Microstructure and mechanical properties of Co-28Cr-6Mo-0.22C investment castings by current solution treatment

This study examined the impact of current solution treatment on the microstructure and mechanical properties of the Co-28Cr-6Mo-0.22C alloy investment castings.The findings reveal that the current solution treatment significantly promotes the dissolution of carbides at a lower temperature.The optimal conditions for solution treatment are determined as a solution temperature of 1,125°C and a holding time of 5.0 min.Under these parameters,the size and volume fraction of precipitated phases in the investment castings are measured as6.2μm and 1.1vol.%.The yield strength,ultimate tensile strength,and total elongation of the Co-28Cr-6Mo-0.22C investment castings are 535 MPa,760 MPa,and 12.6%,respectively.These values exceed those obtained with the conventional solution treatment at 1,200°C for 4.0 h.The findings suggest a phase transformation of M_(23)C_(6)→σ+C following the current solution treatment at 1,125°C for 5.0 min.In comparison,the traditional solution treatment at 1,200°C for 4.0 h leads to the formation of M_(23)C_(6)and M_(6)C carbides.It is noteworthy that the non-thermal effect of the current during the solution treatment modifies the free energy of both the matrix and precipitation phase.This modification lowers the phase transition temperature of the M_(23)C_(6)→σ+C reaction,thereby facilitating the dissolution of carbides.As a result,the current solution treatment approach achieves carbide dissolution at a lower temperature and within a significantly shorter time when compared to the traditional solution treatment methods.

Research on Mechanism of Diversified Investment and Financing in Building Ecological Cities

Ecological city is the advanced mode of harmonious development of city. Constant improvement is being made in the development of ecological city. However, building ecological city is an enormous project that calls for a huge amount of capital. The government fund is far from adequate. This paper probes into the fund issue and discusses in detail the mechanism of investment and financing in building ecological city from various aspects such as diversification of the investment subjects and the modes of financing.

Competition vs cooperation:renewable energy investment under cap-and-trade mechanisms

This paper explores the incentives of investment in renewable energy of two utility firms who compete or cooperate under either a cap-and-trade grandfathering mechanism(GM)or benchmarking mechanism(BM).We find that utility firms will invest in renewable energy more under BM than under GM,in both competitive and cooperative markets,and they will invest more in a competitive market than in a cooperative market,under either GM or BM.Furthermore,utility firms will produce more electricity and generate more total carbon emissions under BM than under GM.The profits of two firms,however,are higher in cooperative market than in competitive market.The government will benefit from implementing a BM to encourage utility firms to invest in renewable energy in a competing market.

Design of the contingent royalty rate as related to the type of investment

This study investigates the design of the royalty rate in a first-price auction across three types of investments:incremental and lumpy with or without an exogenously given intensity.A bidder’s investment cost comprises private information.This,together with the stochastic evolution of the price of the output generated from the auctioned project,precludes the seller from setting the exact dates of investment with the winner.However,the seller can set the royalty rate to equate the winner’s royalty payment with the winner’s information rent so that the winner acts as if to maximize the seller’s revenue.We derive two main conclusions.First,compared with the case in which investment is lumpy with an exogenously given intensity,the seller can set a lower royalty rate on incremental investment because she can collect additional royalty payments from the winner,who has the option to later expand capacity.Second,the impact of output price uncertainty on the optimal royalty rate for the three types of investments exhibits two different patterns.When investment is either incremental or lumpy with an exogenously given intensity,greater output price uncertainty reduces the royalty rate.When investment is lumpy with variable intensity,greater output uncertainty raises the royalty rate.Our results imply that auctioneers may charge differential royalty rates for different types of investments.

Mechanical characterization of cp-Ti produced by investment casting

The influence of hot swaging（SW） and annealing treatment on microstructure and mechanical properties of commercially pure titanium produced by investment casting was evaluated.The as-cast samples showed a typical microstructure consisting of a variety of α-morphologies,while the hot swaged samples exhibited a kinked lamellar microstructure.Annealing at 500 °C did not significantly change this microstructure while annealing at 700 and 870 °C led to recrystallization and formation of equiaxed microstructures.The cast bars exhibited a typical hard α-layer in near-surface regions with a maximum depth and maximum hardness of 720 μm and HV0.5 660,respectively.Due to SW,the tensile strength of the as-cast material drastically increased from 605 MPa to 895 MPa.Annealing at 500 °C decreased the tensile strength slightly from 895 to 865 MPa while annealing at 700 °C led to a further pronounced drop in tensile strength from 865 to 710 MPa.No additional decrease in tensile strength was noticed with increasing the annealing temperature from 700 to 870 °C.The true fracture strain of the as-cast and hot swaged samples was in the range of 0.05 to 0.12,while the annealed samples showed values in the range of 0.25 to 0.53.In addition,the as-cast and hot swaged samples revealed a brittle cleavage fracture surfaces.However,the annealed samples showed a transgranular ductile fracture with formation of dimples.

Effects of Ag,Co,and Ge additions on microstructure and mechanical properties of Be-Al alloy fabricated by investment casting

The effects of Ag,Co,and Ge additions on microstructure and mechanical properties of Be-35Al(wt.%)alloys fabricated by investment casting were studied.The results reveal that the trace metals 1.5wt.%Ag,0.7wt.%Co,and 0.8wt.%Ge additions do not change the nucleation temperature of Be phase.However,the nucleation temperature of the Al phase decreases from 642℃ to 630℃ by DSC due to the Ge addition.The strength of the alloys sharply increases due to the dissolution of the Ag and Ge solutes into the Al phase and the Co into the Be phase characterized by SEM and EDS.Obviously,the strength of Be-Al-Ag-Co-Ge alloy is improved by the solution strengthening.Furthermore,a few Ag_(3) Al particles contribute to the strength of the Al phase.Be-Fe-Al ternary intermetallic compounds which can effectively reduce the negative effect of an impurity element Fe on the mechanical properties of Be-Al alloys are also found by XRD and EDS.

Study on the Establishment of a Long-effect Mechanism for China＇s Securities Investor Education

Investor education is not only one of the most important and fundamental institutional constructions at capital market, but also an important part of the cultural construction of capital market. At the present stage, the long-effect mechanism for investor education is not only a demand of China＇s securities market on its healthy development, but also an objective reality that China＇s investor education is necessary to confront with. For these reasons, it is necessary for China to deepen investor education, expand investor education platform, strengthen risk prevention, and take initiative to build up a multi-level investor education system, and ultimately establish and improve a long-effect mechanism for investor education, so as to ensure the stable, harmonious and order development of China＇s Securities market in futures.

Application research of centrifugal investment cast TiAl component used for advanced aircraft engine

A more complex structural component with small size and very thin walls and blades used for advanced aircraft engine was fabricated well by induction skull melting and centrifugal investment casting with a proper ceramic mold. The tensile elongation and ultimate strength of the hot isostatically pressed (HIPped) Ti 46.5Al 2.5V 1Cr (mole fraction, %) casting alloys are up to 2.5% and 645?MPa at room temperature, and 31% and 593?MPa at 800?℃. The fracture roughness at room temperature is up to 28?MPa·m 1/2 . The endurance tensile strength at 800?℃ for 150?h, is higher than 200?MPa. The high cycle rotary bending fatigue strengths for 1×10 7 cycles at room temperature and 800?℃ are 412?MPa and 270?MPa, respectively.

Tactics research of enterprise's manpower capital investment

In the era of knowledge-driven economy, the manpower capital is the most active factor of production and core of social economic development. This text proceeds with the concept of capital manpower, and probes into the importance of manpowe r capital investment to the survival and development of enterprises. In order to maximize the income of manpower capital investment, enterprises need to set up corresponding incentive mechanism to inspire the enthusiasm of manpower capital, and it is also the key factors that promoting the development modern economic a nd the enterprises’ success.

颠覆性技术多元化投入的利益分配及激励机制

我国颠覆性创新多元化投入机制的平台支撑体系建设亟待完善,因此需深入研究适用于颠覆性技术多元化投入的利益分配以及政府补贴机制。其中,公平的利益分配和合理化的激励机制是促使颠覆性技术多元投入有效性的关键因素。因此,针对颠覆性技术多元化投入利益分配以及激励机制设计等问题,采取合作-非合作博弈分析颠覆性技术多元投入的各个参与主体行为,引入风险因子探讨不同主体主导下的情况,并进一步研究政府补贴对各主体投入积极性的影响,进而以明晰多元化投入的激励机制方案选择。研究发现:在颠覆性创新多元化投入的过程中会存在创新投入积极性不足的情况,这是由于各主体出于自身利益最大化考虑;由政府牵头时,整个颠覆性技术投入合作较由其他主体主导下的合作收益高;在政府主导下采取政府补贴形式,可以有效激励其他各个颠覆性创新投入主体的积极性。为此,促进颠覆性创新的投入多元化,政府要构建多元化投入机制,设计合理的利益分配机制与激励机制,并在参与合作时设定恰当的成本补贴额度。

我国城市轨道交通既有线改造投融资机制研究

我国城市轨道交通现已进入从“增量扩张”向“存量优化”转型的新发展阶段,既有线改造的现实紧迫性催生了庞大的资金需求,同时对资金长期可持续提出更高要求,构建与既有线改造需求相适应和匹配的投融资机制对于保障我国城轨交通高质量发展具有重要价值。然而,既有线改造类型多样且利益主体复杂,目前实践层面缺乏统一且完整的指导规划,理论层面也亟需为投融资模式创新提供充分研究支撑。本文在总结伦敦、日本、北京、上海、深圳、天津等典型案例经验的基础上,结合项目的经济属性、周期属性、多主体特征,探究分级分类的投融资体系和实践思路,并构建财政补贴与激励协同、存量资产与新增投资互促融合的投融资机制。以期为完善既有线改造顶层设计、形成多主体协同且面向中长期的投融资机制体系提供参考与决策依据。

可再生能源投资的政企随机演化博弈研究——基于动态碳价视角

针对传统确定性演化博弈模型的不足,引入几何布朗运动模型模拟动态的碳价参数,构建了具有随机支付矩阵的演化博弈模型,以全国碳市场背景下的发电企业为例,研究了政企双方的演化过程和策略选择,探究了不同因素对演化均衡和政企决策的影响.结果显示:碳价是影响政企决策的重要因素,碳价较低时,政企的最优决策分别是选择作为策略即采取奖惩措施和不投资可再生能源,碳价较高时最优决策转变为不作为和投资.火力发电的成本、收益和碳排放系数以及可再生能源发电的成本、收益和建设成本是影响政府和发电企业策略选择的关键因素.发电企业投资意愿与政府的奖惩力度正相关,政府作为意愿与奖惩力度负相关,短期内提高政府的奖惩力度可激励发电企业的投资行为,但会缩短政府作为时长.

论强制调解于“一带一路”投资争端解决的适用

“一带一路”倡议实施十年间,沿线国直接投资数额显著增加、投资结构持续多元化,但也有若干项目由于投资者和当地政府矛盾而被迫中断。“一带一路”是和平之路、合作共赢之路,可以效仿国内法中的强制调解制度,通过引入程序上的强制性来扩大调解在投资者-东道国投资争端解决中的适用,发挥其比投资仲裁更为经济、灵活、有助于合作关系修复的优势。强制调解制度并不会改变调解作为ADR自愿性的本质特征,和解协议的达成仍取决于双方同意。“一带一路”投资争端解决引入强制调解制度时,应该选择适当的路径,明确适用范围,综合考虑磋商、仲裁、东道国法院诉讼等其他争端解决方式的优劣,通过程序规则衔接,着眼于一整套高效、灵活争端解决机制的构建。

国家文化公园投融资机制创新研究

建设国家文化公园,是一项宏大的系统文化工程,是我国促进传统文化资源保护、传承与弘扬的重大战略决策。此举对于建设社会主义文化强国、坚定文化自信具有深远而重大的意义。创新国家文化公园投融资机制,是国家文化公园高质量发展的内在要求。国家文化公园投融资机制创新需从强化政府主导、拓宽融资渠道、强化金融产品和服务创新、提升运营管理能力、完善法律制度体系等方面努力,形成新时代我国国家文化公园投融资机制创新的强大合力。

基于解雇威胁的股东与经理人非合作微分博弈模型研究

本文针对存在解雇威胁时公司股东与项目经理人之间的非合作问题,构建了两阶段连续时间下双方进行非合作博弈的微分对策模型。通过求解HJB方程得到了该博弈的均衡结果,运用“逆向归纳法”推导出经理人最优投资决策的表达形式,最后从理论推导和数值模拟两个方面分析了“解雇机制”对于经理人最优投资决策和最优努力的影响。研究表明:(1)当企业实物资本所占比例超过某一阈值时,初始资本的增加以及解雇概率的降低会提高经理人的投资积极性;当该比例低于阈值时,初始资本的增加会对经理人最优投资比例的选择产生负向影响,但随着解雇风险的上升,经理人会提高投资比例。(2)经理人所选择的再投资比例,会随着一定范围内企业实物资本所占比重的增加而逐渐降低。(3)解雇机制在参数设置满足约束条件的企业中能够有效激励经理人努力工作。

异质性数字化投入对制造业绩效的影响机理——基于文本分析的实证方法

基于2016-2021年制造业上市企业平衡面板数据,以异质性数字化投入为切入点,运用文本分析方法和面板回归模型,研究通用型数字化投入和专用型数字化投入对企业绩效的影响及作用机制。研究发现:第一,通用型数字化投入与企业绩效之间存在非线性关系(先上升再下降),且投入临界值为0.3678;第二,专用型数字化投入与企业绩效之间关系不显著;第三,管理效率优化是企业数字化投入作用于企业绩效的中间机制,在通用型数字化投入影响企业绩效的过程中发挥非线性中介传导作用,而商业模式创新在目前尚未发挥有效作用。研究结论表明,经过通用型数字化投入的“红利期”,其对企业绩效的正向影响呈递减趋势。

民办职业教育现状及经费投入体制机制创新研究

民办职业教育是我国教育体系的重要组成部分,为我国经济社会的发展培养了数千万技能型人才,在中国式现代化建设中发挥着人才培育功能。但我国民办职业教育的发展走深、走实、走远遇到了制约瓶颈。文章以民办职业教育与公办高职教育的经费投入比较为切入点,描述了民办职业教育的困境及当前教育经费分配现状,为给民办职业教育创造良好的投入机制,建议采取补贴或资助的方式对民办职业教育给予资助,建立民办职业教育奖补机制,以保障民办职业教育的教育教学水平。

基于中国重点城市生态环境政策的“污染天堂假说”准自然实验

为了揭示生态环境政策对投资的影响,在“双碳”目标下,基于“污染天堂假说”理论,选取2003—2020年全国287个地级市的面板数据,以是否为环境保护重点监控城市作为标准,将287个城市划分为控制组与对照组,分别构建了实证模型,开展了双重差分研究,并对双重差分结果进行了稳健性检验和异质性检验。结果表明:(1)实证模型的双重差分结果均具有稳健性。(2)环境规制对外商投资具有抑制作用;相较于非重点城市,环保重点城市的实际利用外资水平降低了0.125%。(3)环保重点城市中,东部城市受环保重点城市政策的影响较中西部城市的更为显著,且相比高污染城市,低污染城市的实际利用外资水平的下降幅度更大。

农村人居环境整治农民付费制度研究——以河南省为例

建设和运营资金保障不充分是影响农村人居环境整治效果的重要因素。农民作为农村人居环境整治的主要参与者和直接受益人,在农村人居环境整治中处于主体地位。探索农民付费制度是破解农村人居环境整治资金投入不足难题、健全长效管护机制的重要途径。本研究以河南省为例,基于典型案例调研和农户问卷调查,以农村改厕、农村污水处理、农村垃圾处理三大领域为重点,深入研究农村人居环境整治农民付费制度的可行性、实现方式及效果,系统总结农村人居环境整治农民付费制度的经验与问题,为完善农村人居环境整治农民付费制度、健全农村人居环境整治可持续性长效投入机制提供针对性建议。

产业政策对企业股价崩盘风险的影响及其作用机制

为进一步厘清宏观政策影响微观企业行为的作用机制,以2007—2021年我国A股上市公司为研究样本,采用固定效应模型分析产业政策对企业股价崩盘风险影响及其作用机制。结果表明,产业政策的鼓励显著降低了企业股价崩盘风险,且政策效应在非高科技行业、信息透明度低和机构投资者持股比例低的样本中更为显著。政府补助和信贷支持增加了股价崩盘风险,而税收优惠的影响不显著。产业政策对企业股价崩盘风险的影响主要通过企业投资效率和市场竞争这两个中介因素来实施,一方面,产业政策会降低企业投资效率,企业低效投资导致股价崩盘风险增高;另一方面,产业政策通过促进市场竞争降低企业股价崩盘风险。建议通过产业政策建立一个有效的产业政策资源减少和退出机制,引导企业合理、适度投资,营造有效竞争、良性竞争的市场环境,平衡政府补助、信贷支持与税收优惠等不同工具的使用,有效发挥公司信息透明度、高科技行业,以及机构投资者持股比例对产业政策实施效果的影响,以增强我国资本市场的内在稳定性,降低企业股价崩盘风险。