Maritime network dynamics before and after international events

Investigating the influence of international events on global maritime networks is a challenging task that must comprehensively incorporate geographical, political, and maritime sciences. Understanding global maritime network dynamics is an initial and critical step in this investigation. This study proposes an automatic identification system (AIS)-based approach to understanding maritime network dynamics before and after international events. In this approach, a spatiotemporal modeling method is introduced to measure the similarity in shipping trends before and after international events. Then, a spatiotemporal analytic framework is proposed to understand the maritime network dynamics by grouping similar situation, and assessing possible indirect effects within a network. Finally, three case studies of international events, military conflict, lifted economic sanctions, and government elections, were used to investigate the observed network dynamics possibly affected by international events. The results indicate that container, tanker, and bulk shipping between India and its connected countries all declined more than 69% after military conflicts between India and Pakistan in August 2015. Tanker shipping between Iran and the United Arab Emirates increased 51% after economic sanctions on Iran were lifted. Container shipping between Sri Lanka and Singapore, Malaysia, and India increased more than 74% after the general election in Sri Lanka. These investigations demonstrate the feasibility of the proposed approach in assessing the possible effects of international events on maritime network dynamics.     

Development history and accessibility evolution of land transportation network in Beijing-Tianjin-Hebei region over the past century

From the development of modern transportation to the current era of high-speed transportation networks, the Beijing-Tianjin-Hebei (BTH) region has always played a national leading role in land transportation development of China. In order to explore the long-term evolutionary characteristics of land transportation in the BTH region, this paper utilized a temporal scale of 100 years to systematically interpret the development process of the land transportation network. Taking 13 cities within the BTH region as research anchor cities, we took into account “leaping” mode of transportation in order to investigate the evolution of accessibility. Our research shows the following results: (1) The land transportation network in the BTH region has undergone five stages of development: the initial period of modernization (1881–1937); the period of stagnation of transportation development (1937–1949); the network expansion period (1949–1980); the period of trunk construction (1980–1995), and the period of high-speed transportation network development (1995–present). The network structure centered around Beijing has existed from the outset of modern transportation development. (2) The accessibility spatial pattern of land transportation in BTH region has evolved from expansion along traffic corridors to the formation of concentric circles. The stratified circular structure of transportation in anchor cities has gradually developed into a contiguous development pattern. (3) There are clear hierarchical differences in the transportation structures of anchor cities. Beijing has always been at the top of this hierarchy, while the hierarchical position of Zhangjiakou has fallen noticeably since 1949. The Beijing-Tianjin region was the first region to form a short-duration transportation circle structure, while the transportation advantages of the central part of Hebei Province, which is located in the center of the BTH transportation region, have yet to be realized.     

Landscape-Basin Approach in Water Supply Assessments of the Population and Economy of the Regions of Western Siberia

The landscape-basin approach based on the sequential operation algorithm developed for determining potential and actual water supply of Western Siberia territories is proposed to adjust the existing assessments of water availability. The technique for estimating the water availability at the regional and sub-regional level is presented. The assessment of potential water availability is carried out within the boundaries of landscape provinces, whereas actual water availability is assessed for separate river basins and water management sites. Future water consumption is estimated with due regard for the current peculiarities of water use in Western Siberia regions and trends in water use efficiency, including the intensity of water consumption for industrial and agricultural production as well as strategic plans for territorial development. Superposition of natural and administrative-territorial boundaries has been achieved through the use of GIS technologies. Assessment results on the potential water availability in 83 landscape provinces of Western Siberia from 12 federal subjects of Russia are presented. Future water consumption has been assessed for the Western Barabinsk landscape province of Omsk oblast where the city of Omsk and the Omskii municipal district are located. The actual water availability has been estimated for a water management site in the Tom river basin, Kemerovo oblast. The size of the Western Siberia population living in conditions of extremely low, very low and low potential water availability has been calculated. The assessment results are given in tabular form and as geoinformation-cartographic models.     

Morphological and phylogenetic analysis of a new Melosira species and revision of freshwater Melosira in China

Journal of Oceanology and Limnology - Melosira is one of the most common diatom genera found in freshwater ecosystems. There are many freshwater species of Melosira, of which M. varians is the most...     

活动双星AR Lac的周期研究

用Ｋａｌｉｍｅｒｉｓ等人提出的分析周期新方法对ＲＳＣＶｎ型双星系统ＡＲＬａｃ的ＯＣ曲线进行分析,结果表明这颗食双星的轨道周期在长期减小的同时也含有周期为４７年、振幅为１．５６×１０－５天的周期性变化．对引起轨道周期变化（非周期性变化和周期性变化）的各种物理机制进行了分析研究,并求出了它们的关键性物理参量．研究表明该系统轨道周期的变化可能是由于次子星周期性的磁场活动和由磁滞引起的角动量损失引起     

海洋浮游植物的生物富集热力学模型——对疏水性污染有机物生物富集双箱热力学模型

依据疏水性有机物（ＨＯＣ）在有机相／水相之间简单物理化学分配的基本原理,提出了浮游植物对ＨＯＣ生物富集双箱热力学模型。得出浮游植物对ＨＯＣ的生物富集因子ＢＣＦ与浮游植物比表面积Ｓ,有机物正辛醇／水分配系数ｋｏｗ,有机物在水中浓度Ｃｗ之间皆存在ｌｏｇ－ｌｏｇ相关性的结论,并且由海洋浮游植物对氯代苯的生物富集实验结果验证了该模型。     

用于激光二极管泵浦的Nd：YAG激光器中声光Q开关的研究

近年来,激光二极管泵浦的Ｎｄ：ＹＡＧ激光器（ＤＰＬ）以其诸多优点引起人们的关注,因此开发小型和高效率,适用于ＤＰＬ中的声光Ｑ开关（ＭＡＯＱ）成为重要的研究方向,据文献报道,以熔石英玻璃为声光介质,研制成功的ＭＡＯＱ,工作了Ｂｒａｇｇ衍射区,驱动功率１～５Ｗ,衍射效率１０％－３０％可调。本文从激光原理出发,详细地探讨了ＭＡＯＱ的工作原理,对声光互作用长度的选取进行了分析,对入射角与衍射损失进行了实验     

岭澳核电站厂址转移和定位

在广东第二核电站确定在深圳市岭澳地区建设后, 广东省电力设计研究院进一步分析了岭澳地区内各候选地点的特点, 果断地提出厂址由原先推荐的岭澳东移至岭澳西, 并据此完成了项目的可行性研究。实践证明： 厂址转移工作是成功的, 将带来巨大的社会效益。特大型工矿企业的定位是基本建设中的一项战略部署, 本文以岭澳核电站为例, 就厂址转移的原因、工作思路及工作过程作了具体的论述     

基于数据挖掘探究何永恒治疗功能性便秘的用药规律

目的：通过数据挖掘技术探究何永恒教授治疗功能性便秘（FC）的用药规律。方法：收集2022年9月1日至2023年9月30日何教授门诊诊治的FC患者病案资料,运用中医传承辅助平台V3.0进行辨证分型统计,对使用药物进行频次、四气、五味、归经、关联规则及聚类分析。结果：纳入医案174则,患者174 例。辨证分型频次以气滞秘、热积秘、阴虚秘为主;共涉及中药82味,药物使用频次前3位者依次为白术、火麻仁、枳壳;药物四气以温、寒、平为主,五味以苦、甘、辛为主;多归脾、胃、大肠经;药物功效频次排名前5位者为补虚、理气、清热、泻下、利水渗湿。关联规则分析得到以“白术、白芍、火麻仁、苦杏仁、枳壳、厚朴、决明子”为核心药物的组方。聚类分析发现5组药物核心组合。结论：何教授治疗FC强调行气导滞、清热利湿为核心治则,确定了“白术、白芍、火麻仁、苦杏仁、枳壳、厚朴、决明子”的核心组方,为临床治疗FC提供参考。     

Whether human-induced activities could change the gradient pattern of coastal land use along the sea-land direction: a case study in Manila Bay,Philippines

Increasing intense human activities have largely changed the coastal landscape and caused many environmental issues. However, whether human-induced activities could change the coastal land use gradient pattern, an important coastal zonal characteristic along the sea–land direction, remains unclear. Manila Bay was selected as the study area in this work. According to the distance of the land use and land cover(LULC) to the coastline, we clustered the typical coastal land use sequence patterns(CLU...