In this study,the Mg-3Zn-0.5Zr-χNd(χ=0,0.6)alloys were subjected to final rolling treatment with large deformation of 50%.The impact of annealing temperatures on the microstructure and mechanical properties was inve...In this study,the Mg-3Zn-0.5Zr-χNd(χ=0,0.6)alloys were subjected to final rolling treatment with large deformation of 50%.The impact of annealing temperatures on the microstructure and mechanical properties was investigated.The rolled Mg-3Zn-0.5Zr-0.6Nd alloy exhibited an ultimate tensile strength of 386 MPa,a yield strength of 361 MPa,and an elongation of 7.1%.Annealing at different temperatures resulted in reduced strength and obviously increased elongation for both alloys.Optimal mechanical properties for the Mg-3Zn-0.5Zr-0.6Nd alloy were achieved after annealing at 200℃,with an ultimate tensile strength of 287 MPa,a yield strength of 235 MPa,and an elongation of 26.1%.The numerous deformed microstructures,twins,and precipitated phases in the rolled alloy could impede the deformation at room temperature and increase the work hardening rate.After annealing,a decrease in the work hardening effect and an increase in the dynamic recovery effect were obtained due to the formation of fine equiaxed grains,and the increased volume fraction of precipitated phases,which significantly improved the elongation of the alloy.Additionally,the addition of Nd element could enhance the annealing recrystallization rate,reduce the Schmid factor difference between basal and prismatic slip systems,facilitate multi-system slip initiation and improve the alloy plasticity.展开更多
BACKGROUND As one of the fatal diseases with high incidence,lung cancer has seriously endangered public health and safety.Elderly patients usually have poor self-care and are more likely to show a series of psychologi...BACKGROUND As one of the fatal diseases with high incidence,lung cancer has seriously endangered public health and safety.Elderly patients usually have poor self-care and are more likely to show a series of psychological problems.AIM To investigate the effectiveness of the initial check,information exchange,final accuracy check,reaction(IIFAR)information care model on the mental health status of elderly patients with lung cancer.METHODS This study is a single-centre study.We randomly recruited 60 elderly patients with lung cancer who attended our hospital from January 2021 to January 2022.These elderly patients with lung cancer were randomly divided into two groups,with the control group taking the conventional propaganda and education and the observation group taking the IIFAR information care model based on the conventional care protocol.The differences in psychological distress,anxiety and depression,life quality,fatigue,and the locus of control in psychology were compared between these two groups,and the causes of psychological distress were analyzed.RESULTS After the intervention,Distress Thermometer,Hospital Anxiety and Depression Scale(HADS)for anxiety and the HADS for depression,Revised Piper’s Fatigue Scale,and Chance Health Locus of Control scores were lower in the observation group compared to the pre-intervention period in the same group and were significantly lower in the observation group compared to those of the control group(P<0.05).After the intervention,Quality of Life Questionnaire Core 30(QLQ-C30),Internal Health Locus of Control,and Powerful Others Health Locus of Control scores were significantly higher in the observation and the control groups compared to the pre-intervention period in their same group,and QLQ-C30 scores were significantly higher in the observation group compared to those of the control group(P<0.05).CONCLUSION The IIFAR information care model can help elderly patients with lung cancer by reducing their anxiety and depression,psychological distress,and fatigue,improving their tendencies on the locus of control in psychology,and enhancing their life qualities.展开更多
The loss of Baryonic Matter through Black Holes from our spatial 3-D Universe into its 4th dimension as Dark Matter, is used along with the Conservation of Angular Momentum Principle to prove theoretically the acceler...The loss of Baryonic Matter through Black Holes from our spatial 3-D Universe into its 4th dimension as Dark Matter, is used along with the Conservation of Angular Momentum Principle to prove theoretically the accelerated expansion of the 3-D Universe, as has already been confirmed experimentally being awarded the 2011 Nobel Prize in Physics. Theoretical calculations can estimate further to indicate the true nature of the acceleration;that the outward acceleration is due to the rotation of the Universe caused by Dark Energy from the Void, that the acceleration is non-linear, initially increasing from zero for the short period of about a Million years at a constant rate, and then leveling off non-linearly over extended time before the outward acceleration begins to decrease in a non-linear fashion until it is matched by the gravitational attraction of the matter content of 4D Space and the virtual matter in 3-D Vacuum Space. m = m(4D) + m(Virtual). The rotation of our 3D Universe will become constant once all 3D matter has entered 4D space. As the 3-D Universe tries to expand further it will be pulled inward by its gravitational attraction and will then keep on oscillating about a final radius r<sub>f</sub> while it also keeps on oscillating at right angles to the radius r<sub>f</sub> around final angular velocity ω<sub>f</sub>, until it becomes part of the 4-D Universe. The constant value of the Angular Momentum of our Universe is L = .展开更多
The most difficult and delicate part of the learning process is assessment.Assessment is difficult because during his/her accomplishment the teacher has to consider not only the acquisition of knowledge from students,...The most difficult and delicate part of the learning process is assessment.Assessment is difficult because during his/her accomplishment the teacher has to consider not only the acquisition of knowledge from students,but also the overall degree of development of their competencies.It is delicate,because through assessment we can influence the emotional side of students and their“willingness”to learn.Despite these facts,teachers need to evaluate students during the learning process.The purpose of the research is to find out what is the perception of teachers about the level of evaluation of students with final grade.The overall results showed that 89%of teachers agree,9%of them have a neutral attitude,and 2%do not agree that the evaluation of students with a final grade is done taking into account many aspects and using many methods,the overall average of the results,M=4.36.Based on the empirical results,it was found that teachers who have completed assessment training have a more positive approach to student assessment,as the average score is higher than teachers who have not completed assessment training.From the qualitative results it was understood that the Teachers did not encounter any difficulties during the assessment of the students.展开更多
After a two-year gap year following high school,I finally departed my hometown in Malaysia for a solo journey to China.Upon arrival,the most frequent question I encountered was:“Why do you Malaysians speak such fluen...After a two-year gap year following high school,I finally departed my hometown in Malaysia for a solo journey to China.Upon arrival,the most frequent question I encountered was:“Why do you Malaysians speak such fluent Mandarin?”Well,not only can we speak and write Mandarin,but many of us are also proficient in dialects such as Hakka,Cantonese,Hokkien,and Teochew.Our mastery of these dialects transcends mere convenience in communication;more importantly,it is about our strong desire to preserve the culture and language of our ancestral homeland:China.Indeed,as an ethnic Chinese person born and raised in Malaysia,my roots are forever tied to China.展开更多
One of the most challenging factors affecting impression quality and good marginal fit is the gingival retraction method, which aims to separate the gingiva from the tooth to expose the finishing line of the prepared ...One of the most challenging factors affecting impression quality and good marginal fit is the gingival retraction method, which aims to separate the gingiva from the tooth to expose the finishing line of the prepared tooth. Bleeding and contamination from the crevicular fluid may compete for space with the impression material within the sulcus, leading to indistinct preparations and a lack of detail at the margin. In addition, such procedures might damage the PDL and cause permanent recession. Flowable composite cable, as opposed to traditional retraction cords, offers the proper marginal seal and visibility during the impression record because of its lower viscosity, improved adaptability, and elastic properties. The aim of this report is to present a brand-new, innovative method for controlling gingival hemorrhage in addition to the gingival retraction in restorative and prosthodontic treatment by utilizing a flowable composite during the final impression record procedure. In these case reports, the flowable composite cord technique is used instead of traditional gingival cords to modify and refine the gingival tissue before taking the traditional final impression or digital scan. Two cases were done for patients undergoing fixed prosthodontics and veneer treatment within a 2-year follow-up period. In addition, the flowable composite cord was used as temporary restoration before the final prosthetic cementation or under the provisional crowns. As a result, clean and healthy gingival tissues render cementation of the final prosthesis quicker and easier to perform. The patients in both cases claimed that their prosthodontic treatments, which involved the application of a flowable composite cord to temporarily retraction the gingiva, had produced good outcomes at the yearlong follow-up. In conclusion, the flowable composite cord technique is found to be a useful tool to improve the quality of impressions in fixed prosthodontics by providing excellent access for impression material to record fine details of the finish line of the prepared tooth structure, and to alter the inflamed tissue into a healthy tissue.展开更多
Thanks to the charitable organization Rescue 2000,an elderly woman who had been living in terrible conditions for 32 years finally has a brand new home.82yearold Ibu Latris former residence provided her with the bare ...Thanks to the charitable organization Rescue 2000,an elderly woman who had been living in terrible conditions for 32 years finally has a brand new home.82yearold Ibu Latris former residence provided her with the bare minimal shelter from the elements.However,with the help of generous donors,Rescue 2000 was able to build her a beautiful house where shell be way more comfortable.Cris Araya,the founder of the nonprofit,recently shared footage of Ibus upgraded home.展开更多
In the present work,a 5-kW hybrid PV solar system was installed on the roof of a house in Diyala,Iraq(33.77°N,45.14°E elevation 44 m).The system consists of two strings,where each string consists of nine pol...In the present work,a 5-kW hybrid PV solar system was installed on the roof of a house in Diyala,Iraq(33.77°N,45.14°E elevation 44 m).The system consists of two strings,where each string consists of nine polycrystalline PV modules with 355 Wp in series,and the two strings are in parallel.The energy storage system(ESS)consists of two parallel strings,each with four 12 V and 150 Ah tubular deep cycle batteries in series.A hybrid inverter of 5 kW rated power was operated in different modes.The results showed that May’s monthly energy consumption was about 822.9 and 1085 kWh,respectively.The percentage distribution of the DC energy produced was about 1%system energy losses,27.9%was used to charge the ESS,34.3%was used to feed the grid,and the remaining 37.64%was used to share the load.The energy percentage sharing the load was 16.67%from ESS,33.33%from the PV system,and 50%purchased.The average daily reference,array,and final yields were 6.07,4.327,and 3.991 h/day,respectively.The average array and load efficiencies were 12.3%and 92.24%,with the performance ratio at 65.4%.展开更多
Summary1.There are 12 power systems including 5 regional powersystems with over 1000MW of capacity each.In 1989 Central andEast China power systems were interconnected by a±500kV HVDC Line.2.The hierarchical cont...Summary1.There are 12 power systems including 5 regional powersystems with over 1000MW of capacity each.In 1989 Central andEast China power systems were interconnected by a±500kV HVDC Line.2.The hierarchical control organization can be divided into 5levels,i.e.NCC,6 RCCs,25 PCCs,250 DCCs and more than 2000CCCs. 3.All control centers will be equipped with SCADA and EMSin the near future.4.China power system has a large,dedicated communicationnetwork of its own.展开更多
1.Introduction Carbon neutrality is an important strategy to address the acute problems of resource and environmental constraints.Currently,afforestation,energy conservation,emissions reduction,and other measures have...1.Introduction Carbon neutrality is an important strategy to address the acute problems of resource and environmental constraints.Currently,afforestation,energy conservation,emissions reduction,and other measures have been adopted to offset the total amount of carbon dioxide and other greenhouse gas emissions generated by countries,businesses,products,activities,or individuals,with the aim of finally achieving zero net emissions(Fig.1(a)).展开更多
The process of producing high viscosity polyester by transesterification polycondensation needs to adjust the operating conditions and equipment structure of pre-polycondensation kettle and final polycondensation kett...The process of producing high viscosity polyester by transesterification polycondensation needs to adjust the operating conditions and equipment structure of pre-polycondensation kettle and final polycondensation kettle to realize process intensification.In view of this,the fluid volume function method of computational fluid dynamics numerical simulation was used to investigate the film formation and surface renewal characteristics of horizontal polycondensation kettle under different operating conditions,including viscosity,rotating speed and liquid height.The results show that the viscosity and rotating speed were positively correlated with the film area and surface renewal in the pre-polycondensation stage.However,increasing the viscosity by several orders of magnitude in the final polycondensation kettle,the larger the film area and film thickness,but the overall surface renewal of the disk decreased.Therefore,a hexagonal hole disk is designed.By comparison,it is found that the film is more uniform,the surface update frequency is higher,and the power consumption can be reduced by more than 20%.展开更多
In the construction process of the Lusail Stadium of the FIFA World Cup-Qatar 2022,over 7,000 constructors of more than 100 companies from 20 plus countries carried out extensive consultation and collaboration,overcam...In the construction process of the Lusail Stadium of the FIFA World Cup-Qatar 2022,over 7,000 constructors of more than 100 companies from 20 plus countries carried out extensive consultation and collaboration,overcame numerous challenges and finally completed the project through close cooperation in global industrial and supply chains.The project showcases the strength of Belt and Road cooperation and becomes a"golden"example of people-to-people connectivity among BRI partnercountries.展开更多
Wine and art are our connection to the land.The land at the foot of the Helan Mountains has been quiet for too long between sand and gravel.It wasn't until the 1980s that there was finally human farming on this la...Wine and art are our connection to the land.The land at the foot of the Helan Mountains has been quiet for too long between sand and gravel.It wasn't until the 1980s that there was finally human farming on this land for the first time.Wine,for the first time,conveyed the vitality of life and thepowerof millions ofyears ofdeposition.展开更多
As China moves to fundamentally improve its virus response by downgrading COVID-19 management to Class B from top-level Class A,one sector that has remained crucial yet bruised by the three-year battle against the dis...As China moves to fundamentally improve its virus response by downgrading COVID-19 management to Class B from top-level Class A,one sector that has remained crucial yet bruised by the three-year battle against the disease finally released a sigh of relief.展开更多
When Li Dongfang finally arrived at her destination after days and nights of taxing travel,she was welcomed by a starlit sky that was unlike anything she’d ever seen.“The sky was like a big pot lid,and the stars cov...When Li Dongfang finally arrived at her destination after days and nights of taxing travel,she was welcomed by a starlit sky that was unlike anything she’d ever seen.“The sky was like a big pot lid,and the stars covered me like a quilt,”Li recalled.展开更多
The reemergence of busy restaurants and shopping malls and bustling airports and railway stations suggests that the world’s second-largest economy is finally on the mend.Wide-ranging indicators point to an economic r...The reemergence of busy restaurants and shopping malls and bustling airports and railway stations suggests that the world’s second-largest economy is finally on the mend.Wide-ranging indicators point to an economic resurgence following a decisive exit from pandemic restrictions,leaving many bullish about potential recovery stories.展开更多
In regression, despite being both aimed at estimating the Mean Squared Prediction Error (MSPE), Akaike’s Final Prediction Error (FPE) and the Generalized Cross Validation (GCV) selection criteria are usually derived ...In regression, despite being both aimed at estimating the Mean Squared Prediction Error (MSPE), Akaike’s Final Prediction Error (FPE) and the Generalized Cross Validation (GCV) selection criteria are usually derived from two quite different perspectives. Here, settling on the most commonly accepted definition of the MSPE as the expectation of the squared prediction error loss, we provide theoretical expressions for it, valid for any linear model (LM) fitter, be it under random or non random designs. Specializing these MSPE expressions for each of them, we are able to derive closed formulas of the MSPE for some of the most popular LM fitters: Ordinary Least Squares (OLS), with or without a full column rank design matrix;Ordinary and Generalized Ridge regression, the latter embedding smoothing splines fitting. For each of these LM fitters, we then deduce a computable estimate of the MSPE which turns out to coincide with Akaike’s FPE. Using a slight variation, we similarly get a class of MSPE estimates coinciding with the classical GCV formula for those same LM fitters.展开更多
In this paper, a disease transmission model with two treatment stages is proposed and analyzed. The results indicate that the basic reproduction number is a critical threshold for the prevalence of the disease. If the...In this paper, a disease transmission model with two treatment stages is proposed and analyzed. The results indicate that the basic reproduction number is a critical threshold for the prevalence of the disease. If the basic reproduction number is less than one, the disease free equilibrium is globally asymptotically stable. Otherwise, the endemic equilibrium is globally asymptotically stable. Therefore, besides the basic reproduction number, a new marker for characterizing the seriousness of the disease, named as dynamical final infective size, is proposed, which differs from traditional final size because the proposed model includes the natural birth and death. Finally, optimization strategies for limited medical resources are obtained from the perspectives of basic reproduction number and dynamical final infective size, and the real-world disease management scenarios are given based on these finding.展开更多
基金Project(202203021221088)supported by the Fundamental Research Program of Shanxi Province,ChinaProject(20230010)supported by the Fund Program for the Scientific Activities of Selected Returned Overseas Professionals in Shanxi Province,China+5 种基金Project(202201050201012)supported by the Shanxi Provincial Science and Technology Major Special Project Plan of Taking the Lead in Unveiling the List,ChinaProject(2023-063)supported by the Research Project Supported by Shanxi Scholarship Council of ChinaProjects(51771129,52271109)supported by the National Natural Science Foundation of ChinaProject(2021YFB3703300)supported by the National Key Research and Development Program for Young Scientists,ChinaProject(YDZJSX2021B019)supported by the Special Fund Project for Guiding Local Science and Technology Development by the Central Government,ChinaProject(SKL-YSJ202103)supported by the Open Foundation of State Key Laboratory of High-end Compressor and System Technology,China。
文摘In this study,the Mg-3Zn-0.5Zr-χNd(χ=0,0.6)alloys were subjected to final rolling treatment with large deformation of 50%.The impact of annealing temperatures on the microstructure and mechanical properties was investigated.The rolled Mg-3Zn-0.5Zr-0.6Nd alloy exhibited an ultimate tensile strength of 386 MPa,a yield strength of 361 MPa,and an elongation of 7.1%.Annealing at different temperatures resulted in reduced strength and obviously increased elongation for both alloys.Optimal mechanical properties for the Mg-3Zn-0.5Zr-0.6Nd alloy were achieved after annealing at 200℃,with an ultimate tensile strength of 287 MPa,a yield strength of 235 MPa,and an elongation of 26.1%.The numerous deformed microstructures,twins,and precipitated phases in the rolled alloy could impede the deformation at room temperature and increase the work hardening rate.After annealing,a decrease in the work hardening effect and an increase in the dynamic recovery effect were obtained due to the formation of fine equiaxed grains,and the increased volume fraction of precipitated phases,which significantly improved the elongation of the alloy.Additionally,the addition of Nd element could enhance the annealing recrystallization rate,reduce the Schmid factor difference between basal and prismatic slip systems,facilitate multi-system slip initiation and improve the alloy plasticity.
文摘BACKGROUND As one of the fatal diseases with high incidence,lung cancer has seriously endangered public health and safety.Elderly patients usually have poor self-care and are more likely to show a series of psychological problems.AIM To investigate the effectiveness of the initial check,information exchange,final accuracy check,reaction(IIFAR)information care model on the mental health status of elderly patients with lung cancer.METHODS This study is a single-centre study.We randomly recruited 60 elderly patients with lung cancer who attended our hospital from January 2021 to January 2022.These elderly patients with lung cancer were randomly divided into two groups,with the control group taking the conventional propaganda and education and the observation group taking the IIFAR information care model based on the conventional care protocol.The differences in psychological distress,anxiety and depression,life quality,fatigue,and the locus of control in psychology were compared between these two groups,and the causes of psychological distress were analyzed.RESULTS After the intervention,Distress Thermometer,Hospital Anxiety and Depression Scale(HADS)for anxiety and the HADS for depression,Revised Piper’s Fatigue Scale,and Chance Health Locus of Control scores were lower in the observation group compared to the pre-intervention period in the same group and were significantly lower in the observation group compared to those of the control group(P<0.05).After the intervention,Quality of Life Questionnaire Core 30(QLQ-C30),Internal Health Locus of Control,and Powerful Others Health Locus of Control scores were significantly higher in the observation and the control groups compared to the pre-intervention period in their same group,and QLQ-C30 scores were significantly higher in the observation group compared to those of the control group(P<0.05).CONCLUSION The IIFAR information care model can help elderly patients with lung cancer by reducing their anxiety and depression,psychological distress,and fatigue,improving their tendencies on the locus of control in psychology,and enhancing their life qualities.
文摘The loss of Baryonic Matter through Black Holes from our spatial 3-D Universe into its 4th dimension as Dark Matter, is used along with the Conservation of Angular Momentum Principle to prove theoretically the accelerated expansion of the 3-D Universe, as has already been confirmed experimentally being awarded the 2011 Nobel Prize in Physics. Theoretical calculations can estimate further to indicate the true nature of the acceleration;that the outward acceleration is due to the rotation of the Universe caused by Dark Energy from the Void, that the acceleration is non-linear, initially increasing from zero for the short period of about a Million years at a constant rate, and then leveling off non-linearly over extended time before the outward acceleration begins to decrease in a non-linear fashion until it is matched by the gravitational attraction of the matter content of 4D Space and the virtual matter in 3-D Vacuum Space. m = m(4D) + m(Virtual). The rotation of our 3D Universe will become constant once all 3D matter has entered 4D space. As the 3-D Universe tries to expand further it will be pulled inward by its gravitational attraction and will then keep on oscillating about a final radius r<sub>f</sub> while it also keeps on oscillating at right angles to the radius r<sub>f</sub> around final angular velocity ω<sub>f</sub>, until it becomes part of the 4-D Universe. The constant value of the Angular Momentum of our Universe is L = .
文摘The most difficult and delicate part of the learning process is assessment.Assessment is difficult because during his/her accomplishment the teacher has to consider not only the acquisition of knowledge from students,but also the overall degree of development of their competencies.It is delicate,because through assessment we can influence the emotional side of students and their“willingness”to learn.Despite these facts,teachers need to evaluate students during the learning process.The purpose of the research is to find out what is the perception of teachers about the level of evaluation of students with final grade.The overall results showed that 89%of teachers agree,9%of them have a neutral attitude,and 2%do not agree that the evaluation of students with a final grade is done taking into account many aspects and using many methods,the overall average of the results,M=4.36.Based on the empirical results,it was found that teachers who have completed assessment training have a more positive approach to student assessment,as the average score is higher than teachers who have not completed assessment training.From the qualitative results it was understood that the Teachers did not encounter any difficulties during the assessment of the students.
文摘After a two-year gap year following high school,I finally departed my hometown in Malaysia for a solo journey to China.Upon arrival,the most frequent question I encountered was:“Why do you Malaysians speak such fluent Mandarin?”Well,not only can we speak and write Mandarin,but many of us are also proficient in dialects such as Hakka,Cantonese,Hokkien,and Teochew.Our mastery of these dialects transcends mere convenience in communication;more importantly,it is about our strong desire to preserve the culture and language of our ancestral homeland:China.Indeed,as an ethnic Chinese person born and raised in Malaysia,my roots are forever tied to China.
文摘One of the most challenging factors affecting impression quality and good marginal fit is the gingival retraction method, which aims to separate the gingiva from the tooth to expose the finishing line of the prepared tooth. Bleeding and contamination from the crevicular fluid may compete for space with the impression material within the sulcus, leading to indistinct preparations and a lack of detail at the margin. In addition, such procedures might damage the PDL and cause permanent recession. Flowable composite cable, as opposed to traditional retraction cords, offers the proper marginal seal and visibility during the impression record because of its lower viscosity, improved adaptability, and elastic properties. The aim of this report is to present a brand-new, innovative method for controlling gingival hemorrhage in addition to the gingival retraction in restorative and prosthodontic treatment by utilizing a flowable composite during the final impression record procedure. In these case reports, the flowable composite cord technique is used instead of traditional gingival cords to modify and refine the gingival tissue before taking the traditional final impression or digital scan. Two cases were done for patients undergoing fixed prosthodontics and veneer treatment within a 2-year follow-up period. In addition, the flowable composite cord was used as temporary restoration before the final prosthetic cementation or under the provisional crowns. As a result, clean and healthy gingival tissues render cementation of the final prosthesis quicker and easier to perform. The patients in both cases claimed that their prosthodontic treatments, which involved the application of a flowable composite cord to temporarily retraction the gingiva, had produced good outcomes at the yearlong follow-up. In conclusion, the flowable composite cord technique is found to be a useful tool to improve the quality of impressions in fixed prosthodontics by providing excellent access for impression material to record fine details of the finish line of the prepared tooth structure, and to alter the inflamed tissue into a healthy tissue.
文摘Thanks to the charitable organization Rescue 2000,an elderly woman who had been living in terrible conditions for 32 years finally has a brand new home.82yearold Ibu Latris former residence provided her with the bare minimal shelter from the elements.However,with the help of generous donors,Rescue 2000 was able to build her a beautiful house where shell be way more comfortable.Cris Araya,the founder of the nonprofit,recently shared footage of Ibus upgraded home.
文摘In the present work,a 5-kW hybrid PV solar system was installed on the roof of a house in Diyala,Iraq(33.77°N,45.14°E elevation 44 m).The system consists of two strings,where each string consists of nine polycrystalline PV modules with 355 Wp in series,and the two strings are in parallel.The energy storage system(ESS)consists of two parallel strings,each with four 12 V and 150 Ah tubular deep cycle batteries in series.A hybrid inverter of 5 kW rated power was operated in different modes.The results showed that May’s monthly energy consumption was about 822.9 and 1085 kWh,respectively.The percentage distribution of the DC energy produced was about 1%system energy losses,27.9%was used to charge the ESS,34.3%was used to feed the grid,and the remaining 37.64%was used to share the load.The energy percentage sharing the load was 16.67%from ESS,33.33%from the PV system,and 50%purchased.The average daily reference,array,and final yields were 6.07,4.327,and 3.991 h/day,respectively.The average array and load efficiencies were 12.3%and 92.24%,with the performance ratio at 65.4%.
文摘Summary1.There are 12 power systems including 5 regional powersystems with over 1000MW of capacity each.In 1989 Central andEast China power systems were interconnected by a±500kV HVDC Line.2.The hierarchical control organization can be divided into 5levels,i.e.NCC,6 RCCs,25 PCCs,250 DCCs and more than 2000CCCs. 3.All control centers will be equipped with SCADA and EMSin the near future.4.China power system has a large,dedicated communicationnetwork of its own.
基金financially supported by the National Natural Science Foundation of China(51972172 and 62205142)the Natural Science Foundation of Jiangsu Province for Distinguished Young Scholars,China(BK20200034)+7 种基金the Jiangsu Provincial Departments of Science and Technology(BE2022023 and BK20220010)the Innovation Project of Optics Valley Laboratory(OVL2021BG006)the Open Project Program of Wuhan National Laboratory for Optoelectronics(2021WNLOKF003)Projects of International Cooperation and Exchanges NSFC(51811530018)the Young 1000 Talents Global Recruitment Program of ChinaInnovation Foundation for Doctor Dissertation of Northwestern Polytechnical University(CX2021041)the Natural Science Basic Research Plan in Shaanxi Province of China(2021JLM-43)the Joint Research Funds of Department of Science and Technology of Shaanxi Province and Northwestern Polytechnical University(2020GXLH-Z007 and 2020GXLH-Z-014)。
文摘1.Introduction Carbon neutrality is an important strategy to address the acute problems of resource and environmental constraints.Currently,afforestation,energy conservation,emissions reduction,and other measures have been adopted to offset the total amount of carbon dioxide and other greenhouse gas emissions generated by countries,businesses,products,activities,or individuals,with the aim of finally achieving zero net emissions(Fig.1(a)).
基金the financial support of the National Key Research and Development Program of China(2020YFA0710202,2018YFC0808805)。
文摘The process of producing high viscosity polyester by transesterification polycondensation needs to adjust the operating conditions and equipment structure of pre-polycondensation kettle and final polycondensation kettle to realize process intensification.In view of this,the fluid volume function method of computational fluid dynamics numerical simulation was used to investigate the film formation and surface renewal characteristics of horizontal polycondensation kettle under different operating conditions,including viscosity,rotating speed and liquid height.The results show that the viscosity and rotating speed were positively correlated with the film area and surface renewal in the pre-polycondensation stage.However,increasing the viscosity by several orders of magnitude in the final polycondensation kettle,the larger the film area and film thickness,but the overall surface renewal of the disk decreased.Therefore,a hexagonal hole disk is designed.By comparison,it is found that the film is more uniform,the surface update frequency is higher,and the power consumption can be reduced by more than 20%.
文摘In the construction process of the Lusail Stadium of the FIFA World Cup-Qatar 2022,over 7,000 constructors of more than 100 companies from 20 plus countries carried out extensive consultation and collaboration,overcame numerous challenges and finally completed the project through close cooperation in global industrial and supply chains.The project showcases the strength of Belt and Road cooperation and becomes a"golden"example of people-to-people connectivity among BRI partnercountries.
文摘Wine and art are our connection to the land.The land at the foot of the Helan Mountains has been quiet for too long between sand and gravel.It wasn't until the 1980s that there was finally human farming on this land for the first time.Wine,for the first time,conveyed the vitality of life and thepowerof millions ofyears ofdeposition.
文摘As China moves to fundamentally improve its virus response by downgrading COVID-19 management to Class B from top-level Class A,one sector that has remained crucial yet bruised by the three-year battle against the disease finally released a sigh of relief.
文摘When Li Dongfang finally arrived at her destination after days and nights of taxing travel,she was welcomed by a starlit sky that was unlike anything she’d ever seen.“The sky was like a big pot lid,and the stars covered me like a quilt,”Li recalled.
文摘The reemergence of busy restaurants and shopping malls and bustling airports and railway stations suggests that the world’s second-largest economy is finally on the mend.Wide-ranging indicators point to an economic resurgence following a decisive exit from pandemic restrictions,leaving many bullish about potential recovery stories.
文摘In regression, despite being both aimed at estimating the Mean Squared Prediction Error (MSPE), Akaike’s Final Prediction Error (FPE) and the Generalized Cross Validation (GCV) selection criteria are usually derived from two quite different perspectives. Here, settling on the most commonly accepted definition of the MSPE as the expectation of the squared prediction error loss, we provide theoretical expressions for it, valid for any linear model (LM) fitter, be it under random or non random designs. Specializing these MSPE expressions for each of them, we are able to derive closed formulas of the MSPE for some of the most popular LM fitters: Ordinary Least Squares (OLS), with or without a full column rank design matrix;Ordinary and Generalized Ridge regression, the latter embedding smoothing splines fitting. For each of these LM fitters, we then deduce a computable estimate of the MSPE which turns out to coincide with Akaike’s FPE. Using a slight variation, we similarly get a class of MSPE estimates coinciding with the classical GCV formula for those same LM fitters.
文摘In this paper, a disease transmission model with two treatment stages is proposed and analyzed. The results indicate that the basic reproduction number is a critical threshold for the prevalence of the disease. If the basic reproduction number is less than one, the disease free equilibrium is globally asymptotically stable. Otherwise, the endemic equilibrium is globally asymptotically stable. Therefore, besides the basic reproduction number, a new marker for characterizing the seriousness of the disease, named as dynamical final infective size, is proposed, which differs from traditional final size because the proposed model includes the natural birth and death. Finally, optimization strategies for limited medical resources are obtained from the perspectives of basic reproduction number and dynamical final infective size, and the real-world disease management scenarios are given based on these finding.