一种柴油机热力循环火用平衡计算法     

李湛  万小山  邱伟光 《广东海洋大学学报》2005,25(3)

针对柴油机热力循环的特点,提出了一种柴油机火用平衡计算方法,该方法可以计算出工质与冷却介质之间由于温差传热而引起的火用损失。计算结果表明,减少排气损失和工质与冷却水的温差传热损失、改善燃料燃烧过程是提高内燃机可用能利用率的主要途径。  相似文献   

Development and Characterization of Microsatellite Markers for the Pacific Abalone （Haliotis discus） via EST Database Mining     

Aibin Zhan  Zhenmin Bao  Mingling Wang  Dan Chang  Jian Yuan  Xiaolong Wang  Xiaoli Hu  Chengzhu Liang  Jingjie Hu 《中国海洋大学学报(英文版)》2008,7(2):219-222

The EST database of the Pacific abalone (Haliotis discus) was mined for developing mierosatellite markers. A total of 1476 EST sequences were registered in GenBank when data mining was performed. Fifty sequences (approximately 3.4%) were found to contain one or more mierosatellites. Based on the length and GC content of the flanking regions, duster analysis and BLASTN, 13 microsatellite-containing ESTs were selected for PCR primer design. The results showed that 10 out of 13 primer pairs could amplify seorable PCR products and showed polymorphism. The number of alleles ranged from 2 to 13 and the values of Hoand He varied from 0.1222 to 0.8611 and 0.2449 to 0.9311, respectively. No significant linkage disequilibrium (LD) between any pairs of these loci was found, and 6 of 10 loci conformed to the Hardy-Weinberg equilibrium (HWE). These EST-SSRs are therefore potential tools for studies of intraspecies variation and hybrid identification.  相似文献   

The polypeptide in Chlamys farreri can protect human dermal fibroblasts from ultraviolet B damage     

Zhang Yujiang  Zhan Songmei  Cao Pengli  Liu Ning  Chen Xuehong  Wang Yuejun  Wang Chunbo 《中国海洋湖沼学报》2005,23(3):357-362

To investigate the effect of polypeptide fromChlamys farreri (PCF) on NHDFin vitro, we modeled oxidative damage on normal human dermal fibroblasts (NHDF) exposed to ultraviolet B (UVB). In this study, 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) were tested to measure cell viability. Enzymes including superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), catalase (CAT) and xanthine oxidase (XOD) were determined biochemically. Total antioxidative capacity (T-AOC) and anti-superoxide anion capacity (A-SAC) were also determined. Ultrastructure of fibroblasts was observed under transmission electron microscope. The results showed that: UVB (1.176×10⁻⁴ J/cm²) suppressed the growth of fibroblasts and the introduction of PCF (0.25%–1%) before UVB reduced the suppression in a concentration-dependent manner. PCF could enhance the activities of SOD, GSH-PX and T-AOC as well as A-SAC. Also PCF could inhibit XOD activity, while it did not affect CAT activity. Ultrastructure of fibroblasts were damaged after UVB irradiation, concentration-dependent PCF reduced the destructive effect of UVB on cells. These results indicated that PCF can protect human dermal fibroblasts from being harmed by UVB irradiation via its antioxidant proerty. This work was supported by the National Natural Science Foundation of China (No. 39970638) and the Science and Technology Bureau of Qingdao (No. 2001-28-50).  相似文献   

Derivation of the Spiral Motion of an Eruptive Prominence and Its Explanation     

Xiao-Ma Gu  Shu-Hua Zhong  Hong-Fei Liang  La-Sheng Zhan National Astronomical Observatories / Yunnan Observatory  Chinese Academy of Sciences  Kunming  Jingdezhen ceramic institute  Jingdezhen 《中国天文和天体物理学报》2006,6(5)

A 2D velocity field of the eruptive prominence (EP) of 1991 March 5 is obtained from its spectral data observed at the Yunnan Observatory and the velocity distributions along the entrance slit are derived for different observing frames. Under the assumption that matter in the EP undergoes axial, radial and possible rotational motions, we construct a theoretical velocity distribution of the EP along the entrance slit, to derive, by fitting, the angular velocity of rotation w and the other three parameters (axial velocityυ0, radial velocityυr and the angle between the EP plane and the line of sightφ). We found: an averaged angular velocityωof 3.0 f6 10-3 arc s-1 and the variation ofωwith the height above the solar limb. As the EP rises, the matter within it in fact moves along a spiral path around its axis. The spiral motion may be explained by the theory of plasma 'double pole diffusion' (DPD) caused by a sharp density gradient between the eruptive prominence and the surrounding corona. A theoretical angular velocityω' is estimated based on the DPD and basically coincides withωobtained from the optimal velocity fitting.  相似文献   

Neoproterozoic ana texts of the yunkai metamorphic Complex; Evidence from U-Pb geochronology of zircon in migniatite北大核心CSCD     

Yang W.  Qin X.-F.  Wang Z.-Q.  Gong J.-H.  Zhao G.-Y.  Hu H.  Zhan J.-Y. 《矿物岩石地球化学通报》2016,(6):1238-1247

In order to determine the migmatization time of the Preeambrian metamorphic basement(the Yunkai metamorphic complex) of the Yunkai terrain, a study of LA-MC-1CP-MS U-Pb dating of zircon in matrixes and felsic veins of mig-matites from the Tiantangshan Group. Results show that the inherited magmatic cores of zircon grains from the matrix of migmatite have oscillatory zoning and yield a U-Pb age of 1086 ±24 Ma, representing the pmtolith age, whereas the metamprohic rims of zircon grains from the felsic vein of migmatite yield an age of 852. 6±8. 8 Ma, representing the timing of the anatex is (migmatization). These results imply that there is a Mesoproterozoic metamorphic basement with a Neoproterozoic anatexis event in the Yunkai area. The timing of this anatexis event is consistent with that of the Sibao Movement. Therefore, we conclude that the timing of the anataxis could be an important geological record for the amalgamation of the Yangtze and Cathaysian blocks.  相似文献   

连阴雨对玉米的影响研究进展     

王秀萍  刘荣花  詹静 《气象与环境科学》2016,39(4):121-125

概述了玉米连阴雨灾害的研究方法和研究现状,重点对玉米连阴雨灾害研究方法、连阴雨灾害指标、玉米耐阴指标及耐阴机理等进行了总结与评述。目前,研究已初步形成了玉米连阴雨气象灾害指标和玉米品种的耐阴性评价指标,并从玉米生长发育、光合生理、碳氮代谢和分子生物学等角度对玉米耐阴机制进行了有益的探索。但目前尚未有明确的灾损评估指标,品种耐阴性评价指标尚未统一,前人研究多注重阴雨天气带来的光辐射减弱的影响,后续研究需考虑土壤墒情和气温因素与光辐射对玉米产量的协同影响规律。加强玉米品种耐阴性评价指标的研究和耐阴种质的筛选,以减缓连阴雨灾害对玉米生产的不利影响。  相似文献   

鄂尔多斯盆地西缘煤田构造演化及其控制因素          下载免费PDF全文

曹代勇  徐浩  刘亢  魏迎春  占文锋  王信国 《地质科学》2015,50(2):410-427

鄂尔多斯盆地西缘位于华北陆块和秦祁昆山造山带两个一级大地构造单元之间的过渡带内,特定的大地构造背景使其具有复杂的构造演化历程及特殊的煤田构造格局。鄂尔多斯盆地西缘由贺兰山逆冲推覆构造系统和六盘山东麓逆冲推覆构造系统组成,具有"南北分段、东西分带"的特点。为了进一步探讨鄂尔多斯盆地西缘煤田构造格局的形成演化及区域构造控制因素,本文基于野外地质调查和煤田勘查资料,恢复了本区自晚古生代以来的沉降抬升史和古构造应力场特征。印支期:研究区北部最大主压应力方向为北西-南东向,南部最大主压应力方向为北东-南西向;燕山期:北部最大主压应力方向为北西西-南东东向,南部最大主压应力方向为北东东-南西西向;喜马拉雅山期:北部受北西西-南东东向拉张应力,南部最大主压应力方向为北东-南西向。采用有限元数值模拟,探讨了鄂尔多斯盆地西缘煤田构造格局的形成与区域构造的演化的关系,强调北段贺兰山逆冲推覆构造系统的形成与阿拉善地块的向东挤出逃逸密切相关。  相似文献   

涠洲12-A油田流二段Ⅱ油组沉积特征及演化   总被引：3，自引：0，他引：3  

曾小明  张辉  彭松  周展  王磊  谢京 《沉积学报》2015,33(1):153-159

北部湾盆地涠西南凹陷涠洲12-A油田流沙港组二段Ⅱ油组构造复杂,沉积差异大,横向变化快,对物源和沉积相的认识存在争议.通过测井、岩壁芯和地震等资料的分析研究,明确了涠洲12-A油田流沙港组二段Ⅱ油组物源来自于西南方向的涠洲12-8构造脊;划分了2长期基准面旋回、3个中期基准面旋回,建立了相应的等时层序格架;通过分析不同油组的沉积特征差异,识别出了两种沉积相,其中底部为扇三角洲沉积,顶部为正常三角洲沉积;并从基准面旋回的角度探讨了其沉积模式和演化规律.  相似文献   

江南雨季地理区域及起止时间的客观确定   总被引：3，自引：0，他引：3  

詹丰兴  何金海  章毅之  朱志伟 《海洋学报》2015,37(6):1-11

本文基于国家气象信息中心整编的全国1 675个台站观测资料以及NCEP/NCAR的再分析资料,定义了候降水指数,利用旋转正交经验函数分解(REOF)法对全国候降水的季节进程进行了诊断分析,得到了表征气候态降水逐候进程的南、北方模态及各自的时间系数,发现REOF第二模态对应降水季节进程中的江南雨季。综合考虑我国南方(31°N以南、110°E以东区域)气候态降水的候进程、降水季节进程(4-6月降水指数减去6-8月降水指数)年际变率以及雨季(4-6月降水指数)降水年际变率的一致性,客观定义了江南雨季的地理范围。利用客观划定区域内的降水指数、925hPa经向风以及西北太平洋副热带高压500hPa脊线位置3个指标,制定了判定江南雨季起止时间的方法,进而对1961-2012年江南雨季起止时间进行了客观确定,给出了江南雨季起止时间序列。本文旨在为规范江南雨季的监测提供参考和借鉴,并为其预测提供科学基础。  相似文献   

一种基于概率框架的遥感影像分割方法     

赵展  闰利  夏旺 《测绘通报》2018,(4):10-15

基于区域增长的影像分割方法存在着种子选择和分割参数设置的难点。针对这两点,本文提出了一种基于概率合并框架的高分辨率遥感影像分割方法。首先,利用基于标记的分水岭变换和区域合并获得一个初始分割结果,避开种子点的选择;其次,利用初始分割所获得的具有一定大小的区域,计算统计、上下文和形状特征信息;然后,在贝叶斯准则的基础上,计算一个尺度无关的相邻区域间的合并概率,其应用于区域增长合并过程,合并概率具有直观统计意义,可以减少阈值确定的难度;同时由于区域的合并概率具有尺度无关性,可以在一次分割中成功地分割出不同尺度的地物;最后进行了试验,通过目视和定量分析及与eCognition分割结果的对比证明了本文算法的有效性。  相似文献