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Exploring Patent Effects on Higher Stock Price and Stock Return Rate-A Study in China Stock Market 被引量:1
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作者 Hong-Wen Tsai Hui-Chung Che Bo Bai 《Chinese Business Review》 2021年第5期168-180,共13页
Based on the valid patent data and stock price data of China A-shares,the patent effects of four patent species including the invention publication,the invention grant,the utility model grant,and the design grant,on t... Based on the valid patent data and stock price data of China A-shares,the patent effects of four patent species including the invention publication,the invention grant,the utility model grant,and the design grant,on the stock price and the stock return rate were analyzed via analysis of variance(ANOVA).It was proved that the A-shares having new patents of any patent species shown the higher stock price mean and the higher stock return rate mean than those A-shares having no new patents did.The A-shares having new design grants were found to show the highest stock price mean among the A-shares having new patents of any patent species.The A-shares in the group of top 25%patent count of either the invention publication or the invention grant shown the highest stock return rates mean than those A-shares in other groups of less patent count did.The invention grant,following the general concept,showed its excellent patent effect.The design grant,beyond the expectation,also showed patent effects on the higher stock price and the higher stock return rate.The finding would improve the state of the art in the patent valuation and the listing company evaluation. 展开更多
关键词 patent species stock price stock return rate ANOVA A-share
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Effective Return Rate Prediction of Blockchain Financial Products Using Machine Learning
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作者 K.Kalyani Velmurugan Subbiah Parvathy +4 位作者 Hikmat A.M.Abdeljaber T.Satyanarayana Murthy Srijana Acharya Gyanendra Prasad Joshi Sung Won Kim 《Computers, Materials & Continua》 SCIE EI 2023年第1期2303-2316,共14页
In recent times,financial globalization has drastically increased in different ways to improve the quality of services with advanced resources.The successful applications of bitcoin Blockchain(BC)techniques enable the... In recent times,financial globalization has drastically increased in different ways to improve the quality of services with advanced resources.The successful applications of bitcoin Blockchain(BC)techniques enable the stockholders to worry about the return and risk of financial products.The stockholders focused on the prediction of return rate and risk rate of financial products.Therefore,an automatic return rate bitcoin prediction model becomes essential for BC financial products.The newly designed machine learning(ML)and deep learning(DL)approaches pave the way for return rate predictive method.This study introduces a novel Jellyfish search optimization based extreme learning machine with autoencoder(JSO-ELMAE)for return rate prediction of BC financial products.The presented JSO-ELMAE model designs a new ELMAE model for predicting the return rate of financial products.Besides,the JSO algorithm is exploited to tune the parameters related to the ELMAE model which in turn boosts the classification results.The application of JSO technique assists in optimal parameter adjustment of the ELMAE model to predict the bitcoin return rates.The experimental validation of the JSO-ELMAE model was executed and the outcomes are inspected in many aspects.The experimental values demonstrated the enhanced performance of the JSO-ELMAE model over recent state of art approaches with minimal RMSE of 0.1562. 展开更多
关键词 Financial products blockchain return rate prediction model machine learning parameter optimization
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Optimization of Pension Asset Portfolio in Nigeria with Contributors’ Specified Return Rate
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作者 Bright O. Osu Godswill A. Egbe 《Open Journal of Optimization》 2016年第4期103-119,共17页
This work focuses on the optimization of investment contributions of pension asset with a view to improving contributors’ participation in achieving better return on investment (RoI) of their funds. We viewed some ne... This work focuses on the optimization of investment contributions of pension asset with a view to improving contributors’ participation in achieving better return on investment (RoI) of their funds. We viewed some new regulations on Nigeria’s Contributory Pension Scheme” (CPS) from amended legislation of 2014, some of which are yet to be implemented when their regulations are approved. A mathematical model involving 5 variables, 5 inequality constraints covering regulatory limitations and limitation on scarce resource known as Asset Under Management (AUM), suggested and mathematically shown to be possible through “maximization of return irrespective of risk” while obeying all regulatory controls as our constraints optimized. Optimized portfolio using MatLab shows that the portfolio representing AES 2013 portfolio with a deficit growth of 15.75 m representing 3.27% less than the portfolio’s full growth potential within defined assumptions would have been averted if contributors actually set their targets and investment managers optimize from forecasts of future prices using trend analysis. 展开更多
关键词 Optimization Portfolio Contributory Pension Scheme return rate Pension Reform
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Does the Shanghai-Hong Kong Stock Connect Program Enhance the Abnormal Rate of Return and Transaction Volatility of the Underlying Stocks:A Quasi-Natural Experimental Design
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作者 Puzhen He Zhehao Zhu 《经济管理学刊(中英文版)》 2021年第1期53-62,共10页
Shanghai-Hong Kong Stock Connect Program,which is a new starting point for the opening up of the mainland capital market,still has many uncertainties.Research on the benefits and market volatility of such policies can... Shanghai-Hong Kong Stock Connect Program,which is a new starting point for the opening up of the mainland capital market,still has many uncertainties.Research on the benefits and market volatility of such policies can provide investors with time to invest in such policies,fluctuations in the underlying stocks of the Chinese stock market,and decision support for the formulation and revision of relevant policies.This paper studies whether there is significant abnormal rate of return in the selected stocks which are in the Shanghai Stock Connect Program within the specified period,the excess return gap between the stocks which are in the program and which are not in the program,and the impact of the Shanghai Stock Connect Program on the volatility of the relevant stocks.Based on the CAPM model and the Fama-French 3-factor model,this paper uses t test to study the significance of the abnormal rate of return.By establishing a difference-in-difference(DID)model,the regression of the abnormal rate of return is tested,and the sample volatility is analyzed according to the influence of the fund transaction.The study found that the stocks in the program have significant abnormal rate of returns during the window period.The Shanghai Stock Connect has brought about a huge change in transaction amount,and policy makers need to improve related and similar policies. 展开更多
关键词 Shanghai Stock Connect Program Abnormal rate of return DID Model Event Study
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Return to sport following tibial plateau fractures: A systematic review 被引量:11
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作者 Greg A J Robertson Seng J Wong Alexander M Wood 《World Journal of Orthopedics》 2017年第7期574-587,共14页
AIM To systemically review all studies reporting return to sport following tibial plateau fracture, in order to provide information on return rates and times to sport, and to assess variations in sporting outcome for ... AIM To systemically review all studies reporting return to sport following tibial plateau fracture, in order to provide information on return rates and times to sport, and to assess variations in sporting outcome for different treatment methods.METHODS A systematic search of CINAHAL, Cochrane, EMBASE, Google Scholar, MEDLINE, PEDro, Scopus, SPORTDiscus and Web of Science was performed in January 2017 using the keywords "tibial", "plateau", "fractures", "knee", "athletes", "sports", "non-operative", "conservative", "operative", "return to sport". All studies which recorded return rates and times to sport following tibial plateau fractures were included. RESULTS Twenty-seven studies were included: 1 was a randomised controlled trial, 7 were prospective cohort studies, 16 were retrospective cohort studies, 3 were case series. One study reported on the outcome of conservative management(n = 3); 27 reported on the outcome of surgical management(n = 917). Nine studies reported on Open Reduction Internal Fixation(ORIF)(n = 193), 11 on Arthroscopic-Assisted Reduction Internal Fixation(ARIF)(n = 253) and 7 on Frame-Assisted Fixation(FRAME)(n = 262). All studies recorded "return to sport"rates. Only one study recorded a "return to sport" time. The return rate to sport for the total cohort was 70%. For the conservatively-managed fractures, the return rate was 100%. For the surgically-managed fractures, the return rate was 70%. For fractures managed with ORIF, the return rate was 60%. For fractures managed with ARIF, the return rate was 83%. For fractures managed with FRAME was 52%. The return rate for ARIF was found to be significantly greater than that for ORIF(OR 3.22, 95%CI: 2.09-4.97, P < 0.001) and for FRAME(OR 4.33, 95%CI: 2.89-6.50, P < 0.001). No difference was found between the return rates for ORIF and FRAME(OR 1.35, 95%CI: 0.92-1.96, P = 0.122). The recorded return time was 6.9 mo(median), from a study reporting on ORIF.CONCLUSION Return rates to sport for tibial plateau fractures remain limited compared to other fractures. ARIF provides the best return rates. There is limited data regarding return times to sport. Further research is required to determine return times to sport, and to improve return rates to sport, through treatment and rehabilitation optimisation. 展开更多
关键词 TIBIAL PLATEAU Fracture KNEE return SPORT rate Time
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The efficiency of long-term straw return to sequester organic carbon in Northeast China's cropland 被引量:24
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作者 WANG Shi-chao ZHAO Ya-wen +5 位作者 WANG Jin-zhou ZHU Ping CUI Xian HAN Xiao-zeng XU Ming-gang LU Chang-ai 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2018年第2期436-448,共13页
Black soil is one of the most precious soil resources on earth because it has abundant carbon stocks and a relatively high production capacity. However, decreasing organic matter after land reclamation, and the effect... Black soil is one of the most precious soil resources on earth because it has abundant carbon stocks and a relatively high production capacity. However, decreasing organic matter after land reclamation, and the effects of long-term inputs of organic carbon have made it less fertile black soil in Northeast China. Straw return could be an effective method for improving soil organic carbon(SOC) sequestration in black soils. The objective of this study was to evaluate whether straw return effectively increases SOC sequestration. Long-term field experiments were conducted at three sites in Northeast China with varying latitudes and SOC densities. Study plots were subjected to three treatments: no fertilization(CK); inorganic fertilization(NPK); and NPK plus straw return(NPKS). The results showed that the SOC stocks resulting from NPKS treatment were 4.0 and 5.7% higher than those from NPK treatment at two sites, but straw return did not significantly affect the SOC stocks at the third site. Furthermore, at higher SOC densities, the NPKS treatment resulted in significantly higher soil carbon sequestration rates(CSR) than the NPK treatment. The equilibrium value of the CSR for the NPKS treatment equated to cultivation times of 17, 11, and 8 years at the different sites. Straw return did not significantly increase the SOC stocks in regions with low SOC densities, but did enhance the C pool in regions with high SOC densities. These results show that there is strong regional variation in the effects of straw return on the SOC stocks in black soil in Northeast China. Additional cultivations and fertilization practices should be used when straw return is considered as an approach for the long-term improvement of the soil organic carbon pool. 展开更多
关键词 soil organic carbon(SOC) SOC stock straw return soil sequestration rate straw-C sequestration efficiency black soil long-term experiments
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Optimizing Nutrient Use Efficiency and Returns from Soybean Production under Smallholders in Three Agro-Ecologies of Malawi 被引量:1
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作者 Moses Munthali Patson Nalivata +5 位作者 Wilkson Makumba Emmanuel Mbewe Hastings Manase George Oduor Martin Macharia Kaizzi Kayuki 《Agricultural Sciences》 2017年第8期801-815,共15页
Field trials were conducted to determine the economically optimum fertilizer rates for soybean production and for optimizing net profits in Dedza, Lilongwe and Salima Districts of Malawi. The effects of PK fertilizer ... Field trials were conducted to determine the economically optimum fertilizer rates for soybean production and for optimizing net profits in Dedza, Lilongwe and Salima Districts of Malawi. The effects of PK fertilizer rates on rain use efficiency (RUE), harvest index, agronomic use efficiency of phosphorous (AEP) and potassium (AEK), and value cost ratio (VCR) were evaluated. The applied diagnostic PK fertilizer rates significantly improved soybean grain yields, harvest index, rainwater use efficiency, AEP, AEK and returns to fertilizer use expressed as value cost ratio (VCR). However, the results differed significantly 展开更多
关键词 SOYBEAN Net returns Economically OPTIMUM rates AGRONOMIC Use Efficiency of Phosphorous and POTASSIUM NUTRIENT Combination Value Cost Ratio
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Is the Limit of Four Times the Primary Interest Rate of Loan Reasonable
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作者 HU Yuan-cheng 《当代财经》 CSSCI 北大核心 2013年第S1期57-68,共12页
On the basis of the observation of the real earnings rates and the debt repayment ability of China’s enterprises,considering the maintenance of the normal order of the borrowing and lending markets,this paper believe... On the basis of the observation of the real earnings rates and the debt repayment ability of China’s enterprises,considering the maintenance of the normal order of the borrowing and lending markets,this paper believes that a 20 percent level of interest rate or rate of return is a suitable cutoff point for the up limit,which is in line with China’s conditions.For this reason,we recommend that the primary interest rate of three times of the loan should be adopted to determine the up limit of annual rate of private borrowing and lending allowed by policy,this is relatively consistent with China’s current reality. 展开更多
关键词 private BORROWING and LENDING PRIMARY interest rate return on assets debt REPAYMENT ability
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Effect of Macro Factor Volatility on the Returns of Financial Sector in Southeast Asian Stock Markets
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作者 Siriwun Wongsrida Prasert Chaitip 《Chinese Business Review》 2014年第1期28-33,共6页
The emphasis of this study is on the practice of the Pooled Mean Group (PMG) estimators to investigate the magnitude of macroeconomic performances: Real Gross Domestic Product (RGDP), Foreign Exchange Rate (EX)... The emphasis of this study is on the practice of the Pooled Mean Group (PMG) estimators to investigate the magnitude of macroeconomic performances: Real Gross Domestic Product (RGDP), Foreign Exchange Rate (EX), and Deposit Interest Rate (DINT) affecting on the rate of financial sector returns in Southeast Asian Stock Markets including Stock Exchange Of Thailand (SET) index (Thailand), the Kuala Lumpur Composite Index (KLSE) index (Malaysia), Financial Times Share Index (FTSI) (Singapore), Philippine Stock Exchange (PSE), and the Jakarta Composite Index (JKSE) (Indonesia). The Panel Autoregressive Distributed Lag (Panel ARDL) is applied to model the relations. The study applies the Levin, Lin, and Chu (LLC) test (2002) and Im, Pesaran, and Shin (IPS) test (2003) to investigates a set of time series data to examine whether the determinants and the rate of financial sector returns contain a unit root, the next step is investigated the cointegration and causality relationship of the determinants of financial sector influencing on long-run rate of returns of financial sector in Southeast Asian Stock Markets. 展开更多
关键词 rate of returns financial sector Southeast Asian Stock Markets panel unit root Panel AutoregressiveDistributed Lag (Panel ARDL)
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组合式稻麦兼用播种开沟器设计与试验
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作者 臧英 罗锋 +3 位作者 黄子顺 姜有聪 李嘉琦 张明华 《农业工程学报》 北大核心 2025年第19期42-53,共12页
为了减小双圆盘开沟器工作阻力,改善种沟沟底不平整、沟壁倾斜不合适的问题,从而为稻麦种子提供更适宜的种床环境,该研究结合切割挤压及滑切原理,设计了一种组合式稻麦兼用播种开沟器,利用双圆盘开沟部件与滑切部件协同配合开出种沟。首... 为了减小双圆盘开沟器工作阻力,改善种沟沟底不平整、沟壁倾斜不合适的问题,从而为稻麦种子提供更适宜的种床环境,该研究结合切割挤压及滑切原理,设计了一种组合式稻麦兼用播种开沟器,利用双圆盘开沟部件与滑切部件协同配合开出种沟。首先,通过理论分析确定了开沟器的关键结构参数;其次,基于EDEM仿真软件,结合土槽试验验证构建了开沟器高可靠性仿真模型;随后,采用EDEM软件进行开沟过程仿真试验,以工作阻力、回土率及土壤扰动宽度为试验指标开展单因素试验,得到各关键参数的取值范围;最后,通过Box-Behnken正交组合仿真试验,得出开沟器的最优参数组合为:圆盘夹角16°、入土角40°、竖直距离14 mm;以此参数组合进行土槽试验,明确了开沟器工作阻力为105.5 N,回土率为41.3%,土壤扰动宽度为108 mm,相较于稻麦轮作区常用双圆盘开沟器,工作阻力减小了13.74%,回土率增加了20.41%,土壤扰动宽度减小了6.25%。播种试验进一步表明,所设计的开沟器作业效果满足稻麦播种农艺要求。 展开更多
关键词 农业机械 开沟器 稻麦兼用 工作阻力 回土率
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货币政策有效性变化的新解释——基于宏观经济结构的新视角
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作者 陈小亮 刘沁璇 《南开经济研究》 北大核心 2025年第8期104-126,共23页
近年来,中国货币政策有效性有待提高,亟需找出货币政策传导机制中的堵点、卡点,并提出有针对性的应对策略。已有研究主要从央行和货币政策本身入手,寻找货币政策有效性有待提高的原因。本文从宏观经济结构这一新视角出发,为货币政策有... 近年来,中国货币政策有效性有待提高,亟需找出货币政策传导机制中的堵点、卡点,并提出有针对性的应对策略。已有研究主要从央行和货币政策本身入手,寻找货币政策有效性有待提高的原因。本文从宏观经济结构这一新视角出发,为货币政策有效性变化提供了新解释。本文基于1996年一季度至2022年四季度的宏观数据进行实证研究,发现宏观经济结构失衡是近年来中国货币政策有效性变化的重要原因之一,而且宏观经济结构失衡主要削弱了货币政策对企业投资而非居民消费的影响。机制检验表明,宏观经济结构失衡会通过资本回报率机制、潜在增速机制、企业家信心机制,削弱货币政策有效性,尤其是货币政策拉动企业投资的有效性。具体而言,宏观经济结构失衡会通过降低资本回报率来减少企业投资意愿,通过降低潜在增速来降低企业投资倾向,通过削弱企业家信心来削弱企业投资信心,最终削弱货币政策有效性。要想完成党的二十届三中全会《决定》提出的“畅通货币政策传导机制”重要任务,需要加强对结构政策的使用,推动宏观经济结构向最优状态靠拢,以缓解宏观经济结构失衡对货币政策传导机制的阻碍。 展开更多
关键词 货币政策有效性 宏观经济结构 资本回报率 潜在增速 企业家信心
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Calculation and analysis of the number of return photons from sodium laser beacon excited by the long pulse laser with circular polarization
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作者 刘向远 钱仙妹 +1 位作者 李玉杰 饶瑞中 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第12期240-248,共9页
The number of return photons from sodium laser beacon(SLB) greatly suffers down-pumping, recoil, and geomagnetic field when the long pulse laser with circular polarization interacts with sodium atoms in the mesosphe... The number of return photons from sodium laser beacon(SLB) greatly suffers down-pumping, recoil, and geomagnetic field when the long pulse laser with circular polarization interacts with sodium atoms in the mesosphere. Considering recoil and down-pumping effects on the number of return photons from SLB, the spontaneous radiation rates are obtained by numerical computations and fittings. Furthermore, combining with the geomagnetic field effects, a new expression is achieved for calculating the number of return photons. By using this expression and considering the stochastic distribution of laser intensity in the mesosphere under different turbulence models for atmosphere, the number of return photons excited by the narrow-band single mode laser and that by the narrow-band three-mode laser are respectively calculated. The results show that the narrow-band three-mode laser with a specific spectrum structure has a higher spontaneous radiation rate and more return photons than a narrow-band single mode laser. Of note, the effect of the atmospheric turbulence on the number of return photons is remarkable. Calculation results indicate that the number of return photons under the HV5/7 model for atmospheric turbulence is much higher than that under the Greenwood and Mod HV models. 展开更多
关键词 sodium laser beacon spontaneous radiation rates the number of return photons down-pumping recoil geomagnetic field
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富油煤原位热解U型水平井产能预测:试验与数值模拟 被引量:4
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作者 东振 陈艳鹏 +8 位作者 张梦媛 王兴刚 焦立新 冯烁 任博 陈浩 薛俊杰 赵宇峰 黄蝶芳 《煤炭学报》 北大核心 2025年第2期1175-1191,共17页
“双碳”目标下“取氢留碳”成为煤炭清洁利用的必然选择,煤炭原位热解为国内油气增产提供了新思路,科学预测富油煤原位热解产能对于项目经济性和能量回报率评估至关重要。目前针对中深层富油煤原位热解的研究较少,考虑真实围压条件的... “双碳”目标下“取氢留碳”成为煤炭清洁利用的必然选择,煤炭原位热解为国内油气增产提供了新思路,科学预测富油煤原位热解产能对于项目经济性和能量回报率评估至关重要。目前针对中深层富油煤原位热解的研究较少,考虑真实围压条件的块煤热解试验尚未见到报道,为预测中深层富油煤原位热解产能、查明油气生产规律,提出基于中深层煤炭原位热解特点的水平井开发方式,开展了三塘湖盆地2套主力煤层的块煤覆压热解试验,建立了基于Boltsmann函数的八道湾组富油煤覆压热解产率评价模型和U型水平井产能预测方法,并对油气产能变化规律、能量回报率进行了讨论。结果表明:①煤炭原位热解具有资源丰度高、气体产物清洁低碳、地质风险小等优势,U型、L型、多分支水平井可采用间歇或连续方式生产。②八道湾组煤比西山窑组煤具有更高的焦油和煤气产率,焦油在400~500℃时产量达到峰值,围压具有降低热解产物传质能力的负面作用和提高传热效率的正向作用,温度低于400℃时负面作用占据主导,随着温度升高,正向作用逐渐占据主导。煤气在300~400℃时产量快速增大,400~600℃时产量增速减缓,600℃后产量快速降低,煤气中H_(2)和CO随温度增加单调递增,CH_(4)和CO_(2)随温度先增后减,施加围压后更有利于八道湾组煤的煤气生产。③富油煤热解产物产率随温度增加呈现“缓慢增大—快速增大—趋于平稳”的S形变化规律,Boltsmann函数能够较好的拟合富油煤热解产物产率变化规律,直线形和三角形井网分别形成类矩形和类圆形的温度场,井间煤层达到有效热解温度(350℃)所需的水平井井距分别为4.5、5.5 m,三角形井网的加热效果优于直线形井网。④油气产能分为“初期低产、中期快速上产、后期稳产”3个阶段,按照煤的导热系数为1 W/(m·℃)预测,单口U型井生产5 a的焦油、CH_(4)、H_(2)产能有望达到1.56×10^(4)t/a、260.21×10^(4)m^(3)/a和201.83×10^(4)m^(3)/a,能量回报率能达到2.09,热解水和焦油在热解产物中质量比最大、产能最先企稳,煤气中CH_(4)和CO_(2)质量比最高,CO_(2)随生产年限先增后降,CO和H_(2)随生产年限单调递增,加热后期的产能贡献主要来自于煤气中CO和H_(2)。⑤等热值情况下,煤炭原位热解相比地面煤燃烧减碳97%,理想情况下热解产生的CO_(2)能够通过半焦层吸附埋存以实现自身“碳中和”。总体来看,煤炭原位热解具备规模发展的资源基础、技术可行性以及良好的经济前景,是一项具有发展潜力的化石能源清洁低碳开发新技术。 展开更多
关键词 煤炭原位热解 富油煤 水平井 产能预测 能量回报率
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公路交通运输温室气体自愿减排项目可行性决策模型及流程
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作者 朱立伟 周炜 +2 位作者 李枭 柴华 汤筠筠 《公路交通科技》 北大核心 2025年第9期195-202,共8页
【目标】为促进公路交通运输业户积极参与温室气体自愿减排项目设计及交易,助力公路交通领域降低碳排放,对公路交通运输温室气体自愿减排项目可行性决策及交易流程进行研究。【方法】基于温室气体自愿减排交易系统要素和特征,提出了以... 【目标】为促进公路交通运输业户积极参与温室气体自愿减排项目设计及交易,助力公路交通领域降低碳排放,对公路交通运输温室气体自愿减排项目可行性决策及交易流程进行研究。【方法】基于温室气体自愿减排交易系统要素和特征,提出了以公路交通运输温室气体自愿减排项目行业基准收益率(R_(s))、不考虑中国核证自愿减排量(CCER)收入时的项目内部收益率(R_(1))和考虑CCER收入时的项目内部收益率(R_(2))为主要指标的项目可行性决策模型。分析了公路交通运输温室气体自愿减排项目可行的内部收益率取值范围,研究了不同内部收益率与交易基准价格(P_(ccer))的关系,给出了公路交通运输温室气体自愿减排项目核证减排量交易流程。【结果】项目可行性判定应满足R_(1)小于R_(s),且R_(2)不小于R_(s)。在交易预期价格(P_(d)),R_(s)和R_(1)不变时,P_(ccer)随R_(2)增加而降低,项目可行性越高,同样价格条件下项目越容易完成交易决策。在P_(d),R_(s),R_(2)不变时,P_(ccer)随R_(1)增加而降低,在R_(2)大于R_(s)的条件下,R_(1)越高,项目越容易完成交易决策。在P_(d),R_(1),R_(2)不变时,P_(ccer)随R_(s)的增加而增加,R_(s)越高,同样价格条件下项目越不容易完成交易决策。【结论】通过项目可行性决策模型分析和交易流程,可为公路交通运输行业参与温室气体自愿减排项目设计及交易提供支撑。 展开更多
关键词 环境工程 可行性决策模型 交易流程 温室气体自愿减排项目 核证减排量 内部收益率
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苏里格气田致密气藏经济极限井网密度确定方法
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作者 李鹏 范倩倩 +3 位作者 徐文 刘莉莉 范继武 白慧 《新疆石油地质》 北大核心 2025年第3期382-387,共6页
致密气藏井网优化均针对井网整体部署阶段,然而苏里格气田中区已开发至中—后期,产能建设已进入加密部署阶段,为了保障加密井的开发效果,需评价不同储集层条件、加密时机及天然气价格条件下经济极限井网密度。在苏里格气田中区分别选取... 致密气藏井网优化均针对井网整体部署阶段,然而苏里格气田中区已开发至中—后期,产能建设已进入加密部署阶段,为了保障加密井的开发效果,需评价不同储集层条件、加密时机及天然气价格条件下经济极限井网密度。在苏里格气田中区分别选取不同储量丰度典型井区开展数值模拟研究,结合不同井网密度气井及气藏开发指标,评价不同井网密度气井干扰程度和老井不同生产年限地层压力分布规律,在此基础上预测加密井最终累计产气量;结合天然气价格等经济参数,确定不同加密时机经济极限井网密度,实现了加密井经济效益部署。在苏里格气田的应用显示,当天然气价格为1.119元/m^(3)时,在未动用区可直接整体部署密度为4.5口/km^(2)的经济极限井网;当需要进行井网加密时,在生产3年内的老井附近井网可加密到3.5口/km^(2);当天然气价格上涨到1.550元/m^(3)时,在生产5年内的老井附近井网可加密到5.0口/km^(2)。 展开更多
关键词 苏里格气田 致密气藏 经济极限井网密度 累计产气量 内部收益率 加密时机 采收率 储量丰度
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秸秆还田和施磷量对豫西旱地小麦土壤酶活性和产量形成的影响 被引量:8
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作者 王鹏博 张冬霞 +2 位作者 乔唱唱 黄明 王贺正 《作物学报》 北大核心 2025年第2期534-547,共14页
为了明确秸秆还田和施磷量对豫西旱地小麦土壤酶活性和产量形成的影响规律,2020年10月至2022年6月,以洛旱22为材料,采用裂区试验设计,主区为玉米秸秆还田:秸秆不还田(S0)、秸秆全量还田(S1),副区为施磷量:P0 (0 kg hm^(-2))、P1 (75.0 k... 为了明确秸秆还田和施磷量对豫西旱地小麦土壤酶活性和产量形成的影响规律,2020年10月至2022年6月,以洛旱22为材料,采用裂区试验设计,主区为玉米秸秆还田:秸秆不还田(S0)、秸秆全量还田(S1),副区为施磷量:P0 (0 kg hm^(-2))、P1 (75.0 kg hm^(-2))、P2 (112.5 kg hm^(-2))、P3 (150.0 kg hm^(-2))和P4 (187.5 kg hm^(-2)),测定了土壤酶活性以及小麦干物质转运特征、籽粒灌浆动态和产量及其构成因素。结果表明,0~20 cm与20~40 cm土层中土壤速效磷含量及土壤脲酶、蔗糖酶、过氧化氢酶和碱性磷酸酶活性,以及小麦籽粒最大灌浆速率(V_(max))、最大灌浆速率出现时间(T_(max))、灌浆速率达到最大时的籽粒生长量(W_(max))、平均灌浆速率(V_(mean))、灌浆渐增期持续时间(T_(1))以及快增期持续时间(T_(2))在同一施磷水平下均表现为S1高于S0,在同一秸秆还田处理下均随施磷水平的提高呈先升后降趋势,总体表现为P3处理最高。同一施磷量下,花后干物质同化量及其对籽粒的贡献率也均表现为S1高于S0,且在最高的P3处理分别显著提高38.67%和5.76%。秸秆还田和施磷量互作对土壤速效磷含量、土壤酶活性、小麦干物质转运特征、籽粒灌浆动态和产量的影响均达显著水平,且多在S1P3处理达到最大值。S1P3与S0P3相比,前后两年度土壤速效磷含量及土壤脲酶、蔗糖酶、过氧化氢酶活性分别显著提高5.32%、5.04%、10.30%、2.92%和7.37%、3.88%、11.64%、3.31%。秸秆还田和增施磷肥均能提高小麦穗数、穗粒数、千粒重和产量,且除千粒重外同一秸秆还田下均随施磷量的提高呈先升后降趋势。S1P3与S0P3相比,小麦穗数和产量在2020—2021年度分别提高4.74%和3.78%,在2021—2022年度分别提高9.06%和4.51%,且2021—2022年度的穗粒数也提高5.25%。综上,秸秆还田配施150 kg hm^(-2)磷肥(S1P3)是豫西旱地及其类似生态区小麦适宜种植方式。 展开更多
关键词 秸秆还田 施磷量 土壤酶活性 小麦 产量形成
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黑龙江省主要农作物秸秆时空分布及还田现状
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作者 郝玉波 宫秀杰 +5 位作者 韩林静 钱春荣 张思涛 于洋 姜宇博 吕国依 《黑龙江农业科学》 2025年第7期1-7,共7页
为进一步提高秸秆利用率,推动区域秸秆全量化应用,利用统计年鉴数据,以黑龙江省主要作物秸秆为研究对象,分析黑龙江省内主要种植作物(玉米、水稻和大豆)在各地市的秸秆产量及秸秆还田利用率,明确各地市内秸秆利用现状。结果表明,黑龙江... 为进一步提高秸秆利用率,推动区域秸秆全量化应用,利用统计年鉴数据,以黑龙江省主要作物秸秆为研究对象,分析黑龙江省内主要种植作物(玉米、水稻和大豆)在各地市的秸秆产量及秸秆还田利用率,明确各地市内秸秆利用现状。结果表明,黑龙江省玉米、水稻和大豆秸秆总产量均随着时间呈指数上升,且秸秆总产量在地市间分布不均,玉米秸秆产量呈由南向北减少的趋势,水稻秸秆产量分布总体上呈由西南部向东北部减少的趋势,大豆秸秆产量主要分布在北部和西部。2023年秋冬季黑龙江省玉米秸秆直接还田面积450.87万hm^(2),占播种面积的63.53%,水稻秸秆直接还田面积为270.93万hm^(2),占总播种面积的79.85%,大豆秸秆直接还田面积为428.55万hm^(2),占总播种面积的90.39%。其中播种面积最大的哈尔滨市、齐齐哈尔市和绥化市秋冬季玉米秸秆直接还田比例分别为59.44%、54.63%和59.36%,水稻秸秆直接还田比例分别为72.17%、61.00%和60.82%,秸秆直接还田面积有待于进一步提高。各地大豆秸秆还田比例均较高,全省平均达90.39%。因此,黑龙江省秸秆资源丰富,具有较强秸秆利用潜力,但各地市秸秆还田比例不均,各地市应当结合当地资源现状合理优化秸秆资源利用方式。 展开更多
关键词 黑龙江省 农作物 草谷比 秸秆资源 利用率 还田量 还田面积
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360 m^(2)烧结机节能降耗关键技术研究及应用 被引量:5
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作者 庄清云 李光石 +1 位作者 鲁雄刚 贺淑珍 《钢铁》 北大核心 2025年第4期13-20,共8页
为降低烧结过程中的固体碳燃料,宝钢德盛通过含铁原料配矿优化、超厚料层烧结技术和热废气循环耦合富氧低碳烧结等关键技术在360 m^(2)烧结机实际生产中顺利实现节能降碳和提升烧结矿产量和质量指标目的。对以赤铁矿和褐铁矿为主的烧结... 为降低烧结过程中的固体碳燃料,宝钢德盛通过含铁原料配矿优化、超厚料层烧结技术和热废气循环耦合富氧低碳烧结等关键技术在360 m^(2)烧结机实际生产中顺利实现节能降碳和提升烧结矿产量和质量指标目的。对以赤铁矿和褐铁矿为主的烧结矿进行配矿方案优化试验,配用质量分数为15%磁铁精矿粉(FeO质量分数超过28%)替代一部分赤铁矿粉,能够提升烧结利用系数和烧结矿转鼓强度,降低烧结固体碳燃料。通过超厚料层烧结技术的研究与应用实施,通过分析料层厚度与垂直烧结速度、利用系数、转鼓强度、成品率和固体燃料消耗量等指标结果,明确了料层厚度为900 mm时综合性能最佳,料层厚度的提高能够促进矿物结晶,使针网状的铁酸钙与其他形晶的磁铁矿形成交织熔蚀结构,进而有利于提升烧结矿强度、成品率及冶金性能。采用热废气循环耦合富氧进行烧结,热废气能够促进烧结层上下热量和温度均匀分布,避免急冷造成烧结表层强度降低;而耦合富氧后的热废气能够提升燃料燃烧速度及燃料利用率,改善烧结过程的气氛条件并降低烧结矿固体燃料消耗。对热废气循环耦合富氧烧结技术与烧结矿的烧结速度、利用系数、转鼓强度和成品率的研究表明,当氧气体积分数为23%时,对应烧结产量和质量指标为最佳。应用热废气耦合富氧烧结技术可将烧结矿产量提升51 t/(台·时),返矿率降低1.65%,固体燃料单耗降低1.67 kg/t。 展开更多
关键词 烧结矿 配矿优化 超厚料层 烧结技术 热废气循环 富氧 烧结固体燃料消耗 返矿率
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教育扩张政策与少数民族的教育收益率:收入效应与分配效应
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作者 方超 《安徽师范大学学报(社会科学版)》 2025年第2期116-124,共9页
利用中国家庭收入调查数据(2019),实证检验了公共教育扩张政策对少数民族教育收益率的影响。(1)利用普通最小二乘法发现,少数民族劳动力的义务教育和大学教育收益率为43.6%和61.7%,高于汉族劳动力的35.6%和47.3%;(2)利用工具变量的第一... 利用中国家庭收入调查数据(2019),实证检验了公共教育扩张政策对少数民族教育收益率的影响。(1)利用普通最小二乘法发现,少数民族劳动力的义务教育和大学教育收益率为43.6%和61.7%,高于汉族劳动力的35.6%和47.3%;(2)利用工具变量的第一阶段回归发现,义务教育改革和高校扩招政策大幅实现了不同民族的教育人力资本积累,但少数民族接受义务教育和大学教育的概率值比汉族低4.6和0.3个百分点;(3)第二阶段回归则发现教育扩张政策具有极强的社会经济价值,少数民族劳动力的大学教育收益率高于汉族,表明高等教育更好地的促进少数民族的个体增收;(4)利用无条件分位数回归进行异质性检验,发现教育扩招政策的收入分配效应存在差异,义务教育改革扩大了少数民族的组内工资差异,高校扩招政策具有具收收入收均等化的作用。 展开更多
关键词 教育扩张政策 教育收益率 少数民族 收入分配 人力资本
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