永康市副中心城镇绿色空间系统规划探索

城市绿色空间系统规划是城市规划的重要方面,也与城市形象息息相关。文章以浙江省永康市副中心城镇为例,探讨城镇密集地区绿色空间系统规划的内容及方法,主要包括城镇污染综合防治、总体布局及景观规划三个方面的内容。     

超距空间的连通性

利用超距空间的基本性质及拓扑空间的连通理论,得出超距空间及其子空间、积空间既不是连通空间,也不是弧连通空间,而非离散的超距空间不是局部连通空间。     

Ishikawa迭代的非线性算子不动点逼近

本文在一致光滑的 Banach 空间,运用 Ishikawa 迭代,给出了方程解的逼近,进而将 C.E.Chidume 所研究结果从 Lipschitz 条件降至一致连续。关键词:巴拿赫空间;非线性算子;Ishikawa 迭代;强增生算子;强伪压缩算子;一致连续     

两个灰距离空间(■d)(■.ρ)

本文在邓聚龙教授提出的层次型灰数和信息型灰数——经典有理灰数的基础上,用近代分析的方法,给出两种灰距离空间(/.d)和(/.p),并结合几何直观将两种灰距离进行了比较。     

Forecasting China's foreign exchange reserves using dynamic model averaging: The roles of macroeconomic fundamentals,financial stress and economic uncertainty

We develop models for examining possible predictors of growth of China's foreign exchange reserves that embrace Chinese and global trade, financial and risk (uncertainty) factors. Specifically, by comparing with other alternative models, we show that the dynamic model averaging (DMA) and dynamic model selection (DMS) models outperform not only linear models (such as random walk, recursive OLS-AR(1) models, recursive OLS with all predictive variables models) but also the Bayesian model averaging (BMA) model for examining possible predictors of growth of those reserves. The DMS is the best overall across all forecast horizons. While some predictors matter more than others over the forecast horizons, there are few that stand the test of time. The US–China interest rate differential has a superior predictive power among the 13 predictors considered, followed by the nominal effective exchange rate and the interest rate spread for most of the forecast horizons. The relative predictive prowess of the oil and copper prices alternates, depending on the commodity cycles. Policy implications are also provided.     

ZY5000/15/32掩护式液压支架的优化设计

当支架工作一定时间后出井维护时,需要将前梁与顶梁之间的销轴拿掉后改为运输销轴连接,由于井底空间、设备有限,操作极为不便;另外,由于前梁千斤顶是靠销轴受力,因为支架工作时间比较长且井下环境恶劣,导致销轴出现变形、生锈等现象,以致销轴不易拆卸。     

终身学习视角下公共图书馆的转型与发展思考

公共图书馆作为公共文化服务体系的重要组成部分,在构建学习型社会的大背景下,为促进终身学习的理念,借鉴国外图书馆的前沿探索,提升人文素质和知识内涵,实现公共图书馆在新的历史形势下自身的转型与发展。     

Theoretical analysis and model design of search for ecological conservation redlines based on the sensitivity assessment of ecosystem services

Most small-scale social economies are characterised by their deficiency, lack, and/or difficulty in matching natural data. Against this backdrop, this paper builds a relatively uniform theoretical framework and designs a more economical and objective method for demarcating ecological conservation redlines (ECR) based on sensitivity assessment of ecosystem services. The results show that the sensitivity assessment model designed in this study can identify sensitive zones effectively, and that the ECR in Hubei Province are well within the sensitive zones so identified. The delimited areas based on the sensitive assessment of ecosystem services have great similarities (95%) with the actual ECR areas in Hubei Province. The most ecologically important functional zones (EIFZ) can also be identified using the regional ecological sensitivity coefficient. When the threshold of EIFZ is set higher, the probability that it falls within the ecologically sensitive areas is greater and the ECR delimited by the method proposed in this study will be more reliable. Theoretically, the delimitation of ECR can be inserted at any evaluation level with a grid resolution higher than that of the land use data, which can be used as a supplement to the ECR delimitation method in ecology or geography.     

价值共创行为分析框架构建 ——基于赋能理论视角

通过文献调查并结合案例的描述性分析,提出数字技术时代价值网络中不同行为主体之间的赋能内涵、关键维度以及基于赋能跨层次效应的价值共创行为分析框架。将"赋能氛围""主体赋能"分别作为价值网络中赋能的宏观维度和微观维度进行概念化。界定了两个维度的关键组成要素,分别包括信息共享、开放性结构、协同规则以及主体关系、资源整合和影响。构建了赋能的跨层次效应模型,分析了赋能的宏观-微观跨层次效应及其对价值网络生态和主体价值创造的影响。