2022年冬奥会对张家口城市旅游地形象的影响研究——基于UGC文本分析

重大节事活动对旅游地形象的影响具有时序动态特征,分析其内在机理有利于促进目的地营销和竞争力提升。本文采用Python数据挖掘技术和自然语言处理技术（NLP）,爬取国内知名旅游门户网站的旅游评论,从“认知-情感-整体”3个维度构建分析框架,探究2022年冬奥会申办期、筹备期、预热举办期的张家口城市旅游地形象的时序变化特征,解析特殊时期冬奥会对城市旅游地形象的潜在影响和作用机制。结果表明：(1)张家口市的城市旅游地形象构成要素日趋多元化,冬奥会的作用效果由弱变强。张家口市的冰雪旅游形象关键度不断提升,经历了由模糊向具象转变的细化过程,情感形象产生积极变化;(2)冬奥会对张家口城市旅游地形象产生了渐进式影响效应,通过旅游体验的建构作用、投射形象的引致作用和品牌感知的晕轮作用发挥效果。冬奥会推动张家口市的产品业态创新、基础设施升级及服务水平提升,通过改善游客体验对城市旅游地形象产生积极影响。研究结果对东道主城市的旅游营销和规划具有一定指导意义。     

基于面向对象的山东省冬小麦种植面积监测

利用遥感技术,使用eCognition软件的面向对象分类技术,对RAPIDEYE卫星影像进行分类识别,从而快速、准确的监测小麦种植面积,为冬小麦财政补贴提供数据和技术支持。以兖州市为例,行政区面积6.501 9万hm2,小麦监测面积3.1715万hm2,小麦面积监测精度达到了90.5%。     

参加CMIP5的四个中国气候模式模拟的东亚冬季风年际变率

本文比较了中国参加“国际耦合模式比较计划”（CMIP5）的四个大气环流模式（即FGOALS-g2、FGOALS-s2、BCC-CSM1-1、BNU-ESM大气模式）在观测海温驱动下,对东亚冬季风（EAWM）气候态和年际变率的模拟能力。结果表明,在气候态上,四个模式均合理再现了EAWM高低层环流系统（包括低层西伯利亚高压（SH）、阿留申低压、异常偏北风、和中高层东亚大槽、西风急流）,其中对2 m气温和500 hPa高度场的模拟技巧最高,四个模式模拟的结果与再分析资料的空间相关系数都达到0.99。在年际变率上,分别对东亚北部地区（30°N～60°N,100°E～140°E）和东亚南部地区（0°～30°N,100°E～140°E）的2 m气温进行经验正交函数分解（EOF）,提取变率主导模态。结果表明,在东亚北部地区,四个模式对2 m气温第一模态（简称“北部型”）的空间分布均有很高的模拟技巧,但只有BNU-ESM能够较好再现其对应的年际变率,其模拟的时间序列与观测的相关系数为0.69。四个模式均能模拟出观测中的3.1 a主导周期,但只有FGOALS-s2和BNU-ESM能模拟出观测中的2.5 a主导周期。在东亚南部地区,模式模拟的前两个主模态共同解释观测中第一模态（简称“南部型”）的特征,其中FGOALS-g2、FGOALS-s2和BNU-ESM的综合模拟技巧较高,但只有BNU-ESM成功再现了观测中2.5 a和3.1 a的主导周期。机理分析表明,FGOALS-g2、FGOALS-s2、BNU-ESM三个模式能合理再现菲律宾海反气旋,同时对南部型有较高的模拟能力,而BCC-CSM1-1则未能有效再现菲律宾海反气旋,使得 BCC-CSM1-1对南部型模拟技巧较低。观测和四个模式模拟的结果一致表现出北极涛动（AO）与北部型PC1呈显著相关,影响大于SH。     

Sediment records of environmental changes in the south end of the Zhejiang-Fujian coastal mud area during the past 100 years

Previous studies carried out in the East China Sea （ECS） mud area focused on long-term environmental changes in sedimentary records during the Holoeene, especially during the mid-Holocene high-stand water levels period. These results indicate that sensitive grain size groups can be used as a sedimentary proxy to reconstruct the evolution of the East Asian Winter Monsoon （EAWM）. The studies have been carried out mainly in the northern and middle portions of the Zhejiang-Fujian coastal mud, however, similar research in the southern portion and the comparison between sedimentary proxy and modern measured data of EAWM are lacking. In this paper, we focused on a sedimentary record of the past 100 years with an enhanced resolution of 1.8 years. Investigations of the southern end of the Zhejiang-Fujian coastal mud area were conducted on the basis of 21~Pb chronology, grain-size analysis and chemical element analysis. The correspondence between the mean grain size （Mz） of sediment sensitive grain size and the measured EAWM was confirmed for the first time. We found that during the recent 100 years, the variation of the mean grain size of the sensitive population in the southern portion of the Zhejiang-Fujian mud was mainly controlled by the EAWM intensity changes; and not directly related to changes in the sediment discharge from Datong station of the Changjiang River （DTSD）. Finally, recent changes in the content of heavy metals in study area reflect the impact of human activities on the environment.     

吐鲁番盆地冬季气温变化及特色林果冬季冻害指标分析

利用吐鲁番东坎农业气象试验站和鄯善气象站近52a（1960-2011年）冬季逐日资料,分析入冬期、冬季平均气温、极端最低气温、低温日数、负积温变化特征,以及特色林果葡萄、红枣冻害发生年最低气温的变化特征,探讨冬季气温变化与冻害发生的关系,总结冻害成灾指标,为防止果树冻害提供理论依据。分析结果表明：吐鲁番盆地冬季平均气温和最低气温呈上升趋势,入冬期偏晚,冬季结束时间提早,冬季持续日数缩短;冬季气温在1985年发生突变,存在7a的周期变化。在无稳定积雪的情况下,最低气温负积温较历年平均值低180．0℃以上,日最低气温≤-18．0℃持续15d以上,且日最低气温连续≤-20．0℃持续5d以上,休眠期的红枣、杏树花芽会发生中度冻害;最低气温负积温较常年低200．0℃以上,日最低气温≤-20．0℃持续7d以上,且日最低气温≤-21．0℃持续5d以上,红枣、杏树及无积雪、覆土厚度〈30cm的葡萄会发生严重冻害。     

用微机进行Mie散射算法研究

本文介绍在东海微机上用伦茨算法计算Mie级数的系数,其计算程序已运行成功。计算结果表明此法可使误差传播显著减小,计算精度提高,降低了对微机内存客量的要求,同时,本文得到的计算结果与国外公开发表的计算结果达到同样精度。     

超声波测风仪设计中几个问题的探讨

通过比较Gill仪器的Winsonic 2D测风仪和螺旋浆式风速风向计05103L的实测效果,分析了超声波测风仪测风的特点.进而分析了几种超声波测风的检测机理、系统组成和设计的注意事项;同时探讨了如何解决超声波测风仪目前使用中存在的一些问题(如:全天候使用、环境影响补偿等).最后讨论了超声波的传输特性和大气中的杂质对风速、风向测量的影响.     

Evaluating the relationship between biomass,percent groundcover and remote sensing indices across six winter cover crop fields in Maryland,United States

Winter cover crops are an essential part of managing nutrient and sediment losses from agricultural lands. Cover crops lessen sedimentation by reducing erosion, and the accumulation of nitrogen in aboveground biomass results in reduced nutrient runoff. Winter cover crops are planted in the fall and are usually terminated in early spring, making them susceptible to senescence, frost burn, and leaf yellowing due to wintertime conditions. This study sought to determine to what extent remote sensing indices are capable of accurately estimating the percent groundcover and biomass of winter cover crops, and to analyze under what critical ranges these relationships are strong and under which conditions they break down. Cover crop growth on six fields planted to barley, rye, ryegrass, triticale or wheat was measured over the 2012–2013 winter growing season. Data collection included spectral reflectance measurements, aboveground biomass, and percent groundcover. Ten vegetation indices were evaluated using surface reflectance data from a 16-band CROPSCAN sensor. Restricting analysis to sampling dates before the onset of prolonged freezing temperatures and leaf yellowing resulted in increased estimation accuracy. There was a strong relationship between the normalized difference vegetation index (NDVI) and percent groundcover (r² = 0.93) suggesting that date restrictions effectively eliminate yellowing vegetation from analysis. The triangular vegetation index (TVI) was most accurate in estimating high ranges of biomass (r² = 0.86), while NDVI did not experience a clustering of values in the low and medium biomass ranges but saturated in the higher range (>1500 kg/ha). The results of this study show that accounting for index saturation, senescence, and frost burn on leaves can greatly increase the accuracy of estimates of percent groundcover and biomass for winter cover crops.     

Primary vs. secondary curved fold axes: Deciphering the origin of the Aït Attab syncline (Moroccan High Atlas) using paleomagnetic data

The Aït Attab syncline, located in the Central High Atlas, displays a curved geometry in plan view, and is considered as one of the most spectacular fold shapes in the Central High Atlasic belt. We conducted a paleomagnetic study in Jurassic-Cretaceous red beds to investigate the origin of this geometry. The Natural Remanent Magnetization (NRM) is dominated by a secondary magnetization carried by haematite with unvarying normal polarity that has been dated at about 100 Ma. The regional fold test performed in both limbs of the syncline is positive and the paleomagnetic vectors (after tectonic correction) are parallel throughout the curvature, indicating a negative oroclinal bending test. These results are inconsistent with previous works that consider the bent geometry of this syncline to result from subsequent distortion of originally NE–SW trending structures by rotation about a vertical axis. We interpret the NRM data to demonstrate that the changing trend of the Aït Attab syncline is a primary feature, resulting from the influence of pre-existing, NE–SW and E-W-striking extensional faults that developed during a strike-slip regime. Paleomagnetic results also reveal that the tilting observed in the sampled red beds is post Albian, probably linked to the Cenozoic inversion of the High Atlasic belt.     

随机参数扰动方法对中国冬季降水集合预报的影响

降水数值预报有很大的不确定性,与降水预报密切相关的物理过程参数化方案中关键参数的不确定性是降水数值预报误差来源之一,对这些参数引入随机扰动的随机参数扰动方法（Stochastically Perturbed Parameterization,简称SPP方法）可以代表模式降水预报的不确定性,是国际集合预报前沿研究领域。为了认识该方法能否代表中国冬季降水数值预报的不确定性,为业务应用提供科学依据,基于中国气象局中尺度区域集合预报模式（Global/Regional Assimilation and Prediction System-Regional Ensemble Prediciton System,简称GRAPES-REPS）,从对模式降水预报不确定性有较大影响的积云对流、云微物理、边界层及近地面层等四个参数化方案中选取了16个与降水密切相关的关键参数,引入了随机参数扰动方法,并通过2018年12月12日至2019年1月12日总计31天的冬季集合预报试验,对比分析了SPP方法对等压面要素及降水的集合预报效果。结果显示:在冬季应用SPP方法时,等压面要素的概率预报技巧总体来说优于无SPP方法扰动的对比试验,且对于低层、近地面要素的改进效果优于对中高层等压面要素的改进;但对降水概率预报而言,尽管检验评分数值略优于对比预报试验,但并未通过显著性检验,这表明,在东亚冬季风影响下,随机参数扰动方法对中国冬季降水概率预报技巧没有明显的改进。究其原因,可能是由于SPP方法主要代表对流性降水预报的不确定性,而中国冬季降水过程主要与斜压不稳定发生发展有关,模式降水以大尺度格点降水为主,对流性降水较少,故对冬季降水预报改进不明显,这为业务集合预报模式中应用随机参数扰动方法提供了科学依据。