The observation of geomagnetic field variations is an important approach to studying earthquake precursors.Since 1987,the China Earthquake Administration has explored this seismomagnetic relationship.In particular,the...The observation of geomagnetic field variations is an important approach to studying earthquake precursors.Since 1987,the China Earthquake Administration has explored this seismomagnetic relationship.In particular,they studied local magnetic field anomalies over the Chinese mainland for earthquake prediction.Owing to the years of research on the seismomagnetic relationship,earthquake prediction experts have concluded that the compressive magnetic effect,tectonic magnetic effect,electric magnetic fluid effect,and other factors contribute to preearthquake magnetic anomalies.However,this involves a small magnitude of magnetic field changes.It is difficult to relate them to the abnormal changes of the extremely large magnetic field in regions with extreme earthquakes owing to the high cost of professional geomagnetic equipment,thereby limiting large-scale deployment.Moreover,it is difficult to obtain strong magnetic field changes before an earthquake.The Tianjin Earthquake Agency has developed low-cost geomagnetic field observation equipment through the Beijing–Tianjin–Hebei geomagnetic equipment test project.The new system was used to test the availability of equipment and determine the findings based on big data..展开更多
The development of this technology has favored the advances noted in recent years in the field of precise positioning. It has also paved the way for a wide range of research into the evaluation of their performance an...The development of this technology has favored the advances noted in recent years in the field of precise positioning. It has also paved the way for a wide range of research into the evaluation of their performance and reliability, their potential use in different fields, the improvement of performance and combined systems, etc. Single-frequency GNSS receivers, which for a long time remained the only category of low-cost GNSS receivers, often limited by their level of accuracy (metric) mainly due to their single-frequency nature, have been joined in the last decade by dual-frequency GNSS receivers developed by certain manufacturers of positioning equipment. These receivers now offer possible alternatives to the relatively expensive conventional (topographic quality) or geodetic receivers and. In this study, the performance of these low-cost dual-frequency receivers was evaluated in static and real-time kinematic GNSS positioning modes. Static positioning was carried out on three points with sessions of 2 h and 4 h over three days with antenna swapping (CHC i50, Leica GS14 and Emlid Reach RS2+). Real-time observations were carried out on eleven (11) points in open, poorly open and not at all open environments, in order to assess not only performance but also receiver sensitivity in environments with a high risk of multipath. The results obtained showed an average agreement of 2 cm in planimetry between the low-cost Emlid RS2+ receiver and the Leica GS14 and CHC i50 receivers. The differences in altimetry are nevertheless greater (sometimes up to decimetres for certain points). Real-time positioning results provided an average convergence of around 1 cm on the E, N and H components with the results from the low-cost Emlid Reach RS2+ and Ublox ZED-F9P receivers and the CHC i50 receiver. Analysis of the results obtained has enabled us to highlight the various issues and challenges associated with this new generation of GNSS receivers, with a view to enhancing their appropriation and optimal integration in the professional and research worlds.展开更多
The separator is a key component of sodium-ion battery,which greatly affects the electrochemical performances and safety characteristics of the battery.Conventional glass fiber separator cannot meet the requirements o...The separator is a key component of sodium-ion battery,which greatly affects the electrochemical performances and safety characteristics of the battery.Conventional glass fiber separator cannot meet the requirements of large-scale application because of high cost and poor mechanical properties.Herein,the novel composite separators are prepared by a simple slurry sieving process using glass fiber separator scraps and ordinary qualitative filter paper as raw materials.As the composite mass ratio is 1:1,the composite separator has excellent comprehensive properties,including tensile strength of 15.8 MPa,porosity of 74.3%,ionic conductivity of 1.57×10^(-3)S·cm^(-1)and thermal stability at 210℃.The assembled sodium-ion battery shows superior cycling performance(capacity retention of 94.1%after 500 cycles at 1C)and rate capacity(retention rate of 87.3%at 10C),and it maintains fine interface stability.The above results provide some new ideas for the separator design of high-performance and low-cost sodium-ion batteries.展开更多
In the Research Article“A Low-Cost High-Performance Data Augmentation for Deep Learning-Based Skin Lesion Classification,”Zhihong Zhang was erroneously listed as an author.The PDF and HTML(full text)have been correc...In the Research Article“A Low-Cost High-Performance Data Augmentation for Deep Learning-Based Skin Lesion Classification,”Zhihong Zhang was erroneously listed as an author.The PDF and HTML(full text)have been corrected.展开更多
Low-carbon hydrogen can play a significant role in decarbonizing the world. Hydrogen is currently mainly produced from fossil sources,requiring additional CO_(2)capture to decarbonize, which energy intense and costly....Low-carbon hydrogen can play a significant role in decarbonizing the world. Hydrogen is currently mainly produced from fossil sources,requiring additional CO_(2)capture to decarbonize, which energy intense and costly. In a recent Green Energy & Environment paper, Cheng and Di et al. proposed a novel integration process referred to as SECLR_(HC) to generate high-purity H_(2) by in-situ separation of H_(2)and CO without using any additional separation unit. Theoretically, the proposed process can essentially achieve the separation of C and H in gaseous fuel via a reconfigured reaction process, and thus attaining high-purity hydrogen of ~99%, as well as good carbon and hydrogen utilization rates and economic feasibility. It displays an optimistic prospect that industrial decarbonization is not necessarily expensive, as long as a suitable CCS measure can be integrated into the industrial manufacturing process.展开更多
调整双季铵盐表面活性剂与单季铵盐表面活性剂的使用量,通过协同晶化的方式合成了高结晶度、高介孔容的薄层ZSM-5沸石。利用XRD、XRF、SEM、TEM、NH3-TPD、低温氮气物理吸脱附以及27Al MAS NMR对沸石样品进行表征,并评价其甲醇制丙烯反...调整双季铵盐表面活性剂与单季铵盐表面活性剂的使用量,通过协同晶化的方式合成了高结晶度、高介孔容的薄层ZSM-5沸石。利用XRD、XRF、SEM、TEM、NH3-TPD、低温氮气物理吸脱附以及27Al MAS NMR对沸石样品进行表征,并评价其甲醇制丙烯反应(MTP)催化性能。结果表明,薄层沸石的b轴厚度随着双季铵盐表面活性剂使用量的减少而增加,适量的单季铵盐表面活性剂的加入可以起到协同晶化的作用,能够有效稳定胶束,从而调控沸石的形貌。优化2种季铵盐表面活性剂的使用量所得薄层ZSM-5沸石的比表面积和介孔孔容都有所增加,在甲醇制丙烯反应中的活性稳定性也得到较大改善。此外,协同晶化的方式减少了双季铵盐表面活性剂的使用,有利于降低薄层ZSM-5沸石的合成成本。展开更多
In recent years, the sodium storage mechanism and performance optimization of FeS2 have been studied intensively. However, before the commercial application of FeS2, preconditions of low-cost, simple craft and scale p...In recent years, the sodium storage mechanism and performance optimization of FeS2 have been studied intensively. However, before the commercial application of FeS2, preconditions of low-cost, simple craft and scale production of nanoscale FeS2 are also essential. Based on above challenges, mesh-like FeS2/carbon tube/FeS2 composites are prepared simply from green, low-cost and renewable natural herb in this work. With the assistance of protogenetic interconnected carbon tube network(only 5.3 wt%), FeS2/carbon tube/FeS2 composites show high capacity(542.2 mA h g^-1), good stability(< 0.005% per cycle over 1000 cycles), and excellent rate performance(426.2 mA h g^-1 at 2 A g^-1).The outstanding electrochemical performance of FeS2/carbon tube/FeS2 composites may be attributed to the unique interconnected reticular structure, meaning that FeS2 nanoparticles are effectively immobilized by carbon tube network via physical encapsulation and chemical bonding.More importantly, this work may provide green and low cost preparation method for specially structured metal sulfides/carbon composites,which promotes their commercial utilization in environmentally friendly energy storage system.展开更多
By using high-power and high-efficiency propulsion systems,current hybrid electric vehicles(HEVs) in market can achieve excellent fuel economy and kinetic performance.However,it is the cost of current HEVs that hind...By using high-power and high-efficiency propulsion systems,current hybrid electric vehicles(HEVs) in market can achieve excellent fuel economy and kinetic performance.However,it is the cost of current HEVs that hinders HEVs coming into widespread use.A novel hybrid electric propulsion system is designed to balance HEV cost and performance for developing markets.A battery/supercapacitor-based hybrid energy storage system(HESS) is used to improve energy conversion efficiency and reduce battery size and cost.An all-in-one-controller(AIOC) which integrates engine electronic control unit(ECU),motor ECU,and HESS management system is developed to save materials and energy,and reduce the influence of distribution parameters on circuit.As for the powertrain configuration,four schemes are presented:belt-driven starter generator(BSG) scheme,four-wheel drive HEV scheme,full HEV scheme,and ranger-extender electric vehicle(EV) scheme.Component selection and parameter matching for the propulsion system are performed,and an energy management strategy is developed based on powertrain configuration and selected components.Forward-facing simulation models are built,comprehending the control strategy based on the optimal engine torque for the low-cost hybrid electric propulsion system.Co-simulation of AVL CRUISE and Matlab/Simulink is presented and the best scheme is selected.The simulation results indicate that,for the best design,fuel consumption in urban driving condition is 4.11 L/(100 km) and 0-50 km/h accelerating time is 10.95 s.The proposed research can realize low-cost concept for HEV while achieving satisfactory fuel economy and kinetic performance,and help to improve commercialization of HEVs.展开更多
As the smart home is the end-point power consumer, it is the major part to be controlled in a smart micro grid. There are so many challenges for implementing a smart home system in which the most important ones are th...As the smart home is the end-point power consumer, it is the major part to be controlled in a smart micro grid. There are so many challenges for implementing a smart home system in which the most important ones are the cost and simplicity of the implementation method. It is clear that the major share of the total cost is referred to the internal controlling system network; although there are too many methods proposed but still there is not any satisfying method at the consumers' point of view. In this paper, a novel solution for this demand is proposed, which not only minimizes the implementation cost, but also provides a high level of reliability and simplicity of operation; feasibility, extendibility, and flexibility are other leading properties of the design.展开更多
Electrochemical water splitting into hydrogen and oxygen is a promising strategy for future renewable energy conversion devices.The oxygen evolution reaction(OER)is considered as the bottleneck reaction in an overall ...Electrochemical water splitting into hydrogen and oxygen is a promising strategy for future renewable energy conversion devices.The oxygen evolution reaction(OER)is considered as the bottleneck reaction in an overall water splitting system because it involves 4e- and 4H+ transfer processes.Currently,it is highly desirable to explore low-cost alternative catalysts for OER at ambient conditions.Herein,we report for the first time that nickel phosphide(Ni2P)nanosheets can be facilely grown on Fe foam(FF)as an efficient electrocatalyst for OER with excellent durability and catalytic activity under alkaline conditions.To reach a current density of 10 m A/cm2,the Ni2P-FF catalyst required a low overpotential of only 198 mV for OER.The catalyst’s high OER activity and durability were well maintained at a high current density.The required overpotentials were only 267 and 313 mV to achieve the current densities of 100 and 300 m A/cm2,respectively.The combination of low-cost Fe foam with Ni2P provides a promising low-cost catalyst for large-scale application of electrocatalytic water splitting.展开更多
1.IntroductionSince the Nd-Fe-B magnets appearedin 1983,researchers,producers and users ofthe permanent magnetic materials have paidgreat attention to them.Because the mag-nets have low Curie temperature Tc andbad the...1.IntroductionSince the Nd-Fe-B magnets appearedin 1983,researchers,producers and users ofthe permanent magnetic materials have paidgreat attention to them.Because the mag-nets have low Curie temperature Tc andbad thermal stability as well as easeoxidation,their applications are limited insome fields.The researchers are greatly in-terested in increase energy product展开更多
Drinking water is supplied through a centralized water supply system and may not be accessed by communities in rural areas of Malaysia.This study investigated the performance of a low-cost, self-prepared combined acti...Drinking water is supplied through a centralized water supply system and may not be accessed by communities in rural areas of Malaysia.This study investigated the performance of a low-cost, self-prepared combined activated carbon and sand filtration(CACSF) system for roofharvested rainwater and lake water for potable use. Activated carbon was self-prepared using locally sourced coconut shell and was activated using commonly available salt rather than a high-tech procedure that requires a chemical reagent. The filtration chamber was comprised of local,readily available sand. The experiments were conducted with varying antecedent dry intervals(ADIs) of up to 15 d and lake water with varying initial chemical oxygen demand(COD) concentration. The CACSF system managed to produce effluents complying with the drinking water standards for the parameters p H, dissolved oxygen(DO), biochemical oxygen demand(BOD5), COD, total suspended solids(TSS), and ammonia nitrogen(NH_3-N). The CACSF system successfully decreased the population of Escherichia coli(E. coli) in the influents to less than 30 CFU/m L. Samples with a higher population of E. coli(that is, greater than 30 CFU/m L) did not show 100% removal. The system also showed high potential as an alternative for treated drinking water for roof-harvested rainwater and class II lake water.展开更多
Low cost, high performance supercapacitor electrodes were fabricated using coconut waste as precursor. Simple one step pyrolysis is adopted to get the spherical shaped particle where lignocellulosic nature of carbon c...Low cost, high performance supercapacitor electrodes were fabricated using coconut waste as precursor. Simple one step pyrolysis is adopted to get the spherical shaped particle where lignocellulosic nature of carbon converts into porous carbon nanospheres. Three types of coconut wastes, namely, coconut fiber(CF), coconut leaves(CL) and coconut stick(CS) have been studied and compared for their application in supercapacitors. Uniform spherical shape with particle size ranging from 30 to 60 nm for leaves and sticks and20 nm for fibers was obtained. The electrochemical properties of the porous carbon nanospheres were studied using cyclic voltammetry(CV), chronopotentiometry(CP) and electrochemical impedance spectroscopy(EIS). The porous carbon nanospheres derived from all the three biowaste samples show good electrochemical performance for supercapacitor application. Porous carbon nanospheres derived from coconut fiber exhibited maximum specific capacitance of 236 F/g followed by coconut stick and coconut leaves with 208 and 116 F/g respectively at a scan rate of 2 m V/s. Further impedance studies showed a charge transfer resistance of 4.9 for the porous carbon nanospheres derived from coconut fiber, while those from coconut leaves and coconut stick exhibited a slightly higher resistance of 6 and14.2, respectively. The simple eco-friendly approach we have demonstrated for synthesizing coconut waste based carbon nanospheres makes them excellent candidates for future, low-cost, energy storage devices.展开更多
DNA methylation has been extensively investigated in recent years,not least because of its known relationship with various diseases.Progress in analytical methods can greatly increase the relevance of DNA methylation ...DNA methylation has been extensively investigated in recent years,not least because of its known relationship with various diseases.Progress in analytical methods can greatly increase the relevance of DNA methylation studies to both clinical medicine and scientific research.Microflu-idic chips are excellent carriers for molecular analysis,and their use can provide improvements from multiple aspects.On-chip molecular analysis has received extensive attention owing to its advantages of portability,high throughput,low cost,and high efficiency.In recent years,the use of novel microfluidic chips for DNA methylation analysis has been widely reported and has shown obvious superiority to conventional methods.In this review,wefirst focus on DNA methylation and its applications.Then,we discuss advanced microfluidic-based methods for DNA methylation analysis and describe the great progress that has been made in recent years.Finally,we summarize the advantages that microfluidic technology brings to DNA methylation analysis and describe several challenges and perspectives for on-chip DNA methylation analysis.This review should help researchers improve their understanding and make progress in developing microfluidic-based methods for DNA methylation analysis.展开更多
Silicoaluminophosphate-34(SAPO-34) molecular sieves have important applications in the petrochemical industry as a result of their shape selectivity and suitable acidity. In this work, nanoaggregate SAPO-34 with a lar...Silicoaluminophosphate-34(SAPO-34) molecular sieves have important applications in the petrochemical industry as a result of their shape selectivity and suitable acidity. In this work, nanoaggregate SAPO-34 with a large external surface area was obtained by dissolving pseudoboehmite and tetraethylorthosilicate in an aqueous solution of tetraethylammonium hydroxide and subsequently adding phosphoric acid. After hydrolysis in an alkaline solution, the aluminum and silicon precursors exist as Al(OH)4-and SiO2(OH)-, respectively;this is beneficial for rapid nucleation and the formation of nanoaggregates in the following crystallization process. Additionally, to study the effect of the external surface area and pore size on the catalytic performance of different SAPO-34 structures, the alcoholysis of furfuryl alcohol to ethyl levulinate(EL) was chosen as a model reaction. In a comparison with the traditional cube-like SAPO-34, nanoaggregate SAPO-34 generated a higher yield of 74.1% of EL, whereas that with cube-like SAPO-34 was only 19.9%. Moreover, the stability was remarkably enhanced for nanoaggregate SAPO-34. The greater external surface area and larger number of external surface acid sites are helpful in improving the catalytic performance and avoiding coke deposition.展开更多
Protein-energy malnutrition among children is the major health challenges and it may be related to low nutritional quality of traditional complementary foods and high cost of quality protein-based complementary foods....Protein-energy malnutrition among children is the major health challenges and it may be related to low nutritional quality of traditional complementary foods and high cost of quality protein-based complementary foods. The aim of this study was formulation, preparation and evaluation of low-cost extruded products based on cereals and pulses. Composite flours were prepared using cereals and pulses, then formulated and extruded by a twin screw extruder in Osmania University, Hyderabad, India. Data were analyzed by SPSS software. Results showed: the protein contents of extruded formulas B, D and F were in the highest values. Carbohydrate in the extruded formula A was significantly higher than others. The lowest amount of ash and crude fiber were observed in the formula A. Content of energy in the extruded formulas E, F and C was higher;mean (SD) of Fe content in the extruded formula B, D and F was in the higher ranks among others. Calcium content in the extruded formulas C, E and F was in the highest amounts. Magnesium content in the extruded formulas B, D and F was higher than others. Cu content in the extruded formula C, D, B and F was higher than others. Manganese content in the extruded formulas B, C and F, and zinc content in the formulas B, D and F were higher than others. Tap density showed the lowest amount in the formula B, D and F, while their bulk density was higher. WHC was in the highest amount in the extruded formula A, while WSI in the extruded formula B, D and followed by F was in the highest amount. The mean scores of sensory evaluation of extruded products F showed that this combination has significantly better colour, flavour, texture and overall acceptability than others.展开更多
The amorphous boron nitride ceramic powders were prepared at 750-950 ℃ by the low-cost urea route, and the effects of preparation temperatures, molar ratios of the raw materials and oxidation treatment on the composi...The amorphous boron nitride ceramic powders were prepared at 750-950 ℃ by the low-cost urea route, and the effects of preparation temperatures, molar ratios of the raw materials and oxidation treatment on the composition, structure and surface morphology of the products were investigated through FT-IR, XRD and SEM. The results show that the products ceramize and crystallize gradually with the increase of the temperature. When the molar ratio and reaction temperature are 3:2 and 850 ℃, respectively, the products have high purity, compact structure and nice shape. The oxidation treatment at 450 ℃ will not impair the composition and structure of boron nitride but effectively remove the impurities.展开更多
The necessity of having an effective computer-aided decision support system in the housing construction industry is rapidly growing alongside the demand for green buildings and green building products. Identifying and...The necessity of having an effective computer-aided decision support system in the housing construction industry is rapidly growing alongside the demand for green buildings and green building products. Identifying and defining financially viable low-cost green building materials and components, just like selecting them, is a crucial exercise in subjectivity. With so many variables to consider, the task of evaluating such products can be complex and discouraging. Moreover, the existing mode for selecting and managing, often very large information associated with their impacts constrains decision-makers to perform a trade-off analysis that does not necessarily guarantee the most environmentally preferable material. This paper introduces the development of a multi-criteria decision support system (DSS) aimed at improving the understanding of the principles of best practices associated with the impacts of low-cost green building materials and components. The DSS presented in this paper is to provide designers with useful and explicit information that will aid informed decision-making in their choice of materials for low-cost green residential housing projects. The prototype MSDSS is developed using macro-in-excel, which is a fairly recent database management technique used for integrating data from multiple, often very large databases and other information sources. This model consists of a database to store different types of low-cost green materials with their corresponding attributes and performance characteristics. The DSS design is illustrated with particular emphasis on the development of the material selection data schema, and application of the Analytical Hierarchy Process (AHP) concept to a material selection problem. Details of the MSDSS model are also discussed including workflow of the data evaluation process. The prototype model has been developed with inputs elicited from domain experts and extensive literature review, and refined with feedback obtained from selected expert builder and developer companies. This paper further demonstrates the application of the prototype MSDSS for selecting the most appropriate low-cost green building material from among a list of several available options, and finally concludes the study with the associated potential benefits of the model to research and practice.展开更多
The main focus of this work was to design, develop and implementation of competitively robot arm with en- hanced control and stumpy cost. The robot arm was designed with four degrees of freedom and talented to accompl...The main focus of this work was to design, develop and implementation of competitively robot arm with en- hanced control and stumpy cost. The robot arm was designed with four degrees of freedom and talented to accomplish accurately simple tasks, such as light material handling, which will be integrated into a mobile platform that serves as an assistant for industrial workforce. The robot arm is equipped with several servo motors which do links between arms and perform arm movements. The servo motors include encoder so that no controller was implemented. To control the robot we used Labview, which performs inverse kinematic calculations and communicates the proper angles serially to a microcontroller that drives the servo motors with the capability of modifying position, speed and acceleration. Testing and validation of the robot arm was carried out and results shows that it work properly.展开更多
Hydrological monitoring and real-time access to data are valuable for hydrological research and water resources management. In the recent decades, rapid developments in digital technology, micro-electromechanical syst...Hydrological monitoring and real-time access to data are valuable for hydrological research and water resources management. In the recent decades, rapid developments in digital technology, micro-electromechanical systems, low power micro-sensing technologies and improved industrial manufacturing processes have resulted in retrieving real-time data through Wireless Sensor Networks (WSNs) systems. In this study, a remotely operated low-cost and robust WSN system was developed to monitor and collect real-time hydrologic data from a small agricultural watershed in harsh weather conditions and upland rolling topography of Southern Ontario, Canada. The WSN system was assembled using off-the-shelf hardware components, and an open source operating system was used to minimize the cost. The developed system was rigorously tested in the laboratory and the field and found to be accurate and reliable for monitoring climatic and hydrologic parameters. The soil moisture and runoff data for 7 springs, 19 summer, and 19 fall season rainfall events over the period of more than two years were successfully collected in a small experimental agricultural watershed situated near Elora, Ontario, Canada. The developed WSN system can be readily extended for the purpose of most hydrological monitoring applications, although it was explicitly tailored for a project focused on mapping the Variable Source Areas (VSAs) in a small agricultural watershed.展开更多
基金supported by the Spark Program of Earthquake Science and Technology(No.XH23003C).
文摘The observation of geomagnetic field variations is an important approach to studying earthquake precursors.Since 1987,the China Earthquake Administration has explored this seismomagnetic relationship.In particular,they studied local magnetic field anomalies over the Chinese mainland for earthquake prediction.Owing to the years of research on the seismomagnetic relationship,earthquake prediction experts have concluded that the compressive magnetic effect,tectonic magnetic effect,electric magnetic fluid effect,and other factors contribute to preearthquake magnetic anomalies.However,this involves a small magnitude of magnetic field changes.It is difficult to relate them to the abnormal changes of the extremely large magnetic field in regions with extreme earthquakes owing to the high cost of professional geomagnetic equipment,thereby limiting large-scale deployment.Moreover,it is difficult to obtain strong magnetic field changes before an earthquake.The Tianjin Earthquake Agency has developed low-cost geomagnetic field observation equipment through the Beijing–Tianjin–Hebei geomagnetic equipment test project.The new system was used to test the availability of equipment and determine the findings based on big data..
文摘The development of this technology has favored the advances noted in recent years in the field of precise positioning. It has also paved the way for a wide range of research into the evaluation of their performance and reliability, their potential use in different fields, the improvement of performance and combined systems, etc. Single-frequency GNSS receivers, which for a long time remained the only category of low-cost GNSS receivers, often limited by their level of accuracy (metric) mainly due to their single-frequency nature, have been joined in the last decade by dual-frequency GNSS receivers developed by certain manufacturers of positioning equipment. These receivers now offer possible alternatives to the relatively expensive conventional (topographic quality) or geodetic receivers and. In this study, the performance of these low-cost dual-frequency receivers was evaluated in static and real-time kinematic GNSS positioning modes. Static positioning was carried out on three points with sessions of 2 h and 4 h over three days with antenna swapping (CHC i50, Leica GS14 and Emlid Reach RS2+). Real-time observations were carried out on eleven (11) points in open, poorly open and not at all open environments, in order to assess not only performance but also receiver sensitivity in environments with a high risk of multipath. The results obtained showed an average agreement of 2 cm in planimetry between the low-cost Emlid RS2+ receiver and the Leica GS14 and CHC i50 receivers. The differences in altimetry are nevertheless greater (sometimes up to decimetres for certain points). Real-time positioning results provided an average convergence of around 1 cm on the E, N and H components with the results from the low-cost Emlid Reach RS2+ and Ublox ZED-F9P receivers and the CHC i50 receiver. Analysis of the results obtained has enabled us to highlight the various issues and challenges associated with this new generation of GNSS receivers, with a view to enhancing their appropriation and optimal integration in the professional and research worlds.
基金financially supported by the National Natural Science Foundation of China (Nos.52002106,22262013,and 52102261)the Talent Project of Anhui Provincial Department of Education (Nos.gxyqZD2021127 and gxbjZ D2022050)+1 种基金the Natural Science Foundation of Anhui Province,China (Nos.2108085QB68,2208085QB34,and2022AH052157)the Research Funds for Hefei Normal University (Nos.14098100 and 2021cyxy061)。
文摘The separator is a key component of sodium-ion battery,which greatly affects the electrochemical performances and safety characteristics of the battery.Conventional glass fiber separator cannot meet the requirements of large-scale application because of high cost and poor mechanical properties.Herein,the novel composite separators are prepared by a simple slurry sieving process using glass fiber separator scraps and ordinary qualitative filter paper as raw materials.As the composite mass ratio is 1:1,the composite separator has excellent comprehensive properties,including tensile strength of 15.8 MPa,porosity of 74.3%,ionic conductivity of 1.57×10^(-3)S·cm^(-1)and thermal stability at 210℃.The assembled sodium-ion battery shows superior cycling performance(capacity retention of 94.1%after 500 cycles at 1C)and rate capacity(retention rate of 87.3%at 10C),and it maintains fine interface stability.The above results provide some new ideas for the separator design of high-performance and low-cost sodium-ion batteries.
文摘In the Research Article“A Low-Cost High-Performance Data Augmentation for Deep Learning-Based Skin Lesion Classification,”Zhihong Zhang was erroneously listed as an author.The PDF and HTML(full text)have been corrected.
文摘Low-carbon hydrogen can play a significant role in decarbonizing the world. Hydrogen is currently mainly produced from fossil sources,requiring additional CO_(2)capture to decarbonize, which energy intense and costly. In a recent Green Energy & Environment paper, Cheng and Di et al. proposed a novel integration process referred to as SECLR_(HC) to generate high-purity H_(2) by in-situ separation of H_(2)and CO without using any additional separation unit. Theoretically, the proposed process can essentially achieve the separation of C and H in gaseous fuel via a reconfigured reaction process, and thus attaining high-purity hydrogen of ~99%, as well as good carbon and hydrogen utilization rates and economic feasibility. It displays an optimistic prospect that industrial decarbonization is not necessarily expensive, as long as a suitable CCS measure can be integrated into the industrial manufacturing process.
文摘调整双季铵盐表面活性剂与单季铵盐表面活性剂的使用量,通过协同晶化的方式合成了高结晶度、高介孔容的薄层ZSM-5沸石。利用XRD、XRF、SEM、TEM、NH3-TPD、低温氮气物理吸脱附以及27Al MAS NMR对沸石样品进行表征,并评价其甲醇制丙烯反应(MTP)催化性能。结果表明,薄层沸石的b轴厚度随着双季铵盐表面活性剂使用量的减少而增加,适量的单季铵盐表面活性剂的加入可以起到协同晶化的作用,能够有效稳定胶束,从而调控沸石的形貌。优化2种季铵盐表面活性剂的使用量所得薄层ZSM-5沸石的比表面积和介孔孔容都有所增加,在甲醇制丙烯反应中的活性稳定性也得到较大改善。此外,协同晶化的方式减少了双季铵盐表面活性剂的使用,有利于降低薄层ZSM-5沸石的合成成本。
基金supported by the Natural Science Foundation of China (Grant No. U1804126, U1804129, 21671205, 21771164 and 21701202)Key Scientific Research Projects of Universities in Henan Province (Grant No. 19A430032 and 18A430034)+2 种基金Program for Interdisciplinary Direction Team in Zhongyuan University of Technologythe Collaborative Innovation Centre of Henan Textile and Clothing Industrythe Innovation Scientists and Technicians Troop Construction Projects of Henan Province (Grant No. 164100510007 and CXTD2015018)
文摘In recent years, the sodium storage mechanism and performance optimization of FeS2 have been studied intensively. However, before the commercial application of FeS2, preconditions of low-cost, simple craft and scale production of nanoscale FeS2 are also essential. Based on above challenges, mesh-like FeS2/carbon tube/FeS2 composites are prepared simply from green, low-cost and renewable natural herb in this work. With the assistance of protogenetic interconnected carbon tube network(only 5.3 wt%), FeS2/carbon tube/FeS2 composites show high capacity(542.2 mA h g^-1), good stability(< 0.005% per cycle over 1000 cycles), and excellent rate performance(426.2 mA h g^-1 at 2 A g^-1).The outstanding electrochemical performance of FeS2/carbon tube/FeS2 composites may be attributed to the unique interconnected reticular structure, meaning that FeS2 nanoparticles are effectively immobilized by carbon tube network via physical encapsulation and chemical bonding.More importantly, this work may provide green and low cost preparation method for specially structured metal sulfides/carbon composites,which promotes their commercial utilization in environmentally friendly energy storage system.
基金supported by General Motors (Low-cost Hybrid Electric Propulsion System)
文摘By using high-power and high-efficiency propulsion systems,current hybrid electric vehicles(HEVs) in market can achieve excellent fuel economy and kinetic performance.However,it is the cost of current HEVs that hinders HEVs coming into widespread use.A novel hybrid electric propulsion system is designed to balance HEV cost and performance for developing markets.A battery/supercapacitor-based hybrid energy storage system(HESS) is used to improve energy conversion efficiency and reduce battery size and cost.An all-in-one-controller(AIOC) which integrates engine electronic control unit(ECU),motor ECU,and HESS management system is developed to save materials and energy,and reduce the influence of distribution parameters on circuit.As for the powertrain configuration,four schemes are presented:belt-driven starter generator(BSG) scheme,four-wheel drive HEV scheme,full HEV scheme,and ranger-extender electric vehicle(EV) scheme.Component selection and parameter matching for the propulsion system are performed,and an energy management strategy is developed based on powertrain configuration and selected components.Forward-facing simulation models are built,comprehending the control strategy based on the optimal engine torque for the low-cost hybrid electric propulsion system.Co-simulation of AVL CRUISE and Matlab/Simulink is presented and the best scheme is selected.The simulation results indicate that,for the best design,fuel consumption in urban driving condition is 4.11 L/(100 km) and 0-50 km/h accelerating time is 10.95 s.The proposed research can realize low-cost concept for HEV while achieving satisfactory fuel economy and kinetic performance,and help to improve commercialization of HEVs.
文摘As the smart home is the end-point power consumer, it is the major part to be controlled in a smart micro grid. There are so many challenges for implementing a smart home system in which the most important ones are the cost and simplicity of the implementation method. It is clear that the major share of the total cost is referred to the internal controlling system network; although there are too many methods proposed but still there is not any satisfying method at the consumers' point of view. In this paper, a novel solution for this demand is proposed, which not only minimizes the implementation cost, but also provides a high level of reliability and simplicity of operation; feasibility, extendibility, and flexibility are other leading properties of the design.
基金financially supported by the National Key Research and Development Program of China (2017YFA0402800)the National Natural Science Foundation of China (51772285)the National Synchrotron Radiation Laboratory at USTC.
文摘Electrochemical water splitting into hydrogen and oxygen is a promising strategy for future renewable energy conversion devices.The oxygen evolution reaction(OER)is considered as the bottleneck reaction in an overall water splitting system because it involves 4e- and 4H+ transfer processes.Currently,it is highly desirable to explore low-cost alternative catalysts for OER at ambient conditions.Herein,we report for the first time that nickel phosphide(Ni2P)nanosheets can be facilely grown on Fe foam(FF)as an efficient electrocatalyst for OER with excellent durability and catalytic activity under alkaline conditions.To reach a current density of 10 m A/cm2,the Ni2P-FF catalyst required a low overpotential of only 198 mV for OER.The catalyst’s high OER activity and durability were well maintained at a high current density.The required overpotentials were only 267 and 313 mV to achieve the current densities of 100 and 300 m A/cm2,respectively.The combination of low-cost Fe foam with Ni2P provides a promising low-cost catalyst for large-scale application of electrocatalytic water splitting.
文摘1.IntroductionSince the Nd-Fe-B magnets appearedin 1983,researchers,producers and users ofthe permanent magnetic materials have paidgreat attention to them.Because the mag-nets have low Curie temperature Tc andbad thermal stability as well as easeoxidation,their applications are limited insome fields.The researchers are greatly in-terested in increase energy product
基金supported by the Universiti Kebangsaan Malaysia Grant(Grant No.GUP-2014-077)
文摘Drinking water is supplied through a centralized water supply system and may not be accessed by communities in rural areas of Malaysia.This study investigated the performance of a low-cost, self-prepared combined activated carbon and sand filtration(CACSF) system for roofharvested rainwater and lake water for potable use. Activated carbon was self-prepared using locally sourced coconut shell and was activated using commonly available salt rather than a high-tech procedure that requires a chemical reagent. The filtration chamber was comprised of local,readily available sand. The experiments were conducted with varying antecedent dry intervals(ADIs) of up to 15 d and lake water with varying initial chemical oxygen demand(COD) concentration. The CACSF system managed to produce effluents complying with the drinking water standards for the parameters p H, dissolved oxygen(DO), biochemical oxygen demand(BOD5), COD, total suspended solids(TSS), and ammonia nitrogen(NH_3-N). The CACSF system successfully decreased the population of Escherichia coli(E. coli) in the influents to less than 30 CFU/m L. Samples with a higher population of E. coli(that is, greater than 30 CFU/m L) did not show 100% removal. The system also showed high potential as an alternative for treated drinking water for roof-harvested rainwater and class II lake water.
文摘Low cost, high performance supercapacitor electrodes were fabricated using coconut waste as precursor. Simple one step pyrolysis is adopted to get the spherical shaped particle where lignocellulosic nature of carbon converts into porous carbon nanospheres. Three types of coconut wastes, namely, coconut fiber(CF), coconut leaves(CL) and coconut stick(CS) have been studied and compared for their application in supercapacitors. Uniform spherical shape with particle size ranging from 30 to 60 nm for leaves and sticks and20 nm for fibers was obtained. The electrochemical properties of the porous carbon nanospheres were studied using cyclic voltammetry(CV), chronopotentiometry(CP) and electrochemical impedance spectroscopy(EIS). The porous carbon nanospheres derived from all the three biowaste samples show good electrochemical performance for supercapacitor application. Porous carbon nanospheres derived from coconut fiber exhibited maximum specific capacitance of 236 F/g followed by coconut stick and coconut leaves with 208 and 116 F/g respectively at a scan rate of 2 m V/s. Further impedance studies showed a charge transfer resistance of 4.9 for the porous carbon nanospheres derived from coconut fiber, while those from coconut leaves and coconut stick exhibited a slightly higher resistance of 6 and14.2, respectively. The simple eco-friendly approach we have demonstrated for synthesizing coconut waste based carbon nanospheres makes them excellent candidates for future, low-cost, energy storage devices.
基金support from the National Key R&D Program of China(Grant No.2018YFE0118700)the National Natural Science Foundation of China(NSFC Grant No.62174119)+1 种基金the 111 Project(Grant No.B07014)the Foundation for Talent Scientists of Nanchang Institute for Microtechnology of Tianjin University.
文摘DNA methylation has been extensively investigated in recent years,not least because of its known relationship with various diseases.Progress in analytical methods can greatly increase the relevance of DNA methylation studies to both clinical medicine and scientific research.Microflu-idic chips are excellent carriers for molecular analysis,and their use can provide improvements from multiple aspects.On-chip molecular analysis has received extensive attention owing to its advantages of portability,high throughput,low cost,and high efficiency.In recent years,the use of novel microfluidic chips for DNA methylation analysis has been widely reported and has shown obvious superiority to conventional methods.In this review,wefirst focus on DNA methylation and its applications.Then,we discuss advanced microfluidic-based methods for DNA methylation analysis and describe the great progress that has been made in recent years.Finally,we summarize the advantages that microfluidic technology brings to DNA methylation analysis and describe several challenges and perspectives for on-chip DNA methylation analysis.This review should help researchers improve their understanding and make progress in developing microfluidic-based methods for DNA methylation analysis.
文摘Silicoaluminophosphate-34(SAPO-34) molecular sieves have important applications in the petrochemical industry as a result of their shape selectivity and suitable acidity. In this work, nanoaggregate SAPO-34 with a large external surface area was obtained by dissolving pseudoboehmite and tetraethylorthosilicate in an aqueous solution of tetraethylammonium hydroxide and subsequently adding phosphoric acid. After hydrolysis in an alkaline solution, the aluminum and silicon precursors exist as Al(OH)4-and SiO2(OH)-, respectively;this is beneficial for rapid nucleation and the formation of nanoaggregates in the following crystallization process. Additionally, to study the effect of the external surface area and pore size on the catalytic performance of different SAPO-34 structures, the alcoholysis of furfuryl alcohol to ethyl levulinate(EL) was chosen as a model reaction. In a comparison with the traditional cube-like SAPO-34, nanoaggregate SAPO-34 generated a higher yield of 74.1% of EL, whereas that with cube-like SAPO-34 was only 19.9%. Moreover, the stability was remarkably enhanced for nanoaggregate SAPO-34. The greater external surface area and larger number of external surface acid sites are helpful in improving the catalytic performance and avoiding coke deposition.
文摘Protein-energy malnutrition among children is the major health challenges and it may be related to low nutritional quality of traditional complementary foods and high cost of quality protein-based complementary foods. The aim of this study was formulation, preparation and evaluation of low-cost extruded products based on cereals and pulses. Composite flours were prepared using cereals and pulses, then formulated and extruded by a twin screw extruder in Osmania University, Hyderabad, India. Data were analyzed by SPSS software. Results showed: the protein contents of extruded formulas B, D and F were in the highest values. Carbohydrate in the extruded formula A was significantly higher than others. The lowest amount of ash and crude fiber were observed in the formula A. Content of energy in the extruded formulas E, F and C was higher;mean (SD) of Fe content in the extruded formula B, D and F was in the higher ranks among others. Calcium content in the extruded formulas C, E and F was in the highest amounts. Magnesium content in the extruded formulas B, D and F was higher than others. Cu content in the extruded formula C, D, B and F was higher than others. Manganese content in the extruded formulas B, C and F, and zinc content in the formulas B, D and F were higher than others. Tap density showed the lowest amount in the formula B, D and F, while their bulk density was higher. WHC was in the highest amount in the extruded formula A, while WSI in the extruded formula B, D and followed by F was in the highest amount. The mean scores of sensory evaluation of extruded products F showed that this combination has significantly better colour, flavour, texture and overall acceptability than others.
基金Funded by the National Natural Science Foundation of China (Nos.50902150 & 90916019)the Graduate Innovation Foundation of the National University of Defense Technology(No.S100103)
文摘The amorphous boron nitride ceramic powders were prepared at 750-950 ℃ by the low-cost urea route, and the effects of preparation temperatures, molar ratios of the raw materials and oxidation treatment on the composition, structure and surface morphology of the products were investigated through FT-IR, XRD and SEM. The results show that the products ceramize and crystallize gradually with the increase of the temperature. When the molar ratio and reaction temperature are 3:2 and 850 ℃, respectively, the products have high purity, compact structure and nice shape. The oxidation treatment at 450 ℃ will not impair the composition and structure of boron nitride but effectively remove the impurities.
文摘The necessity of having an effective computer-aided decision support system in the housing construction industry is rapidly growing alongside the demand for green buildings and green building products. Identifying and defining financially viable low-cost green building materials and components, just like selecting them, is a crucial exercise in subjectivity. With so many variables to consider, the task of evaluating such products can be complex and discouraging. Moreover, the existing mode for selecting and managing, often very large information associated with their impacts constrains decision-makers to perform a trade-off analysis that does not necessarily guarantee the most environmentally preferable material. This paper introduces the development of a multi-criteria decision support system (DSS) aimed at improving the understanding of the principles of best practices associated with the impacts of low-cost green building materials and components. The DSS presented in this paper is to provide designers with useful and explicit information that will aid informed decision-making in their choice of materials for low-cost green residential housing projects. The prototype MSDSS is developed using macro-in-excel, which is a fairly recent database management technique used for integrating data from multiple, often very large databases and other information sources. This model consists of a database to store different types of low-cost green materials with their corresponding attributes and performance characteristics. The DSS design is illustrated with particular emphasis on the development of the material selection data schema, and application of the Analytical Hierarchy Process (AHP) concept to a material selection problem. Details of the MSDSS model are also discussed including workflow of the data evaluation process. The prototype model has been developed with inputs elicited from domain experts and extensive literature review, and refined with feedback obtained from selected expert builder and developer companies. This paper further demonstrates the application of the prototype MSDSS for selecting the most appropriate low-cost green building material from among a list of several available options, and finally concludes the study with the associated potential benefits of the model to research and practice.
文摘The main focus of this work was to design, develop and implementation of competitively robot arm with en- hanced control and stumpy cost. The robot arm was designed with four degrees of freedom and talented to accomplish accurately simple tasks, such as light material handling, which will be integrated into a mobile platform that serves as an assistant for industrial workforce. The robot arm is equipped with several servo motors which do links between arms and perform arm movements. The servo motors include encoder so that no controller was implemented. To control the robot we used Labview, which performs inverse kinematic calculations and communicates the proper angles serially to a microcontroller that drives the servo motors with the capability of modifying position, speed and acceleration. Testing and validation of the robot arm was carried out and results shows that it work properly.
文摘Hydrological monitoring and real-time access to data are valuable for hydrological research and water resources management. In the recent decades, rapid developments in digital technology, micro-electromechanical systems, low power micro-sensing technologies and improved industrial manufacturing processes have resulted in retrieving real-time data through Wireless Sensor Networks (WSNs) systems. In this study, a remotely operated low-cost and robust WSN system was developed to monitor and collect real-time hydrologic data from a small agricultural watershed in harsh weather conditions and upland rolling topography of Southern Ontario, Canada. The WSN system was assembled using off-the-shelf hardware components, and an open source operating system was used to minimize the cost. The developed system was rigorously tested in the laboratory and the field and found to be accurate and reliable for monitoring climatic and hydrologic parameters. The soil moisture and runoff data for 7 springs, 19 summer, and 19 fall season rainfall events over the period of more than two years were successfully collected in a small experimental agricultural watershed situated near Elora, Ontario, Canada. The developed WSN system can be readily extended for the purpose of most hydrological monitoring applications, although it was explicitly tailored for a project focused on mapping the Variable Source Areas (VSAs) in a small agricultural watershed.