Dissolved oxygen in the bottom water of the Sea of Japan as a sensitive alarm for global climate change

The Sea of Japan, a semi-closed marginal sea (greatest depth ∼3700 m) in the northwestern-most Pacific Ocean, has an independent, deep convection system, which is driven by the formation and the sinking of cool, saline surface water towards the bottom in severe winters. Continuous measurement of dissolved oxygen using highly precise versions of the Winkler titration method has revealed 8-10% decreases in the bottom concentration of oxygen (O₂) over the past 30 years. The temporal decrease in O₂ means an imbalance between the supply of O₂ from the surface and the in situ consumption of O₂ in decomposing organic matter, suggesting that the change in the deep convection pattern of the Sea of Japan is probably caused by global climate change to reduce winter cooling of surface seawater.     

抗日根据地冬学运动的教师问题

抗日战争时期,抗日根据地冬学运动的轰轰烈烈发展使冬学教师短缺问题日益突出。根据地通过发动干部、选拔在校学生、动员当地知识分子和实行小先生与集体互相学习制等途径弥补了教师的空缺。但教师的选拔是严格的,并且必须经过一定的培训。在待遇差、条件极其艰苦的情况下,冬学教师们克服困难,出色地完成了民众教育与动员的任务。历史应该记住这些为抗战的胜利而在大后方无私奉献的冬学教师们。     

Optimizing winter road maintenance operations under real-time information

This paper introduces a real-time optimization model that can be used by maintenance managers to develop and evaluate alternative resources allocation plans for winter road maintenance operations. The model takes into account a wide range of road and weather condition factors such as road network topology, road class, weather forecasts, and contractual service levels, and produces a vehicle dispatch schedule that is optimal with respect to operating costs and quality of service. The model is then used in an analysis on a realistic case to illustrate the potential impact of improved information on winter maintenance operations.     

Mapping of powdery mildew using multi-spectral HJ-CCD image in Beijing suburban area

Powdery mildew is one of the most serious diseases, which has a significant impact on the production of winter wheat. As an effective alternative to traditional sampling methods, remote sensing can be a useful tool in disease detection. This study examines the potential of a moderate resolution multispectral satellite image in disease monitoring at regional scale. At the suburban area around Beijing, a large size ground survey sample (n = 90) and the corresponding HJ-CCD image were acquired at the grain filling stage of winter wheat. A number of spectral features were found to be sensitive to powdery mildew through an independent t-test. Based on these spectral features, classification models were established using both spectral information divergence (SID) and spectral angle mapper (SAM), respectively. The results showed that the overall accuracies of disease identification and severity estimation were moderate. The estimation of normal and seriously infected samples yielded higher accuracies than slightly infected samples. The single phase HJ-CCD can only be used for locating the infected areas of powdery mildew, whereas is unable to discriminate the severity levels of disease. The presence of several stressors and disturbances other than disease is a possible reason of the unsatisfactory performance of disease monitoring models. Therefore, the integration of multi-phase onboard data and some relevant ancillary data is necessary to improve the accuracy and reliability of disease monitoring at regional scale.     

Maneuver analysis methodology to predict vehicle impacts on training lands

Tactical mobility analysis techniques were merged with land management strategies to assess potential impacts of vehicle operations on training areas for rangeland planning and management. A vehicle mobility analysis was performed for a suite of vehicle types using the NATO Reference Mobility Model (NRMM II). Input parameters include terrain information (soil type, slope, vegetation, surface roughness, soil strength), terrain surface condition based on climate (terrain strength, freeze–thaw, moisture content, snow cover), and vehicle specifications (tire, power train, weight on each axle, ground clearance, dimensions, ride). The vehicle performance was spatially mapped over the terrain for different seasons of the year and used to calculate the maneuverable acreage, which was compared to acreage needed for training requirements. This can be related to land capability based on expected training impact (Maneuver Impact Miles, MIM) and Land Condition Curves which link training density to land condition. This methodology can be used to determine the suitability of training lands and the degree of land management or rehabilitation expected. The methodology was applied to the transformation of the Alaska training lands to support a new brigade unit called the Stryker Brigade Combat Team (SBCT3), but is equally useful for other training areas and military units. For summer use, Alaska training lands are capable of supporting four times the projected training requirements. For winter, when the ground is frozen, more than 10 times the area needed was available.     

印度洋-太平洋海表温度异常的持续性特征

用Reynolds＆Smith重构的1950-1998年月平均SST资料分析了印度洋-太平洋海表温度距平SSTA的持续性特征。结果表明:SSTA的持续性在空间上分布不均匀,可将有明显差异的SSTA持续性特征的海区分为3类:全年各月持续性好的区域,主要包括热带中东太平洋马蹄形海域、赤道中东印度洋、热带西太平洋,持续时间一般在10个月以上;全年各月持续性差的区域,主要包括西北太平洋、东亚沿海和东南太平洋,持续时间一般为3个月左右;各月持续性有季节性变化的区域,主要包括赤道东太平洋,南海。SSTA持续性的整体空间分布存在冬夏两种主要分布型,夏季型SSTA的持续性要比冬季好。冬夏间SSTA持续性最明显的差异出现在赤道东太平洋和东亚沿海、南海区域,由冬季转入夏季时,赤道东太平洋SSTA的持续性由差变好,东亚沿海、南海地区的情况则与之相反。     

郑州机场冬春季大风的分析预报

通过对郑州机场1998~2005年的大风天气进行统计整理分析,总结出主要影响郑州机场飞行的冬春季大风成因及一些特征进行了分型,并提出了2种典型大风天气形势的一般预报思路,以提高大风天气的预报准确率,从而更好地保障飞行安全和航班正点.     

沈阳地区冬小麦幼穗分化规律研究

本文研究了沈阳地区冬小麦的田间存活率、生育期、主茎春生叶龄等几个指标与冬小麦幼穗分化规律的关系.结论表明：田间存活率在品种间差别不显著,播期间显著.不同处理对全生育期及各个生育时期有很大的影响.叶龄可以作为反映幼穗分化阶段的辅助指标.各处理都没有观察到冬前生长锥伸长.返青后开始穗分,成穗分化历时一个半月左右.二棱期至小花分化期间隔日数长短决定能否分化更多的小穗数.     

北京冬奥会延庆赛区施工作业对野生动物的影响分析

【目的】探究冬奥会室外赛事场地建设对野生动物的影响,以利于制定有针对性的保护政策和措施,为落实绿色奥运理念和提升野生动物保护成效提供科学参考。【方法】于2019年4月至2020年3月,在2022年北京冬奥会延庆赛区内布设红外相机进行野生动物丰富度和活动节律监测,通过与2013年的监测数据对比,分析场地施工作业对野生动物种群和活动节律的影响。【结果】利用红外相机工作4 193相机日,获取有效照片5 961份,发现9目23科38种野生动物,其中,兽类13种、鸟类25种。与之前的调查数据相比,赛区内兽类物种减少3种,貉(Nyctereutes procyonoides)、赤狐(Vulpes vulpes)、蒙古兔(Lepus tolai)未在本次监测中发现;鸟类减少22种。经威尔科克森符号秩(Z)检验,豹猫(Prionailurus bengalensis)(Z=-2.981,P<0.01)、亚洲狗獾(Meles leucurus)(Z=-2.578,P<0.05)、猪獾(Arctonyx collaris)(Z=2.197,P<0.05)和野猪(Sus scrofa)(Z...