Quantitative division of succession and spatial patterns among different stand developmental stages in Changbai Mountains

Broadleaf-Korean pine forests exhibit high species richness and distinctive species composition, which are currently becoming more dominant among natural forests in Changbai Mountains of northeastern China. Understanding the ecological process of restored vegetation is quite important for ecosystem reconstruction. Distinguishing stand development stages and analyzing the dynamic spatial patterns could provide insights into significant community coexistence mechanisms. In the present study, eight permanent study areas were established according to the substituting space for time method in Changbai Mountains of north-eastern China. The optimal division method was used to quantify the successional series into different stand development stages, and the point pattern analysis method(L(r) function) was used to analyse the dynamic changes in spatial patterns and interspecific associations. Our results suggested that:(1) The stand development process was divided into five stages: the first three stages were poplar-birch secondary forests in different stages of recovery, the fourth stage was thespruce-fir mixed forest, and the last stage was the primary broadleaf-Korean pine forest;(2) The spatial pattern showed an aggregated distribution at a small scale and changed to a random distribution as the scale increased in poplar-birch secondary forests, but the spatial pattern appeared to be randomly distributed in spruce-fir mixed forest and broadleafKorean pine forest;(3) The interspecific associations between pioneer species and climax species changed from negative to positive among the different stand stages, and environmental resources were shared among these species. Interspecific differences in shade tolerance among the tree species were key determinants of forest dynamics and structure. Our study is vital to the understanding of the forest development;thus, the spatial change features should receive greater attention when forest management is being planned and restoration strategies are being developed for the Changbai Mountains.

Multi-Core Virtual Concatenation Scheme Considering Inter-Core Crosstalk in Spatial Division Multiplexing Enabled Elastic Optical Networks

Spatial division multiplexing enabled elastic optical networks(SDM-EONs) are the potential implementation form of future optical transport networks, because it can curve the physical limitation of achievable transmission capacity in single-mode fiber and single-core fiber. However, spectrum fragmentation issue becomes more serious in SDM-EONs compared with simple elastic optical networks(EONs) with single mode fiber or single core fiber. In this paper, multicore virtual concatenation(MCVC) scheme is first proposed considering inter-core crosstalk to solve the spectrum fragmentation issue in SDM-EONs. Simulation results show that the proposed MCVC scheme can achieve better performance compared with the baseline scheme, i.e., single-core virtual concatenation(SCVC) scheme, in terms of blocking probability and spectrum utilization.

Spatial and Temporal Differences of Climate Suitability of Ice and Snow Sports in Major Ski Tourism Destinations in China

Ice and snow tourism in China has grown significantly since the country successfully hosted the Beijing Winter Olympics.Climatic conditions profoundly impact the development of ice and snow tourism;however,most studies have focused on constructing different climate suitability indicators for ice and snow tourism to evaluate individual regions,lacking horizontal comparative studies across multiple regions.This study aims to enrich the connotation of climate suitability for ice and snow sports,establish an evaluation model based on snowfall amount,temperature,and wind speed,and use daily meteorological data from 1991 to 2021 to horizontally compare the climate suitability for ice and snow sports in major ski tourism destinations in China.This study boasts four major findings:1)the average ice and snow sports climate index of each region decreases over time,and the overall suitability of the climate for ice and snow sports is reducing;2)northern Xinjiang exhibits the most evident regional differentiation from‘very suitable’to‘generally suitable’;3)the spatial zoning of climate suitability for ice and snow sports exhibits heterogeneity,as northern Xinjiang is divided into two‘suitable and above’zones with rotating empirical orthogonal function(REOF).Correspondingly,the four provinces of Hebei,Heilongjiang,Jilin,and Liaoning are divided into three‘generally suitable and above’zones;4)snowfall amount is the main factor affecting the climate suitability of ice and snow sports in the major ski tourist destinations in China.

THE SPATIAL DIVISION OF INDUSTRIES OF THE PEARL RIVER DELTA IN THE 1990s: CHARACTERISTICS AND TRENDSS

The article analyzed the spatial division of industries of the Pearl River Delta (PRD) in the 1990s, a period that witnessed the deepening of the reform and opening policies and continued rapid development of the region. By adopting the index of specialization, the extent of specialization, its change and its spatial distribution in the region are measured and demonstrated. The research revealed that, despite the trend of more balanced development of the secondary sector between the PRD and the rest of the province, in the PRD, it is the unbalanced development that dominated and the spatial division of the secondary sector has been shaped. The tertiary industry has also been experiencing unbalance development and the spatial division of the tertiary sector has been emerging, its extent of concentration appearing even more evident than that of the secondary sector. The author also discussed the linkage between the spatial division of the two sectors. In the end of the paper, the trends of the spatial division of the industries in the PRD are forecasted.

QSM-IDM -A novel quadrature spatial modulation based on interleaving division multiplexing for multiple antenna system

Quadrature Spatial Modulation (QSM) is a high spectral efficiency Multiple-Input Multiple Output (MIMO) technique used to improve the spectral efficiency of wireless communication systems. The main concept of QSM is to extend the spatial constellation of the conventional Spatial Modulation (SM) in both the in-phase and quadrature components of the data symbol. In this paper, because QSM-based on Interleaxdng Division Multiplexing (IDM) has not been introduced in the literature as a multiple antenna system, we introduced a novel scheme, called QSM system based on Interleaving Division Multiplexing (QSM-IDM). The antenna sets are also applied to a spreader, before being used to assign an antenna number for information transmission. Analysis and simulations for a flat fading channel show that the proposed QSM-IDM method significantly outperforms the original QSM system with the same data rate, while maintaining a relatively acceptable complexity. The obtained simulation results show that the conducted analysis yields significant improvements for the accuracy of the proposed scheme, with satisfactory complexity.

Minimizing Traffic Blocking and Inter-Crosstalk in Spatial Division Multiplexing over Elastic Optical Networking

As a promising solution, virtualization is vigorously developed to eliminate the ossification of traditional Internet infrastructure and enhance the flexibility in sharing the substrate network (SN) resources including computing, storage, bandwidth, etc. With network virtualization, cloud service providers can utilize the shared substrate resources to provision virtual networks (VNs) and facilitate a wide and diverse range of applications. As more and more internet applications migrate to the cloud, the resource efficiency and the survivability of VNs, such as single link failure or large-scale disaster survivability, have become crucial issues. Elastic optical networks have emerged in recent years as a strategy for dealing with the divergence of network application bandwidth needs. The network capacity has been constrained due to the usage of only two multiplexing dimensions. As transmission rates rise, so does the demand for network failure protection. Due to their end-to-end solutions, those safe-guarding paths are of particular importance among the protection methods. Due to their end-to-end solutions, those safeguarding paths are of particular importance among the protection methods. This paper presents approaches that provide a failure-independent route-protecting p-cycle for path protection in space-division multiplexed elastic optical networks. This letter looks at two SDM network challenges and presents a heuristic technique (k-shortest path) for each. In the first approach, we study a virtual network embedding (SVNE) problem and propose an algorithm for EONs, which can combat against single-link failures. We evaluate the proposed POPETA algorithm and compare its performance with some counterpart algorithms. Simulation results demonstrate that the proposed algorithm can achieve satisfactory performance in terms of spectrum utilization and blocking ratio, even if with a higher backup redundancy ratio.

Division of Farmland Use in East China at County level Based on Landscape Structure and Output Function——a Case of Pingdu City, Shandong Province

[Objective] The aim was to research the relationships among different e- valuation farmland units and conduct division-of farmland use in order to provide scientific references for protection and rational use of farmland at county level. [Method] Using Pingdu City as a case, the research selected land use indices such as farmland use structure, output, geographical location, eta/., and then performed a cluster analysis for farmland use division. [Result] Farmlands in Pingdu can be classified into 4 groups. In groups 1 and 2, it is necessary to strengthen farmland protection, especially for highly-quality farmlands, to guarantee the quantity and quality of local crops. In groups 1 and 3, it is necessary to improve concentration degree and use rate of construction lands and control farmland pollution possibly caused by constructions. In group 4, priority should be given to maintaining diversity of land use patterns, and avoiding aimless farming expansion. [Conclusion] During urbanization process in eastern coastal agricultural regions, it is of importance to prevent fertile farmlands being occupied by construction lands to enhance use rate of construction lands. Furthermore, agricultural non-point pollution should be detected constantly in intensively used farmlands, especially in vegetable fields. Additionally, land use diversity should be well protected by avoiding farmland expansion and im- proving farmland environment.

Reconsidering “Does the Sum Rule Hold at the Big Bang?” with Pre Planckian HUP, and Division Algebras

In 2012, the author submitted an article to the Prespacetime Journal based upon the premise of inquiry as to the alleged vanishing of disjoint open sets contributing to quantum vector measures no longer working, i.e. the solution in 2012 was that the author stated that quantum measures in 4 dimensions would not work, mandating, if measure theory were used, imbedding in higher dimensions was necessary for a singularity. The idea was to use the methodology of String Theory as to come up with a way out of the impasse if higher dimensions do not exist. We revisit this question, taking into account a derived HUP, for metric tensors if we look at Pre-Planckian space-time introducing a pre-quantum mechanical HUP which may be a way to ascertain a solution not mandating higher dimensions, as well as introducing cautions as to what will disrupt the offered solution. Note that first, measurable spaces allow disjoint sets. Also, that smooth relations alone do not define separability or admit sets Planck’s length, if it exists, is a natural way to get about the “bad effects” of a cosmic singularity at the beginning of space-time evolution, but if a development is to be believed, namely by Stoica in the article, about removing the cosmic singularity as a breakdown point in relativity, there is nothing which forbids space-time from collapsing to a point. Without the use of a Pre Planckian HUP, for metric tensors, the quantum measures in four dimensions break down. We try to ascertain if a Pre Planckian HUP is sufficient to avoid this pathology and also look at if division algebras which can link Octonionic geometry and E8, to Quark spinors, in the standard model and add sufficient definition to the standard model are necessary and sufficient conditions for a metric tensor HUP which may remove this breakdown of the sum rule in the onset of the “Big Bang”.

基于地貌分区的湖北省粮食生产格局与耕地资源匹配关系研究

【目的】研究不同地貌区粮食生产格局与区域耕地资源的匹配关系,为粮食生产布局和耕地资源保护提供决策依据。【方法】采用集中度、变异系数、重心模型、匹配度和LMDI模型等研究湖北省1990—2020年不同地貌区粮食生产格局变化与耕地资源的匹配关系。【结果】1990—2020年鄂西山地、鄂中岗地、鄂东丘陵、江汉平原粮食产量占湖北省粮食总产量的比重逐步调整为11.2%、30.6%、26.2%、32.0%。近30年湖北省各地貌区粮食作物生产集中度及变化趋势存在显著差异,粮食生产向鄂中岗地集中的趋势明显,以小麦和玉米为主,大豆生产则向江汉平原集中。湖北省粮食播种面积重心和粮食产量重心向西北方向移动了5.37和14.63 km,但鄂中岗地粮食生产重心向东北方向移动,江汉平原和鄂西山地则向西南移动。近30年来,鄂西山地、鄂中岗地、鄂东丘陵、江汉平原粮食生产与耕地资源重心的平均空间距离为6.20、3.35、10.57、6.82 km,变动一致性平均指数分别为0.49、0.44、0.40、0.27。湖北省粮食生产与耕地资源的基尼系数均大于0.5,且有增加趋势,鄂西山地和江汉平原不平衡指数为正,鄂中岗地与鄂东丘陵不平衡指数为负。近30年各地貌区粮食产量变化的耕地数量效应与结构效应为负,耕地集约效应和质量效应为正,其中耕地种植结构变化对鄂东丘陵粮食生产的减量作用达到309.70万t,而复种指数变化对鄂中岗地粮食生产的增量作用达到300.46万t。【结论】近30年湖北省各地貌区耕地质量效应和耕地结构效应的增量作用正在减弱,数量效应的减量作用在增强,湖北省面临优质耕地减少的种植风险和粮食种植结构调整带来的产量风险。湖北省粮食生产与耕地资源长期处于不匹配状态,且表现出明显的区域地理特征。粮食生产空间布局和种植结构调整应充分考虑不同地貌区自然地理和耕地资源禀赋特征,推动粮食生产与耕地利用协调发展。

空间众包中隔离敏感的任务匹配算法

随着移动互联网接入普及和共享经济的增长,空间众包平台得到广泛普及。存在一类众包应用尽量使得众包任务在空间局部范围内完成,即在执行空间任务时减少人员在空间区域间的流动。基于此需求,提出了空间隔离敏感的任务匹配问题,给定具有所属空间区域位置的工人集和任务集,在所有任务均可完成的前提下,使得所有匹配任务的工人移动所产生的跨区域代价之和最小。在线平台中高效的空间隔离敏感的任务匹配算法是研究目标。提出了基于空间层次合并分组的匹配算法,将分布在空间区域中的任务与工人转换到区域邻接图节点,提出了δ-clique概念用于将区域节点分组,对分组的节点进行整体匹配,较大程度上提高了匹配算法的效率。在真实数据集上进行充分对比实验,结果表明,与现有的算法相比提出的空间层次合并分组的匹配算法在跨区域代价方面平均减少近16%,在匹配效率方面平均提升近5倍,验证了所提出算法的有效性。

行政区划调整与城市空间结构演化——基于撤县设区的视角

在新型城镇化建设对城市紧凑集约发展提出更高要求的背景下,探讨行政区划调整对城市空间结构的影响具有重要意义。基于2000—2016年全国范围内演进的撤县设区数据,深入考察了撤县设区带来的城市空间结构演化效应的研究发现:(1)撤县设区促使了城市空间形态松散化和内部低密度发展,该结论在考虑多种指标、方法以及政策滞后效应之后仍成立。(2)撤县设区政策对东部城市的空间结构松散化影响更强,且不利于其发挥中心集聚优势;相比于建设规制较弱的城市,规制较强的城市受到撤县设区对城市空间结构分散化的影响更为显著。(3)进一步研究表明,自主选择型撤县设区对城市空间结构分散化的影响更加明显,而顺应融入型撤县设区则会在一定程度上促进城市空间结构趋于紧凑化。

基于环境因子的中国土栖性白蚁地理分布区划分析

【目的】对中国土栖性白蚁地理分布进行准确区划将对我国土栖性白蚁危害的精准防治具有重要指导价值。本研究旨在通过利用数学模型,结合影响土栖性白蚁分布的环境因子,探析中国土栖性白蚁地理分布区划。【方法】遴选影响白蚁分布的温度、降水量、湿度、土壤pH值等环境因子,利用迭代局部搜索算法(iterative local search, ILS)创建中国土栖性白蚁区划模型。【结果】ILS区划模型分区结果与实际的土栖性白蚁分布较为符合,将我国土栖性白蚁密度依次从南至北分为高密度区(D3)、中密度区(D2)和低密度区(D1)。D3最北分界线,东起江苏南京,经安徽芜湖、湖北麻城和沙市、贵州凤岗、四川宜宾,西至云南香格里拉。其北界线基本上沿长江中下游。D2最北分界线,东起江苏盐城,经安徽阜阳、河南驻马店、陕西商州、甘肃成县,西至四川廉定。其北界线东部大致沿淮河形成最后端凸起的曲线。D1最北分界线,东起山东东营,经河北邯郸、山西长治、甘肃华亭和合作、青海玉树,西至西藏日喀则,其北界线基本上沿黄河下游北上,形成一条中间凸起的曲线。【结论】我国土栖性白蚁地理分布已跨过黄河,总体密度呈南多北少和东多西少的特点,从南到北大体以长江、淮河、黄河等自然地理分界划分为高、中、低3个密度区。

基于易经地理思想的国家空间治理结构顶层设计

以国土空间治理能力现代化助推高质量发展,是保障中华民族伟大复兴、推进中国式现代化的必然要求。本文在继承和发展易经地理思想的基础上,构建了“太极空间治理结构模型”,确定山海关为“东亚太极点”。中国国家空间治理结构的顶层设计,应围绕“山海关”而层层展开。在中央核心区,按照“东亚陆海中心+陆地屏障+海洋屏障”的环首都治理结构,将北京扩容至山海关,河北省扩容至大兴安岭中央主峰,天津直辖市扩容至渤海海峡。在四方支撑区,各布局1个直辖市(上海、重庆、天骄、威虎),并增设云北省,扼控各方向的关键节点。在外围屏障区,增设澎湖、昆仑2大直辖市和楼兰、北庭2大特别行政区,形成最有利于中国长治久安的边疆治理结构。

基于EOF-DBSCAN-GRU的分布式光伏集群出力预测方法研究

提出一种基于EOF-DBSCAN划分集群的改进统计升尺度的光伏集群出力预测建模方法。针对传统统计升尺度方法子集群中光伏电站出力特性不一致问题,通过皮尔逊相关系数和经验正交函数(EOF)优化特征空间,再根据密度聚类模型(DBSCAN)对区域内光伏电站划分集群,从而增强光伏电站聚类后集群出力特性的一致性。针对待预测日权重系数时间序列动态特性的提取、预测问题,提出一种基于动态时间规整(DTW)的相似日选取算法。最后利用循环神经网络(GRU)模型进行光伏电站出力预测。实验表明该集群预测方法的平均误差百分数(MAPE)约为6.33%,均方根误差(RMSE)约为13.93 kW,均方误差(MSE)为194.25 kW,通过实际光伏电站数据证明了所提方法的准确性和有效性。

土地空间连续体解析及其尺度划分初探——以阜平县为例

针对当前存在的空间冲突、尺度划分失真、功能错位等土地资源利用所面临的问题,本文以山水林田湖草沙生命共同体理念为指导,通过归纳与演绎分析,探索性提出了土地空间连续体概念,并从概念辨析、哲学解释、分类学解释等方面开展了内涵解析。依托主导因素分析、DEM流域分析、图层叠加空间分析等方法建立了土地空间连续体尺度划分理论框架。结果表明:①土地空间连续体概念能够从土地系统科学视角全方面、多尺度表达土地单元组合体内涵,科学诠释了土地构成单元在空间上连续与间断的辩证关系。②以小流域、土壤、植被、土地现状利用方式为主导要素将阜平县土地空间连续体逐级划分为“小流域尺度−土地链尺度−土地段尺度−土地块尺度”4级尺度类型体系,其中一级小流域尺度包含7种类型单元,二级土地链尺度包含54种类型单元,三级土地段尺度包含140种类型单元,四级土地块尺度包含560种类型单元,为土地空间多尺度开发利用提供了理论与方法借鉴。③土地空间连续体各级尺度类型是从土地单元空间连续的视角考虑了多种主导因素的影响,是一种综合反映环境和土地系统特点的基本研究单元。研究成果可为后续开展特征尺度视角下的土地利用与评价研究提供新的思路和方法。

Weber Law Based Approach for Multi-Class Image Forgery Detection

Today’s forensic science introduces a new research area for digital image analysis formultimedia security.So,Image authentication issues have been raised due to the wide use of image manipulation software to obtain an illegitimate benefit or createmisleading publicity by using tempered images.Exiting forgery detectionmethods can classify only one of the most widely used Copy-Move and splicing forgeries.However,an image can contain one or more types of forgeries.This study has proposed a hybridmethod for classifying Copy-Move and splicing images using texture information of images in the spatial domain.Firstly,images are divided into equal blocks to get scale-invariant features.Weber law has been used for getting texture features,and finally,XGBOOST is used to classify both Copy-Move and splicing forgery.The proposed method classified three types of forgeries,i.e.,splicing,Copy-Move,and healthy.Benchmarked(CASIA 2.0,MICCF200)and RCMFD datasets are used for training and testing.On average,the proposed method achieved 97.3% accuracy on benchmarked datasets and 98.3% on RCMFD datasets by applying 10-fold cross-validation,which is far better than existing methods.

根系功能分离技术在甘薯源库关系研究中的演进及其应用

甘薯根系功能分离技术(RFSD)是通过特殊栽培模式使甘薯养分吸收根和贮藏根在空间和功能上发生分离的一种新型栽培技术。通过此技术不仅可实现在不影响植株生长的情况下观测块根发育,还可在同一遗传背景下开展光合运输效率研究,是开展甘薯源库关系研究和培育空中甘薯的关键技术。本文归纳了“源”“流”“库”对甘薯产量的影响,回顾了甘薯RFSD的发展历程,总结了目前发展的几种RFSD的原理、演进过程、特点及优长,分析了RFSD在甘薯源库关系和空中甘薯研究中的应用。提出RFSD可作为研究甘薯“源”“流”“库”互作关系的重要手段,今后可利用其优势,在同一遗传背景下开展源库关系和理想株型研究;改进和完善RFSD系统,为设施条件下实现空气中稳定结薯创造可能。RFSD的进一步研究和应用,可为甘薯新品种特别是高光效短蔓高产品种选育提供理论和技术参考,为设施栽培及品质精细调控提供技术支撑。

新疆红色既民族团结旅游景点时空分布特征及交通可达性分析

红色既民族团结旅游景点时空分布特征以及交通可达性是区红色既民族团结旅游的基础要素。本文通过对来疆参与红色既民族团结旅游活动的游客游记的信息提取,运用ArcGIS空间分析技术,对新疆红色既民族团结旅游景区的时空分布特征、服务空间范围变化趋势、交通可达性进行测量。在综合考虑三个因素的基础上,对新疆红色既民族团结旅游景区进行空间功能区划分,得到以下结论:(1)新疆红色既民族团结旅游景点在空间上存在明显的多核心聚集态势;(2)新疆红色既民族团结旅游景点的服务范围存在显著的两极化发展趋势;(3)新疆红色既民族团结旅游线路整体交通可达性欠发达;(4)新疆红色既民族团结旅游空间功能区主要可以概括为“三条发展主轴、四个文化核心、五个服务大区”。在此基础上提出了一些建议。

顾及多重分类与粒度划分的国土空间数据模型研究与应用

国土空间数据在分类分级、过程演化等方面都存在着分类、互依赖、组合构成和前后次序等高阶关系,现有的图层、面向对象、数据立方体等数据模型难以完全刻画全部关系.本文提出了基于有向超图的顾及多重分类与颗粒体系的国土空间数据模型,运用关联矩阵进行逻辑描述,基于超级图形数据库进行物理模型实现和国土空间演化过程的时空分析,解决了全域、全要素、全空间国土空间数据多重分类与颗粒体系表达的难题.相关成果在南京市国土空间基础信息平台得到了应用验证,增强了平台对复杂关系的运营效能,实现了多维关系数据的聚合,为平台实现数据资源自动分类和信息智能定向推送奠定了基础.

密度、距离及分割视角下长三角区域城市韧性逻辑建构与实证分析

风险影响的跨区域性凸显了城市网络在增强城市韧性中的重要性。立足新经济地理学理论中密度-距离-分割三大要素(3D要素),从区域及城区层级上构建包含生态密度、空间距离及社会分割指标的城市韧性综合指数模型,以长三角41市为例,运用空间计量方法研究韧性指数特征、均衡发展状态及3D要素对韧性水平的影响效应。结果显示:①区域中城市韧性水平总体偏低,在空间上呈现以“苏锡常”为核心向外梯度递减的圈层式+轴线型韧性发展格局;韧性等级与区位条件、规划衔接以及内外均衡发展状态高度相关。②随着城市韧性水平的提升,城区层级上的抵御恢复力及区域层级上的适应转型力均衡趋势增强。高水平韧性城市中两者趋向均衡发展,中低水平韧性城市中两者存在失衡;③不同层级的3D要素对韧性水平的影响存在差异性,区域层级上的主导要素为距离,而城区层级上则为密度,二者交互后的影响更加显著。