重庆市地学旅游资源研究

重庆市的地学旅游资源极其丰富，可划分为岩石圈旅游资源等4个大类、地质旅游资源等11个基本类型、地层旅游景观等18种景观和黔江县上白垩统正阳组剖面等107个景区(景点)。它们具有类型齐全、分布广泛、岩溶精品和森林独特的特点。从加强岩溶旅游资源调查等6个方面入手，就可提高对它们的开发利用程度.     

可解释性长短期记忆模型用于预测湖泊总磷浓度变化

对湖泊总磷的变化预测和来源识别对水资源调度和流域生态治理有着重要的意义,然而复杂的生化反应和水动力条件导致的非平稳性给湖泊总磷浓度的准确预测带来极大的困难。为克服这一挑战,本文引入了基于加权回归的季节趋势分解(seasonal and trend decomposition using Loess,STL)技术和夏普利加法(SHapley additive exPlanations,SHAP)结合长短期记忆网络(long short-term memory neural network,LSTM)和门控循环单元(gated recurrent unit,GRU)构建了一个可解释的预测框架,以增强对湖泊总磷浓度演变的预测并提高其可解释性。研究表明:(1)在骆马湖总磷浓度的预测中,该框架拥有较好的预报精度(R²=0.878),优于LSTM和卷积长短期记忆模型(convolutional neural networks and long short term memory network,CNN-LSTM)。当预测时间步长增加到8 h时,该框架有效提高了总磷浓度的预测精度,平均相对误差和均方根误差分别降低了47.1%和33.3%。从预测趋势来看,骆马湖在汛期的总磷平均浓度为0.158 mg/L,相较于非汛期的平均浓度,增加了202.1%。(2)运河来水是骆马湖总磷浓度最重要的影响因素,贡献权重为60.0%,并且不同断面(三湾、三场)的污染源受水动力、气象等因素的影响存在显著的时空差异。本文凸显了神经网络模型在预警水体污染方面的可实施性,并且为提高传统神经网络的学习能力和可解释性的开发与验证提供了重要方向。     

Past,present and future climatic forcing due to greenhouse gases

An advanced one-dimensional radiative-convective model (RCM) is used to estimate the past, present and fu-ture climatic forcings induced by greenhouse gases of anthropogenic origin, such as CO2, CH4, N2O and CFCs, in this paper. The results show that the decadal climatic forcing for the last decade is one-order bigger than that prior to the year 1900, and in the case of no control on the emission of the greenhouse gases the climatic forcing for the year 2100 will be almost 4 times as much as now.     

RESPONSE OF EQUATORIAL PACIFIC UPPER OCEAN CURRENT TO WESTERLY WIND BURSTS

The characteristics of the response of equatorial Pacific upper ocean current to westerly wind bursts(WWB)were analyzed in the frequency domain by using wind and ADCP data collected by the Shiyan3 during TOGA-COARE IOP,1992-1993.The preliminary results showed that the response consistedof an eastward surface jet at shallower than 60m depth,a westward counter current centering near100m and a shear layer between them,with the variations of all three being nonlinear and nearlysynchronous.The oceanic responses in the frequency domain were characterized by occurrences of a remotely forced mixed Rossby-gravity wave with period of 8-10 days in the surface jet andcountercurrent at shallower than 110 m depth,and two locally forced waves with periods of 24 daysand 4-5 days limited in shallower than 70m depth.These fluctuations of the responses depended much more on zonal wind than meridional wind.The results also revealed that the oceanic response toWWB resulted from momentum transport and energy propagation assoc     

西北太平洋九州-帕劳海脊北部KPR12岩芯40万年来有机碳来源、埋藏特征及其环境响应

西北太平洋海陆相互作用强烈,受黑潮和亚洲大陆风尘输入影响显著,是研究海洋沉积物中有机碳埋藏与陆源输入、海洋初级生产力和海洋环境演化关系的理想靶区。本研究基于采自九州-帕劳海脊北部的重力活塞647 cm长的KPR12岩芯,分析了总有机碳（TOC）、总氮（TN）、有机碳稳定碳同位素组成（δ¹³C_TOC）、蛋白石（Opal）以及粒度等指标,初步探讨了近40万年来轨道尺度沉积有机碳的来源、埋藏特征及其影响机制。岩芯的TOC含量平均值为0.214%,呈冰期较高、间冰期较低的旋回特征。岩芯沉积物粒度的不同端元反映了研究区风尘输入大致呈冰期较高的趋势。岩芯的δ¹³C_TOC（-25.24‰~-21.04‰,平均值为-22.59‰）显示有机质以海源为主（约62%）,海源有机碳含量趋势与TOC的变化一致。研究区不同时期陆源物质的输入受风尘输送和黑潮的综合控制,黑潮增强可能对该区间冰期陆源有机碳贡献的升高有一定影响。岩芯中TOC与Opal含量的相关性分析表明,海洋初级生产力可能不是控制该岩芯有机碳含量变化的主要原因。冰期-间冰期旋回中的深层水通风条件、黑潮和北太平洋中层水的发育以及陆源细颗粒物质输入可能共同影响着本区沉积有机碳的降解与埋藏保存。

     

生产性服务业发展的动力机制与空间效应研究进展

伴随着全球生产方式从“福特制”向“后福特制”的转变,生产性服务业逐渐取代制造业成为“后工业社会”区域经济增长和城市体系重构的主导产业。本文梳理了国内外相关文献,并结合国家自然科学基金青年项目“政治经济学视角下中国生产性服务业发展的多层级动力机制及其区域城市化效应”的研究成果,对已有理论及其在中国的适应性进行讨论。结论为：①中国生产性服务业在时空演变态势上既呈现出与西方发达国家同期发展阶段趋同的特征,也具有自身独特的发展路径;②转型期政府—市场、政府—企业、中央—地方等关系,决定了政府对经济的调控程度以及资金、土地和劳动力等要素市场的发育程度,形成了中国生产性服务业发展与西方国家不同的动力机制。③中国生产性服务业的增长和集聚促进了巨型城市区域的发展,改变了城市体系的组织模式,但有别于西方的是,中国生产性服务业的空间效应需考虑生产性服务业与制造业联系的影响。     

Mass-front velocity of dry granular flows influenced by the angle of the slope to the runout plane and particle size gradation

The mass-front velocities of granular flows results from the joint action of particle size gradations and the underlying surfaces.However,because of the complexity of friction during flow movement,details such as the slope-toe impedance effects and momentum-transfer mechanisms have not been completely explained by theoretical analyses,numerical simulations,or field investigations.To study the mass-front velocity of dry granular flows influenced by the angle of the slope to the runout plane and particle size gradations we conducted model experiments that recorded the motion of rapid and long-runout rockslides or avalanches.Flume tests were conducted using slope angles of 25°,35°,45°,and 55° and three particle size gradations.The resulting mass-front motions consisted of three stages:acceleration,velocity maintenance,and deceleration.The existing methods of velocity prediction could not explain the slowing effect of the slope toe or the momentum-transfer steady velocity stage.When the slope angle increased from 25° to 55°,the mass-front velocities dropped significantly to between 44.4% and59.6% of the peak velocities and energy lossesincreased from 69.1% to 83.7% of the initial,respectively.The velocity maintenance stages occurred after the slope-toe and mass-front velocity fluctuations.During this stage,travel distances increased as the angles increased,but the average velocity was greatest at 45°.At a slope angle of 45°,as the median particle size increased,energy loss around the slope toe decreased,the efficiency of momentum transfer increased,and the distance of the velocity maintenance stage increased.We presented an improved average velocity formula for granular flow and a geometrical model of the energy along the flow line.     

巴丹吉林沙漠北缘拐子湖流沙下垫面近地层湍流强度和陆面过程特征

利用巴丹吉林沙漠北缘拐子湖流沙下垫面2013年7、10月和2014年1、4月的湍流通量资料,计算并分析了研究区近地层湍流强度,同时针对风速分量、温度、水汽和CO₂归一化标准差随稳定度的变化关系和总体输送系数等陆面过程特征进行分析。结果表明：（1）风速各分量的湍流强度均随风速的增加逐渐减小,风速处于2 m·s^-1以下时湍流发展最为旺盛。湍流强度主要由水平方向风速分量决定,垂直方向风速的作用较小,且近中性和不稳定层结利于湍流的发展。与其他地区相比,平坦且没有建筑物的沙漠地区,机械湍流较弱,湍流强度相应较小。（2）风速各分量的归一化标准差与稳定度（z/L）均满足1/3次方函数规律,其中垂直方向风速分量的拟合曲线方程较好。（3）动量输送系数C_d具有明显的夏季高、冬季低的变化状态且各月的日变化形态均呈夜间低、日间高的循环形态。热量输送系数C_h的不同月份日变化间并没有明显的排列次序,且日出日落前后具有明显的波动。不稳定层结时,C_d和C_h均随风速的增加逐渐减小;稳定层结时,C_d和C_h均随着风速的增加逐渐上升。     

辽东、辽西下石炭统孢粉组合特征

辽东、辽西石炭系（地台型）发育，化石丰富，是研究我国北方石炭系及矿产的理想地区。华北缺失下石炭统早已成“定论”，但笔者通过植物化石研究证实东北南部存在早石炭世地层无疑，并建立了Ｓｕｂ－ｌｅｐｉｄｏｄｅｎｄｒｏｎ－Ａｃｈａｅｏｃａｌａｍｉｔｅｓ－Ｃａｒｄｉｏｐｔｅｒｉｄｉｕｍｓｐｅｔｓｂｅｒｇｅｎｓｅ组合带。与此同时，作者又在辽东、辽西石炭系下部采到了丰富的孢粉化石共３６属７５种，并归结为Ｌｙｃｏｓｐｏｒａｐｕｓｉｌｌａ－Ｃｒａｓｓｉｓｐｏｒａｋｏｓａｎｋｅｉ组合，时代为早石炭世晚期，即维宪－纳缪尔Ａ期。从而孢粉、植物大化石互为佐证，进一步肯定辽东、辽西存在早石炭世地层，进而改写了华北地质史的内容，并对古构造、古地理的研究具有重要意义。另外，孢粉层位还发现了丰富的叶肢介化石，这是我国石炭纪的第３处叶肢介产地，对叶肢介的起源、演化及利用多门类生物化石解决石炭系的内部界线划分积累了资料。     

基于地理核心素养的新高考地理试题分析与复习策略--以浙江省2019年4月选考29题为例

新高考地理试题不仅承载着选拔和教育功能,也是体现立德树人、检验学生核心素养达成与否的重要途径。本文以浙江省2019年4月选考综合题29题为例,从区域认知、综合思维、人地协调观、地理实践力四大地理学科核心素养角度进行分析,解读试题对核心素养的考查,并提出相应的复习策略,以期为地理教师指导学生高考复习提供导向。