Parameter optimization integrating operation parameters and structure parameters for the purpose of high permeate flux,high productivity and low exergy consumption of direct contact membrane distillation (DCMD) proces...Parameter optimization integrating operation parameters and structure parameters for the purpose of high permeate flux,high productivity and low exergy consumption of direct contact membrane distillation (DCMD) process was conducted based on Taguchi experimental design. L16(45) orthogonal experiments were carried out with feed inlet temperature,permeate stream inlet temperature,flow rate,module packing density and length-diameter ratio as optimization parameters and with permeate flux,water productivity per unit volume of module and water production per unit exergy loss separately as optimization objectives. By using range analysis method,the dominance degree of the various influencing factors for the three objectives was analyzed and the optimum condition was obtained for the three objectives separately. Furthermore,the multi-objectives optimization was performed based on a weight grade method. The combined optimum conditions are feed inlet temperature 75℃,packing density 30% ,length-diameter ratio 10,permeate stream inlet temperature 30 ℃ and flow rate 25 L/h,which is in order of their dominance degree,and the validity of the optimization scheme was confirmed.展开更多
Selecting a cost optimum subset of discrete-value dispersion compensation modules (DV-DCMs) subject to maximum module count from an available set of DV-DCMs is a NP-hard problem. We derive a novel dynamic programming ...Selecting a cost optimum subset of discrete-value dispersion compensation modules (DV-DCMs) subject to maximum module count from an available set of DV-DCMs is a NP-hard problem. We derive a novel dynamic programming algorithm with pseudo-polynomial time bound and show that DV-DCM cost re-scaling can improve the running time.展开更多
The clear differences between the atmosphere of Mars and the Earth coupled with the lack of a domestic research basis were significant challenges for the aerodynamic prediction and verification of Tianwen-1.In additio...The clear differences between the atmosphere of Mars and the Earth coupled with the lack of a domestic research basis were significant challenges for the aerodynamic prediction and verification of Tianwen-1.In addition,the Mars entry,descent,and landing(EDL)mission led to specific requirements for the accuracy of the aerodynamic deceleration performance,stability,aerothermal heating,and various complex aerodynamic coupling problems of the entry module.This study analyzes the key and difficult aerodynamic and aerothermodynamic problems related to the Mars EDL process.Then,the study process and results of the design and optimization of the entry module configuration are presented along with the calculations and experiments used to obtain the aerodynamic and aerothermodynamic characteristics in the Martian atmosphere.In addition,the simulation and verification of the low-frequency free oscillation characteristics under a large separation flow are described,and some special aerodynamic coupling problems such as the aeroelastic buffeting response of the trim tab are discussed.Finally,the atmospheric parameters and aerodynamic characteristics obtained from the flight data of the Tianwen-1 entry module are compared with the design data.The data obtained from the aerodynamic design,analysis,and verification of the Tianwen-1 entry module all meet the engineering requirements.In particular,the flight data results for the atmospheric parameters,trim angles of attack,and trim axial forces are within the envelopes of the prediction deviation zones.展开更多
A single die 1.2 V multi-stage noise shaping(Mash) 2-2 delta sigma analog to digital converter(ADC)for wide applications is implemented. The configurable Mash 2-2 modulator with a new decimation filter design is p...A single die 1.2 V multi-stage noise shaping(Mash) 2-2 delta sigma analog to digital converter(ADC)for wide applications is implemented. The configurable Mash 2-2 modulator with a new decimation filter design is presented to achieve wide and high dynamic range(DR) for multiple practical applications. The novel modulator can be configured as a Mash 2-2 modulator for high precision or a 2-order modulator for low DR. The decimation filter is designed to select the OSR flexibly among cascaded integrator comb(CIC) filter and two half-band filters(HBF). The serial peripheral interface(SPI) can be used to adjust the sampling frequency and the oversampling ratio(OSR). The design was fabricated in a 0.13 m CMOS process with an area of 0.91 mm2and a total power of 5.2 mW. The measurement results show that the dynamic range(DR) of the proposed ADC can change from 55to 95 dB with the configurable OSR from 16 to 256. The spurious free dynamic range(SFDR) and signal-to-noise distortion ratio(SNDR) can get 99 dB and 86.5 dB, respectively.展开更多
The targeted construction of donor-acceptor(D-A)materials featuring efficient photothermal(PT)conversion properties has been an attractive but challenging goal.Herein,a new series of coordination polymers(CPs)featurin...The targeted construction of donor-acceptor(D-A)materials featuring efficient photothermal(PT)conversion properties has been an attractive but challenging goal.Herein,a new series of coordination polymers(CPs)featuring different PT performances were constructed with flexible linker 1,1′-Ferrocenedicarboxylic acid(FCA)and 2,4,6-tri(pyridin-4-yl)-1,3,5-triazine(TPT)as acceptor and donor molecules including coronene and tetrathiafulvalene(TTF).Based on the flexible configurations of FCA ligand and the directing of donor dependent D-A interactions,the structures of TF-1 to TF-3 featuring distinctive dimension were obtained based on Cd(Ⅱ)ions for investigating the PT property in configurational perspectives.A systematic investigation of the PT properties of the CPs was performed.Notably,TF-3 exhibits the finest PT conversion effect under the irradiation of560 nm laser,while TF-2 shows optimal PT conversion under 808 nm laser irradiation required for biological PT therapy,illustrating the correlation between the structural and component features of the CPs and their PT performances.Furthermore,Zn(Ⅱ)as bio-friendly ion was utilized to construct hypotoxic TF-4 that reveals similar structure to that of TF-2 for potential application.Polydimethylsiloxane(PDMS)patches doped with TF-4 exhibits considerable NIR PT conversion effect under808 nm,represented by the nearly 80℃temperature increased in 120 s for TF-4@PDMS patch(1.2 wt%)under 0.9 W cm^(-2)irradiation,the results of which herein indicate the potential of D-A CPs as versatile platform for the modulation of PT materials.展开更多
文摘Parameter optimization integrating operation parameters and structure parameters for the purpose of high permeate flux,high productivity and low exergy consumption of direct contact membrane distillation (DCMD) process was conducted based on Taguchi experimental design. L16(45) orthogonal experiments were carried out with feed inlet temperature,permeate stream inlet temperature,flow rate,module packing density and length-diameter ratio as optimization parameters and with permeate flux,water productivity per unit volume of module and water production per unit exergy loss separately as optimization objectives. By using range analysis method,the dominance degree of the various influencing factors for the three objectives was analyzed and the optimum condition was obtained for the three objectives separately. Furthermore,the multi-objectives optimization was performed based on a weight grade method. The combined optimum conditions are feed inlet temperature 75℃,packing density 30% ,length-diameter ratio 10,permeate stream inlet temperature 30 ℃ and flow rate 25 L/h,which is in order of their dominance degree,and the validity of the optimization scheme was confirmed.
文摘Selecting a cost optimum subset of discrete-value dispersion compensation modules (DV-DCMs) subject to maximum module count from an available set of DV-DCMs is a NP-hard problem. We derive a novel dynamic programming algorithm with pseudo-polynomial time bound and show that DV-DCM cost re-scaling can improve the running time.
基金This research comes from the Tianwen-1 Mars exploration mission.The authors gratefully acknowledge the contributions of the entire Tianwen-1 design team.
文摘The clear differences between the atmosphere of Mars and the Earth coupled with the lack of a domestic research basis were significant challenges for the aerodynamic prediction and verification of Tianwen-1.In addition,the Mars entry,descent,and landing(EDL)mission led to specific requirements for the accuracy of the aerodynamic deceleration performance,stability,aerothermal heating,and various complex aerodynamic coupling problems of the entry module.This study analyzes the key and difficult aerodynamic and aerothermodynamic problems related to the Mars EDL process.Then,the study process and results of the design and optimization of the entry module configuration are presented along with the calculations and experiments used to obtain the aerodynamic and aerothermodynamic characteristics in the Martian atmosphere.In addition,the simulation and verification of the low-frequency free oscillation characteristics under a large separation flow are described,and some special aerodynamic coupling problems such as the aeroelastic buffeting response of the trim tab are discussed.Finally,the atmospheric parameters and aerodynamic characteristics obtained from the flight data of the Tianwen-1 entry module are compared with the design data.The data obtained from the aerodynamic design,analysis,and verification of the Tianwen-1 entry module all meet the engineering requirements.In particular,the flight data results for the atmospheric parameters,trim angles of attack,and trim axial forces are within the envelopes of the prediction deviation zones.
基金Project supported by the National Natural Science Foundation of China(No.60976026)the Guangdong Industry University Research Cooperation Project(No.2011A090200106)+1 种基金the Guangdong Industry University High-Tech Development Guidance(No.2011B010700065)the Second Batch of Strategic Development Special Fund(No.2011912004)
文摘A single die 1.2 V multi-stage noise shaping(Mash) 2-2 delta sigma analog to digital converter(ADC)for wide applications is implemented. The configurable Mash 2-2 modulator with a new decimation filter design is presented to achieve wide and high dynamic range(DR) for multiple practical applications. The novel modulator can be configured as a Mash 2-2 modulator for high precision or a 2-order modulator for low DR. The decimation filter is designed to select the OSR flexibly among cascaded integrator comb(CIC) filter and two half-band filters(HBF). The serial peripheral interface(SPI) can be used to adjust the sampling frequency and the oversampling ratio(OSR). The design was fabricated in a 0.13 m CMOS process with an area of 0.91 mm2and a total power of 5.2 mW. The measurement results show that the dynamic range(DR) of the proposed ADC can change from 55to 95 dB with the configurable OSR from 16 to 256. The spurious free dynamic range(SFDR) and signal-to-noise distortion ratio(SNDR) can get 99 dB and 86.5 dB, respectively.
基金supported by the National Natural Science Foundation of China(22375104,22371134,and 22035003)the National Key R&D Program of China(2022YFA1503301)Haihe Laboratory of Sustainable Chemical Transformations(YYJC202101)。
文摘The targeted construction of donor-acceptor(D-A)materials featuring efficient photothermal(PT)conversion properties has been an attractive but challenging goal.Herein,a new series of coordination polymers(CPs)featuring different PT performances were constructed with flexible linker 1,1′-Ferrocenedicarboxylic acid(FCA)and 2,4,6-tri(pyridin-4-yl)-1,3,5-triazine(TPT)as acceptor and donor molecules including coronene and tetrathiafulvalene(TTF).Based on the flexible configurations of FCA ligand and the directing of donor dependent D-A interactions,the structures of TF-1 to TF-3 featuring distinctive dimension were obtained based on Cd(Ⅱ)ions for investigating the PT property in configurational perspectives.A systematic investigation of the PT properties of the CPs was performed.Notably,TF-3 exhibits the finest PT conversion effect under the irradiation of560 nm laser,while TF-2 shows optimal PT conversion under 808 nm laser irradiation required for biological PT therapy,illustrating the correlation between the structural and component features of the CPs and their PT performances.Furthermore,Zn(Ⅱ)as bio-friendly ion was utilized to construct hypotoxic TF-4 that reveals similar structure to that of TF-2 for potential application.Polydimethylsiloxane(PDMS)patches doped with TF-4 exhibits considerable NIR PT conversion effect under808 nm,represented by the nearly 80℃temperature increased in 120 s for TF-4@PDMS patch(1.2 wt%)under 0.9 W cm^(-2)irradiation,the results of which herein indicate the potential of D-A CPs as versatile platform for the modulation of PT materials.