福鼎市冬季坡地低温考察和龙眼、荔枝园地选择

据福鼎市2003／2004年度冬季低温考察资料分析,对于一百多米的小山坡,在相对高差约2／3附近的山坡中上部,晴天其最低气温常出现最高,逆温效应最明显,该地段种植龙眼、荔枝可减轻或避免低温造成的冻害。     

苍山5.2级地震前的测震学异常特征

本利用山东,江苏省地震台网的资料,对苍山５．２级地震前沂沭带南段地震活动性参 的变化特征进行了分析研究。发现苍山５．２级地震前沂沭带南段３、４级地震活动增强,应变能释放速率加速,地震波速比的时空变化,震前出现明显的低值异常时段和低值异常区。据比异常变化曾在震前提出过预报意见。     

大别山北麓侏罗系大理岩砾石的碳—氧同位素组成及地质意义

在大别山北麓、合肥盆地南缘侏罗系三尖铺组和凤凰台组地层中含有大理岩砾石, 属山麓冲积扇环境沉积。它们的δ１３ Ｃ数值范围为－ １．７‰～１．３‰, 大多数近于零值, 它们的δ１８Ｏ数值从６．５‰～２３．０‰。大别地块佛子岭群大理岩的δ１３Ｃ数值为－ ２．０‰～－ ２．５‰, δ１８Ｏ数值范围从６．３‰～１３．１‰。大别地块高压和超高压变质岩带的大理岩的δ１３ Ｃ数值为１‰～６‰,δ１８Ｏ数值为５‰～２３‰。碳同位素组成的明显差别表明现今大别地块佛子岭群和高压、超高压变质岩不是合肥盆地南缘侏罗系大理岩砾石的来源区。由于δ１３Ｃ的数值不随δ１８Ｏ值的降低而变化, 且分布在一个狭窄的范围, 合肥盆地南缘侏罗系大理岩砾石的碳同位素组成代表了它的原岩在沉积时海水的同位素记录。     

利用祁连山主动源资料研究2016年门源6.4级地震前后波速变化

采用叠加、互相关、插值拟合等方法对祁连山气枪主动源台网数据进行处理,针对2016年1月21日青海门源6.4级地震前后气枪激发地震P波、S波震相的走时变化特征进行了分析,结果表明,地震前约6个月时,震中附近3个台站的相对走时出现下降变化（走时减少）,至震前约3个月时低值异常恢复正常,之后再次出现走时下降变化,地震即发生于走时变化恢复过程中。S波走时变化最大下降幅度达18ms,震后走时变化逐渐恢复正常,且3个台站变化趋势较为一致,其中,距震中最近的台站的S波走时变化最明显（ZDY38台）,较远台站的走时变化幅度较小,其变化特征与震源区位置有关。走时缩短意味着速度增加,可能与区域应力积累间存在一定的关系。     

Quantitative reconstruction of Holocene sediment sources contributing to the central Jiangsu coast,China: New insights into source-to-sink processes

Coastal deltaic deposits are the primary locations for sediment storage on Earth, and quantifying their source contributions is a critical prerequisite for delineating S2S patterns in marginal seas. In most cases, quantification for the contribution by fine-grained sediments (i.e. particle size < 63 μm) is considered to be representative to constrain the overall sediment supply. However, this approach may be inappropriate because large differences exist between the two quantities. Here we propose an approach to solve the problem, which is based on the maximum number of tracers from multiple sediment size fractions incorporating the content of all size fractions of sediment. Using this approach, absolute source contributions during the Holocene are reconstructed that provide a first-order model for the S2S pattern of the central Jiangsu coast, China. The Huanghe River is the strongest driver for the Holocene sedimentation, with a mean contribution of ~72 ± 6% (1417 × 10⁸ t). The absolute contributions from the Changjiang and offshore areas were of secondary importance, (i.e. ~17 ± 1% (330 × 10⁸ t) and ~11 ± 5% (217 × 10⁸ t), respectively). The results show that a large difference between the relative and absolute source contributions and the assumption that the relative contribution represents the absolute contribution is invalid in a coastal setting. The impact of the Huanghe is mainly based on episodic events, such as the event of 1128–1855 AD . The model also reveals that the offshore sediments are as important as the Changjiang sediments for the central Jiangsu coast during the Holocene. Thus, the model provides both the time series and overall quantities of sediment supply during the formation and evolution of the Holocene tidal flats on the Jiangsu coast. Our findings shed new light on quantitative analysis of sediment sources applicable to future S2S studies of marginal seas. © 2020 John Wiley & Sons, Ltd.     

Contaminant transport with non‐equilibrium processes in unsaturated soils and implicit characteristic Galerkin scheme

A non‐equilibrium sorption—advection—diffusion model to simulate miscible pollutant transport in saturated–unsaturated soils is presented. The governing phenomena modelled in the present simulation are: convection, molecular diffusion, mechanical dispersion, sorption, immobile water effect and degradation, including both physical and chemical non‐equilibrium processes. A finite element procedure, based on the characteristic Galerkin method with an implicit algorithm is developed to numerically solve the model equations. The implicit algorithm is formulated by means of a combination of both the precise and the traditional numerical integration procedures. The stability analysis of the algorithm shows that the unconditional stability of the present implicit algorithm is enhanced as compared with that of the traditional implicit numerical integration procedure. The numerical results illustrate good performance of the present algorithm in stability and accuracy, and in simulating the effects of all the mentioned phenomena governing the contaminant transport and the concentration distribution. Copyright © 2000 John Wiley & Sons, Ltd.     

国外旅游风险研究综述——基于Web of Science的统计分析

西方国家对风险的研究已较为成熟,但旅游风险作为关注点在2001年“9?11”事件后才逐渐被学界所重视,相关综述较少且多侧重于旅游风险感知,对旅游风险研究整体把握的成果较少。近年来,一些研究已应用文献计量可视化来探索旅游学科的网络结构,但在旅游风险、安全研究领域运用此方法的成果不多。回溯相关概念后,以2001—2018年“Web of Science核心合集”中296篇与国外旅游风险研究高度相关的论文、会议文章、综述为基础,利用科学计量工具CiteSpace为研究工具,对国外旅游风险研究发文数量、期刊分布、知识基础、关键词进行可视化分析。研究发现：①国外旅游风险研究可分为三个阶段,各时期研究区域、对象、主体、热点不断演进;②文献数据库的期刊分布表明,目前国外旅游风险研究涉及多个学科,主力军是旅游类和医学类;③发现了7篇高突现性文献,可分为医学及传染病、风险感知、风险容忍度3类。对深入认识国外旅游风险研究领域的知识基础及其演化关系具有一定价值,同时也能为国内旅游风险研究与实践提供参考。     

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江西晚三叠世安源煤系沉积特征及沉积环境探讨

江西省晚三叠世安源煤系，为江西省主要含煤地层之一，其煤种为烟煤，煤质好且为较好的动力用煤。然而，由于煤矿资源减少，造成我省乃至全国动力用煤的紧张状况，在一定程度上制约了经济的发展。通过对江西晚三叠世安源煤系（组）的沉积特征和沉积环境的分析，指出了研究区安源煤系的分布状况和赋存特征，对寻找后续煤炭资源具有一定的指导意义。