In this paper,we generalize the Hall-Higman’s reduction theorem by dropping the restrictive hypothesis(丨G丨,丨H丨)=1 and determine the detailed structure of G.
Based on seven carbon sources including chemical fertilizer, pesticide, agricultural film, nitrogen fertilization, agricultural machinery, irri- gation and straw burning, the carbon emissions in agricultural productio...Based on seven carbon sources including chemical fertilizer, pesticide, agricultural film, nitrogen fertilization, agricultural machinery, irri- gation and straw burning, the carbon emissions in agricultural production of China during 1995-2011 was calculated. The results showed that both total agricultural carbon emission and per capita agricultural carbon emission overall presented growth trends, and the growth rate began to slow in recent years. The agricultural carbon emission intensity decreased year by year. Straw burning was the primary carbon source in China＇s agricul- ture, followed by chemical fertilizer. Total agricultural carbon emission in China in 17 years experienced three stages of ＂fluctuated growth -slow drop-new growth＂. Finally, suggestions and countermeasures of the low-carbon agriculture development in China from three aspects were proposed.展开更多
In view of the fact that the prediction effect of influential financial customer churn in the Internet of Things environment is difficult to achieve the expectation,at the smart contract level of the blockchain,a cust...In view of the fact that the prediction effect of influential financial customer churn in the Internet of Things environment is difficult to achieve the expectation,at the smart contract level of the blockchain,a customer churn prediction framework based on situational awareness and integrating customer attributes,the impact of project hotspots on customer interests,and customer satisfaction with the project has been built.This framework introduces the background factors in the financial customer environment,and further discusses the relationship between customers,the background of customers and the characteristics of pre-lost customers.The improved Singular Value Decomposition(SVD)algorithm and the time decay function are used to optimize the search and analysis of the characteristics of pre-lost customers,and the key index combination is screened to obtain the data of potential lost customers.The framework will change with time according to the customer’s interest,adding the time factor to the customer churn prediction,and improving the dimensionality reduction and prediction generalization ability in feature selection.Logistic regression,naive Bayes and decision tree are used to establish a prediction model in the experiment,and it is compared with the financial customer churn prediction framework under situational awareness.The prediction results of the framework are evaluated from four aspects:accuracy,accuracy,recall rate and F-measure.The experimental results show that the context-aware customer churn prediction framework can be effectively applied to predict customer churn trends,so as to obtain potential customer data with high churn probability,and then these data can be transmitted to the company’s customer service department in time,so as to improve customer churn rate and customer loyalty through accurate service.展开更多
目的观察电针联合手牵足蹬手法复位对初次肩关节脱位患者肩关节功能的影响。方法将78例初次肩关节脱位的患者,随机分为对照组和观察组,每组39例。对照组采用手牵足蹬法复位进行治疗,观察组在对照组的基础上联合电针治疗。观察两组治疗前...目的观察电针联合手牵足蹬手法复位对初次肩关节脱位患者肩关节功能的影响。方法将78例初次肩关节脱位的患者,随机分为对照组和观察组,每组39例。对照组采用手牵足蹬法复位进行治疗,观察组在对照组的基础上联合电针治疗。观察两组治疗前后Neer肩关节功能评分、Rowe氏评分系统中稳定性及活动度评分、肩关节角度及治疗前、出院时和出院后1个月疼痛视觉模拟量表(visual analog scale,VAS)评分变化,并比较两组不良反应发生率。结果治疗后,两组Neer肩关节功能评分各项评分及总分均升高(P<0.05),且观察组疼痛和运动范围评分及总分高于对照组(P<0.05);两组Rowe氏评分中的稳定性和活动度评分均升高(P<0.05),且观察组高于对照组(P<0.05);两组前屈上举、外展外旋角度均增大(P<0.05),且观察组大于对照组(P<0.05),两组体侧外旋角度比较差异无统计学意义(P>0.05)。两组出院时、出院后1个月VAS评分均低于治疗前,且观察组出院时、出院后1个月VAS评分均低于对照组,差异有统计学意义(P<0.05)。两组不良反应发生率比较,差异无统计学意义(P>0.05)。结论针刺联合手牵足蹬手法复位可改善初次肩关节脱位患者的肩关节功能及疼痛情况,无明显不良反应,是一种安全、有效的治疗方法。展开更多
By asing the nonclassical method of symmetry reductions, the exact solutions for general variable coefficient KdV equation with dissipative loss and nonuniformity terms are obtained. When the dissipative loss and non...By asing the nonclassical method of symmetry reductions, the exact solutions for general variable coefficient KdV equation with dissipative loss and nonuniformity terms are obtained. When the dissipative loss and nonuniformity terms don't exist, the multisoliton solutions are found and the corresponding Painleve II type equation for the variable coefficient KdV equation is given.展开更多
以水稻土浸提液为接种液、人工合成的无定形氧化铁为唯一的电子受体、添加的苯系物(甲苯、苯胺、苯酚、苯甲酸)为唯一碳源,在适量无机N,P,K营养供给条件下,采用厌氧恒温混合培养方法,研究了厌氧微生物对氧化铁还原的影响。结果表明,由...以水稻土浸提液为接种液、人工合成的无定形氧化铁为唯一的电子受体、添加的苯系物(甲苯、苯胺、苯酚、苯甲酸)为唯一碳源,在适量无机N,P,K营养供给条件下,采用厌氧恒温混合培养方法,研究了厌氧微生物对氧化铁还原的影响。结果表明,由水稻土中提取的微生物可以利用苯系物作为唯一碳源,在厌氧降解的同时将电子转移给F e(Ⅲ),使其还原为F e(Ⅱ);利用不同苯系物的铁还原过程难易程度有所差异,铁还原率表现为苯甲酸最高(53.99%),甲苯最低(19.55%),利用苯系物的铁还原率均低于以葡萄糖为碳源时的铁还原率(71.16%);不同浓度苯系物对氧化铁还原过程有不同程度的影响,在一定浓度范围内,随着苯系物浓度的增加其对氧化铁还原过程具有促进作用,而高浓度苯系物则对氧化铁还原过程表现出抑制趋势;以2.0 mm o l/L苯系物作为碳源时,蒽醌-2,6二-磺酸盐(AQDS)可明显增加F e(Ⅱ)的累积量。展开更多
Based on some known facts of integrable models, this paper proposes a new （2＋1）-dimensional bilinear model equation. By virtue of the formal series symmetry approach, the new model is proved to be integrable becaus...Based on some known facts of integrable models, this paper proposes a new （2＋1）-dimensional bilinear model equation. By virtue of the formal series symmetry approach, the new model is proved to be integrable because of the existence of the higher order symmetries. The Lie point symmetries of the model constitute an infinite dimensional Kac- Moody Virasoro symmetry algebra. Making use of the infinite Lie point symmetries, the possible symmetry reductions of the model are also studied展开更多
基金Supported in part by NSCF and Guangdong STCF.The author deeply thanks Professor Chen Zhongmu for his kind advice and help.
文摘In this paper,we generalize the Hall-Higman’s reduction theorem by dropping the restrictive hypothesis(丨G丨,丨H丨)=1 and determine the detailed structure of G.
文摘Based on seven carbon sources including chemical fertilizer, pesticide, agricultural film, nitrogen fertilization, agricultural machinery, irri- gation and straw burning, the carbon emissions in agricultural production of China during 1995-2011 was calculated. The results showed that both total agricultural carbon emission and per capita agricultural carbon emission overall presented growth trends, and the growth rate began to slow in recent years. The agricultural carbon emission intensity decreased year by year. Straw burning was the primary carbon source in China＇s agricul- ture, followed by chemical fertilizer. Total agricultural carbon emission in China in 17 years experienced three stages of ＂fluctuated growth -slow drop-new growth＂. Finally, suggestions and countermeasures of the low-carbon agriculture development in China from three aspects were proposed.
基金This work was supported by Shandong social science planning and research project in 2021(No.21CPYJ40).
文摘In view of the fact that the prediction effect of influential financial customer churn in the Internet of Things environment is difficult to achieve the expectation,at the smart contract level of the blockchain,a customer churn prediction framework based on situational awareness and integrating customer attributes,the impact of project hotspots on customer interests,and customer satisfaction with the project has been built.This framework introduces the background factors in the financial customer environment,and further discusses the relationship between customers,the background of customers and the characteristics of pre-lost customers.The improved Singular Value Decomposition(SVD)algorithm and the time decay function are used to optimize the search and analysis of the characteristics of pre-lost customers,and the key index combination is screened to obtain the data of potential lost customers.The framework will change with time according to the customer’s interest,adding the time factor to the customer churn prediction,and improving the dimensionality reduction and prediction generalization ability in feature selection.Logistic regression,naive Bayes and decision tree are used to establish a prediction model in the experiment,and it is compared with the financial customer churn prediction framework under situational awareness.The prediction results of the framework are evaluated from four aspects:accuracy,accuracy,recall rate and F-measure.The experimental results show that the context-aware customer churn prediction framework can be effectively applied to predict customer churn trends,so as to obtain potential customer data with high churn probability,and then these data can be transmitted to the company’s customer service department in time,so as to improve customer churn rate and customer loyalty through accurate service.
文摘目的观察电针联合手牵足蹬手法复位对初次肩关节脱位患者肩关节功能的影响。方法将78例初次肩关节脱位的患者,随机分为对照组和观察组,每组39例。对照组采用手牵足蹬法复位进行治疗,观察组在对照组的基础上联合电针治疗。观察两组治疗前后Neer肩关节功能评分、Rowe氏评分系统中稳定性及活动度评分、肩关节角度及治疗前、出院时和出院后1个月疼痛视觉模拟量表(visual analog scale,VAS)评分变化,并比较两组不良反应发生率。结果治疗后,两组Neer肩关节功能评分各项评分及总分均升高(P<0.05),且观察组疼痛和运动范围评分及总分高于对照组(P<0.05);两组Rowe氏评分中的稳定性和活动度评分均升高(P<0.05),且观察组高于对照组(P<0.05);两组前屈上举、外展外旋角度均增大(P<0.05),且观察组大于对照组(P<0.05),两组体侧外旋角度比较差异无统计学意义(P>0.05)。两组出院时、出院后1个月VAS评分均低于治疗前,且观察组出院时、出院后1个月VAS评分均低于对照组,差异有统计学意义(P<0.05)。两组不良反应发生率比较,差异无统计学意义(P>0.05)。结论针刺联合手牵足蹬手法复位可改善初次肩关节脱位患者的肩关节功能及疼痛情况,无明显不良反应,是一种安全、有效的治疗方法。
基金Supported by the Develop Programme Foundation of the National Basic research(G1 9990 3 2 80 1 )
文摘By asing the nonclassical method of symmetry reductions, the exact solutions for general variable coefficient KdV equation with dissipative loss and nonuniformity terms are obtained. When the dissipative loss and nonuniformity terms don't exist, the multisoliton solutions are found and the corresponding Painleve II type equation for the variable coefficient KdV equation is given.
文摘以水稻土浸提液为接种液、人工合成的无定形氧化铁为唯一的电子受体、添加的苯系物(甲苯、苯胺、苯酚、苯甲酸)为唯一碳源,在适量无机N,P,K营养供给条件下,采用厌氧恒温混合培养方法,研究了厌氧微生物对氧化铁还原的影响。结果表明,由水稻土中提取的微生物可以利用苯系物作为唯一碳源,在厌氧降解的同时将电子转移给F e(Ⅲ),使其还原为F e(Ⅱ);利用不同苯系物的铁还原过程难易程度有所差异,铁还原率表现为苯甲酸最高(53.99%),甲苯最低(19.55%),利用苯系物的铁还原率均低于以葡萄糖为碳源时的铁还原率(71.16%);不同浓度苯系物对氧化铁还原过程有不同程度的影响,在一定浓度范围内,随着苯系物浓度的增加其对氧化铁还原过程具有促进作用,而高浓度苯系物则对氧化铁还原过程表现出抑制趋势;以2.0 mm o l/L苯系物作为碳源时,蒽醌-2,6二-磺酸盐(AQDS)可明显增加F e(Ⅱ)的累积量。
基金Project supported by the National Natural Science Foundation of China(Grant Nos10475055 and 90503006)the Science Research Fund of Zhejiang Provincial Education Department,China(Grant No20040969)
文摘Based on some known facts of integrable models, this paper proposes a new （2＋1）-dimensional bilinear model equation. By virtue of the formal series symmetry approach, the new model is proved to be integrable because of the existence of the higher order symmetries. The Lie point symmetries of the model constitute an infinite dimensional Kac- Moody Virasoro symmetry algebra. Making use of the infinite Lie point symmetries, the possible symmetry reductions of the model are also studied
