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(|Y_(GSM)|13R_E, |Z_(GSM)|5R_E, –30R_EX_(GSM)–6R_E), 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) θ angles(θ=arctan(B_Z/((B_x~2)+(B_y~2))~(1/2) which are averaged 3 hours before the observation time. Further analysis indicates that both HSFs and BPSs become denser during the northward IMF period.     

海洋平台板架结构简化评估对比研究

在海洋浮体平台设计初期,为了快速评估设计方案的结构强度水平,需要研究高效的简化方法。本文基于正交异性板理论,综合了平面应力和横向弯曲两种承载方式,改进了板架结构的正交简化评估方法。改进方法克服了原来只针对单一载荷型式的局限性,可以满足组合载荷状态下板架参数的等效变换。为了验证改进方法的适用性和精度水平,分别采用常规方法和改进方法,针对某案例平台的局部板架结构和整体结构开展了强度评估。评估结果表明,采用改进方法得到的结构区域应力水平误差在15%以内,满足初始阶段总强度评估的精度要求。     

海参低聚肽对肾阳虚小鼠的影响

分析海参低聚肽和海参粉的基本营养成分,研究并比较了海参低聚肽和海参粉对氢化可的松致肾阳虚小鼠的作用.小鼠随机分为空白、阴性、阳性对照组(丙酸睾酮,5mg/kg)、海参低聚肽组(0.5g/kg)和海参粉组(0.5g/kg).连续灌胃24 d后测定小鼠的体温、体重、自主活动次数和低温游泳时间,以及胸腺、脾脏指数和肾上腺、包...     

江苏海域文蛤周年性腺发育的初步研究

江苏文蛤(Meretrixmeretrix)属于较为独立的地理种群。为提高江苏文蛤苗种生产能力,于2003年12月到2004年11月在江苏沿海海域的东凌、新港、吕四、大丰等采样点,定期取样,计算文蛤各采样时期的丰满度,并及时测量水温,对性腺进行直接和显微切片观察,以研究其性腺发育特点。观察表明,其发育可分为5个期:形成期、生长期、成熟期、排放期及耗尽期。形成期在3~4月,水温10.5~16.5℃;生长期在4~5月,水温18~20.5℃;成熟期在5~6月,水温24~25℃;放散期在6~8月,水温24~32℃;耗尽期在9月以后,直到11月份,水温从24℃左右下降到10℃左右。水温在10℃以下时,文蛤的生长发育处于停滞状态,从11月持续到第二年的3月初。江苏文蛤性腺发育的时间比辽宁文蛤早1个月左右,比广西文蛤迟1个月左右。     

一种运动目标轨迹提取方法

针对基于区域的轨迹提取类算法的时间复杂度高等问题,该文提出了一种基于FasterR-CNN的目标轨迹提取方法,利用FasterR-CNN能够快速定位和特征提取的原理,快速确定目标区域,在此基础上提出距离加阈值限制的方法进行目标关联。该方法不要求FasterR-CNN模型具有较高目标框回归精度,且充分利用卷积神经网络能够高效提取图像特征的特点,在保证轨迹提取精度的同时,降低了目标区域确定的时间和数据量,且通过均匀抽取和目标参考点关联的方法,进一步降低了目标关联的时间。与基于Camshift的区域提取法对比,在时间复杂度基本一致的情况下,大大提高了复杂背景和复杂纹理条件下目标区域确定的准确率,使得轨迹提取率更高。     

湖北清江和尚洞洞穴滴水脂肪酸分布特征及其古生态意义

对采自湖北省清江和尚洞滴水样品,采用XAD大孔径树脂吸附法及气相色谱-质谱联用仪(GC-MS)检测出种类丰富的脂肪酸,包括直链(nC12:0～nC30:0)与支链(iC14:0～iC26:0,及aC15:0和aC17:0)饱和脂肪酸,直链单不饱和脂肪酸(nC15:1,nC16:1,nC17:1和nC18:1),多不饱和脂肪酸(nC18:2)及微量的支链不饱和脂肪酸(iC17:1).滴水脂肪酸分布特征显示有机质以微生物来源为主,兼有高等植物贡献.占优势的偶碳直链饱和脂肪酸(主要是nC16:0,nC18:0和nC14:0),含量相对较高的单不饱和脂肪酸及多不饱和脂肪酸可能主要来源于地下水微藻.滴水中还检出含量较高的nC17:1和nC15:1及微量的iC17:1和iC15:1,它们很可能来自洞顶土壤厌氧层中的硫酸盐还原菌.洞顶土壤、滴水与现代石笋碳酸钙沉积脂肪酸分布对比揭示,石笋有机质主要来源于土壤,也有地下水微生物及洞穴原地微生物贡献.     

Sequence analysis of the ITS region and 5.8S rDNA of <Emphasis Type="Italic">Porphyra haitanensis</Emphasis>

The sequences of the ITS(internal transcribed spacer) and 5.8S rDNA of three cultivated strains of Porphyra haitanensis thalli(NB,PT and ST) were amplified,sequenced and analyzed.In addition,the phylogenic relationships of the sequences identified in this study with those of other Porphyra retrieved from GenBank were evaluated.The results are as follows:the sequences of the ITS and 5.8S rDNA were essentially identical among the three strains.The sequences of ITS1 were 331 bp to 334 bp,while those of the 5.8...     

Petrology,geochemistry and genesis of Kuiqi granite batholith

The Kuiqi granite batholith outcrops in the vicinity of Fuzhou City, Fujian Province and constitutes one of the typical alkali granitic complexes in the “Belt of Miarolitic Granites” extending along the southeast coast of China. The complex is believed to have been emplaced at higher levels of the crust in a tensional fault environment. Petrographically it is composed mainly of aegirine-arfvedsonite granites with early biotite granites scattered. Miarolitic structure and granophyric texture are commonly observed. The Rb-Sr isochron age of the complex is 107.65 m.y. Both petrological and petrochemical studies show that the Kuiqi granite is of A-type. Data on chemical composition, REE pattern and transition elements reveal that there is a close genetic connection between granites and associated volcanic rocks. Thus, syntexistype (I-type) granite, A-type granite and volcanic rocks form a cogenetic “trinity”, in which the A-type granite is usually the latest member of the volcanic-intrusive series.