A1—10%Pb—钢双金属材料水平连铸复合结晶器的选用

本文从冷却速度及其对连铸复合材料组织和性能的影响的角度分析所选择的结晶器材料的适用性,在此基础上,选用了石墨结晶器外加水冷铜套的连铸复合系统来生产Al—10％Pb—钢双金属材料,并定量地给出了石墨结晶器上下型的主要尺寸。     

热膨胀对超静定轴的固有横振的频率影响

采用新的近似法研究了热膨胀对超静定轴固有横振频率的影响。     

8mm三次谐波复合腔回旋管研究

对８ｍｍ波段三次谐波复合腔回旋管进行了系统研究。对具有模式转换段的复合腔的特性进行了数值优化计算，在三次回旋谐波下，对电子注与复合腔中的场的互作用进行了非线性自洽数值模拟。设计并研制了三次谐波复合腔回旋管，在注电压Ｖｂ＝４３ｋＶ与磁场４．５ｋＧ下，得到脉冲输出动率大于５０ｋｗ，互作用电子效率为１２％的结果。     

高能重离子碰撞末态分布的探讨

应用流体动力学模型,分别采用包含相变的状态方程和不含相变的状态方程,计算了每对核子能量为100GeV~(197)Au—~(197)Au 碰撞的末态碎裂时空分布、末态快度分布,并分析讨论了影响末态分布的因素.     

唯一远达点和极大化序列的收敛性

本文主要讨论唯一远达点和极大化序列的收敛性，即给出如下定理：设X具（H）性质且为严格凸的Banach空间，K是X中弱M紧集，Fk(x)在X上fr■chet可微，则是X中的稠G_δ集。     

On the Advantage of Quantity Leadership When Outsourcing Production to a Competitive Contract Manufacturer

This study investigates a supply chain comprising an original equipment manufacturer (OEM) and a contract manufacturer (CM), in which the CM acts as both upstream partner and downstream competitor to the OEM. The two parties can engage in one of three Cournot competition games: a simultaneous game, a sequential game with the OEM as the Stackelberg leader, and a sequential game with the CM as the Stackelberg leader. On the basis of these three basic games, this study investigates the two parties' Stackelberg leadership/followership decisions. When the outsourcing quantity and wholesale price are exogenously given, either party may prefer Stackelberg leadership or followership. For example, when the wholesale price or the proportion of production outsourced to the CM is lower than a threshold value, both parties prefer Stackelberg leadership and, consequently, play a simultaneous game in the consumer market. When the outsourcing quantity and wholesale price are decision variables, the competitive CM sets a wholesale price sufficiently low to allow both parties to coexist in the market, and the OEM outsources its entire production to this CM. This study also examines the impact of the supply chain parties' bargaining power on contract outcomes by considering a wholesale price that is determined via the generalized Nash bargaining scheme, finding a Stackelberg equilibrium to be sustained when the CM's degree of bargaining power is great and the non‐competitive CM's wholesale price is high.     

Land‐Price Dynamics and Macroeconomic Fluctuations

We argue that positive co‐movements between land prices and business investment are a driving force behind the broad impact of land‐price dynamics on the macroeconomy. We develop an economic mechanism that captures the co‐movements by incorporating two key features into a DSGE model: We introduce land as a collateral asset in firms' credit constraints, and we identify a shock that drives most of the observed fluctuations in land prices. Our estimates imply that these two features combine to generate an empirically important mechanism that amplifies and propagates macroeconomic fluctuations through the joint dynamics of land prices and business investment.     

数字经济、人工智能制造与劳动力错配

文章基于2013—2019年中国30个省份的面板数据,先运用模拟退火优化投影寻踪模型测算中国数字经济发展指数,再采用双向固定效应模型和广义空间两阶段最小二乘法验证数字经济和人工智能制造对劳动力资源错配的影响效应。结果表明,2013—2019年我国数字经济发展水平整体呈现稳中有进的趋势,年均增速为11.8%。尽管数字经济发展先行区主要位于东部沿海地区,但近年来西部地区各省份年均增速较高,已形成"东部领跑,西部追赶"的空间分异格局。数字经济能显著缓解劳动力错配,人工智能制造在其中发挥着重要的中介作用,这一结论经过稳健性检验后依然成立。     

WEF全球竞争力评价体系下中美国家制度竞争力比较研究——基于WEF数据的实证分析

中国国家竞争力的提升与35年来改革开放即制度建设密不可分。改革极大地改变了我国宏观制度环境,也是促进我国制度竞争力提升进而提高我国国家竞争力水平的重要因素。文章以国家竞争力理论为基础,基于WEF建立的全球竞争力评价体系和相关数据,在对比分析中美制度竞争力发展现状和历史回顾的基础上,运用灰色关联度方法进一步对影响中美两国制度竞争力各因素的强弱、大小和次序进行实证分析,发现中国不仅在私人制度竞争力方面与美国相比差距明显,而且影响两国制度竞争力各因素的关联度也存在明显差异。     

基于化学镀银法制备尼龙6/银复合材料

为增加尼龙基体和银镀层之间的界面结合力,将机械打磨引入到传统的化学镀工艺中,并利用 无毒、环保的葡萄糖溶液作为施镀过程中的还原剂,代替传统化学镀中常用的甲醛溶液,快速制备了尼 龙6/银复合材料。利用X射线衍射（XRD）、扫描电子显微镜（SEM）分别对尼龙6/银复合材料的物相及显 微形貌进行了表征;并研究了化学镀工艺对施镀过程的影响,着重研究了施镀温度、施镀时间、硝酸银 溶液（主盐）浓度及葡萄糖溶液（还原剂）浓度对银镀层厚度的影响。结果表明,银镀层的厚度随着硝 酸银浓度、葡萄糖浓度、施镀时间、施镀温度的升高整体呈先增大后减小的趋势。过高的施镀温度、硝 酸银浓度及葡萄糖浓度会使镀液中的还原反应速率过快,不利于银粒子在尼龙6基材上的沉积,从而引起 银镀层厚度的下降;过长的施镀时间会使银镀层表面出现很多划痕,从而导致银镀层质量的下降。通过 优化施镀工艺参数,得到银镀层厚度可控的尼龙6/银复合材料。