Investigations on Fluid Resonance Within A Narrow Gap Formed by Two Fixed Bodies with Varying Breadth Ratios

The resonant motion of the fluid inside a narrow gap between two fixed boxes induced by incident regular waves with various wave heights is investigated by adopting a two-dimensional numerical wave flume based on an opensourced CFD package,OpenFOAM.The two boxes have identical draft and height,but the upstream box has a variable breadth.This article focuses on the influences of the breadth ratio,defined as the ratio of the breadth of the upstream box to that of the downstream box,on the following three aspects of hydrodynamic characteristics of gap resonance:(1)the wave height amplifications inside the gap,and in front and at the rear of the structure system,(2)the reflection,transmission,and energy loss coefficients of the structure system,and(3)the response and damping time of the fluid resonance.It is found that the fluid resonant frequency,the amplification factor of the resonant wave height inside the gap and the maximum energy loss coefficient of the structure system are shown to gradually decrease with the increase of the breadth ratio.The response time of gap resonance is shown to first increase and then decrease with the breadth ratio overall,regardless of the incident wave height,and the configuration that the two boxes have the same breadth would bring the largest response time of gap resonance.

Macroecological Patterns of Climatic Niche Breadth Variation in Lacertid Lizards

Measuring climatic niche position and breadth may help to determine where species can occur over space and time. Using GIS-based and phylogenetic comparative methods, we investigated global patterns of variation in climatic niche breadth in lacertid lizards to test the following three hypotheses about climatic niche widths. First, does a species' temperature or precipitation niche breadth relate to its temperature or precipitation niche position(the mean value of annual mean temperature or annual precipitation across sampled localities in the range of each species)? Second, are there trade-offs between a species' temperature niche breadth and precipitation niche breadth? Third, does a species' temperature or precipitation niche breadth relate to altitude or latitude? We expect that:(1) species distributed in cold regions are specialized for low-temperature environments(i.e. narrow niche breadth center around low temperatures);(2) a negative relationship between species niche breadth on temperature and precipitation axes according to the tradeoff hypothesis(i.e. species that tolerate a broad range of precipitation regimes cannot also tolerate a broad range of temperatures);(3) precipitation niche breadth decreases with altitude or latitude, whereas temperature climatic niche breadth increases with altitude or latitude. Based on the analytical results we found that:(1) temperature niche breadth and position are negatively related, while precipitation niche breadth and position are positively related;(2) there is no trade-off between temperature and precipitation niche breadths; and (3) temperature niche breadth and latitude/altitude are positively related, but precipitation niche breadth and latitude/altitude are not significantly related. Our results show many similarities with previous studies on climatic niche widths reported for amphibians and lizards, which provide further evidence that such macroecological patterns of variation in climatic niche breadths may be widespread.

Kinematical system of breadth cam profile design

The design solutions for breadth cam mechanism was presented. The main topics of the shape design for breadth cam was to calculate the coordinate at each contact point to determine the cam profile. The proposed method according to velocity and geometric relationships of instant velocity centers can easily determine each contact point at any instant moment. The cam profile was defined by contouring of the contact points. And also a program was developed by using Microsoft Visual C++ program,which can quickly and easily draw a 2D cam profile through the displacement diagram. Finally,the program was used to confirm the accuracy on the breadth cam profile design by computer animation graphically.

Network Defense Methodology: A Comparison of Defense in Depth and Defense in Breadth

The defense in depth methodology was popularized in the early 2000’s amid growing concerns for information security;this paper will address the shortcomings of early implementations. In the last two years, many supporters of the defense in depth security methodology have changed their allegiance to an offshoot method dubbed the defense in breadth methodology. A substantial portion of this paper’s body will be devoted to comparing real-world usage scenarios and discussing the flaws in each method. A major goal of this publication will be to assist readers in selecting a method that will best benefit their personal environment. Scenarios certainly exist where one method may be clearly favored;this article will help identify the factors that make one method a clear choice over another. This paper will strive not only to highlight key strengths and weaknesses for the two strategies listed, but also provide the evaluation techniques necessary for readers to apply to other popular methodologies in order to make the most appropriate personal determinations.

Financial depth or breadth:What really matters for fighting air pollution in China?

China's rapid economic development leads to a series of environmental problems in the long run,such as air pollution.Environmental pollution has become a bottleneck restricting the sustainable development of China's economy.As such,pollution has become a key issue for China as让tries to continuously improve environmental quality and establish a harmonious coexistence between man and nature.This paper uses spatial econometric analysis to empirically test the existence of the Environmental Kuznets Curve(EKC)in China while also examining the impact of financial development on its inflection point by applying Air Quality Index and PM_(2.5) data of 283 prefecture-level cities in China from 2015 to 2017.Findings from this study indicate that the EKC of air pollution in the whole country presents an inverted U-shape based on both the traditional and new EKC models.After testing the sub-sample in different areas,the EKC still presents an inverted U-shape based on the new EKC model in the eastern and central areas,though not in the western area.In considering the moderating role of financial development based on the new EKC model,we find that the increase of financial depth will cause the EKC inflection point to shift to the left on the national scale and in the eastern region,while the effect of the financial breadth will be largely insignificant.With regard to the central area,both the breadth and the depth of financial development will significantly shift the inflection point to the right,delaying the arrival of the EKC inflection point.Therefore,the local authority of each area should formulate differentiated financial development policies to promote the early arrival of the EKC inflection point.

BRI Develops in Depth and Breadth

The Second Belt and Road Forum of International Cooperation was held in Beijing in late April. Thousands of representatives from more than 100 countries around the world discussed new strategies for achieving high-quality development of the Belt and Road Initiative (BRI) and shared cooperation experience.

Research on Knight Covering Based on Breadth First Search Algorithm

This paper introduces the general process of the search algorithm Structure through the knight problem. According to the characteristics of the problem, we detailed discuss the DFS（Depth First Search） algorithm and BFS（Breadth First Search） algorithm, and combine the two algorithms together to solve the knights coverage problem. This article has a good reference for the mixed-use scenarios which requires a variety of search algorithms.

Seasonal resource use and niche breadth in an assemblage of coexisting grazers in a fenced Park

Many small Parks inKenyaare being fenced to control human-wildlife conflict. Some of these Parks have a diversity of large herbivores which might increase in density in the wake of fencing and subsequent compression of their home ranges due to closure of their migratory routes. It is important to understand the consequences of such an increase on the structuring of insularised herbivore assemblages in such Parks. We studied seasonal resource segregation and niche breadth variation as mechanisms of coexistence in a high density grazer assemblage inLakeNakuruNational Parkwhich is small and completely fenced. Diet composition and habitat use were considered as variables of resource use. We predicted that overlap in resource use and niche breadth would be the smallest among grazers with similar body weights in the dry season which is the most resource limiting for grazers in East Africa. Our results were contrary to the predictions because of lack of seasonal differentiation in the overlap of diet composition and habitat use, and in niche breadth. Overlaps in resource use were consistently high during both the wet and dry seasons, and niche breadth contraction during the dry season was not possible probably because of lack of species-specific niches during the dry season. Our results suggest that there might be competitive interactions in this grazer assemblage which is an important parameter to consider in the management of the Park.

生态位视角下创新型产业集群竞争力测度研究

创新型产业集群是通过聚合创新形成现代产业竞争优势的战略性力量。在生态位理论视角下,构建创新型产业集群竞争力评价的理论分析框架,选取技术、组织、资本、服务创新资源生态位因子,运用生态位宽度、重叠度、适宜度及竞争力综合评价模型对中国70个创新型产业集群的生态位竞争力进行多维测度。研究发现,中国创新型产业集群的生态位宽度呈递增趋势,涵盖的资源空间日益广泛,资源聚合竞争力逐年增强;生态位重叠度存在过度竞争、过度分散等问题,其中地理位置邻近、主导产业相同的创新集群间生态位重叠度偏高;生态位适宜度总体偏低,进化动量总体较高,说明多数集群在生境适应能力方面的竞争力较弱,与领先集群间差距较大,但呈现出较好的成长性。生态位竞争力综合分析显示,创新集群形成了由四个梯队构成的产业创新空间格局。从产业特征看,新一代信息技术及相关服务业集群的生态位竞争优势明显,而节能环保、高端装备与新能源汽车产业的创新集群则处于生态位竞争劣势;从空间维度看,南部沿海区域的创新集群生态位竞争力最强,形成珠三角经济圈创新生态高地,而大西北区域的创新集群则面临着创新生态脆弱性的挑战,存在更大的进化动量空间。据此,提出资源协同集聚、集群错位竞争和区域协调发展策略以进一步提升中国创新型产业集群的生态位竞争力。

新生代员工资质过剩感对越轨创新行为的影响——一个被调节的多中介模型

随着数字经济蓬勃发展,新兴数字技术在传统领域的应用不断深入,给企业数字化转型带来巨大创新潜能和机会。新生代员工在创新过程中面临“创新悖论”,导致自发性越轨创新行为的发生。根据自我调节理论和自我一致性理论,基于332份调查问卷,构建一个被调节的多中介模型,探讨新生代员工资质过剩感对越轨创新的影响。结果表明,资质过剩感正向影响员工越轨创新行为;角色宽度自我效能感、消极情绪分别在认知和情绪路径上对资质过剩感与越轨创新间的关系起到部分中介作用;心理安全感正向调节角色宽度自我效能感、消极情绪与员工越轨创新间的关系。研究结果有助于厘清新生代员工资质过剩感与越轨创新间的作用机制和边界条件,为有效发挥新生代员工资质过剩感的作用、适当引导员工越轨创新行为、促进组织管理实践提供人力资源的辨识与思考。

基于广度-深度采样和图卷积网络的谣言检测方法

现有谣言检测方法存在早期数据丢失、特征利用不充分问题,为此提出新的检测方法.为了充分挖掘事件的早期传播特征,提出广度采样方法并构建与事件对应的传播序列,利用Transformer挖掘长距离评论间的语义相关性并构建事件的传播序列特征.为了有效挖掘事件的传播结构特征,提出基于路径长度的深度采样方法,构建事件对应的信息传播子图和信息聚合子图,利用图卷积网络在挖掘图结构特征方面的优势,获得与事件对应的传播结构特征.将事件对应的传播序列特征表示与传播结构特征表示进行拼接,得到事件对应的最终特征表示.在公开数据集Weibo2016和CED上开展所提方法的有效性验证实验.结果表明,所提方法普遍优于现有典型方法.与基线方法相比,所提方法的准确率和F1值均有显著提升,所提方法在谣言检测领域的有效性得到验证.

顾客授权行为对员工工作重塑的影响:有调节的中介模型

基于自我决定理论,通过373位员工多时点追踪样本探讨顾客授权行为对员工工作重塑的影响及其机制和作用边界,结果表明:顾客授权行为正向影响员工工作重塑,角色宽度自我效能感在这一过程中起正向调节作用;和谐式工作激情在顾客授权行为和工作重塑之间起部分中介作用;角色宽度自我效能感不仅强化了顾客授权行为与和谐式工作激情的正向关系,还进一步强化顾客授权行为通过和谐式工作激情影响员工工作重塑的间接效应。

兼听则明:寻求反馈性质对员工越轨创新行为的影响——自我反思的中介作用与角色宽度自我效能的调节作用

寻求反馈能帮助个体获取认知与情感资源,进而促进员工创新。但寻求不同性质的反馈能否通过获取矛盾性评价引发思维的深层演进,进而激发越轨创新还有待探索。基于社会信息加工理论,探讨寻求反馈性质对越轨创新行为的作用机制。结果表明:①寻求正、负向反馈均能通过自我反思激发越轨创新,且相较于“低正向寻求—低负向寻求”,“高正向寻求—高负向寻求”对自我反思的影响更为显著;②角色宽度自我效能正向调节寻求负向反馈与自我反思间关系;③角色宽度自我效能和创新资源结构性紧张的交互显著调节寻求正、负向反馈与自我反思间关系。

依托生态位战略的国产工业软件发展

工业软件被称为工业制造的大脑与神经,然而由于欧美软件占据市场主导地位,工业软件成为我国工业行业中的弱势领域。生态位战略立足国产工业软件行业现状,有助于企业厘清市场竞争法则,选择合适的生存战略。借鉴生态位理论,依托企业生态位重叠度、生态位宽度的内涵,对减轻国产工业软件的竞争压力作出尝试性探索。并通过创元对北仑模具行业进行数字化改造的案例,对我国工业软件的生态位发展策略进行适用性分析。该研究可为国产工业软件企业提供借鉴参考,使其找准发展空间,推动国产工业软件持续健康发展。

中国出口产品质量特征演变——基于不同测算方法的比较研究

将出口产品质量测算的两种方法——需求信息反推法和供需信息推导法纳入同一模型框架内,使用2000-2013年微观样本数据对中国出口产品质量进行了全面测算、多维度分析。研究发现:不同方法测算的产品质量指标之间存在正向的相关性,但在使用需求信息反推法时对回归方程的处理应更加谨慎;考察期内中国出口产品质量实现了一定程度的提升,其中私营企业出口产品质量水平低于国有企业和外资企业,一般贸易出口产品质量水平低于加工贸易,低技术出口产品的质量水平低于高技术出口产品,但质量水平较低的类型均表现出更高的提升速度,从而使质量差距逐渐缩小甚至实现赶超;从企业出口行为看,企业出口深度与其产品质量表现出显著的正相关,而企业出口广度则无此特征。

取向与广度:时间知觉对于铸牢中华民族共同体意识的意义

铸牢中华民族共同体意识是治国理政的重要方略,也是实现国家发展和民族复兴的关键所在。通过操纵时间知觉取向和测量时间知觉广度探索时间知觉对中华民族共同体意识即族际感知相似性、族际接触意愿、政策支持态度和助人行为等的影响。结果显示,启动过去和未来取向的时间知觉均能提升中华民族共同体意识,其中少数民族被试偏好过去时间取向,汉族被试偏好未来时间取向;自我连续性在时间知觉广度与族际接触意愿和助人行为中起到中介作用。由此揭示了时间知觉的民族差异及其在铸牢中华民族共同体意识中的心理机制和重要意义。

RTA知识产权保护强度对出口贸易稳定性的影响研究

在国际贸易不确定性加剧的背景下,RTA知识产权保护强度对其成员国间出口贸易有着重要的影响。基于DESTA数据库2003—2020年间有效运行的RTA,选取有RTA关系的165个国家组成的2927组国家对作为研究对象,测度了RTA的知识产权保护强度,并构建回归模型探究RTA知识产权保护强度对出口贸易稳定性的影响。研究发现:RTA知识产权保护强度越大,越有利于提高RTA成员国间出口贸易的稳定性。此外,国家间信息流动性越强,以及进口国经济自由度越高,RTA知识产权保护对出口贸易稳定性的促进作用就越强。该效应对于不同类型国家和不同出口行业而言不一样:RTA知识产权保护对南北国家间的双边出口贸易稳定有促进作用,而对南南国家和北北国家间的促进作用不显著;对动植物及食品制造类,皮革、纺织及杂制类,电子、化工及机械制造类行业出口贸易稳定有促进作用。这些研究结论对国家间开展贸易合作,签订合理知识产权保护强度的RTA,维护长久稳定的出口贸易关系具有重要意义。

Assessing the Roles of Breadth and Depth of Vocabulary Knowledge in Chinese EFL Learners' Listening Comprehension

This study intends to investigate the effects of receptive vocabulary breadth and depth on listening comprehension by college students. The experimental results indicate that both the breadth and depth have a significant correlation with listening comprehension; vocabulary breadth contributes more to EFL learners＇ listening comprehension. The findings of this study give pedagogical implications for the teaching of listening in China.

我国交叉性金融业务分析与穿透式监管指数编制初探

中央金融工作会议提出防范风险跨区域、跨市场传递共振,中国人民银行提出构建以资管产品为代表的交叉性金融业务风险监测评估框架。通过对交叉性金融概念、衍生背景、演变历程、运行状况的分析,为提升我国交叉性金融风险管控能力提供有益参考。在交叉性金融统计数据缺口较大和信息公开程度较低的情况下,通过对资管产品与银行理财产品发展情况的分析了解我国交叉性金融业务的演变特征,同时通过构造投资广度指数与投资集中度指数为交叉性金融业务的穿透式监管提供有益的分析工具。研究发现,我国交叉性金融业务取得了长足的发展,交叉性金融业务野蛮扩张的势头得到了有效控制,交叉性金融业务发展的业务模式和资金运用方式都呈现出新的变化趋势。对投资广度指数和投资集中度指数进行试算分析发现,构造投资广度指数与集中度指数,能够加强对交叉性金融业务投资复杂程度的把握,仅依托公开数据即可初步实现穿透式监管。由于交叉性金融业务的底层资产难以穿透,蕴含着较大的系统性风险,因此应该规范交叉性金融业务活动,加强穿透式监管,避免金融风险的跨机构、跨市场传递共振;金融监管部门与金融机构应该积极依托业务数据对交叉性金融活动开展常规性和专项性的穿透式监管。

不同采集年份大花红景天种子萌发对温度的响应

为确定温度变化对大花红景天(Rhodiola crenulata)种子萌发的影响,本研究以云南省香格里拉市大雪山居群的种子为材料,探究不同采集年份(2014、2015、2016、2019、2020、2021年)种子的萌发对温度(恒温:1、5、10、15、20、25、30、35℃;变温:15℃/5℃、25℃/15℃)的响应机制。结果表明:大花红景天种子萌发温度阈值较宽,1~35℃均可萌发,具有较宽的萌发温度生态位幅度(0.831~0.891),15~25℃萌发效果最佳;变温与相应恒温相比不能显著增加最终萌发率。通过积温模型模拟,种子萌发最低温度(Tb)为−0.49~0.82℃,萌发最适温度(To)为19.38~20.88℃,萌发最高温度(Tc)为34.21~38.76℃,亚适温条件下的种子萌发积温值为40.7~67.11℃·d。综上,大花红景天种子具有“机会主义”萌发行为,萌发最低温度较低且具有较宽的萌发温度窗口,使其可以在早春大量萌发,以保证幼苗拥有较长的生长季。研究结果为保护与利用野生大花红景天资源提供了一些参考。