环境分权、环保约谈与环境污染

环境政策的实施及其效应是现有文献研究的热点问题。文章基于长江经济带2003-2017年108个城市市级面板数据，手工搜集整理河长制与环保约谈数据，采用双重差分法实证研究了环境分权和环保约谈对环境污染的影响。研究发现：环境分权对环境污染具有显著的长期抑制作用，河长制的实施可以改善生态环境质量，从空间角度看，环境分权对长江经济带不同区域环境污染的影响存在异质性，对长江中游城市环境污染的影响最为显著；环保约谈对环境污染具有显著的负向影响，其治污效力远高于环境分权的政策效果，但环保约谈对环境污染的滞后效用有所减小，表明环保约谈对环境污染的影响是一种短期影响；环境分权与环保约谈双管齐下的治污效果更为显著，对环境污染的抑制作用高于两者单独的政策影响，但二者双管齐下的治污效力随着时间推移有所减弱。因此，文章从构建环境监督执法垂直管理机制、重视事前预警约谈、建立跨流域环境联防联治体系等角度提出改善环境污染的相关政策。     

Spatial hidden Markov models and species distributions

A spatial hidden Markov model (SHMM) is introduced to analyse the distribution of a species on an atlas, taking into account that false observations and false non-detections of the species can occur during the survey, blurring the true map of presence and absence of the species. The reconstruction of the true map is tackled as the restoration of a degraded pixel image, where the true map is an autologistic model, hidden behind the observed map, whose normalizing constant is efficiently computed by simulating an auxiliary map. The distribution of the species is explained under the Bayesian paradigm and Markov chain Monte Carlo (MCMC) algorithms are developed. We are interested in the spatial distribution of the bird species Greywing Francolin in the south of Africa. Many climatic and land-use explanatory variables are also available: they are included in the SHMM and a subset of them is selected by the mutation operators within the MCMC algorithm.     

一类多元Bernstein算子的加权逼近

主要讨论了一类二元的Bernstein算子的加权逼近问题。首先，我们举例说明在通常的加权范数下它是无界的。然后我们给出了一类新的加权范数，在此范数下它是有界的。最后我们利用一类新的加权K一泛函给出了二元Bernstein算子加Jacobi权逼近的特征刻划。     

谈中国古代诗歌重译中词语差异

在中国古代诗歌重译中,词语差异在译入语的诗句中特征显著。本文分析词语差异产生的原因以及词语差异所给予读者的美感效应。     

中国城市民生发展的区域差异测度、来源分解与形成机理

本文基于熵值法构建城市民生发展指数,利用Dagum基尼系数和方差分解方法首次从空间和结构两个视角考察我国城市民生发展的差异大小及来源,并运用关系数据分析范式研究其形成机理。研究发现:我国城市民生发展水平持续向好,但2010年之后民生发展不均衡现象显著;民生发展总体差异主要来源于区域间差异,其中东部和中部区域间差异贡献最大,东部区域内差异贡献显著高于中部、西部地区;社会发展差异和生态建设差异是民生发展差异的主要结构来源;人民生活差异、科技创新差异对民生发展差异的影响均从东向西依次减弱,社会发展差异的作用则依次增强,生态建设差异的影响在中部地区最为突出,经济发展差异对东部地区的影响较弱;人民生活差异、科技创新差异上升是导致2010年之后民生发展差异扩大的主要原因。本研究丰富了城市民生评价体系的构建方案,为揭示我国城市民生发展差异状况、探索协同提升对策提供了重要借鉴经验。     

Getting grey hairs in the labour market. An alternative experiment on age discrimination

This study presents a new field experimental approach for measuring age discrimination in hiring. In addition to the classical approach in which candidates’ ages are randomly assigned within pairs of fictitious résumés that are sent to real vacancies, we randomly assign between these pairs the activities undertaken by the older candidates during their additional post-educational years. When applying this design to the case of Belgium, we find that age discrimination depends fundamentally on the older candidates’ career patterns. Older age only robustly affects call-back if the older candidate was employed in an out-of-field job during his or her extra post-educational years.     

公民不服从与良知拒绝之关系探析

作为宪政的一个特例,公民不服从在稳定宪政制度方面的作用不容忽视。缘于公民不服从概念本身的模糊性,人们常或将公民不服从和与之有密切关系的良知拒绝相等同,或将二者完全割裂开来。从二者的思想源泉与概念解析出发,我们可得出二者之间的关系并非是非此即彼,而是同一概念的两个不同侧面。     

Difficult differences pave the creative road from diversity to performance

In this article, we argue that engagement with differences is important for the relationship between diversity and organizational performance. This importance is explained by the increased potential for creativity and innovation coming out of working in diverse teams. We recognize that difference and diversity can act as a double-edged sword for creativity and also contend that such differences are a fundamental condition for novelty and value to emerge. It is because of differences and not despite them that we create at individual, group, and organizational levels and a European approach to this topic – given Europe's history and philosophical traditions – recognizes the major role played of creative tensions and even conflict in innovation and in society more broadly. In this paper, we review literature that relates creativity and business performance, creativity, and diversity and examine the role of disagreement and tension, both conceptually and based on empirical evidence. We conclude by stressing the point that creativity often comes out of difficult differences, a European lesson that is easily forgotten, in Europe as well as globally.     

A genetic algorithm for assembly line balancing

Assembly line balancing is a very important aspect in any mass production setup. However, finding the optimal balance is a very difficult proposition because of the computational complexity involved. Hence sub-optimal solutions are preferred over optimal solutions. In this work, a genetic algorithm (GA) is presented for obtaining good quality solutions for assembly line balancing problems. A major feature of GA is the ability to take care of a variety of objective functions. A modified GA working with two populations, one of which allows infeasible solutions, and exchange of specimens at regular intervals is proposed for handling irregular search spaces. The experimental results obtained with a single population, as well as two populations are encouraging.     

Constructing 1-rotational NRDFs through an optimization approach: new (46,9,8), (51,10,9) and (55,9,8)-NRBDs

In this paper we formulate the problem of constructing 1-rotational near resolvable difference families as a combinatorial optimization problem where a global optimum corresponds to a desired difference family. Then, we develop an algorithm based on scatter search in conjunction with a tabu search to construct many of these difference families. In particular, we construct three new near resolvable difference families which lead to an equal number of new 1-rotational near resolvable block designs with parameters: (46,9,8), (51,10,9) and (55,9,8). Our results indicate that this conjunction outperforms both scatter search and tabu search.