Membrane desalination is an economical and energy-efficient method to meet the current worldwide water scarcity.However,state-of-the-art reverse osmosis membranes are gradually being replaced by novel membrane materia...Membrane desalination is an economical and energy-efficient method to meet the current worldwide water scarcity.However,state-of-the-art reverse osmosis membranes are gradually being replaced by novel membrane materials as a result of ongoing technological advancements.These novel materials possess intrinsic pore structures or can be assembled to form lamellar membrane channels for selective transport of water or solutes(e.g.,NaCl).Still,in real applications,the results fall below the theoretical predictions,and a few properties,including large-scale fabrication,mechanical strength,and chemical stability,also have an impact on the overall effectiveness of those materials.In view of this,we develop a new evaluation framework in the form of radar charts with five dimensions(i.e.,water permeance,water/NaCl selectivity,membrane cost,scale of development,and stability)to assess the advantages,disadvantages,and potential of state-of-the-art and newly developed desalination membranes.In this framework,the reported thin film nanocomposite membranes and membranes developed from novel materials were compared with the state-of-the-art thin film composite membranes.This review will demonstrate the current advancements in novel membrane materials and bridge the gap between different desalination membranes.In this review,we also point out the prospects and challenges of next-generation membranes for desalination applications.We believe that this comprehensive framework may be used as a future reference for designing next-generation desalination membranes and will encourage further research and development in the field of membrane technology,leading to new insights and advancements.展开更多
The paper aims at providing a computerized design environment to support product design practically. The authors solved this problem by taking the product life-cycle issues into consideration as more as possible durin...The paper aims at providing a computerized design environment to support product design practically. The authors solved this problem by taking the product life-cycle issues into consideration as more as possible during the design process from the designer-oriented perspective of view. Design for X-abilities (DFX) is an effective approach to this philosophy. So the paper mainly presents the infrastructure of an intelligent DFX mechanism which is the essential part of the developed product design environment. At first the designer-oriented computer environment DesignerSpace is introduced for understanding the designer how to implement design activities and DFX method better. In order to integrate design knowledge from downstream aspects for the optimization and the design decision-making, an intelligent DFX mechanism is developed to incorporate knowledge base, algorithm-base and monitoring/debugging tools. DesignerSpace is implemented with DFX abilities and applied to the blisk design of aircraft engine and the further development is strongly intended.展开更多
This paper presents a novel approach to design a compact circular rat-race coupler with an ultrawide stopband, with the aim to reduce its size while maintaining performance. The design methodology begins with a common...This paper presents a novel approach to design a compact circular rat-race coupler with an ultrawide stopband, with the aim to reduce its size while maintaining performance. The design methodology begins with a common miniaturization technique to replace the conventional quarter-wavelength transmission line with an equivalent low-pass filter loaded with parallel coupled line and radial stubs. Since the latter leads to produce higher order harmonics, parasitic open-ended stubs are then properly introduced in the structure not only to overcome the issue but also to produce controllable transmission zeros. A versatile analytical model is also developed taking into account manufacturing restrictions, which makes it possible to extract the physical parameters of the coupler unit-cell for a given desired compactness percentage with respect to the conventional rat-race coupler. A prototype is fabricated and measured to validate the design,demonstrating the predicted behavior fairly achieved by numerical analysis. A significant size reduction of about 86.1% was achieved compared to the conventional design, while effectively suppressing higher order modes up to 23.4 GHz(including the 13th harmonic based on |S11|>-5 dB and |S21|<-17 dB)with high isolation level(|S41|<-17 dB) between the ports.展开更多
Dryopteridaceae are the largest fern family and include nearly 20%of extant fern diversity,with 24 currently recognized genera.Recognition and delineation of genera within this family have varied greatly.The three-sub...Dryopteridaceae are the largest fern family and include nearly 20%of extant fern diversity,with 24 currently recognized genera.Recognition and delineation of genera within this family have varied greatly.The three-subfamily classification of Dryopteridaceae was based primarily on molecular phylogenetic relationships but lacked morphological evidence,and the phylogenetic relationships of the subfamilies and genera of Dryopteridaceae are only partially resolved.A comprehensive and robust phylogeny is urgently needed.The heterogeneous morphology of the current members of Dryopteridaceae makes the family and its subfamilies difficult to define by single morphological characteristics or even character combinations.We carried out phylogenetic analyses to reconstruct a highly supported phylogeny of Dryopteridaceae.Our analyses recovered 24 strongly supported clades grouped into seven major clades of Dryopteridaceae.Seven morphological characters including habit,rhizome shape,frond morphology,rachis-costae architecture,appendages on stipe base and lamina,and soral arrangement were found to be informative for identifying different major clades and clades in Dryopteridaceae.Based on phylogenetic reconstruction and morphological analysis,we presented an updated infra-familial classification of Dryopteridaceae with seven subfamilies and 24 genera including four newly proposed subfamilies(Ctenitidoideae,Lastreopsidoideae,Pleocnemioideae,and Polystichopsidoideae).Morphological character combinations of each subfamily are summarized,and a key is provided.Most genera sensu PPG I are recognized,with Stigmatopetris reclassified into Dryopteridoideae and Arthrobotrya considered a synonym of Teratophyllum.A new genus Pseudarachniodes is introduced.This revised classification will serve as a foundational framework for future investigations on taxonomy,biogeography,and diversification of the most species-rich Dryopteridaceae in ferns.展开更多
The present study aims to analyzse alternative passive design solutions for enhancing building energy and hygrothermal efficiency in the Sahelian zone.To achieve this,a model representing a standard single-storey ceme...The present study aims to analyzse alternative passive design solutions for enhancing building energy and hygrothermal efficiency in the Sahelian zone.To achieve this,a model representing a standard single-storey cementhollow block dwelling building and its relevant parameters was input into EnergyPlus,combined with OpenStudio or SketchUp.Scenarios were then analyzed to evaluate the effects of roof solar reflectivity,wall external insulation,natural ventilation,and their combined options.First,the base case,serving as a reference model,was validated using measured and simulated temperatures by calculating the scientific criteria,such as the NBME and CVRMSE coefficients recommended by the ASHRAE and IPVM standards.Additionally,the numerical simulation was used to compare interior temperatures,discomfort hours,thermal parameters,and the hygrothermal index(IHT)across seven cases studied.The reference model simulation indicated that cement-based hollow blocks are less effective for building envelopes in the Sahelian climate,with 51.48%discomfort hours and an IHT of 1.6,as shown in the Givoni diagram.The results revealed that the wall external insulation was the most effective passive solution,with 56%of comfort hours and an IHT of 0.7,which indicates the expected position of the model within the hygrothermal comfort zone of the Sahelian climate.Combining passive strategies yields the best scenario,resulting in a 28.25%reduction in annual total discomfort hours compared to the base case.These simulations demonstrated the effectiveness of accessible passive design solutions applicable in dwelling construction for the sustainable development of countries in the Sahelian climate.展开更多
Sea cucumber Apostichopus japonicus is a crucial aquatic species known for its nutritional value.However,the genetic basis and regulatory mechanisms underlying its nutritional quality remain underexplored.This study i...Sea cucumber Apostichopus japonicus is a crucial aquatic species known for its nutritional value.However,the genetic basis and regulatory mechanisms underlying its nutritional quality remain underexplored.This study investigates the nutritional quality of A.japonicus from different geographical regions and identifies genetic markers associated with these traits through a genome-wide association study(GWAS).We observed significant regional variations in the nutritional content of A.japonicus.Samples collected from Nanhuangcheng Island displayed the highest levels of saponins,whereas those from Laizhou exhibited the highest concentrations of glycosaminoglycans.Lingshan Island samples were the richest in amino acids,while samples from Rizhao contained the highest levels of polyunsaturated fatty acids.Through GWAS,265 candidate genes and related single nucleotide polymorphisms(SNPs)were identified as being significantly associated with essential nutritional traits,including genes like ubiquitin domain-containing protein 1(UBTD1),inactive pancreatic lipase-related protein 1,protein arginine N-methyltransferase 5(PRMT5)and GDP-fucose protein O-fucosyltransferase 1(POFUT1).This study advanced our knowledge of the genetic mechanisms underlying the nutritional quality of A.japonicus.The genetic markers identified herein o ffer crucial insights for breeding initiatives aimed at optimizing the nutritional profile of sea cucumbers.展开更多
Silica(SiO_(2))anodes are promising candidates for enhancing the energy density of next-generation Li-ion batteries,offering a compelling combination of high storage capacity,stable cycling performance,low cost,and su...Silica(SiO_(2))anodes are promising candidates for enhancing the energy density of next-generation Li-ion batteries,offering a compelling combination of high storage capacity,stable cycling performance,low cost,and sustainability.This performance stems from SiO_(2) unique lithiation mechanism,which involves its conversion to electroactive silicon(Si)and electrochemically inactive species.However,widespread adoption of SiO_(2) anodes is hindered by their slow initial lithiation.展开更多
The satisfaction rate of desired velocity in the case of a mixture of fast and slow vehicles is studied by using a cellular automaton method. It is found that at low density the satisfaction rate depends on the maxima...The satisfaction rate of desired velocity in the case of a mixture of fast and slow vehicles is studied by using a cellular automaton method. It is found that at low density the satisfaction rate depends on the maximal velocity. However, the behavior of the satisfaction rate as a function of the coefficient of variance is independent of the maximal velocity. This is in good agreement with empirical results obtained by Lipshtat [Phys. Rev. E 79 066110 （2009）]. Furthermore, our numerical result demonstrates that at low density the satisfaction rate takes higher values, whereas the coefficient of variance is close to zero. The coefficient of variance increases with increasing density, while the satisfaction rate decreases to zero. Moreover, we have also shown that, at low density the coefficient variance depends strongly on the probability of overtaking.展开更多
A general research program, focusing on activated carbon fiber cloths （ACFC） and felt for environmental protection was performed. The objectives were multiple： （i） a better understanding of the adsorption mecha- ...A general research program, focusing on activated carbon fiber cloths （ACFC） and felt for environmental protection was performed. The objectives were multiple： （i） a better understanding of the adsorption mecha- nisms of these kinds of materials; （ii） the specification and optimization of new processes using these adsorbents; （iii） the modeling of the adsorption of organic pollutants using both the usual and original approaches; （iv） applications of ACFC in industrial processes. The general question was： how can activated carbon fiber cloths and felts be used in air treatment processes for the protection of environment. In order to provide an answer, different approaches were adopted. The materials （ACFC） were characterized in terms of macro structure and internal porosity. Specific studies were performed to get the air flow pattern through the fabrics. Head loss data were generated and modeled as a fi.mction of air velocity. The performances of ACF to remove volatile organic compounds （VOCs） were approached with the adsorption isotherms and breakthrough curves in various operating conditions. Regenera- tion by Joule effect shows a homogenous heating of adsorber modules with rolled or pleated layers. Examples of industrial developments were presented showing an interesting technology for the removal of VOCs, such as dichloromethane, benzene, isopropyl alcohol and toluene, alone or in a complex mixture.展开更多
ASIC or FPGA implementation of a finite word-length PID controller requires a double expertise： in control system and hardware design. In this paper, we only focus on the hardware side of the problem. We show how to ...ASIC or FPGA implementation of a finite word-length PID controller requires a double expertise： in control system and hardware design. In this paper, we only focus on the hardware side of the problem. We show how to design configurable fixed-point PIDs to satisfy applications requiring minimal power consumption, or high control-rate, or both together. As multiply operation is the engine of PID, we experienced three algorithms： Booth, modified Booth, and a new recursive multi-bit multiplication algorithm. This later enables the construction of finely grained PID structures with bit-level and unit-time precision. Such a feature permits to tailor the PID to the desired performance and power budget. All PIDs are implemented at register-transfer4evel （RTL） level as technology-independent reusable IP-cores. They are reconfigurable according to two compilemtime constants： set-point word-length and latency. To make PID design easily reproducible, all necessary implementation details are provided and discussed.展开更多
The Virtual Resistor based Active Damping(VR-AD) is widely employed in converters connected to the grid via LCL filters in order to mitigate the inherent resonance of the filters. Nevertheless, in digitally controlled...The Virtual Resistor based Active Damping(VR-AD) is widely employed in converters connected to the grid via LCL filters in order to mitigate the inherent resonance of the filters. Nevertheless, in digitally controlled systems, the PWM and the calculating delays modify the system characteristics in terms of frequency and phase, thus destabilizing the system and degrading the VR-AD performances, mainly in low switching frequencies. Moreover, the stability of the system is greatly affected under weak grid operation characterized by large grid impedance variation. This paper solves these problems by proposing a systematic, robust and optimized design procedure of voltage oriented PI control(VOC) with VRAD. The considered design procedure ensures robust control(sufficient stability margins) and high quality of grid current(reduced steady-state error and minimized THD value) despite the negative impact of digital time delay, grid impedance variation and filter parameters change. Simulation and experimental results are presented to show robustness and efficiency of the suggested design procedure.展开更多
Polypeptide brushes are attractive platforms to generate functional and responsive interfaces that are of potential interest due to their possible biodegradability, biocompatibility and tunable secondary structures. S...Polypeptide brushes are attractive platforms to generate functional and responsive interfaces that are of potential interest due to their possible biodegradability, biocompatibility and tunable secondary structures. Surface-initiated ringopening polymerization（SI-ROP） of α-amino acid N-carboxyanhydrides represents a powerful and versatile strategy to generate polypeptide brushes. This review is an attempt to capture the state-of-the-art in this field and highlights the latest developments in several selected areas. In addition to presenting an overview of the synthetic methods that have been used to generate polypeptide brushes via SI-ROP, this article will discuss the preparation of patterned polypeptide brushes, the conformational properties of surface-tethered polypeptides, ways to control chain orientation at surfaces as well as properties and applications of these thin polymer films.展开更多
The Curie temperatures(T_(C))of La_(0.7)Ce_(0.3)Fe_(13-x-y)Mn_(x)Si_(y)compounds that are hydrogenated to saturation are raised to near room temperature.The age stability was inves-tigated for the fully hydrogenated L...The Curie temperatures(T_(C))of La_(0.7)Ce_(0.3)Fe_(13-x-y)Mn_(x)Si_(y)compounds that are hydrogenated to saturation are raised to near room temperature.The age stability was inves-tigated for the fully hydrogenated La_(0.7)Ce_(0.3)Fe_(11.5-x)Mn_(x)Si_(1.5) compounds.This result indicates that the H content will slowly decrease in the hydrides,leading to a decrease in T_(C).However,no age splitting is observed after the hydrides are held at room temperature for two years,indicating the excellent age stability of the hydrides.Further structural analysis by neutron diffrac-tion shows that Mn atoms preferentially substitute Fe in the 96i sites.The T_(C)of La_(0.7)Ce_(0.3)Fe_(11.55-y)Mn_(y)Si_(1.45)hydrides can be adjusted to the desired working temperature by regulating Mn content based on the linear relationship between T_(C)and Mn content.Moreover,the La_(0.7)Ce_(0.3)Fe_(11.55-y)Mn_(y)Si_(1.45)hydrides exhibit a giant magnetic entropy change of 15 J·kg^(-1)·K^(-1) under a low magneticfield change of 0-1 T.As a result,the giant magnetocaloric effect,linearly adjustable T_(C),and excel-lent age stability make the La_(0.7)Ce_(0.3)Fe_(11.55-y)Mn_(y)Si_(1.45)hydrides be one of the ideal candidates for room temperature magnetic refrigerants.展开更多
Insects attack vegetable crop, leading to an overuse of pesticides. Organic amendments are recommended to increase soil fertility. The impact of two insecticides, on soil macrofauna under rainfed cultivation of tomato...Insects attack vegetable crop, leading to an overuse of pesticides. Organic amendments are recommended to increase soil fertility. The impact of two insecticides, on soil macrofauna under rainfed cultivation of tomato (Lycopersicon esculentum L.) with or without organic amendments was evaluated. The insecticides were Lambda Super (lambda-cyhalothrin) and Dursban (chlorpyrifos ethyl) and organic amendments were compost, pig manure and cattle manure. An experimental device in split-plot with three replicate was installed. Pesticides were applied periodically each week during the experiment. The results have showed that with organic amendments, Lambda super increased the earthworm population compared to the control. Indeed, we found 42 individuals/m2 with compost;1 individuals/m2 with pig manure and 27 individuals/m2 with cattle manure but the control was 0 individuals/m2 in the presence of Lambda super without organic amendment. Similarly, Dursban increased the population of earthworms in the presence of organic amendment with 11, 37 and 91 individuals/m2 respectively for compost, pig manure and cattle manure. Lambda super with compost has led to a total elimination of termites. In the presence of Dursban, a decrease in the number of termites was observed when adding cattle manure (11 individuals/ m2) compared to the control containing only Dursban (21 individuals/m2). Better distribution of macrofauna was obtained with treatment with Dursban and compost (E = 0.99 for earthworms and E = 0.96 for termites). All organic amendments used in our study stimulated earthworm population, but more in the presence of Lambda super or Dursban.展开更多
In the southern Algerian Sahara, populations of the desert locust have been monitored during the past 43 years. On a limited study area, the use of remote sensing data from Landsat 7 ETM+ and Terra MODIS, coupled with...In the southern Algerian Sahara, populations of the desert locust have been monitored during the past 43 years. On a limited study area, the use of remote sensing data from Landsat 7 ETM+ and Terra MODIS, coupled with the locust population database, allowed the identification and mapping of solitary desert locust breeding areas during remission periods. These sites are mainly located in wadis and in areas of accumulation/spreading of rainwater. The use of this methodology to all the Algerian Sahara is surely possible in order to improve the preventive management of this pest.展开更多
Diagnosis of Trypanosoma brucei rhodesiense human African trypanosomiasis requires demonstration of parasites in body fluids by microscopy. The microscopy methods that are routinely used are difficult to deploy in res...Diagnosis of Trypanosoma brucei rhodesiense human African trypanosomiasis requires demonstration of parasites in body fluids by microscopy. The microscopy methods that are routinely used are difficult to deploy in resource-limited settings due to practical challenges, including lengthy and tedious procedures, and the need for specific equipment to centrifuge samples in glass capillary tubes. We report here on a study that was conducted in a rural region of eastern Uganda to evaluate new methods that take advantage of a field-deployable LED fluorescence microscope. Examination of acridine orange-stained blood smears by LED fluorescence microscopy resulted in a diagnostic accuracy that was similar to that of routine methods, while the time needed to identify parasites was shortened significantly. These findings make these new microscopy methods attractive alternatives to procedures that are currently used for diagnosis of T. b. rhodesiense human African trypanosomiasis.展开更多
The integration of additive manufacturing(AM)in design and engineering has prompted a wide spectrum of research efforts,involving topologically optimized solid/lattice structures,multimaterial structures,bioinspired o...The integration of additive manufacturing(AM)in design and engineering has prompted a wide spectrum of research efforts,involving topologically optimized solid/lattice structures,multimaterial structures,bioinspired organic structures,and multiscale structures,to name a few.However,except for obvious cases,very little attention has been given to the design and printing of more complex three-dimensional(3D)hollow structures or folded/creased structures.One of the main reasons is that such complex open or closed 3D cavities and regular/freeform folds generally lead to printing difficulties from support-structure-related issues.To address this barrier,this paper aims to investigate four-dimensional(4D)printing as well as origami-based design as an original research direction to design and build 3D support-free hollow structures.This work consists of describing the rough 3D hollow structures in terms of two-dimensional(2D)printed origami precursor layouts without any support structure.Such origami-based definitions are then embodied with folding functions that can be actuated and fulfilled by 3D printed smart materials.The desired 3D shape is then built once an external stimulus is applied to the active materials,therefore ensuring the transformation of the 2D origami layout to 3D structures.To demonstrate the relevance of the proposal,some illustrative cases are introduced.展开更多
Modeling experimental design was used to study the main effects and the interaction effects between operational parameters in the photocatalytic degradation of pesticide methomyl. The important parameters which affect...Modeling experimental design was used to study the main effects and the interaction effects between operational parameters in the photocatalytic degradation of pesticide methomyl. The important parameters which affect the removal efficiency of methomyl such as concentration of Fe(NO3)3, concentration of H2O2, initial concentration of the pesticide and pH. The parameters were coded as x1, x2, x3 and x4, consecutively, and were investigated at two levels (–1 and +1). The effects of individual variables and their interaction effects for dependent variables, namely, photocatalytic degradation efficiency (%) were determined. From the statistical analysis, the most effective parameters in the photocatalytic degradation efficiency were initial concentrations of the methomyl and Fe(NO3)3. The interaction between initial concentration of the pesticide and Fe(NO3)3 was the most influencing interaction. The optimum conditions that were obtained for the photocatalytic degradation of methomyl were: minimum quantity of contaminant: 6 × 10–5 mol.L–1, maximum quantity of Fe(NO3)3: 5 × 10–4 mol.L-1, initial pH of the solution: 3 and maximum quantity H2O2: 10–2 mol.L–1.展开更多
The paper is devoted to the elastostatic calibration of industrial robots,which is used for precise machining of large-dimensional parts made of composite materials.In this technological process,the interaction betwee...The paper is devoted to the elastostatic calibration of industrial robots,which is used for precise machining of large-dimensional parts made of composite materials.In this technological process,the interaction between the robot and the workpiece causes essential elastic deflections of the manipulator components that should be compensated by the robot controller using relevant elastostatic model of this mechanism.To estimate parameters of this model,an advanced calibration technique is applied that is based on the non-linear experiment design theory,which is adopted for this particular application.In contrast to previous works,it is proposed a concept of the user-defined test-pose,which is used to evaluate the calibration experiments quality.In the frame of this concept,the related optimization problem is defined and numerical routines are developed,which allow generating optimal set of manipulator configurations and corresponding forces/torques for a given number of the calibration experiments.Some specific kinematic constraints are also taken into account,which insure feasibility of calibration experiments for the obtained configurations and allow avoiding collision between the robotic manipulator and the measurement equipment.The efficiency of the developed technique is illustrated by an application example that deals with elastostatic calibration of the serial manipulator used for robot-based machining.展开更多
Two new compounds 7-hydroxy-5-O-（β-D-glucopyranoside） flavan （1） and （Z）-4＇,6＇-dihydroxy-2＇-O-（β-D-glucopyranoside） chalcone （2）, along with eight known compounds, were isolated from the stem bark of Dr...Two new compounds 7-hydroxy-5-O-（β-D-glucopyranoside） flavan （1） and （Z）-4＇,6＇-dihydroxy-2＇-O-（β-D-glucopyranoside） chalcone （2）, along with eight known compounds, were isolated from the stem bark of Drypetes parvifolia （Euphorbiaceae）. Their structures were established on the basis of spectroscopic analysis and chemical evidence.展开更多
基金supported by a grant from the Research Grants Council of the Hong Kong Special Administration Region,China(SRFS2021-7S04)Partial support was also received from the Seed Funding for Strategic Interdisciplinary Research Scheme(102010174)+1 种基金Seed Fund for Basic Research(202111159075)of The University of Hong KongIn addition,part of this work was supported by the European Union’s Horizon 2020 research and innovation programme under grant agreement INTELWAT(No 958454).
文摘Membrane desalination is an economical and energy-efficient method to meet the current worldwide water scarcity.However,state-of-the-art reverse osmosis membranes are gradually being replaced by novel membrane materials as a result of ongoing technological advancements.These novel materials possess intrinsic pore structures or can be assembled to form lamellar membrane channels for selective transport of water or solutes(e.g.,NaCl).Still,in real applications,the results fall below the theoretical predictions,and a few properties,including large-scale fabrication,mechanical strength,and chemical stability,also have an impact on the overall effectiveness of those materials.In view of this,we develop a new evaluation framework in the form of radar charts with five dimensions(i.e.,water permeance,water/NaCl selectivity,membrane cost,scale of development,and stability)to assess the advantages,disadvantages,and potential of state-of-the-art and newly developed desalination membranes.In this framework,the reported thin film nanocomposite membranes and membranes developed from novel materials were compared with the state-of-the-art thin film composite membranes.This review will demonstrate the current advancements in novel membrane materials and bridge the gap between different desalination membranes.In this review,we also point out the prospects and challenges of next-generation membranes for desalination applications.We believe that this comprehensive framework may be used as a future reference for designing next-generation desalination membranes and will encourage further research and development in the field of membrane technology,leading to new insights and advancements.
文摘The paper aims at providing a computerized design environment to support product design practically. The authors solved this problem by taking the product life-cycle issues into consideration as more as possible during the design process from the designer-oriented perspective of view. Design for X-abilities (DFX) is an effective approach to this philosophy. So the paper mainly presents the infrastructure of an intelligent DFX mechanism which is the essential part of the developed product design environment. At first the designer-oriented computer environment DesignerSpace is introduced for understanding the designer how to implement design activities and DFX method better. In order to integrate design knowledge from downstream aspects for the optimization and the design decision-making, an intelligent DFX mechanism is developed to incorporate knowledge base, algorithm-base and monitoring/debugging tools. DesignerSpace is implemented with DFX abilities and applied to the blisk design of aircraft engine and the further development is strongly intended.
文摘This paper presents a novel approach to design a compact circular rat-race coupler with an ultrawide stopband, with the aim to reduce its size while maintaining performance. The design methodology begins with a common miniaturization technique to replace the conventional quarter-wavelength transmission line with an equivalent low-pass filter loaded with parallel coupled line and radial stubs. Since the latter leads to produce higher order harmonics, parasitic open-ended stubs are then properly introduced in the structure not only to overcome the issue but also to produce controllable transmission zeros. A versatile analytical model is also developed taking into account manufacturing restrictions, which makes it possible to extract the physical parameters of the coupler unit-cell for a given desired compactness percentage with respect to the conventional rat-race coupler. A prototype is fabricated and measured to validate the design,demonstrating the predicted behavior fairly achieved by numerical analysis. A significant size reduction of about 86.1% was achieved compared to the conventional design, while effectively suppressing higher order modes up to 23.4 GHz(including the 13th harmonic based on |S11|>-5 dB and |S21|<-17 dB)with high isolation level(|S41|<-17 dB) between the ports.
基金funded by the National Natural Science Foundation of China(Grant No.31970232)the National Key Basic Research Program of China(Grant No.2014CB954100).
文摘Dryopteridaceae are the largest fern family and include nearly 20%of extant fern diversity,with 24 currently recognized genera.Recognition and delineation of genera within this family have varied greatly.The three-subfamily classification of Dryopteridaceae was based primarily on molecular phylogenetic relationships but lacked morphological evidence,and the phylogenetic relationships of the subfamilies and genera of Dryopteridaceae are only partially resolved.A comprehensive and robust phylogeny is urgently needed.The heterogeneous morphology of the current members of Dryopteridaceae makes the family and its subfamilies difficult to define by single morphological characteristics or even character combinations.We carried out phylogenetic analyses to reconstruct a highly supported phylogeny of Dryopteridaceae.Our analyses recovered 24 strongly supported clades grouped into seven major clades of Dryopteridaceae.Seven morphological characters including habit,rhizome shape,frond morphology,rachis-costae architecture,appendages on stipe base and lamina,and soral arrangement were found to be informative for identifying different major clades and clades in Dryopteridaceae.Based on phylogenetic reconstruction and morphological analysis,we presented an updated infra-familial classification of Dryopteridaceae with seven subfamilies and 24 genera including four newly proposed subfamilies(Ctenitidoideae,Lastreopsidoideae,Pleocnemioideae,and Polystichopsidoideae).Morphological character combinations of each subfamily are summarized,and a key is provided.Most genera sensu PPG I are recognized,with Stigmatopetris reclassified into Dryopteridoideae and Arthrobotrya considered a synonym of Teratophyllum.A new genus Pseudarachniodes is introduced.This revised classification will serve as a foundational framework for future investigations on taxonomy,biogeography,and diversification of the most species-rich Dryopteridaceae in ferns.
文摘The present study aims to analyzse alternative passive design solutions for enhancing building energy and hygrothermal efficiency in the Sahelian zone.To achieve this,a model representing a standard single-storey cementhollow block dwelling building and its relevant parameters was input into EnergyPlus,combined with OpenStudio or SketchUp.Scenarios were then analyzed to evaluate the effects of roof solar reflectivity,wall external insulation,natural ventilation,and their combined options.First,the base case,serving as a reference model,was validated using measured and simulated temperatures by calculating the scientific criteria,such as the NBME and CVRMSE coefficients recommended by the ASHRAE and IPVM standards.Additionally,the numerical simulation was used to compare interior temperatures,discomfort hours,thermal parameters,and the hygrothermal index(IHT)across seven cases studied.The reference model simulation indicated that cement-based hollow blocks are less effective for building envelopes in the Sahelian climate,with 51.48%discomfort hours and an IHT of 1.6,as shown in the Givoni diagram.The results revealed that the wall external insulation was the most effective passive solution,with 56%of comfort hours and an IHT of 0.7,which indicates the expected position of the model within the hygrothermal comfort zone of the Sahelian climate.Combining passive strategies yields the best scenario,resulting in a 28.25%reduction in annual total discomfort hours compared to the base case.These simulations demonstrated the effectiveness of accessible passive design solutions applicable in dwelling construction for the sustainable development of countries in the Sahelian climate.
基金Supported by the Key Research and Development Program of Shandong(Nos.2021LZGC029,2023LZGC019)the National Natural Science Foundation of China(No.42076093)+1 种基金the Special Funds for the Central Government to Guide Local Science and Technology Development(No.YDZX2023043)the Taishan Scholars Program(No.tsqn202306279)。
文摘Sea cucumber Apostichopus japonicus is a crucial aquatic species known for its nutritional value.However,the genetic basis and regulatory mechanisms underlying its nutritional quality remain underexplored.This study investigates the nutritional quality of A.japonicus from different geographical regions and identifies genetic markers associated with these traits through a genome-wide association study(GWAS).We observed significant regional variations in the nutritional content of A.japonicus.Samples collected from Nanhuangcheng Island displayed the highest levels of saponins,whereas those from Laizhou exhibited the highest concentrations of glycosaminoglycans.Lingshan Island samples were the richest in amino acids,while samples from Rizhao contained the highest levels of polyunsaturated fatty acids.Through GWAS,265 candidate genes and related single nucleotide polymorphisms(SNPs)were identified as being significantly associated with essential nutritional traits,including genes like ubiquitin domain-containing protein 1(UBTD1),inactive pancreatic lipase-related protein 1,protein arginine N-methyltransferase 5(PRMT5)and GDP-fucose protein O-fucosyltransferase 1(POFUT1).This study advanced our knowledge of the genetic mechanisms underlying the nutritional quality of A.japonicus.The genetic markers identified herein o ffer crucial insights for breeding initiatives aimed at optimizing the nutritional profile of sea cucumbers.
基金supported by the Norwegian Research Council project number 315947support from the Research Council of Norway through the Norwegian Center for Transmission Electron Microscopy,NORTEM(197405/F50)+2 种基金The Norwegian Infrastructure for Microand Nanofabrication,Nor Fab(245963/F50)Grants No.PCI2022-132993 funded by MCIN/AEI/10.13039/501100011033 and DGA/M4 from Diputación General de Aragónfinancial support and for provision of synchrotron radiation facilities at BM25-Sp Line(PIE 201060E 013 and PIE 202160 E 030)。
文摘Silica(SiO_(2))anodes are promising candidates for enhancing the energy density of next-generation Li-ion batteries,offering a compelling combination of high storage capacity,stable cycling performance,low cost,and sustainability.This performance stems from SiO_(2) unique lithiation mechanism,which involves its conversion to electroactive silicon(Si)and electrochemically inactive species.However,widespread adoption of SiO_(2) anodes is hindered by their slow initial lithiation.
文摘The satisfaction rate of desired velocity in the case of a mixture of fast and slow vehicles is studied by using a cellular automaton method. It is found that at low density the satisfaction rate depends on the maximal velocity. However, the behavior of the satisfaction rate as a function of the coefficient of variance is independent of the maximal velocity. This is in good agreement with empirical results obtained by Lipshtat [Phys. Rev. E 79 066110 （2009）]. Furthermore, our numerical result demonstrates that at low density the satisfaction rate takes higher values, whereas the coefficient of variance is close to zero. The coefficient of variance increases with increasing density, while the satisfaction rate decreases to zero. Moreover, we have also shown that, at low density the coefficient variance depends strongly on the probability of overtaking.
文摘A general research program, focusing on activated carbon fiber cloths （ACFC） and felt for environmental protection was performed. The objectives were multiple： （i） a better understanding of the adsorption mecha- nisms of these kinds of materials; （ii） the specification and optimization of new processes using these adsorbents; （iii） the modeling of the adsorption of organic pollutants using both the usual and original approaches; （iv） applications of ACFC in industrial processes. The general question was： how can activated carbon fiber cloths and felts be used in air treatment processes for the protection of environment. In order to provide an answer, different approaches were adopted. The materials （ACFC） were characterized in terms of macro structure and internal porosity. Specific studies were performed to get the air flow pattern through the fabrics. Head loss data were generated and modeled as a fi.mction of air velocity. The performances of ACF to remove volatile organic compounds （VOCs） were approached with the adsorption isotherms and breakthrough curves in various operating conditions. Regenera- tion by Joule effect shows a homogenous heating of adsorber modules with rolled or pleated layers. Examples of industrial developments were presented showing an interesting technology for the removal of VOCs, such as dichloromethane, benzene, isopropyl alcohol and toluene, alone or in a complex mixture.
文摘ASIC or FPGA implementation of a finite word-length PID controller requires a double expertise： in control system and hardware design. In this paper, we only focus on the hardware side of the problem. We show how to design configurable fixed-point PIDs to satisfy applications requiring minimal power consumption, or high control-rate, or both together. As multiply operation is the engine of PID, we experienced three algorithms： Booth, modified Booth, and a new recursive multi-bit multiplication algorithm. This later enables the construction of finely grained PID structures with bit-level and unit-time precision. Such a feature permits to tailor the PID to the desired performance and power budget. All PIDs are implemented at register-transfer4evel （RTL） level as technology-independent reusable IP-cores. They are reconfigurable according to two compilemtime constants： set-point word-length and latency. To make PID design easily reproducible, all necessary implementation details are provided and discussed.
基金supported by the Tunisian Ministry of High Education and Research under Grant LSE-ENIT-LR11ES15
文摘The Virtual Resistor based Active Damping(VR-AD) is widely employed in converters connected to the grid via LCL filters in order to mitigate the inherent resonance of the filters. Nevertheless, in digitally controlled systems, the PWM and the calculating delays modify the system characteristics in terms of frequency and phase, thus destabilizing the system and degrading the VR-AD performances, mainly in low switching frequencies. Moreover, the stability of the system is greatly affected under weak grid operation characterized by large grid impedance variation. This paper solves these problems by proposing a systematic, robust and optimized design procedure of voltage oriented PI control(VOC) with VRAD. The considered design procedure ensures robust control(sufficient stability margins) and high quality of grid current(reduced steady-state error and minimized THD value) despite the negative impact of digital time delay, grid impedance variation and filter parameters change. Simulation and experimental results are presented to show robustness and efficiency of the suggested design procedure.
基金financially supported by the Sino-Swiss Science and Technology Cooperation(No.EG41-092011)as well as the Chinese Academy of Sciences(Visiting Professorship for Senior International Scientists to H.A.K.)
文摘Polypeptide brushes are attractive platforms to generate functional and responsive interfaces that are of potential interest due to their possible biodegradability, biocompatibility and tunable secondary structures. Surface-initiated ringopening polymerization（SI-ROP） of α-amino acid N-carboxyanhydrides represents a powerful and versatile strategy to generate polypeptide brushes. This review is an attempt to capture the state-of-the-art in this field and highlights the latest developments in several selected areas. In addition to presenting an overview of the synthetic methods that have been used to generate polypeptide brushes via SI-ROP, this article will discuss the preparation of patterned polypeptide brushes, the conformational properties of surface-tethered polypeptides, ways to control chain orientation at surfaces as well as properties and applications of these thin polymer films.
基金financially supported by the National Key Research and Development Program of China (No. 2017YFB0702704)the National Science Foundation of China (No. 51571018)。
文摘The Curie temperatures(T_(C))of La_(0.7)Ce_(0.3)Fe_(13-x-y)Mn_(x)Si_(y)compounds that are hydrogenated to saturation are raised to near room temperature.The age stability was inves-tigated for the fully hydrogenated La_(0.7)Ce_(0.3)Fe_(11.5-x)Mn_(x)Si_(1.5) compounds.This result indicates that the H content will slowly decrease in the hydrides,leading to a decrease in T_(C).However,no age splitting is observed after the hydrides are held at room temperature for two years,indicating the excellent age stability of the hydrides.Further structural analysis by neutron diffrac-tion shows that Mn atoms preferentially substitute Fe in the 96i sites.The T_(C)of La_(0.7)Ce_(0.3)Fe_(11.55-y)Mn_(y)Si_(1.45)hydrides can be adjusted to the desired working temperature by regulating Mn content based on the linear relationship between T_(C)and Mn content.Moreover,the La_(0.7)Ce_(0.3)Fe_(11.55-y)Mn_(y)Si_(1.45)hydrides exhibit a giant magnetic entropy change of 15 J·kg^(-1)·K^(-1) under a low magneticfield change of 0-1 T.As a result,the giant magnetocaloric effect,linearly adjustable T_(C),and excel-lent age stability make the La_(0.7)Ce_(0.3)Fe_(11.55-y)Mn_(y)Si_(1.45)hydrides be one of the ideal candidates for room temperature magnetic refrigerants.
文摘Insects attack vegetable crop, leading to an overuse of pesticides. Organic amendments are recommended to increase soil fertility. The impact of two insecticides, on soil macrofauna under rainfed cultivation of tomato (Lycopersicon esculentum L.) with or without organic amendments was evaluated. The insecticides were Lambda Super (lambda-cyhalothrin) and Dursban (chlorpyrifos ethyl) and organic amendments were compost, pig manure and cattle manure. An experimental device in split-plot with three replicate was installed. Pesticides were applied periodically each week during the experiment. The results have showed that with organic amendments, Lambda super increased the earthworm population compared to the control. Indeed, we found 42 individuals/m2 with compost;1 individuals/m2 with pig manure and 27 individuals/m2 with cattle manure but the control was 0 individuals/m2 in the presence of Lambda super without organic amendment. Similarly, Dursban increased the population of earthworms in the presence of organic amendment with 11, 37 and 91 individuals/m2 respectively for compost, pig manure and cattle manure. Lambda super with compost has led to a total elimination of termites. In the presence of Dursban, a decrease in the number of termites was observed when adding cattle manure (11 individuals/ m2) compared to the control containing only Dursban (21 individuals/m2). Better distribution of macrofauna was obtained with treatment with Dursban and compost (E = 0.99 for earthworms and E = 0.96 for termites). All organic amendments used in our study stimulated earthworm population, but more in the presence of Lambda super or Dursban.
文摘In the southern Algerian Sahara, populations of the desert locust have been monitored during the past 43 years. On a limited study area, the use of remote sensing data from Landsat 7 ETM+ and Terra MODIS, coupled with the locust population database, allowed the identification and mapping of solitary desert locust breeding areas during remission periods. These sites are mainly located in wadis and in areas of accumulation/spreading of rainwater. The use of this methodology to all the Algerian Sahara is surely possible in order to improve the preventive management of this pest.
文摘Diagnosis of Trypanosoma brucei rhodesiense human African trypanosomiasis requires demonstration of parasites in body fluids by microscopy. The microscopy methods that are routinely used are difficult to deploy in resource-limited settings due to practical challenges, including lengthy and tedious procedures, and the need for specific equipment to centrifuge samples in glass capillary tubes. We report here on a study that was conducted in a rural region of eastern Uganda to evaluate new methods that take advantage of a field-deployable LED fluorescence microscope. Examination of acridine orange-stained blood smears by LED fluorescence microscopy resulted in a diagnostic accuracy that was similar to that of routine methods, while the time needed to identify parasites was shortened significantly. These findings make these new microscopy methods attractive alternatives to procedures that are currently used for diagnosis of T. b. rhodesiense human African trypanosomiasis.
基金the Ministère de l’Enseignement Supérieur et de la Recherche, the French ‘Investissements d’Avenir’ program, project ISITE-BFC (contract ANR-15-IDEX-0003)China Scholarship Council as the main financial supports of this research program
文摘The integration of additive manufacturing(AM)in design and engineering has prompted a wide spectrum of research efforts,involving topologically optimized solid/lattice structures,multimaterial structures,bioinspired organic structures,and multiscale structures,to name a few.However,except for obvious cases,very little attention has been given to the design and printing of more complex three-dimensional(3D)hollow structures or folded/creased structures.One of the main reasons is that such complex open or closed 3D cavities and regular/freeform folds generally lead to printing difficulties from support-structure-related issues.To address this barrier,this paper aims to investigate four-dimensional(4D)printing as well as origami-based design as an original research direction to design and build 3D support-free hollow structures.This work consists of describing the rough 3D hollow structures in terms of two-dimensional(2D)printed origami precursor layouts without any support structure.Such origami-based definitions are then embodied with folding functions that can be actuated and fulfilled by 3D printed smart materials.The desired 3D shape is then built once an external stimulus is applied to the active materials,therefore ensuring the transformation of the 2D origami layout to 3D structures.To demonstrate the relevance of the proposal,some illustrative cases are introduced.
文摘Modeling experimental design was used to study the main effects and the interaction effects between operational parameters in the photocatalytic degradation of pesticide methomyl. The important parameters which affect the removal efficiency of methomyl such as concentration of Fe(NO3)3, concentration of H2O2, initial concentration of the pesticide and pH. The parameters were coded as x1, x2, x3 and x4, consecutively, and were investigated at two levels (–1 and +1). The effects of individual variables and their interaction effects for dependent variables, namely, photocatalytic degradation efficiency (%) were determined. From the statistical analysis, the most effective parameters in the photocatalytic degradation efficiency were initial concentrations of the methomyl and Fe(NO3)3. The interaction between initial concentration of the pesticide and Fe(NO3)3 was the most influencing interaction. The optimum conditions that were obtained for the photocatalytic degradation of methomyl were: minimum quantity of contaminant: 6 × 10–5 mol.L–1, maximum quantity of Fe(NO3)3: 5 × 10–4 mol.L-1, initial pH of the solution: 3 and maximum quantity H2O2: 10–2 mol.L–1.
文摘The paper is devoted to the elastostatic calibration of industrial robots,which is used for precise machining of large-dimensional parts made of composite materials.In this technological process,the interaction between the robot and the workpiece causes essential elastic deflections of the manipulator components that should be compensated by the robot controller using relevant elastostatic model of this mechanism.To estimate parameters of this model,an advanced calibration technique is applied that is based on the non-linear experiment design theory,which is adopted for this particular application.In contrast to previous works,it is proposed a concept of the user-defined test-pose,which is used to evaluate the calibration experiments quality.In the frame of this concept,the related optimization problem is defined and numerical routines are developed,which allow generating optimal set of manipulator configurations and corresponding forces/torques for a given number of the calibration experiments.Some specific kinematic constraints are also taken into account,which insure feasibility of calibration experiments for the obtained configurations and allow avoiding collision between the robotic manipulator and the measurement equipment.The efficiency of the developed technique is illustrated by an application example that deals with elastostatic calibration of the serial manipulator used for robot-based machining.
基金One of the authors(J.Wandji)is grateful for grant(No.F/2624-3F)from the International Foundation for Science(Sweden)the sponsorship of the"UniversitéParis Descartes,France"during his multiple research visits in Paris.
文摘Two new compounds 7-hydroxy-5-O-（β-D-glucopyranoside） flavan （1） and （Z）-4＇,6＇-dihydroxy-2＇-O-（β-D-glucopyranoside） chalcone （2）, along with eight known compounds, were isolated from the stem bark of Drypetes parvifolia （Euphorbiaceae）. Their structures were established on the basis of spectroscopic analysis and chemical evidence.
