台风登陆衰减后造成降水加强的概况

对1965-2008年101例登陆台风衰减后3d内仍存在较强降水的天气过程,运用客观分离方法及其改进方案,分离提取了台风降水(Tropical Cyclone Precipitation;TCP),结果表明:即使登陆台风衰减为热带低压或停编后,因台风系统的存在而产生高强度降水是一种普遍现象,仍旧是预报服务中需要高度关注的问题.采用气候趋势系数和功率谱等方法得到TCP及台风的气候特征:台风衰减点的位置分布具有很强的区域性,与南岭、武夷山脉的走势大致吻合;台风衰减后降水并非单纯性减少,随着时间的推移,空间分布具有向北、向西扩散的特点,特别是中纬度地区的江汉一江淮一带,仍然是防灾减灾的重点.对于衰减后降水反而加强的台风,防御重点可以有针对性地对登陆华南类和登陆华东类两类路径的台风展开.     

一个区域气候模式对ENSO衰减年夏季中国东部降水的模拟

The performance of the Climate version of the Regional Eta-coordinate Model (CREM), a regional climate model developed by State Key Laboratory of Nu- merical modeling for Atmospheric Science and Geophysical Fluid Dynamics/Institute of Atmospheric Physics (LASG/IAP), in simulating rainfall anomalies during the ENSO decaying summers from 1982 to 2002 was evaluated. The added value of rainfall simulation relative to reanalysis data and the sources of model bias were studied. Results showed that the model simulated rainfall anomalies moderately well. The model did well at capturing the above-normal rainfall along the Yangtze River valley (YRV) during El Nio decaying summers and the below and above-normal rainfall centers along the YRV and the Huaihe River valley (HRV), respectively, during La Nia decaying summers. These features were not evident in rainfall products derived from the reanalysis, indicating that rainfall simulation did add value. The main limitations of the model were that the simulated rainfall anomalies along the YRV were far stronger and weaker in magnitude than the observations during El Nio decaying summers and La Nia decaying summers, respectively. The stronger magnitude above-normal rainfall during El Nio decaying summers was due to a stronger northward transport of water vapor in the lower troposphere, mostly from moisture advection. An artificial, above-normal rainfall center was seen in the region north to 35°N, which was associated with stronger northward water vapor transport. Both lower tropospheric circulation bias and a wetter model atmosphere contributed to the bias caused by water vapor transport. There was a stronger southward water vapor transport from the southern boundary of the model during La Nia decaying summers;less remaining water vapor caused anomalously weaker rainfall in the model as compared to observations.     

澳洲冷空气活动的季节内和年际变化特征

用澳洲850 hPa上空的变温和温度权重相结合的冷空气活动日数定义了澳洲冷空气活动指标（cold air index,CAI）,据CAI分析了澳洲冷空气活动的季节内和年际变化特征,结果表明：澳洲西南部地区是冷空气活动的关键区,5月其收缩于澳洲西南角,7月和8月其中心及影响范围均向北移动,主要分布区向澳洲东部伸展;整个冬季（6—8月）的澳洲冷空气活动没有显著的年际差异,而5—8月各月的冷空气活动却存在明显的年际变化特征。     

珠江口盆地东部中新统珠江组碳酸盐岩沉积微相研究

基于对珠江口盆地东部新近系下中新统珠江组碳酸盐岩1483块常规及铸体薄片显微特征的观察、描述以及古生物特征和岩石学特征的研究,依据碳酸盐岩颗粒组分和结构构造等特点,将珠江组碳酸盐岩划分为8个主要微相类型,并根据灰岩颗粒类型及相对含量的多少,将其进一步细分为22个次一级的微相类型。根据这些微相类型在纵向上的组合特征与环境意义,可在珠江组碳酸盐岩中识别出碳酸盐岩缓坡、局限台地、开阔台地、台地边缘滩、台地边缘礁、台地前斜坡等6个沉积相带。这些沉积相的纵向演化规律揭示了东沙隆起在早中新世海平面上升过程中经历了由碳酸盐岩缓坡到台地的沉积演化历程。      

丹霞地貌景观调查的遥感技术应用研究

以江西省丹霞地貌景观为研究对象,介绍了遥感和地理信息系统技术在丹霞地貌景观旅游资源调查中应用的原理和方法;根据已知丹霞地貌景观的遥感影像、地质背景、三维地形模型、地形坡度等多元信息特征,总结了丹霞地貌景观的解译标志;利用这些解译标志对江西省丹霞地貌景观进行详细解译。结果表明,江西省有丹霞地貌景观123处,其中新发现的有78处。为江西省的旅游发展规划和丹霞地貌景观旅游资源的开发评价提供了重要依据。     

Study on the Free Radical Scavenging Activity of Sea Cucumber(Paracaudina chinens var.) Gelatin Hydrolysate

Gelatin from the sea cucumber(Paracaudina chinens var.) was hydrolyzed by bromelain and the hydrolysate was found to have a high free radical scavenging activity. The hydrolysate was fractionated through an ultrafiltration membrane with 5 kDa molecular weight cutoff(MWCO). The portion(less than 5 kDa) was further separated by Sephadex G-25. The active peak was col-lected and assayed for free radical scavenging activity. The scavenging rates for superoxide anion radicals(O2·-) and hydroxyl radi-cals(·OH) of the fraction with the highest activity were 29.02% and 75.41%,respectively. A rabbit liver mitochondrial free radical damage model was adopted to study the free radical scavenging activity of the fraction. The results showed that the sea cucumber gelatin hydrolysate can prevent the damage of rabbit liver and mitochondria.     

青海湖东岸全新世风成沉积地球化学特征及其古气候意义

青海湖地区因独特的地理位置,其古气候演化一直为学者们所关注.由于各类环境替代指标的多解性,以往研究中对青海湖地区末次冰消期以来特别是早全新世的气候特征存在不一致的认识.对青海湖东岸种羊场风成沉积物的元素地球化学特征及其古气候意义进行分析,结合磁化率、粒度和色度指标重建了过去约11 ka青海湖地区古气候演变过程.结果表明...     

赣南崇义—大余—上犹矿集区不同类型含矿石英中白云母40Ar/39Ar年龄及其地质意义

崇义—大余—上犹矿集区是世界著名的黑钨矿床集中区,本文选择钨锡多金属硫化物石英脉型（柯树岭和漂塘矿床）和锡钨石英脉型（仙鹅塘矿床）3个矿床石英中的白云母开展40Ar/39Ar年代学研究,测得坪年龄分别是：钨锡多金属硫化物石英脉型是 158.9 ± 1.4 Ma（漂塘）、158.8 ± 1.2 Ma（柯树岭）;钨锡石英脉型的是231.4 ± 2.4 Ma（仙鹅塘）,在反等时线图上,其对应的截距年龄分别是158.8 ± 1.6 Ma、158.7 ± 1.9Ma和232.5 ± 2.4 Ma。由此表明,在崇余犹矿集区内存在两个不同成矿时期,即以黑钨矿为主的多金属硫化物石英脉型矿床形成于中侏罗世,集中于160~150Ma之间,与南岭地区钨锡矿床的主成矿期是一致的;而以锡石为主的,并含有大量白钨矿的石英脉型矿床可形成于印支期     

Extraction of Lithium from Salt Lake Brine using N523-TBP Mixture System

In this work,problems encountered by tri-butyl phosphate( TBP) in the industrialization of lithium extraction from salt lake brine were discussed in detail. The behavior of N,N-bi-( 2-ethylhexyl) acetamide( N523) during lithium extraction was investigated,and its disadvantages were analyzed in the view of practical application. An N523-TBP mixture extraction system was proposed to alleviate or avoid the defects that N523 and TBP met when they were used separately. The optimal composition of this mixture extraction system was determined to be 20% N523-30% TBP-50% kerosene.The effects of brine acidity,Fe/Li molarity ratio,phase ratio and chloride ion concentration on lithium extraction efficiency were discussed. The operation conditions in single-stage extraction were optimized as brine acidity = 0. 05 mol/L,Fe/Li molarity ratio = 1. 3,and phase ratio = 2. The high concentration of chloride ions in brine was beneficial for the extraction of lithium. The structure of the extracted complex was proposed as( LiFeCl_4·n N523·m TBP)·( 2-n) N523·( 2-m) TBP( m + n = 2) by chemical analysis and slope-fitting methods. The extraction thermodynamic functions were calculated preliminarily,and the results suggested that the extraction process was an exothermic( ΔH 0) and spontaneous( ΔG 0) reaction,and the degree of disorder increased( ΔS 0) during the extraction process. This work will give some guidance to the lithium industry of Qinghai in both the fundamental theory and practical application.     

汶川地震灾后农田和森林植被恢复遥感监测

2008年汶川8.0级特大地震对当地的生态系统造成了极大的破坏,为了评估5年来灾区农田和森林植被的恢复情况,利用逐年机载高分辨率遥感影像,结合星载遥感数据和地面调查数据,开展了灾区农林植被恢复状况监测。在农田恢复监测方面,结合2008年地震发生后以及2013年5月中旬的机载高分辨率遥感数据,采用目视解译的方式对汶川地震中受损农田的恢复状况进行监测与评估,同时利用GVG(GPS、Video和GIS)农情采样系统的作物种植成数调查结果,分析了灾后作物种植结构的变化。结果表明,灾区1592 ha受损农田,5年后仅有约17.5%得到了恢复和耕种使用。就耕地利用强度而言,重灾区耕地利用率较高,作物种植结构没有发生重大变化。在森林恢复状况监测方面,对典型区(岷江干旱河谷区和盆周山地区的3个重点区域)采用目视解译方式识别出森林变化,并结合大区域尺度规一化植被指数(NDVI)时间序列变化分析,对整个灾区的森林损毁和恢复情况做出评价。监测结果显示,汶川县、什邡市和绵竹市的森林植被恢复情况总体较好,但是一些坡度较大的损毁区、次生灾害频发区的森林尚未恢复,大区域尺度的统计结果显示,地震重灾区的46381 ha重度损毁森林植被和177025 ha中度损毁森林植被区域,完全恢复的区域占13.52%和25.84%,部分恢复的区域都占到50%。在自然恢复较为困难的区域,如汶川县中部和东北部、都江堰市北部、彭州市北部、什邡市北部、绵竹市北部、安县北部及北川县南部等,需要加强人工干预。遥感监测方法既适用于震后的农田和森林恢复状况动态监测,也适用于其他自然灾害发生时对灾区农田和森林植被破坏状况进行应急监测,具有实际应用价值和良好的发展前景。