丹霞山陡坡上风化洞穴的基本特征及成因探讨     

史月欣  陈留勤  杜丁丁  柴乐  王子涵 《热带地理》2023,43(1):103-114

风化洞穴在全球不同气候区广泛发育,其形成过程和主控因素是地貌学研究的热点问题,但形成机制至今仍存在不少争议,尤其对丹霞地貌区风化洞穴的研究还较少。丹霞山是世界自然遗产地“中国丹霞”的典型代表,陡坡上发育形态和规模各异的风化洞穴,是丹霞地貌的重要景观要素,为认识亚热带湿润气候风化洞穴成因提供了良好的机会。文章以丹霞山砾岩和砂岩陡坡上的5处典型风化洞穴为研究对象,利用野外考察、形态测量、气象监测、样品显微观察及盐化学实验等方法,在已有研究的基础上进一步对湿润气候丹霞地貌区风化洞穴的特征和成因进行探讨。结果表明：1）在砾岩中发育的洞穴一般个体形态较大,洞穴具有较明显的向上和向内生长趋势;砂岩中发育的洞穴大多密集排列,形态较小,常具有蜂巢结构。2）岩石性质是洞穴发育的基本影响因素,在宏观尺度上决定了洞穴的发育位置和排列方式,也决定了不同岩性下发育的风化洞穴的形态特征。在微观尺度上,岩石含有较多长石、钙质胶结物等易溶矿物组分,在酸性雨水渗流过程中发生化学溶解,加上盐结晶作用导致岩石微观结构破坏,诱发洞穴初始形成。3）洞穴尺寸变大后,洞穴内适宜的微气候是洞穴演化的关键因素,为水和盐的聚集及盐风化提...  相似文献   

Properties of Klebsiella phage P13 and associated exopolysaccharide depolymerase     

LIU Yang  LI Guiyang  MO Zhaolan  CHAI Zihan  SHANG Anqi  and MOU Haijin 《中国海洋大学学报(英文版)》2014,13(1):163-168

The bacteriophage P13 that infects Klebsiella serotype K13 contains a heat-stable depolymerase capable of effective degradation of exopolysaccharide(EPS) produced by this microorganism. In this study, the titer of phage P13, initially 2.0 × 107 pfu mL-1, was found increasing 20 min after infection and reached 5.0 × 109 pfu mL-1 in 60 min. Accordingly, the enzyme activity of depolymerase approached the maximum 60 min after infection. Treatment at 70℃ for 30 min inactivated all the phage, but retained over 90% of the depolymerase activity. Addition of acetone into the crude phage lysate led to precipitation of the protein, with a marked increase in bacterial EPS degradation activity and a rapid drop in the titer of phage. After partial purification by acetone precipitation and ultrafiltration centrifugation, the enzyme was separated from the phage particles, showing two components with enzyme activity on Q-Sepharose Fast Flow. The soluble enzyme had an optimum degradation activity at 60℃ and pH 6.5. Transmission electron microscopy demonstrated that the phage P13 particles were spherical with a diameter of 50 nm and a short stumpy tail. It was a double-strand DNA virus consisting of a nucleic acid molecule of 45976 bp. This work provides an efficient purification operation including thermal treatment and ultrafiltration centrifugation, to dissociate depolymerase from phage particles. The characterization of phage P13 and associated EPS depolymerase is beneficial for further application of this enzyme.  相似文献   

北大西洋涛动指数变化与北半球冬季阻塞活动   总被引：2，自引：0，他引：2  

柴晶品  刁一娜 《大气科学》2011,35(2):326-338

线性回归分析表明北大西洋涛动(NAO)主要与大西洋、欧洲及乌拉尔山地区阻塞的频率和强度的变化存在显著相关关系.在NAO负位相时期阻塞活动在大西洋地区较为频繁且强度较强,正位相时期大西洋地区阻塞活动减少,强度减弱,而欧洲阻塞加强,频率增加,同时乌拉尔山地区的阻塞活动也显著减少.NAO正指数的增强和减弱对应于大西洋和欧洲阻...  相似文献   

CINRAD/SB雷达接收机技术特点及故障诊断方法     

潘新民  柴秀梅  崔柄俭  徐俊领  黄跃青  王全周 《气象科技》2011,39(3):320-325

介绍了CINRAD/SB雷达接收系统技术特点。根据接收机的主通道、测试通道、故障定位通道的信号流程,从监测信息、报警信息、关键点参数测量入手,总结了CINRAD/SB雷达接收系统故障诊断方法和技巧。详细介绍了利用RDA计算机的报警信息直接查找故障、通道测试法和关键点波形测试法3种诊断故障的方法,并列举了接收机主通道前端、后端以及测试通道3个不同类型的典型故障个例的分析和处理步骤。提出了接收系统维修方面的一些建议,为新一代天气雷达技术支持和保障提供借鉴。  相似文献   

CINRAD/CC雷达伺服系统故障分析与处理方法   总被引：1，自引：1，他引：0  

郑洪  柴秀梅  余加贵 《气象与环境科学》2011,34(1):91-95

云南昭通新一代天气雷达自2002年9月安装运行以来,伺服系统出现了方位(俯仰)R/D板故障、方位(俯仰)电源故障、汇流环和驱动器等方面的故障.通过这些故障实例,总结了如何根据故障现象结合雷达生产厂家提供的电路图图册,分析故障所在的伺服系统的工作原理、组成和流程,找到故障成因,排除故障的方法.在分析排查的过程中,总结出一...  相似文献   

CINRAD/SB雷达伺服上电故障诊断分析   总被引：1，自引：1，他引：0  

潘新民  柴秀梅  崔炳俭  黄跃青  徐俊领 《气象科技》2011,39(2):212-216

在详细介绍CINRAD/SB雷达数字伺服系统加电控制、天线状态信号流程的基础上,分析出数字伺服系统无法上电3方面原因：负载过载导致空气开关保护性断电;伺服系统加电信号不正常;制动器过流导致温度超限。总结了CINRAD/SB雷达伺服系统无法上电故障的分析方法和诊断流程。通过诊断流程详细论述两例伺服无法上电的复杂故障分析和排除过程,以及在台站无配件更换情况下,充分利用雷达线路特点暂时采用应急方法尽快恢复雷达运转的方法,保证灾害性天气监测的需求。为新一代天气雷达技术支持和保障提供借鉴。  相似文献   

2011年度地球科学部面上项目、青年基金和地区基金项目会议评审工作报告     

宋长青  柴育成  李军 《地球科学进展》2011,26(12):1306-1309

2011年是科学基金“十二五”发展的开局之年。中央财政对科学基金的投入大幅度提高。科学基金工作总体要求是,全面落实党的十七届五中全会精神,以邓小平理论和“三个代表”重要思想为指导,深入贯彻科学发展观,围绕服务科学发展、支撑经济发展方式转变的战略需求,  相似文献   

Seasonal and interannual variability of carbon cycle in South China Sea: A three-dimensional physical-biogeochemical modeling study   总被引：5，自引：1，他引：4  

Fei Chai  Guimei Liu  Huijie Xue  Lei Shi  Yi Chao  Chun-Mao Tseng  Wen-Chen Chou  Kon-Kee Liu 《Journal of Oceanography》2009,65(5):703-720

The South China Sea (SCS) exhibits strong variations on seasonal to interannual time scale, and the changing Southeast Asian Monsoon has direct impacts on the nutrients and phytoplankton dynamics, as well as the carbon cycle. A Pacific basin-wide physical-biogeochemical model has been developed and used to investigate the physical variations, ecosystem responses, and carbon cycle consequences. The Pacific basin-wide circulation model, based on the Regional Ocean Model Systems (ROMS) with a 50-km spatial resolution, is driven with daily air-sea fluxes derived from the National Centers for Environmental Prediction (NCEP) reanalysis between 1990 and 2004. The biogeochemical processes are simulated with the Carbon, Si(OH)₄, Nitrogen Ecosystem (CoSINE) model consisting of multiple nutrients and plankton functional groups and detailed carbon cycle dynamics. The ROMS-CoSINE model is capable of reproducing many observed features and their variability over the same period at the SouthEast Asian Time-series Study (SEATS) station in the SCS. The integrated air-sea CO₂ flux over the entire SCS reveals a strong seasonal cycle, serving as a source of CO₂ to the atmosphere in spring, summer and autumn, but acting as a sink of CO₂ for the atmosphere in winter. The annual mean sea-to-air CO₂ flux averaged over the entire SCS is +0.33 moles CO₂ m⁻²year⁻¹, which indicates that the SCS is a weak source of CO₂ to the atmosphere. Temperature has a stronger influence on the seasonal variation of pCO₂ than biological activity, and is thus the dominant factor controlling the oceanic pCO₂ in the SCS. The water temperature, seasonal upwelling and Kuroshio intrusion determine the pCO₂ differences at coast of Vietnam and the northwestern region of the Luzon Island. The inverse relationship between the interannual variability of Chl-a in summer near the coast of Vietnam and NINO₃ SST (Sea Surface Temperature) index in January implies that the carbon cycle and primary productivity in the SCS is teleconnected to the Pacific-East Asian large-scale climatic variability.  相似文献   

同时检测监测网的异常形变和粗差   总被引：5，自引：3，他引：2  

柴艳菊  欧吉坤 《大地测量与地球动力学》2003,23(1):64-68

粗差干扰影响形变分析成果的质量，以往都是粗差与异常变形分开来检测，即对每一期观测锡除粗差后再进行平差，然后利用两期或多期平差结果进行形变分析，这两步是重复的，为此，从位移观测方程入手，根据粗差检测与异常形变检测相似的特点，提出将粗差与异常形变同时检测，根据二者的不同特点，将它们区分开的新思路。通过算例分析比较了拟准检定法、假设检验法及相关抗差估计方案的检测效果，结果表明拟准检定法具有比其它两种方法实施简单、定位准确的优点，同时验证了这种思路的可行性。  相似文献   

基于断层相互作用的地震活动有限元模型   总被引：5，自引：1，他引：4  

陈化然  李轶群  汪翠芝  柴金翼  董晓阳 《大地测量与地球动力学》2002,22(2):86-90

基于断层相互作用，初步建立了西南地区有限元动力学模型，讨论了由于地震发生产生的应力变化对西南地区整个系统的应力调整情况。初步结果表明，许多强震均发生在应力增强区。因此，本模型对判断未来强震危险区有一定的意义。  相似文献