Siting of Dark Sky Reserves in China Based on Multi-source Spatial Data and Multiple Criteria Evaluation Method

With the rapid development of population and urbanization and the progress of lighting technology, the influence of artificial light sources has increased.In this context, the problem of light pollution has attracted wide attention.Previous studies have revealed that light pollution can affect biological living environments, human physical and mental health, astronomical observations and many other aspects.Therefore, organizations internationally have begun to advocate for measures to prevent light pollution, many of which are recognized by the International Dark-Sky Association(IDA).In addition to improving public awareness, legal protections, technical treatments and other means, the construction of Dark Sky Reserves(DSR) has proven to be an effective preventive measure.So far, as a pioneer practice in this field, the IDA has identified 11 DSRs worldwide.Based on the DA requirements for DSRs, this paper utilizes NPP-VIIRS nighttime light data and other multi-source spatial data to analyze possible DSR sites in China.The land of China was divided into more than ten thousand 30 km × 30 km fishnets, and constraint and suitable conditions were designated, respectively, as light and cloud conditions, and scale, traffic and attractiveness conditions.Using a multiple criteria evaluation, 1443 fishnets were finally selected as most suitable sites for the construction of DSRs.Results found that less than 25% of China is not subject to light pollution, and less than 13% is suitable for DSR construction, primarily in western and northern areas, including Tibet, Xinjiang, Qinghai, Gansu and Inner Mongolia.

Multiple Time-scale Characteristics of Runoff Variations in Middle Reaches of Huolin River and Their Effects

The Huolin River is one of the most important water sources for Xianghai wetland, Horqin wetland, and Chaganhu wetland in the western Songnen Plain of Northeast China. The annual runoff series of 46 years at Baiyunhushuo Hydrologic Station, which is located in the middle reaches of the Huolin River, were analyzed by using wavelet analysis. Main objective was to discuss the periodic characteristics of the runoff, and examine the temporal patterns of the Huolin River recharging to the floodplain wetlands in the lower reaches of the river, and the corresponding effects of recharging variation on the environmental evolution of the wetlands. The results show that the annual runoff varied mainly at three time scales. The intensities of periodical signals at different time scales were strongly characterized by local distribution in its time frequency domain. The interdecadal variation at a scale of more than 30yr played a leading role in the temporal pattern ofrnnoffvariation, and at this scale, the runoffat Baiyunhushuo Hydrologic Station varied in turn of flood, draught and flood. Accordingly, the landscape of the floodplain wetlands presented periodic features, especially prominent before the 1990s. Compared with intense human activities, the runoff periodic pattern at middle （10-20yr） and small （1-10yr） scales, which has relatively low energy, exerted unobvious effects on the environmental evolution of the floodplain wetlands, especially after the 1990s.

Reservation-based dynamic admission control scheme for wideband code division multiple access systems

Call admission control (CAC) and resource reservation (RR) for mobile communication are two important factors that guarantee system efficiency and quality of service (QoS) required for different services in a very scarce resource as the radio spectrum. A new scheme was proposed which extends the concepts of resource sharing and reservations for wideband code division multiple access (WCDMA) systems with a unique feature of soft capacity. Voice and data traffic were considered. The traffic is further classified into handoff and new requests. The reservation thresholds were dynamically adjusted according to the traffic pattern and mobility prediction in order to achieve the maximum channel utilization, while guaranteeing different QoS constraints. The performance of proposed scheme was evaluated using Markov models. New call blocking probability, handoff call dropping probability, and channel utilization were used as benchmarks for the proposed scheme.

Minimizing the Impact of Long Propagation Delay on Multiple Access for Wireless Networks

A multiple access protocol is proposed to greatly improve multiple access performance of wireless networks with long propagation delay. All the nodes with packets to send can make rapid successful reservation in access reservation mini-slots, which is adaptively adjusted according to current traffic load and idle channel resources. A Central Control Node (CCN) coordinates channel reservation and allocates on-demand channel resources to the successfully accessed nodes on two channels. Each node can employ only one handshake to accomplish each communication session, and transmit one or multiple data packets piggybacked with acknowledgment (ACK) information to one or multiple destination nodes in each frame until the end of their communication sessions, which greatly minimizes the impact of long propagation delay caused by handshakes and improves channel efficiency. Simulation results show that the proposed protocol obviously outperforms the Centralized Scheduling-based Medium Access Control (CSMAC) protocol, especially in the presence of long propagation delay.

系统观视域下新时代我国竞技体育后备人才多元培养困境与优化策略

借助新时代党的系统观理念,对当前我国竞技体育后备人才多元培养动向、特征及其现实困境进行分析,并提出优化策略。结果表明:体教系统各级学校高水平运动队建设规模大幅增长,部分运动项目已形成涵盖11~19岁范围的竞赛体系,体教系统U系列立体竞赛网络初步形成,社会多系统合作普遍展开。以环境适应需要、赛事平台引领和资源优势推动的多元培养模式逐渐成形,但仍面临人才培养提质增效有待加强、竞技体育多元价值挖掘不足、人才培养环节衔接亟待优化等困境。优化策略:加快多元培养新模式建设,完善多系统协同共促机制;提升赛事平台规模与质量,带动竞技体育多元价值转化;增强多主体利益共识,发挥各系统资源优势,进而有效推动后备人才培养规模和质量的双提升。

中国竞技体操后备人才培养多元共治的影响因素研究

文章主要采用建构式案例研究方法,以扎根理论编码技术为辅助,对参与竞技体操后备人才培养治理的组织进行多案例分析,构建出竞技体操后备人才培养多元共治影响因素的理论框架。研究发现:竞技体操后备人才培养多元共治的影响因素包括价值认同、资源投入、合作机制、组织能力和制度环境。其中,价值认同是实现竞技体操后备人才培养多元共治的原动力;资源投入和合作机制均对多元共治绩效产生正向的促进作用;组织能力和制度环境通过与其他因素产生交互作用而对竞技体操后备人才培养多元共治绩效产生正向的促进作用。

卵巢功能减退患者多周期累积与非累积胚胎移植临床结局比较

目的探讨卵巢功能减退(DOR)患者多周期累积与非累积胚胎移植体外受精-胚胎移植(IVF-ET)临床结局的差异。方法回顾性分析2019-01至2022-12于首都医科大学附属北京妇产医院生殖医学科进行IVF-ET治疗的卵巢储备功能减退的不孕患者174例的临床资料,纳入患者均已完成所有胚胎移植及最终随访。收集患者的基础内分泌、抗苗勒管激素水平及窦卵泡计数,记录促排卵治疗后的卵巢反应参数及妊娠结局等相关临床资料,比较多周期累积胚胎移植(累积组)与非累积胚胎移植(非累积组)两种IVF-ET治疗的临床结局。结果DOR患者多周期累积胚胎移植与非累积胚胎移植两组间的累积妊娠率(35.24%vs.27.54%)、早期流产率(32.43%vs.26.32%)及累积活产率(21.90%vs.18.84%)差异无统计学意义(P>0.05);纳入移植策略、BMI、首次取卵年龄、AMH、胚胎移植数、优质胚胎移植数、累积获卵数等多个因素后进行logistic回归分析,两种不同的胚胎移植策略(OR=1.522,95%CI 0.608~3.814)对活产无明显影响(P>0.05)。结论对于DOR患者,进行多周期重复取卵后的累积胚胎移植并不能提高患者的累积妊娠率及活产率。

Fast X-ray imaging beamline at SSRF

The fast X-ray imaging beamline(BL16U2)at Shanghai Synchrotron Radiation Facility(SSRF)is a new beamline that provides X-ray micro-imaging capabilities across a wide range of time scales,spanning from 100 ps toμs and ms.This beamline has been specifically designed to facilitate the investigation of a wide range of rapid phenomena,such as the deformation and failure of materials subjected to intense dynamic loads.In addition,it enables the study of high-pressure and high-speed fuel spray processes in automotive engines.The light source of this beamline is a cryogenic permanent magnet undulator(CPMU)that is cooled by liquid nitrogen.This CPMU can generate X-ray photons within an energy range of 8.7-30 keV.The beamline offers two modes of operation:monochromatic beam mode with a liquid nitrogen-cooled double-crystal monochromator(DCM)and pink beam mode with the first crystal of the DCM out of the beam path.Four X-ray imaging methods were implemented in BL16U2:single-pulse ultrafast X-ray imaging,microsecond-resolved X-ray dynamic imaging,millisecond-resolved X-ray dynamic micro-CT,and high-resolution quantitative micro-CT.Furthermore,BL16U2 is equipped with various in situ impact loading systems,such as a split Hopkinson bar system,light gas gun,and fuel spray chamber.Following the completion of the final commissioning in 2021 and subsequent trial operations in 2022,the beamline has been officially available to users from 2023.

考虑多阻尼状态与限幅环节的新能源电力系统一次调频备用整定

一次调频是电力系统抑制扰动后频率变化的重要手段,该文针对新能源电力系统一次调频备用整定问题开展研究。首先,分析新能源电源渗透率上升对系统频率响应模型阻尼比的影响,建立适用于多阻尼状态的系统频率响应模型。随后,考虑新能源电源调频动态响应的快速性与同步电源调速器限幅值的差异性,提出计及多机调速器限幅环节的系统频率响应改进模型。接着,将构建的系统频率响应改进模型等价转化到时域,建立各类电源一次调频备用与系统扰动后频率最低点的时域解析关系,并进一步提出其线性化表征方法。最后,面向扰动后频率稳定要求,在新能源电力系统经济调度问题中添加一次调频备用约束,建立新能源电力系统一次调频备用整定模型。IEEE 39节点算例仿真结果表明该文提出模型的正确性与有效性。

体教融合背景下我国青少年篮球后备人才多元培养路径与培养质量提高路径

该文主要的研究目的是分析在体教融合的背景下培养我国青少年篮球后备人才的多元路径。篮球运动一直以来受到广大群众的喜爱,随着时代的发展,人们思想的进一步活跃以及我国体育强国等一系列名词的提出,体育运动日渐走进家长们的视野,重要程度逐渐变得与文化课教育不相上下。在体教融合的大背景下,为了满足当代民众对篮球运动方面的高要求,培养青少年篮球技能的路径也需要进一步拓展及开发。

Contingency Reserve Evaluation for Fast Frequency Response of Multiple Battery Energy Storage Systems in a Large-scale Power Grid

Recently,the fast frequency response(FFR)service by large-scale battery energy storage systems(BESSs)has been successfully proved to arrest the frequency excursion during an unexpected power outage.However,adequate frequency response relies on proper evaluation of the contingency reserve of BESSs.The BESS FFR reserve is commonly managed under fixed contracts,ignoring various response characteristics of different BESSs and their coexisting interactions.This paper proposes a new methodology based on dynamic grid response and various BESS response characteristics to optimise the FFR reserves and prevent the frequency from breaching the under-frequency load shedding(UFLS)thresholds.The superiority of the proposed method is demonstrated to manage three large-scale BESSs operating simultaneously in an Australian power grid under high renewable penetration scenarios.Further,the proposed method can identify remaining battery power and energy reserve to be safely utilised for other grid services(e.g.,energy arbitrage).The results can provide valuable insights for integrating FFR into conventional ancillary services and techno-effective management of multiple BESSs.

从多树种古树群中优选造林乡土树种研究——以怀化市为例

对怀化市156个古树群(含3个树种、15株古树以上)进行研究,分析树种和古树群结构特征,选择适宜在怀化市造林的乡土树种及配置模式。实地调查古树群,按照平均胸径、平均树高、株数和重要值计算树种得分,按分值优选造林树种。古树群以树种数、株数、平均胸径、平均树高计算分值,选取前20个古树群研究树种配置。选出枫香树、青冈、香樟、马尾松、黄连木、朴树、钩栲、木荷、银杏、甜槠等23种适宜造林的乡土树种。树种配置不固定到种,采取6种以上树种混交,喜光树种作先锋种,根据经营目的搭配中性和耐荫树种的模式。选出的造林乡土树种和树种配置模式,实用性强,可以为当地建设长期稳定的森林群落提供树种选择理论依据。

基于调频服务的新型光-储电站容量规划及运行策略

为充分利用新型光-储电站参与电网调频的优势并考虑运行经济性问题,针对光伏组件、飞轮储能、磷酸铁锂储能的特点,建立各自全生命周期模型,并提出一种降低储能电池衰减、提高调频性能的协调运行策略。然后,依据一、二次调频机制,以调频收益最大为优化目标,建立光-储电站参与电网调频容量规划模型。最后,在Matlab软件中搭建光-储系统仿真模型。仿真结果表明:混合储能联合光伏备用容量在保障秒级一次调频、分钟级二次调频需求的基础上,可以实现资源合理规划,提高调频经济性和可靠性;此外,飞轮储能成本降低可以提高自身容量配置及电站调频收益,缩短投资回报年限。

面向矿产资源储量计算的三维训练图像构建方法

矿产资源储量计算有助于合理开发利用矿产资源,目前多点地质统计学是矿产资源储量计算的热门技术,但多点地质统计学中高质量三维训练图像构建较为困难。因此,提出了一种面向矿产资源储量计算的三维训练图像构建方法。该方法首先基于原始钻孔等数据构建三维地质模型,并对其使用不规则四面体网格剖分得到体元模型;然后基于钻孔属性数据采用插值算法构建规则体元品位模型,并对体元模型进行欧氏距离的属性赋值得到三维训练图像;最后采用多点地质统计学改进的Snesim算法构建搜索树获取条件概率,并进行相关性的属性融合给矿体待估值体元模型赋属性,进而计算矿产资源储量。以黑牛洞Ⅰ-3号矿体为例,计算得到该矿体铜平均品位为2.90%,与开采后的铜平均品位2.33%相比,相差仅0.57个百分点,证明了所提方法的正确性和有效性。

PCA-OPLS联合法快速评价页岩气井储量动用程度

川南地区已经钻探完成了上千口页岩气井,地质评价、钻探和生产过程中产生了大量高维度的数据,利用生产获得的各种数据预测页岩气储量动用程度,是指导页岩气勘探开发的一项重要工作。耦合主成分分析法(PCA)与正交偏最小二乘法(OPLS)分析方法是形成一种快速、准确的储量动用程度预测新方法。通过结合主成分分析和正交偏最小二乘法,建立了PCA-OPLS联合法,借助昭通页岩气井样本,检验了新方法在储量动用程度评价中的应用效果。实例应用表明,页岩气井储量动用预测准确率满足要求,可以用于预测新钻井的储量动用程度,从而证明PCA-OPLS联合法能达到快速、准确预测储量动用程度的目的。该方法操作简单,准确率高,在页岩气储量动用评价中具有较好的应用前景。

多情景模拟区域土地利用变化对碳储量的影响

以洞庭湖生态经济区为例,利用InVEST模型评估1990~2020年土地利用变化带来的碳储量效应,耦合Markov-FLUS模型模拟2030年、2060年在自然演变、耕地保护、生态保护、综合保护四种情景下土地利用变化及其对碳储量的影响.结果表明:1990~2020年洞庭湖生态经济区呈现出耕地、林地和草地面积减少,水域、建设用地和未利用地的面积持续增加的特征.区域内整体碳储量较高,但随着土地利用变化,造成区域固碳能力和潜力有所降低,1990~2020年区域碳储量总共减少0.433×10^(6)t.在自然演变、耕地保护、生态保护和综合保护四种不同情景下,2030年、2060年区域均表现出建设用地的变化量较大,综合保护情景建设用地的增加量得到较好控制.2030年、2060年洞庭湖生态经济区自然演变情景碳储量分别为19.927×10^(6)t、19.696×10^(6)t,耕地保护情景为19.891×10^(6)t、19.903×10^(6)t,生态保护情景为19.952×10^(6)t、19.873×10^(6)t,综合保护情景为20.004×10^(6)t、19.949×10^(6)t,相比可知在综合考虑耕地与生态保护的情景下,区域碳汇能力较强.研究结果有助于构建高碳汇国土空间格局,可为实现区域碳平衡和土地利用结构优化提供依据.

我国竞技体育后备人才培养多元主体协同治理的演化博弈与仿真分析

竞技体育后备人才培养协同治理作为推动竞技体育高质量发展的关键环节,其实质是不同治理主体为获得各自利益而反复博弈的动态演化过程。该研究基于协同治理理论与演化博弈理论构建了政府、社会组织和市场的协同治理演化博弈模型,对演化博弈系统均衡点的局部稳定性进行了分析,并运用MATLAB 2021a对不同情景下各主体的稳定策略进行数值仿真,分析不同因素的参数变动对系统演化路径的影响。研究发现:三方演化博弈存在(1,1,1)与(1,1,0)两个稳定策略;多元主体协同治理是竞技体育后备人才培养发展的必然趋势,既离不开政府的主导,也离不开社会组织与市场的配合;同时,扶持额度、奖励额度以及惩罚额度是影响各主体策略演化走向的重要因素。研究建议:建立完善的竞技体育后备人才培养协同治理影响机制;建立长效的竞技体育后备人才培养协同治理合作机制;建立科学的竞技体育后备人才培养协同治理评估机制。

基于红外相机技术的云龙天池国家级自然保护区鸟兽多样性调查

为了解由不相连的天池片区(天池)和龙马山片区(龙马山)组成的云龙天池国家级自然保护区的鸟兽多样性,2019年3月—2020年7月,沿海拔梯度布设61台红外相机(天池29台,龙马山32台)进行调查。天池和龙马山的累计工作日分别为6228 d和9498 d;独立有效照片分别为1211张和1160张。共鉴定出兽类6目12科21种,鸟类6目17科60种,其中,国家一、二级重点保护野生动物分别为2种、20种,保护区新记录25种。保护区内相对丰富度最高的5种野生动物从高到低依次为珀氏长吻松鼠Dremomys pernyi、赤腹松鼠Callosciurus erythraeus、猕猴Macaca mulatta、黄喉貂Martes flavigula、白腹锦鸡Chrysolophus amherstiae。2个片区共同调查到的物种占总物种数的53%;相似性检验表明,2个片区的群落组成有显著差异(鸟类:R=0.068,P=0.044;兽类:R=0.149,P=0.001)。本研究更新了保护区内鸟兽物种名录,分析了2个片区的群落差异,为保护区野生动物监测和保护管理提供了科学参考。

烤烟新品种湘烟7号高效制种技术研究

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