辛勤耕耘,为祖国鞠躬尽瘁——纪念黄秉维先生逝世一周年

黄秉维先生以他渊博的学识和辛勤的劳动 ,为推动中国现代地理学的发展 ,促进地理学研究水平的提高 ,做出了卓越的贡献。他实事求是、追求真理的优良作风和全心全意为人民、为祖国鞠躬尽瘁的崇高品德汇集一身 ,是我国知识分子的优秀代表 ,是地学界的一代师表和学习的榜样。黄秉维先生对发展中国地理学的贡献以及在治学、工作和为人等方面的师表风范是中国地理界的宝贵财富 ,将永远被后人学习、传颂。结合实践 ,服务建设黄秉维先生从 1 7岁起就始终活跃在科研第一线 ,在地理学的领域中涉足深广 ,对于自然地理和人文地理的许多方面都有探索 ,尤其精于中国自然环境的综合研究 ,在国内外地理学界具有广泛的影响。     

西藏朋曲流域不同地貌部位流动沙丘粒度特征

沙丘粒度特征不仅能反映沙丘沙物质的来源与动力,也可以体现地形对风沙流运移的改变。对西藏朋曲流域不同地貌部位流动沙丘表层沉积物的粒度特征进行分析。结果表明：（1）朋曲流域流动沙丘表层沉积物粒度组分以中沙（46.51%）和细沙（40.52%）为主,粗沙（5.87%）与极细沙（5.87%）次之,黏土（0.37%）与粉沙（0.85%）含量最低。流动沙丘表层沉积物平均粒径1.41—2.32 Φ,分选系数0.45—0.79 Φ,偏度0.01—0.24,峰度0.98—1.80。（2）从河漫滩到河流阶地到山坡,流动沙丘粒度逐渐变小,频率分布曲线逐渐变高变窄,粒径越来越集中,沿主导风向自西南向东北概率累积曲线斜率逐渐增大,分选性逐渐变好。（3）河漫滩至河流高级阶地流动沙丘表层沉积物随海拔升高粒径变小,坡麓至坡顶随海拔升高粒径变大,分选却变好,表明山坡上沙丘与阶地上沙丘的沙物质来自于不同河段的河床或河漫滩。     

莫高窟PM10浓度与气象要素的关系

采用2018年敦煌莫高窟第16窟窟内与窟区PM₁₀浓度及气象数据,分析PM₁₀时空分布特征及其影响因素。结果表明：（1）两处监测点PM₁₀浓度主要分布在50 μg·m^-3以下,受重污染天气影响较小;春、冬、秋、夏季依次降低,窟区PM₁₀浓度在春、冬季高于窟内,夏、秋季反之。（2）PM₁₀浓度3月最高,9月最低,5—9月窟内月均值高于窟区。PM₁₀污染日数窟内5月最多,而窟区3、5月较多。（3）PM₁₀浓度日变化曲线在春季和秋季呈“双峰”型,夏季和冬季呈“单峰”型。（4）在半封闭环境的洞窟内,沙尘暴发生前后,PM₁₀浓度达到极值及恢复至原来水平的时间均滞后于窟区。（5）在不同季节PM₁₀浓度与气温、风速和降水呈负相关。除秋季外,PM₁₀浓度与相对湿度、气压呈正相关。（6）窟区全年主风向为ESE,在冬春两季,此风向PM₁₀浓度最高,PM₁₀主要来自三危山前的戈壁滩、干涸的大泉河河道以及窟前裸露的地表积尘。     

Effect of copper on the growth of shrimps Litopenaeus vannamei: water parameters and copper budget in a recirculating system

Shrimps( Litopenaeus vannamei) were intensively cultured in a recirculating aquaculture system for 98 days to investigate effects of 0.3 mg/L Cu on its performance, Cu budget, and Cu distribution. Shrimps in Cu-treated systems had greater mean final weight(11.10 vs 10.50 g), body length(107.23 vs 106.42 mm), survival rate(67.80% vs 66.40%), and yield(6.42 vs 5.99 kg/m 3), and lower feed conversion ratio(1.20 vs 1.29) than those in control systems but the differences were not significant. Vibrio numbers remained stable(10 4 –10 6 colony forming units/mL) in the rearing tanks of both control and treated systems. Total ammonium-N, nitrite-N, nitrate-N, pH, chemical oxygen demand, 5-day carbonaceous biochemical oxygen demand, and total suspended solids were similar in controls and treatments. Dissolved Cu concentration in the treated systems decreased from 0.284 to 0.089 mg/L while in the control systems it increased from 0.006 2 to 0.018 mg/L. The main sources of Cu in the treated systems were the artificially added component(75.7% of total input), shrimp feed(21.0%), water(2.06%), and shrimp biomass(1.22%). The major outputs of Cu occurred via the mechanical filter(41.7%), water renewal(15.6%), and draining of the sediment trap(15.1%). The foam fractionator removed only 0.69% of total Cu input. Harvested shrimp biomass accounted for 11.68% of Cu input. The Cu concentration of shrimps in the Cu-treated systems(30.70 mg/kg wet weight) was significantly higher than that in control systems(22.02 mg/kg). Both were below the maximum permissible concentration(50 mg/kg) for Cu in seafood for human consumption in China. Therefore, recirculating systems can be used for commercial on-growing of Litopenaeus vannamei without loss of shrimp quality, even in water polluted by 0.30 mg/L Cu. The mechanical filter is the main route for Cu removal.     

强化“大地质”意识 在服务地方经济发展中有为有位

地质工作如何"更加紧密地与国民经济与社会发展相结合,更加主动地为经济与社会发展服务",是我们面对的时代课题。在国家加强地质工作的大好形势下,强化"大地质"意识则是     

毫秒脉冲量计时方法和实验研究的进展

介绍脉冲星的时间频率特征。阐述了该课题研究的意义,国内外毫秒脉冲星计时理论,方法和技术方面的研究进展,分析了我国开展毫秒脉冲星计划时研究的可行性、目标及任务,并对其中的关键问题给予讨论,最后对该领域的研究发展前景进行展望。     

北昆仑奥依亚依拉克岩体锆石ＬＡ－ＩＣＰ－ＭＳＵ－Ｐｂ定年及其地质意义

主、微量元素分析结果表明,ｗ（ＳｉＯ２）介于６６．６２％～７２．３６％之间,全碱ｗ（Ｎａ２Ｏ＋Ｋ２Ｏ）在７．８２％～８．８３％之间;里特曼组合指数（σ）在２．１３～３．２６之间,Ｋ２Ｏ／Ｎａ２Ｏ 比值为１．６３～１．８４,属高钾钙碱性或钾玄岩系列岩浆。铝饱和指数（Ａ／ＣＮＫ）为１．０～１．２,结合岩石类型判别图解（ＡＣＦ）,岩石属过铝质 Ｓ型花岗岩。稀土元素总量较高,轻重稀土元素比值为９．４６～１５．６,（Ｃｅ／Ｙｂ）Ｎ＝７．６２～１５．２０,曲线为右倾,属轻稀土元素富集型。δＥｕ集中在０．３３～０．４９之间,铕具明显负异常。微量元素表现为 Ｒｂ、Ｔｈ的强烈富集,Ｚｒ、Ｈｆ、Ｙｂ亏损,结合构造环境判别认为其形成环境为后碰撞。据其主、微量元素特征,ＣａＯ／Ｎａ２Ｏ 比值为０．４２～０．７６,均大于０．３,认为源区物质成分主要为杂砂岩;Ｒｂ／Ｓｒ比值介于０．７９～１．８２之间,结合构造环境综合分析,认为岩浆主要来源于未完全成熟陆壳的部分熔融。利用锆石 Ｕ－Ｐｂ测年,２０６Ｐｂ／２３８Ｕ 表面年龄加权平均值为（４２３．９９±０．９１）Ｍａ,代表原岩结晶年龄。      

黄河北岸兰州段丘陵区土壤生态化学计量与空间变异北大核心CSCD

为探究黄河北岸兰州段丘陵区土壤碳、氮、磷含量及化学计量比的空间变异特征,基于12个样地数据,采集1 m剖面内不同发生层土壤进行土壤含水率(SWC)、pH、有机碳(SOC)、全氮(STN)和全磷(STP)的测定。分析了研究区土壤碳、氮、磷含量及其生态化学计量特征在植被和土层上的差异及空间变异特征。结果表明:(1)研究区SOC、STN、STP均值分别为4.53、0.74、0.13 g·kg^(-1),C∶N、C∶P、N∶P均值分别为7.85、55.17、8.40;(2)研究区SOC、STN、C∶N和N∶P的块基比C_(0)/(C_(0)+C)<0.25,主要受气候、植被、地形等自然因素影响;STP、C∶P则C/(C+C)>0.75,主要受退耕还草等人为因素影响;(3)研究区土壤整体受到氮限制,与此同时有机碳更为匮乏,磷则在短期内不会成为限制因子。在黄河流域兰州段北岸丘陵区北岸的生态治理与恢复中,应重视有机肥和氮肥的配置与施加,同时需减少人为干扰,这对于植被的快速恢复与养分的固定具有重要意义。     

A PILOT STUDY ON THE POSSIBLE IMPACTS OF SEA LEVEL RISE ON EAST CHINA

The possible global sea level rise and its magnitude in the next century induced by the doubling of atmospheric carbon dioxide concentration are briefly discussed. The rates of crustal sinking, ground surface aggradation, and sediment compaction which might give rise to the regional characteristics of relative sea level (RSL) changes, are studied in detail. Attention is focused on the following problems that are closely associated to the sea level rise in the next century: 1) the flood susceptibility of the low-lying East Qhina plains in the next century and its historical evidences, 2) the frequency of disastrous floods and storm surges, 3) the aggradational rate and the potential danger to the dikes along die Changjiang River's lower reaches and 4) the salt water intrusion and the water quality in the Changjiang River estuary. The study shows that the adverse impacts would be very great even if only the lower estimate of sea-level rise in the next century is considered. Therefore, comprehensive resear