The ONIOM quantum mechanics method is used to study the reaction of one-carbon unit transfer from an imidazolidine to 6- aminouracil model with the participation of water molecules.The computation results show that in...The ONIOM quantum mechanics method is used to study the reaction of one-carbon unit transfer from an imidazolidine to 6- aminouracil model with the participation of water molecules.The computation results show that in this reaction the participation of H_2O molecule makes the energy barrier lower because of the H-bond interaction.展开更多
Density Functional Theory (DFT) method was used in this paper to study one-carbon transfer from 1,10-tetrahydroquinoxaline, an analogue of tetrahydrofolic acid, to methylamine. This reaction can be completed via two ...Density Functional Theory (DFT) method was used in this paper to study one-carbon transfer from 1,10-tetrahydroquinoxaline, an analogue of tetrahydrofolic acid, to methylamine. This reaction can be completed via two paths. From the computation result we can conclude that a general-acid catalysis exists in this reaction. By computation we find DFT has its limitation in describing a newly incorporated structure with a unit charge.展开更多
It is a theoretical study on the water-assisted mechanism of one-carbon unit transfer reaction, in which the en-ergy barrier for each transition state lowered by about 80—100 kJ/mol when compared with the one in no-w...It is a theoretical study on the water-assisted mechanism of one-carbon unit transfer reaction, in which the en-ergy barrier for each transition state lowered by about 80—100 kJ/mol when compared with the one in no-water-involved mechanism. The water-assisted path 4 is the favorite reaction way. Our results well explained the presumption from experiments.展开更多
One-carbon unit transfer reaction of folate cofactor model compound, 1-acetyl-2-methyl-imidazolinium, with 1,2-diaminobenzene has been studied theoretically with ONIOM method. The result shows that there are two pathw...One-carbon unit transfer reaction of folate cofactor model compound, 1-acetyl-2-methyl-imidazolinium, with 1,2-diaminobenzene has been studied theoretically with ONIOM method. The result shows that there are two pathways to complete this reaction because the imidazolinium ring has two breaking patterns. Both the two pathways have six steps. They are combination of two reactants, proton migration, break of five-membered ring, formation of benzimidazole derivate, another proton migration, and formation of final products. In each of the above pathways, the two proton migration steps have higher energy, which illuminate that the reaction is catalyzed by general acid-base. This fact agrees with the experimental results of enzymatic one-carbon unit transfer at oxidation level of formate.展开更多
ONIOM quantum mechanics method is used in this paper to study one-carbon unit transfer from imidazolidine to 6-aminouracil derivates. The computation results show that this reaction can be completed via three paths ow...ONIOM quantum mechanics method is used in this paper to study one-carbon unit transfer from imidazolidine to 6-aminouracil derivates. The computation results show that this reaction can be completed via three paths owing to the three different proton transfer modes. By calculation and analysis, we can find the direct proton transfer is the preferable pathway.展开更多
The FCC unit with addition of various inventories of the FP-DSN type sulfur transfer additive was tested in a commercial scale. The effect of the sulfur transfer additive was analyzed by investigating the indicators r...The FCC unit with addition of various inventories of the FP-DSN type sulfur transfer additive was tested in a commercial scale. The effect of the sulfur transfer additive was analyzed by investigating the indicators related with the regenerator flue gas composition,the dry gas composition before desulfurization,the LPG composition before desulfurization,the acid gas,and the yield of gasoline and diesel. The test results indicated that the sulfur was trans ferred from the feed stream into the dry gas,LPG and acid gas,and the sulfur transfer effect was obvious only when the inventory of sulfur transfer additive exceeded over 2.0% of total FCC catalyst inventory.展开更多
Multi-level pressure source system is a novel hydraulic system with distinct advantage of energy saving. In order to balance each pressure level of the multi-level pressure source system, a pump motor energy transfer ...Multi-level pressure source system is a novel hydraulic system with distinct advantage of energy saving. In order to balance each pressure level of the multi-level pressure source system, a pump motor energy transfer unit is usually equipped. However, the pump motor energy transfer has the characteristics of poor starting and low response, which cause long time of pressure adjustment and large pressure jitter when the transformer is switched to system suddenly and the motor-side pressure has pressure impact when rail of the pump-side is switched. To address these problems, this paper proposes a compound control strategy of feedforward compensation control with Fuzzy-PID to improve the controllability of the multi-level pressure source system. A test rig of the pump motor energy transfer unit is built and the controllability of compound controller and PID controller are compared. The experiment results show that, compared with the traditional PID, the adjustment time and the pressure impact are reduced by 20% and 25% with the proposed compound control strategy. Therefore, the presented compound control strategy can be used to improve starting performance and robustness of the pump motor energy transfer unit control system.展开更多
Although different NbO_(x) units are present in Nb_(2)O_(5)‐based catalysts,the correlations between these structures and activity remain unclear,which considerably hinders the further development of Nb_(2)O_(5) phot...Although different NbO_(x) units are present in Nb_(2)O_(5)‐based catalysts,the correlations between these structures and activity remain unclear,which considerably hinders the further development of Nb_(2)O_(5) photocatalysis.Herein,we utilized N‐hydroxyphthalimide(NHPI)as the probe molecule to distinguish the role of different NbO_(x) units in the activation of C–H bond under visible light irradia‐tion.With the addition of NHPI,Nb_(2)O_(5) catalysts with highly disordered NbO_(6) units exhibited higher activities than that with slightly disordered NbO_(6) units(419‒495 vs.82μmol·g^(-1)·h^(-1))in photocata‐lytic selective oxidation of ethylbenzene.Revealed by Raman spectra,electron paramagnetic reso‐nance spectra,and transmission‐electron‐microscopy images,highly disordered NbO_(6) units were confirmed to act as the active sites for the transfer of photogenerated electrons from NHPI,pro‐moting the generation of phthalimide‐N‐oxyl(PINO)radicals for the enhanced conversion of ethylbenzene under visible light irradiation.This study provides guidance on the role of local NbO_(x) units in Nb_(2)O_(5) photocatalysis.展开更多
Based on single drop mass transfer models and two phase flow equation,a general equationfor calculating the‘true’height of transfer unit of extraction columns was derived and tested withfour types of extraction colu...Based on single drop mass transfer models and two phase flow equation,a general equationfor calculating the‘true’height of transfer unit of extraction columns was derived and tested withfour types of extraction columns with some different working systems.The calculated results fittedwell with those obtained by experiments.展开更多
<strong>Introduction:</strong> Patient’s transfer from the intensive care unit (ICU) to the general ward indicates their improving health status. However, the transfer produces anxiety when patients enter...<strong>Introduction:</strong> Patient’s transfer from the intensive care unit (ICU) to the general ward indicates their improving health status. However, the transfer produces anxiety when patients enter an unfamiliar environment with different care protocols and circumstances. <strong>Objectives:</strong> This study aimed to examine the level of ICU transfer anxiety among open heart surgery patients and determine the psychosocial factors associated with ICU transfer anxiety among open heart surgery patients. <strong>Methods:</strong> Data were collected in a cardiac center in Kathmandu City, Nepal among 95 open heart surgery patients within 24 hours of their transfer from an ICU to a general ward. The study used four self-reported questionnaires, namely the modified Mishel Uncertainty in Illness Scale for Adults, modified Brief COPE Inventory, Nurses’ Support Questionnaire, and State Anxiety Inventory. <strong>Results:</strong> Fifty-two patients (54.7%) had a high level of transfer anxiety. Spearman’s rank correlation showed that uncertainty in illness, coping, and nurses’ support were significantly related to transfer anxiety (<em>p</em> < 0.001). <strong>Conclusion:</strong> The results of this study suggest nurses to address uncertainty in illness of the patients, improve their coping abilities, and provide need-based nursing support to them during the transitional phase. Besides, clinicians and governmental agencies should contribute to implication of transitional guidelines, which can reduce transfer anxiety and promote health and recovery of the patients.展开更多
Accurate carbon price forecasting is essential to provide the guidance for production and investment.Current research is mainly dependent on plenty of historical samples of carbon prices,which is impractical for the n...Accurate carbon price forecasting is essential to provide the guidance for production and investment.Current research is mainly dependent on plenty of historical samples of carbon prices,which is impractical for the newly launched carbon market due to its short history.Based on the idea of transfer learning,this paper proposes a novel price forecasting model,which utilizes the correlation between the new and mature markets.The model is firstly pretrained on large data of mature market by gated recurrent unit algorithm,and then fine-tuned by the target market samples.An integral framework,including complexity decomposition method for data pre-processing,sample entropy for feature selection,and support vector regression for result post-processing,is provided.In the empirical analysis of new Chinese market,the root mean square error,mean absolute error,mean absolute percentage error,and determination coefficient of the model are 0.529,0.476,0.717%and 0.501 respectively,proving its validity.展开更多
目的系统分析中国重症监护室(intensive care unit,ICU)转出患者家属迁移应激的影响因素,为减轻转出患者家属迁移应激水平提供循证依据。方法计算机检索中国知网、万方数据知识服务平台、维普、中国生物医学文献数据库、Web of Science...目的系统分析中国重症监护室(intensive care unit,ICU)转出患者家属迁移应激的影响因素,为减轻转出患者家属迁移应激水平提供循证依据。方法计算机检索中国知网、万方数据知识服务平台、维普、中国生物医学文献数据库、Web of Science、PubMed、the Cochrane Library、Embase中有关ICU转出患者家属迁移应激影响因素的队列研究、病例对照研究、横断面研究等观察性研究,检索时限为建库至2023年10月。由2名研究者按照纳入及排除标准单独进行文献筛选、质量评价和资料提取。采用RevMan5.4软件对数据结果进行Meta分析。结果最终纳入15篇研究,总样本量2558,共提取12个影响因素。将15篇文献根据测量结局指标的工具分为正向计分组(得分越高,迁移应激水平越高,共9篇文献)、反向计分组(得分越高,迁移应激水平越低,共6篇文献)。分析每个组别时,仅对组内提及≥2次的影响因素进行Meta分析。Meta分析结果显示:正向计分组内,家属文化程度、家属性别、患者意识、ICU治疗时间、家属疾病不确定感是ICU转出患者家属迁移应激的影响因素(P<0.05);反向计分组内,家属文化程度、家属性别、患者年龄、ICU治疗时间是ICU转出患者家属迁移应激的影响因素(P<0.05)。敏感度分析结果显示各个因素的结果均较为稳定。结论家属文化程度、家属性别、患者年龄、ICU治疗时间、家属疾病不确定感是中国ICU转出患者家属迁移应激的影响因素,家属宗教信仰、患者意识对其影响还需进一步论证。展开更多
文摘The ONIOM quantum mechanics method is used to study the reaction of one-carbon unit transfer from an imidazolidine to 6- aminouracil model with the participation of water molecules.The computation results show that in this reaction the participation of H_2O molecule makes the energy barrier lower because of the H-bond interaction.
基金This work was supported by the grant from the National Natural Science Foundation of China (No. 29973021)
文摘Density Functional Theory (DFT) method was used in this paper to study one-carbon transfer from 1,10-tetrahydroquinoxaline, an analogue of tetrahydrofolic acid, to methylamine. This reaction can be completed via two paths. From the computation result we can conclude that a general-acid catalysis exists in this reaction. By computation we find DFT has its limitation in describing a newly incorporated structure with a unit charge.
基金Project supported by the National Natural Science Foundation of China (Nos. 20173032 and 29973021) the Foundation for Invited Professor of Shandong University and Ph.D. Special Foundation of Chinese Education Ministry.
文摘It is a theoretical study on the water-assisted mechanism of one-carbon unit transfer reaction, in which the en-ergy barrier for each transition state lowered by about 80—100 kJ/mol when compared with the one in no-water-involved mechanism. The water-assisted path 4 is the favorite reaction way. Our results well explained the presumption from experiments.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 29973021).
文摘One-carbon unit transfer reaction of folate cofactor model compound, 1-acetyl-2-methyl-imidazolinium, with 1,2-diaminobenzene has been studied theoretically with ONIOM method. The result shows that there are two pathways to complete this reaction because the imidazolinium ring has two breaking patterns. Both the two pathways have six steps. They are combination of two reactants, proton migration, break of five-membered ring, formation of benzimidazole derivate, another proton migration, and formation of final products. In each of the above pathways, the two proton migration steps have higher energy, which illuminate that the reaction is catalyzed by general acid-base. This fact agrees with the experimental results of enzymatic one-carbon unit transfer at oxidation level of formate.
文摘ONIOM quantum mechanics method is used in this paper to study one-carbon unit transfer from imidazolidine to 6-aminouracil derivates. The computation results show that this reaction can be completed via three paths owing to the three different proton transfer modes. By calculation and analysis, we can find the direct proton transfer is the preferable pathway.
文摘The FCC unit with addition of various inventories of the FP-DSN type sulfur transfer additive was tested in a commercial scale. The effect of the sulfur transfer additive was analyzed by investigating the indicators related with the regenerator flue gas composition,the dry gas composition before desulfurization,the LPG composition before desulfurization,the acid gas,and the yield of gasoline and diesel. The test results indicated that the sulfur was trans ferred from the feed stream into the dry gas,LPG and acid gas,and the sulfur transfer effect was obvious only when the inventory of sulfur transfer additive exceeded over 2.0% of total FCC catalyst inventory.
基金Supported by the National Natural Science Foundation of China(No.51575471)the Key Project of Science and Technology Plan of Higher Education of Hebei Education Department(No.ZD2017077)
文摘Multi-level pressure source system is a novel hydraulic system with distinct advantage of energy saving. In order to balance each pressure level of the multi-level pressure source system, a pump motor energy transfer unit is usually equipped. However, the pump motor energy transfer has the characteristics of poor starting and low response, which cause long time of pressure adjustment and large pressure jitter when the transformer is switched to system suddenly and the motor-side pressure has pressure impact when rail of the pump-side is switched. To address these problems, this paper proposes a compound control strategy of feedforward compensation control with Fuzzy-PID to improve the controllability of the multi-level pressure source system. A test rig of the pump motor energy transfer unit is built and the controllability of compound controller and PID controller are compared. The experiment results show that, compared with the traditional PID, the adjustment time and the pressure impact are reduced by 20% and 25% with the proposed compound control strategy. Therefore, the presented compound control strategy can be used to improve starting performance and robustness of the pump motor energy transfer unit control system.
文摘Although different NbO_(x) units are present in Nb_(2)O_(5)‐based catalysts,the correlations between these structures and activity remain unclear,which considerably hinders the further development of Nb_(2)O_(5) photocatalysis.Herein,we utilized N‐hydroxyphthalimide(NHPI)as the probe molecule to distinguish the role of different NbO_(x) units in the activation of C–H bond under visible light irradia‐tion.With the addition of NHPI,Nb_(2)O_(5) catalysts with highly disordered NbO_(6) units exhibited higher activities than that with slightly disordered NbO_(6) units(419‒495 vs.82μmol·g^(-1)·h^(-1))in photocata‐lytic selective oxidation of ethylbenzene.Revealed by Raman spectra,electron paramagnetic reso‐nance spectra,and transmission‐electron‐microscopy images,highly disordered NbO_(6) units were confirmed to act as the active sites for the transfer of photogenerated electrons from NHPI,pro‐moting the generation of phthalimide‐N‐oxyl(PINO)radicals for the enhanced conversion of ethylbenzene under visible light irradiation.This study provides guidance on the role of local NbO_(x) units in Nb_(2)O_(5) photocatalysis.
基金Supported by the National Natural Science Foundation of China.
文摘Based on single drop mass transfer models and two phase flow equation,a general equationfor calculating the‘true’height of transfer unit of extraction columns was derived and tested withfour types of extraction columns with some different working systems.The calculated results fittedwell with those obtained by experiments.
文摘<strong>Introduction:</strong> Patient’s transfer from the intensive care unit (ICU) to the general ward indicates their improving health status. However, the transfer produces anxiety when patients enter an unfamiliar environment with different care protocols and circumstances. <strong>Objectives:</strong> This study aimed to examine the level of ICU transfer anxiety among open heart surgery patients and determine the psychosocial factors associated with ICU transfer anxiety among open heart surgery patients. <strong>Methods:</strong> Data were collected in a cardiac center in Kathmandu City, Nepal among 95 open heart surgery patients within 24 hours of their transfer from an ICU to a general ward. The study used four self-reported questionnaires, namely the modified Mishel Uncertainty in Illness Scale for Adults, modified Brief COPE Inventory, Nurses’ Support Questionnaire, and State Anxiety Inventory. <strong>Results:</strong> Fifty-two patients (54.7%) had a high level of transfer anxiety. Spearman’s rank correlation showed that uncertainty in illness, coping, and nurses’ support were significantly related to transfer anxiety (<em>p</em> < 0.001). <strong>Conclusion:</strong> The results of this study suggest nurses to address uncertainty in illness of the patients, improve their coping abilities, and provide need-based nursing support to them during the transitional phase. Besides, clinicians and governmental agencies should contribute to implication of transitional guidelines, which can reduce transfer anxiety and promote health and recovery of the patients.
文摘Accurate carbon price forecasting is essential to provide the guidance for production and investment.Current research is mainly dependent on plenty of historical samples of carbon prices,which is impractical for the newly launched carbon market due to its short history.Based on the idea of transfer learning,this paper proposes a novel price forecasting model,which utilizes the correlation between the new and mature markets.The model is firstly pretrained on large data of mature market by gated recurrent unit algorithm,and then fine-tuned by the target market samples.An integral framework,including complexity decomposition method for data pre-processing,sample entropy for feature selection,and support vector regression for result post-processing,is provided.In the empirical analysis of new Chinese market,the root mean square error,mean absolute error,mean absolute percentage error,and determination coefficient of the model are 0.529,0.476,0.717%and 0.501 respectively,proving its validity.
文摘目的系统分析中国重症监护室(intensive care unit,ICU)转出患者家属迁移应激的影响因素,为减轻转出患者家属迁移应激水平提供循证依据。方法计算机检索中国知网、万方数据知识服务平台、维普、中国生物医学文献数据库、Web of Science、PubMed、the Cochrane Library、Embase中有关ICU转出患者家属迁移应激影响因素的队列研究、病例对照研究、横断面研究等观察性研究,检索时限为建库至2023年10月。由2名研究者按照纳入及排除标准单独进行文献筛选、质量评价和资料提取。采用RevMan5.4软件对数据结果进行Meta分析。结果最终纳入15篇研究,总样本量2558,共提取12个影响因素。将15篇文献根据测量结局指标的工具分为正向计分组(得分越高,迁移应激水平越高,共9篇文献)、反向计分组(得分越高,迁移应激水平越低,共6篇文献)。分析每个组别时,仅对组内提及≥2次的影响因素进行Meta分析。Meta分析结果显示:正向计分组内,家属文化程度、家属性别、患者意识、ICU治疗时间、家属疾病不确定感是ICU转出患者家属迁移应激的影响因素(P<0.05);反向计分组内,家属文化程度、家属性别、患者年龄、ICU治疗时间是ICU转出患者家属迁移应激的影响因素(P<0.05)。敏感度分析结果显示各个因素的结果均较为稳定。结论家属文化程度、家属性别、患者年龄、ICU治疗时间、家属疾病不确定感是中国ICU转出患者家属迁移应激的影响因素,家属宗教信仰、患者意识对其影响还需进一步论证。