股权质押、盈余管理与审计师风险应对

基于2007—2018年我国A股1109家上市公司的数据,研究大股东股权质押、真实盈余管理与审计师风险应对之间的关系,探究真实盈余管理程度是否增强了大股东股权质押与审计师风险应对的正向关系。研究发现:大股东股权质押正向影响了审计费用和审计意见;真实盈余管理程度加剧了大股东股权质押后的负面效果,进而加强了大股东股权质押与审计费用间的正向关系,但对审计意见的影响不显著;进一步的研究发现:上期的审计费用反向助长了当期的股权质押率;存在大股东股权质押的上市公司,审计师出具非标准审计意见的概率会随审计费用的提高而加大。该结论扩展了审计师风险应对的研究范围及影响大股东股权质押的其他因素,对提高审计师风险应对及完善大股东股权质押政策具有一定的参考价值。     

家庭农场与其它农业经营组织的比较分析

家庭农场是以家庭组织为基础,以追求利润为目的,通过土地集中形成适度规模,实行商品化生产、集约化经营的新型农业经营组织。家庭农场在家庭经营、社会化生产、适度规模等方面有独特的内涵。文章对比分析了家庭农场与专业大户、农民专业合作社、农业企业等新型农业经营主体的异同。研究结果表明,家庭农场与专业大户相比,在家庭经营、土地规模、土地来源等方面有相似之处,在工商登记、制度规范化等方面区别较大。家庭农场与农民专业合作社在工商注册登记、适度规模经营方面相似,但两者在规模经营的前提条件、规模化途径、经营方式等方面存在较大差别。家庭农场与农业企业相比,都是国家积极培育的新型农业经营主体,但两者在组织形式、监督费用、分工水平、生产要素来源方面有明显不同。多种新型农业经营主体共存,并不矛盾,无高低优劣之分。国家鼓励发展多种形式的适度规模经营,本身就是一种较为灵活的制度创新。     

大动态PCM/FM信号的载波频率同步

针对大动态脉冲编码-频率调制（PCM/FM）遥测信号的载波频率同步，提出了基于快速傅里叶变换（FFT）及频谱重心的载波频率估计方法，并采用了频谱叠加及频谱截取的优化方法提高算法估计精度。相对于其他基于FFT的频率估计算法，频谱重心法有着更高的估计精度及更好的抗噪声性能，而且复杂度代价很小。仿真的均方误差结果表明，基于FFT长度为2 048和2块叠加以及保留信号99.9%能量的频谱截取方案有最好的估计性能。在最大多普勒频率、多普勒一阶变化率及二阶变化率分别为0.5倍、0.3倍及0.2倍符号率的大动态条件下，基于频谱重心法的二阶锁频环能够较好地完成载波频率跟踪。误码率曲线表明，经过频偏校正后的多符号非相干解调（MSD)性能与无频偏情况相比，无性能损失。     

混合梁桥大节段中跨钢梁吊装与合龙技术——以龙翔大桥为例

龙翔大桥主桥是采用大节段钢梁作为跨中结合段的大跨径双主跨刚构连续梁组合体系。依托龙翔大桥主桥施工提出一种新型提升系统，实现了悬臂梁施工、钢混结合段吊装、大节段跨中钢梁吊装3个施工阶段的快速转换。采用有限元法分析提升系统在施工各阶段的强度、刚度及稳定性验算，并与大节段跨中钢梁吊装时的位移实测数据进行对比，验证了提升系统能满足施工效率、安全和质量的要求，为类似桥梁在施工和合龙过程中提供了参考经验。     

近10年长江中下游典型水稻主产区种粮大户的 耕地承包规模变化研究 ——以江西省北部为例

研究目的：以长江中下游典型的水稻主产区江西省北部的南昌、九江、上饶等市辖区为研究区，研究近10年种粮大户耕地承包规模的时空变化及其影响因素。研究方法：Theil指数、空间自相关模型、地理探测器。研究结果：（1）与2011年相比，2021年耕地承包规模显著增加，种粮大户数量由6 298户增加到26 781户，耕地承包面积由138.2万亩增加为462.91万亩，耕地的大户承包率由10.94%提升至28.85%，但种粮大户的户均耕地承包面积由219.43亩减少为172.85亩。（2）Theil指数由2011年0.831 2下降至2021年0.610 7，表明研究区耕地承包规模的空间异质性显著，但空间异质性显著下降。（3）种粮大户的耕地承包规模呈现以鄱阳湖平原的高高集聚和两翼山地丘陵农业区低低集聚为主的空间集聚特征。（4）农业机械总动力、农业总产值、乡村人口和农村劳动力等是种粮大户耕地承包规模空间分异的主要原因，双因子交互作用能够更好地解释承包规模的空间分异。研究结论：在政府鼓励农村土地流转和发展农业适度规模经营的政策背景下，种粮大户的耕地承包规模受自然环境、农业发展水平及社会经济等要素的共同...     

钢筋混凝土箱梁廊桥受力分析与设计计算

随着学校、医院等场所的院区逐渐扩大,在连接院区内各个地块的桥梁形式中,廊桥被原来越多的设计师青睐。而钢筋混凝土廊桥其连廊自重大,受力复杂,故其设计和计算时需明确其受力特点,知晓其计算方法。本文以某简支钢筋混泥土箱梁廊桥为例,通过有限元软件建立全桥模型求解受力状态,并以现行规范的相关条文作为设计标准进行计算和受力分析。结果表明该桥均满足设计需求,并有一定安全保障。本文旨在为类似工程提供相关参考和计算思路。     

Second-language acquisition behavior and hegemonic language

We construct a game-theoretic model in which there are multiple countries with their own languages and each citizen can gain from additional communication in her secondarily acquired language. We demonstrate that in any equilibrium, a hegemonic language, which is a language that all citizens in other countries want to study, emerges. Such an equilibrium is more likely to exist if the size of the population of a country that is not the largest increases, or if the ratio of the gain from the additional communication in the second language to the cost of acquisition increases.     

超大型基坑与地下隧道群相互影响研究

为了解决城市复杂地下结构群之间相互影响的工程难题，依托深圳某预建商业建筑基坑和地下规划交通隧道工程，对基坑与隧道群相互影响力学行为以及考虑建筑附加荷载作用下下穿隧道管片配筋设计进行研究。采用有限元计算软件建立基坑与规划交通隧道群三维数值模型和高铁隧道管片配筋荷载-结构模型，分析管片内力、基坑结构位移等指标，评价基坑与地下隧道群的相互影响。结果表明：1)在现有基坑桩-筏板基础结构设计情况下，管片内力变化幅度最大为10.85%,对后期交通隧道近接建筑基坑的影响较小；2)地下规划交通隧道施工过程中对基坑结构位移影响有限，隧道开挖后桩基础最大水平位移为1.36 mm,竖向沉降为2.44 mm,筏板基础最大水平位移为0.41 mm,竖向沉降为2.40 mm; 3)在建筑附加荷载作用下，隧道管片最大内力出现在拱顶内侧和拱腰外侧，考虑弯矩传递系数ξ时隧道管片配筋需要加强。研究成果优化了既有桩基础影响下的隧道结构配筋，可以为城市复杂隧道群的设计与施工提供参考。     

Large lending and banks performance. Is there any relationship? Empirical evidence from US banks

Large lending in the banking industry has sparked concerns about banks’ efficiency performance, particularly, if it is related to their credit risk, as trade credit, provided by large, creditworthy firms. We provide evidence of a rather neglected issue regarding the impact of large lending on banks’ efficiency using cost and profit stochastic functions. A unique dataset was constructed concerning all US banks collected from the Statistics on Depository Institutions report compiled by the Federal Deposit Insurance Corporation. Our sample contains US banks tracked yearly for the period 2010–2017, creating an unbalanced panel of year observations. An econometric framework based on nested non-neutral frontiers was developed to estimate the influence and the decomposition of large lending on the three banks’ performance aspects. Moreover, different types of frontiers aiming at the cost and profit sides have been investigated, and the associated elasticities have been calculated. We notice that large lending plays a crucial role in banks’ technical efficiency. Variations among different frontier models, type of bank and size, banks’ ownership structure, and macroeconomic conditions appear to be present. By considering all capital adequacy asset quality management earnings liquidity parameters, we notice that banks’ financial strength affects banks’ efficiency.     

Firm size-specific trade effects of regional trade agreements: Estimating extensive and intensive margins of trade

We estimate the impacts of Korean firms’ participation in regional trade agreements (RTAs) on the extensive and intensive export margins by identifying exporting firms based on their firm size—small and medium-sized enterprises (SMEs) and large enterprises (LEs) at the 5 399 HS six-digit commodity level—and specifying characteristics of RTAs from 2004 to 2015. We apply the EK Tobit estimation technique to control zero trade and the OLS estimation with importer-product and time fixed effects to alleviate the endogeneity problem. We find that firm size, product type, and depth of RTA significantly matter. Specifically, we find that deeper RTAs with larger, developing, and closer members significantly enhance the export creation effects of SMEs and LEs. Regarding the firm size-specific effects, we find that SMEs are less sensitive to exploiting RTA participation but more sensitive to the import market size, bilateral and relative trade costs, and the RTA characteristics. LEs’ export creation is mainly driven by the intensive margin, while SMEs’ export creation is driven by extensive and intensive margins (slightly more by the extensive margin). For the product-specific effects, we find that Korea's major exportable products such as chemicals, basic metals, motor vehicles, and transport equipment generate significantly strong export creation effects for both LEs and SMEs through their participation in RTAs.