of ozone consumed in the reaction, it can be confirmed that oxygen free radicals from dissociation of ozone are reactive as an efficient oxidant and oxygen from ozone generator participates in the reaction with SO2. 0.602 mol of effective oxygen was introduced into the reaction by one mole of ozone in 10.15 rain at sulphuric acid concentration of 3% （by mass）, SO2 concentration of 1.33% （by volume） and oxygen flow rate of 1.5 L.min^-1 from ozone generator.

不同钾效率烟草品种钾素吸收特性及动力学特征分析

为探讨不同钾效率烟草品种对钾素吸收利用的差异,通过砂培盆栽试验研究了10个烟草品种的钾素营养特性,对其生物量、钾含量(质量分数)、钾积累量、根系生理指标以及钾离子吸收动力学特征进行分析,并对钾效率进行评价和分类。结果表明,10个烟草品种的钾素吸收效率和利用效率总体上呈负相关,可划分为3种类型。高效吸收低效利用型烟草具有较高的钾含量,低效吸收高效利用型烟草钾含量较低。根系钾离子吸收动力学参数显示,高效吸收低效利用型烟草的最大吸收速率(V_(max))和综合吸收能力(α)分别较低效吸收低效利用型升高90.6%和215.6%,较低效吸收高效利用型升高36.1%和90.6%。低效吸收高效利用型烟草的V_(max)和α较低效吸收低效利用型分别升高40.0%和65.6%,而米氏常数(K_m)下降8.6%。低效吸收高效利用型烟草的最低吸收浓度(C_(min))和耐瘠能力(β)分别较高效吸收低效利用型下降15.7%和10.2%,较低效吸收低效利用型下降15.9%和13.1%。根系生理指标显示,高效吸收低效利用型烟草具有更高的根系活力、可溶性蛋白含量和钾离子内流速率。

木霉对盐渍逆境下枸杞根系氮素吸收和氮素利用效率的影响

本研究采集滨海盐渍土开展盆栽试验,分析施加有机肥、木霉菌剂及菌肥对枸杞氮素吸收、同化、积累和利用效率的影响,以揭示木霉对盐渍逆境下枸杞的促生机理。有机肥为木霉菌肥的灭菌物,不含木霉活菌,但两者氮、磷、钾等养分含量无显著差异。结果表明:施加有机肥、木霉菌剂和菌肥处理较对照均显著提高了根系分生区NO_(3)^(-)、NH_(4)^(+)内流速率和成熟区NO_(3)^(-)内流速率,且施加菌肥的提升幅度高于施加有机肥。与对照相比,盐渍土壤施加木霉菌剂及菌肥显著增加了根、茎、叶生物量和氮含量以及植株氮累积量,增强了枸杞根和叶中硝酸还原酶、亚硝酸还原酶和谷氨酰胺合成酶活性,提高了枸杞氮素吸收效率、光合速率、稳定碳同位素丰度值和光合氮素利用效率,而且施加菌肥的效果明显优于施加有机肥。综上,木霉能增强盐渍逆境下枸杞氮素吸收、同化和积累,提升光合固碳能力和氮素利用效率,最终促进植株生长。

Discovery of benzamide derivatives as potent Kv1.5 inhibitors

Kv1.5 potassium channel is reported as a potent and safe target for atrial fibrillation.CPUY11018 was proved it had moderate inhibition of Kv1.5.In order to improve the stability of CPUY11018,and investigate the structure-activity relationship,4 series of benzamide derivatives were synthesized and evaluated.Among them,8c is a most potent inhibitor of Kv1.5.

Low Speed Axial Compressor Stall Margin Improvement by Unsteady Plasma Actuation

This research investigates the use of single dielectric barrier discharge(SDBD) actuators for energizing the tip leakage flow to suppress rotating stall inception and extend the stable operating range of a low speed axial compressor with a single rotor.The jet induced by the plasma actuator adds momentum to the flow in the tip region and has a significant impact on the tip-gap flow.Experiments are carried out on a low speed axial compressor with a single rotor.The static pressure is measured at both the rotor inlet and outlet.The flow coefficient and pressure rise coefficient are calculated.Then the characteristic line is acquired to show the overall performance of the compressor.With unsteady plasma actuation of 18kV and 60W the compressor stability range improvement is realized at rotor speed of 1500 r/min – 2400 r/min.

THEMIS statistical study on the plasma properties of high-speed flows in Earth＇s magnetotail

Using Time History of Events and Macroscale Interactions during Substorms （THEMIS） observations from 2007 to 2011 tail seasons, we study the plasma properties of high speed flows （HSFs） and background plasma sheet events （BPSs） in Earth＇s magnetotail （｜YGsM｜〈13RE, ｜ZGsM｜〈5RE, -30RE〈XrsM〈-6RE）, and their correlations with solar wind parameters. Statistical results show that the closer the HSFs and BPSs are to the Earth, the hotter they become, and the temperature increase of HSFs is larger than that of BPSs. The density and temperature ratios between HSFs and BPSs are also larger when events are closer to Earth. We also find that the best correlations between the HSFs （BPSs） density and the solar wind density occur when the solar wind density is averaged 2 （3.5） hours prior to the onset of HSFs （BPSs）. The normalized densities of both HSFs and BPSs are correlated with the interplanetary magnetic field （IMF） 0 angles （ 0 = arctan（Bz √Bx^2＋y^2 ） which are averaged 3 hours before the observation time. Further analysis indicates that both HSFs and BPSs become denser during the northward IMF period.

Characteristics of low altitude ionospheric electric field over Hainan Island,China

A sounding rocket experiment undertaken by the Chinese Meridian Project from a low latitude station on Hainan Island(19.5°N,109.1°E),China,measured the DC electric field during 05:45-05:52 LT on April 5,2013.The data observed using a set of electric field double probes,as part of the rocket's scientific payload,revealed the special profile of how the vectors of the DC electric field vary with altitude between 130 and 190 km.During the experiment,the vertical electric field was downward,and the maximum vertical electric field was nearly 5.1 mV/m near the altitude of 176 km.The zonal electric field was eastward and slightly less than 0.6 mV/m.The plasma drift velocity was estimated from the E×B motion,and the zonal drift velocity was eastward and of the order of 100 m/s.The zonal wind velocity was also estimated using the drift velocity near the maximum density height in the F1-region,and it was found to be nearly 120 m/s.This work constituted the first in situ measurement of the DC electric field conducted within the Fl-region(between 130 and 190 km) in the East Asian Sector.