EFFECTS OF DCMU ON CHLOROPHYLL FLUORESCENCE RATIO F685/F735 IN MARINE RED,BROWN AND GREEN ALGAE

The chorophyll fluorescence ratio F685/F735 in vivo can be a useful indicator for stress detection inhigher plants and seaweed. DCMU [3 - (3, 4 - dichlorophenyl ) - 1, 1 - dimethylurea] treatment influencesthis ratio. Th effects of DCMU on F685/F735 of marine red, brown and green algae under excitationlight of different wavelengths were investigted. In the brown algae, Laminaria japonica and Undariapinnatifida,DCMU did not increase this ratio under blue light excitation but increased the ratio slightlyunder excitation by green light. For the red algea, Halymenia sinensis, DCMU increased the ratiomarkedly under both blue and green ligh excitation. The percentage increase could reach 50% (undergreen light excitation) and was due to unequal enhancement at the two emission maxima by DCMU. Afraction of chlorophyll which contributed to fluorescence in the 735 nm region was less sensitive toDCMU and was likely from photosystem I of red algae. In the green alga, Ulva pertusa, DCMU causeda slight increase in F685     

国外蒸发研究的进展

随着地表能量交换与物质迁移过程研究的深入及水资源合理利用与管理定量化的迫切要求,蒸发问题越来越受到人们的重视,研究蒸发的紧迫性与重要性也愈来愈明显。国际上对蒸发的研究已有近三百年的历史,至今已取得了一系列成果。Dalton 1802年首先综合了风及空气温、湿度对蒸发的影响提出了著名的道尔顿蒸发定律,它对近代蒸发理论的创立有决定性的作用。     

基于多时相主被动遥感的漓江水面监测与水质参数反演(2016-2020年)

以漓江流域为研究区域,以2016-2020年Landsat 8 OLI、GF-1、Sentinel-2A及Sentinel-1A逐月影像为数据源,选用归一化水指数(NDWI)、改进型归一化水指数(MNDWI)、增强型水体指数(EWI)、归一化差值池指数(NDPI)、后向散射系数(S)与主被动遥感加权指数(JQ)提取漓江...     

基于集合经验模态分解的新疆地区温度场预测评估

综合运用经验正交分解法(EOF),集合经验模态分解(EEMD)和最小二乘支持向量机（LS SVM）,构建新疆地区候平均温度距平场预测模型。采用EEMD分别对经过EOF分解得到的前3个模态的时间系数进行分解,对分解得到的结果运用最小二乘支持向量机进行预测并重构得到了各个时间系数的预测结果,将时间系数预测的结果与空间场重构得到了候平均温度距平场的计算结果,在候平均的基础上计算得到了旬平均的结果,在旬平均的基础上计算得到了月平均的结果。通过采用距平相关系数(ACC〖WTBZ〗),预报技巧(SS)〖WTBZ〗和同号率对结果进行评估显示,对于候平均预测,其在前20候内的预测较为理想,平均ACC〖WTBZ〗达到了0.32,平均SS〖WTBZ〗达到了0.70,平均同号率达到了0.80。对于旬平均的预测,其在前10旬内较为理想,10旬以内平均ACC〖WTBZ〗达到了0.50,平均SS〖WTBZ〗达到了0.50,平均同号率达到了0.50。对于月平均的预测,3个月的预测平均ACC〖WTBZ〗达到了0.50,平均SS〖WTBZ〗达到了0.50,平均同号率达到了0.80。3个月内的短期气候预测具有较高的水平。     

深埋长大隧道围岩分类评价的探讨与应用

随着国内外深埋长大隧道规模的增大和工程项目的增多，其围岩分类，评价愈显重要和迫切。深埋长大隧道地质环境条件复杂，施工前期勘探工程量少，控制程度低，勘夺分类，评价极为困难。在总结当前隧道围岩分类，评价方法的基础上，针对其目前存在的问题及不足，结合具体工程探讨了深埋长大隧道围岩分类，评价的实现方法问题。     

天津市供水量与气象因子相关分析及预测模型

利用天津市某区2017年逐日、2017年7月逐时供水资料和气象资料,分析日、时供水量的变化特征及其与气象因子的关系,建立基于气象因子的日供水量预测模型。结果表明:夏季供水量最多,秋季、春季的次之,冬季的最少;日供水量存在明显的节假日效应,特别是在春节长假期间供水量下降明显。分析日供水量与气象因子的相关系数发现,除冬季外,日供水量与气温相关性较高,与其他气象因子相关系数季节差异明显。7月供水时变化特征主要受居民工作生活习惯影响,同一时次的供水量与蒸发量、相对湿度和整点气温相关性较高,但有明显的滞后性,13时的气象条件对全天总供水量影响较大。综合以上分析结论,建立多元回归日供水量预测模型。模型预测结果平均误差为1.48%,可作为日供水量预测参考依据。     

Atmospheric Environmental Capacity of SO2 in Winter over Lanzhou in China： A Case Study

The total emission control method based on atmospheric environmental capacity is the most effective in air pollution mitigation. The atmospheric environmental capacities of SO2 on representative days over Lanzhou are estimated using the numerical models RAMS, HYPACT and a linear programming model, according to the national ambient air quality standard of China （NAAQSCHN）. The results show that the fields of meteorological elements and SO2 simulated by the models agree reasonably well with observations. The atmospheric environmental capacity of SO2 over Lanzhou is around 111.7 × 10^3 kg d^-1, and in order to meet the air quality level Ⅱ of the NAAQSCHN, SO2 emissions need to be reduced by 20%.     

临近绿洲的沙漠上空近地面层内水汽输送特征

1991年7月在HEIFE实验区沙漠站进行了一次水汽输送观测实验。观测发现近地面层内比湿廓线常常出现极小值，该极小值高度为零水汽通量面的高度。这个高度以上水汽向下输送，廓线呈逆湿特征，这个高度以下水汽向上输送，廓线呈蒸发特征。沙漠上空近地面层内水汽不是常通量，在一个固定高度上观测到的水汽通量和“潜热通量”不能代表地面的蒸发量和潜热通量。     

呼和浩特站新一代天气雷达疑难报警故障分析

随着新一代天气雷达在内蒙古的布点不断增多,以及应用范围的不断扩大,这对雷达技术保障工作提出了更高的要求。针对呼和浩特站雷达故障个例,探讨如何进行雷达相关部分的原理分析、判断定位和故障排除,并总结了故障排除的方法。     

What controls early or late onset of tropical North Atlantic hurricane season?

The occurrence of first hurricane in early summer signifies the onset of an active Atlantic hurricane season. The interannual variation of this hurricane onset date is examined for the period 1979-2013. It is found that the onset date has a marked interannual variation. The standard deviation of the interannual variation of the onset day is 17.5 days, with the climatological mean onset happening on July 23.A diagnosis of tropical cyclone (TC) genesis potential index (GPI) indicates that the major difference between an early and a late onset group lies in the maximum potential intensity (MPI). A further diagnosis of the MPI shows that it is primarily controlled by the local SST anomaly (SSTA). Besides the SSTA, vertical shear and mid-tropospheric relative humidity anomalies also contribute significantly to the GPI difference between the early and late onset groups.It is found that the anomalous warm (cold) SST over the tropical Atlantic, while uncorrelated with the Niño3 index, persists from the preceding winter to concurrent summer in the early (late) onset group. The net surface heat flux anomaly always tends to damp the SSTA, which suggests that ocean dynamics may play a role in maintaining the SSTA in the tropical Atlantic. The SSTA pattern with a maximum center in northeastern tropical Atlantic appears responsible for generating the observed wind and moisture anomalies over the main TC development region. A further study is needed to understand the initiation mechanism of the SSTA in the Atlantic.