The objective of this study was to identify determinants of fertility desires in HIV positive women living in the Western Highlands Province, Papua New Guinea, a male-dominated, patrimonial society. A cross-sectional ...The objective of this study was to identify determinants of fertility desires in HIV positive women living in the Western Highlands Province, Papua New Guinea, a male-dominated, patrimonial society. A cross-sectional study was conducted to collect data in February, 2010. Two hundred and ninety one HIV-infected women participated in personal interviews using a structured questionnaire. Sixty-six percent of the respondents were in polygamous relationships. Thirty-four percent of the participants desired a child in the future. Chi-square tests revealed that variables associated with desire for a child were age, marital status, number of children, current co-habitation with a partner, duration of time with a partner, receipt of the bride price, domestic physical violence, sexual activity in the previous three months, partner’s desire for a child, and current contraceptive use. Using multiple logistic regression, a partner’s positive desire for a child was the strongest predictor, with an odds ratio of 13.04 (95% CI = 5.6 -29.91). Fertility desires were largely influenced by dominant culturally sensitive issues and the family-oriented culture. The integration of effective counseling and reproductive healthcare service into HIV clinics is recommended. Holistic, culturally-relevant and family-oriented reproductive health counseling should provide more positive outcomes for both HIV-infected women and their children.展开更多
The Popu lation Research Instit ute of the University of Tibet conduct-ed a survey in 1995 on the fertility intentions and atti-tude towards family planning anong m arried Tibetan women of childbearing age in urban an...The Popu lation Research Instit ute of the University of Tibet conduct-ed a survey in 1995 on the fertility intentions and atti-tude towards family planning anong m arried Tibetan women of childbearing age in urban and rural Tibet.Women aged 2034 made up 59.2%of the 857 women su1veyed.展开更多
To analyze the morality loss of Carrie,the social context and Carrie's own desires are taken in to consideration.At theend of the paper,the analysis of several the metaphorical images is provided to help the reads...To analyze the morality loss of Carrie,the social context and Carrie's own desires are taken in to consideration.At theend of the paper,the analysis of several the metaphorical images is provided to help the reads understand the spiritual consolationof Carrie.展开更多
From international student to professor,Tripathi Mani shares his thoughts on Chinese and Indian cultures and the beneficial exchanges between them.TRIPATHI Vivek Mani first learned about China from bedtime stories tol...From international student to professor,Tripathi Mani shares his thoughts on Chinese and Indian cultures and the beneficial exchanges between them.TRIPATHI Vivek Mani first learned about China from bedtime stories told by his father,a Sanskrit teacher in rural Bihar,a state in east India.Many of the stories were about the Chinese monk Xuanzang’s adventures during his long journey to India to find Buddhist scriptures.They kindled the young boy’s interest in China and the desire to visit it one day.展开更多
Suppressing the coffee ring effect(CRE)of an aqueous suspension through manipulation without affecting the remaining deposit is highly desirable for practical applications;however,this is extremely challenging.Here,we...Suppressing the coffee ring effect(CRE)of an aqueous suspension through manipulation without affecting the remaining deposit is highly desirable for practical applications;however,this is extremely challenging.Here,we demonstrate CRE suppression with undetectable disturbance of the deposit on carbon-based surfaces.This was achieved by adding ammonium bicarbonate(NH4HCO_(3)),which benefits from the dissociation of NH_(4)HCO_(3) to produce NH_(4)^(+),as well as its decomposition into NH_(3) and CO_(2) molecules.Surprisingly,NH_(4)^(+) can also function as Na^(+)/K^(+)to suppress the CRE through cation interactions,although its hydrate state is only partially positively charged.Moreover,we successfully applied this approach to enhance the morphology,resistance,and color uniformity of deposits of graphene oxide quantum dots,conductive inks,and organic dyes,respectively.This study provides a practical strategy for improving the performance of fabricated devices and paves the way for the development of high-accuracy manufacturing techniques in diverse industries.展开更多
The multi-objective optimization of backfill effect based on response surface methodology and desirability function(RSM-DF)was conducted.Firstly,the test results show that the uniaxial compressive strength(UCS)increas...The multi-objective optimization of backfill effect based on response surface methodology and desirability function(RSM-DF)was conducted.Firstly,the test results show that the uniaxial compressive strength(UCS)increases with cement sand ratio(CSR),slurry concentration(SC),and curing age(CA),while flow resistance(FR)increases with SC and backfill flow rate(BFR),and decreases with CSR.Then the regression models of UCS and FR as response values were established through RSM.Multi-factor interaction found that CSR-CA impacted UCS most,while SC-BFR impacted FR most.By introducing the desirability function,the optimal backfill parameters were obtained based on RSM-DF(CSR is 1:6.25,SC is 69%,CA is 11.5 d,and BFR is 90 m^(3)/h),showing close results of Design Expert and high reliability for optimization.For a copper mine in China,RSM-DF optimization will reduce cement consumption by 4758 t per year,increase tailings consumption by about 6700 t,and reduce CO_(2)emission by about 4758 t.Thus,RSM-DF provides a new approach for backfill parameters optimization,which has important theoretical and practical values.展开更多
This study examined how social desirability responses confound the relationship between gender and social media addiction.A total of 496 college student social media users(females=310,62.5%,mean age=20.15,SD=1.26)comp...This study examined how social desirability responses confound the relationship between gender and social media addiction.A total of 496 college student social media users(females=310,62.5%,mean age=20.15,SD=1.26)completed an online questionnaire on Social Media Addiction and Social Desirability.Mediation analysis revealed that females were at higher risk for social media addiction.On the other hand,the indirect effect of gender on social media addiction via social desirability is associated with lower social media addiction,which suggests that social desirability had a suppression effect on social media addiction associated with gender.ANOVA results showed that females reported higher social media addiction scores than males in the low social desirability group;in the high group,gender differences were insignificant.This study’s unique contribution is to suggest that females are at higher risk than males for developing addictive social media behaviors.Based on this finding,student social media safety interventions should be gender sensitive to the social desirability effect on females who may hide their true addiction as a result.展开更多
Cashew processing in Côte d’Ivoire focuses only on the cashew nut, to the detriment of the apple. Only a very small proportion of the apple is processed into juice. The aim of this work is to enhance the value o...Cashew processing in Côte d’Ivoire focuses only on the cashew nut, to the detriment of the apple. Only a very small proportion of the apple is processed into juice. The aim of this work is to enhance the value of cashew apples by transforming them into jam. Specifically, the aim was first to characterize the sensory properties of cashew apple jam formulations using baobab powder as a source of pectin and then to optimise the formulations. A Box-Behken design with pH, Sugar, and Baobab as factors was used to model and characterize the jam sensory descriptors, and a multivariate analysis with SensomineR was used to characterize the jam formulations. The desirability function was used to optimise the formulations. The results show globally significant regressions at the 0.05 threshold for the sensory descriptors Gelling, Brilliance, Smell, Sweetness, and (-)Astringency, with the exception of (-)Salinity. The R2 coefficients are greater than 80%. The factors studied could have effects on the sensory descriptors of cashew jam formulations. The Baobab had the main effect on the gelling, smell, and astringency of the jams. Brilliance depended on the added sugar. A product effect (p < 0.001) was observed for the descriptors Smell, Gelling, Brilliance, and Sweetness, as these allowed the panelists to find differences between the formulations. Optimum jam formulation can be achieved with 51.56% sugar and 2.12% Baobab at a pH of 3.15. Cashew apple jam using Baobab offers opportunities to add value to apples that have long been abandoned in the field. It would be important to find conditions for prolonged storage of this jam.展开更多
In situ recycling is one of the most effective methods to dispose of earth pressure balance(EPB)shield waste muck with residual foaming agents with high moisture content.In this context,response surface methodology(RS...In situ recycling is one of the most effective methods to dispose of earth pressure balance(EPB)shield waste muck with residual foaming agents with high moisture content.In this context,response surface methodology(RSM)was employed to quantify the effects of independent variables,including flocculant dosage,defoamer dosage,and muck drying mass(MDM)and their interactions on defoaming-flocculation-dewatering indices.The polymeric aluminum chloride(PACL)and hydroxy silicone oil-glycerol polypropylene ether(H-G)were selected as the flocculant and defoamer.The contents of surfactants and foam stabilizers in residual foaming agents were determined using the proposed empirical equation.The defoaming ratio,antifoaming ratio,turbidity,moisture content,filtration loss ratio,and fall cone penetration depth were considered as dependent variables.The accuracy of developed RSM models was verified by the analysis results of variance,residuals,and paired t-test.Combined with the desirability approach,an optimal mixing ratio of 0.078 wt%PACL,0.016 wt%H-G,and 27.882 wt%MDM was recommended,leading to a defoaming ratio of 98.34 vol%for residual foams and a moisture content of 56.72 wt%for pressure-filtration cakes.Our findings were demonstrated to be able to provide useful guidance for prediction and optimization of the in situ recycling indicators of EPB shield waste muck in metro tunnel construction sites.展开更多
This paper addresses the time-varying formation-containment(FC) problem for nonholonomic multi-agent systems with a desired trajectory constraint, where only the leaders can acquire information about the desired traje...This paper addresses the time-varying formation-containment(FC) problem for nonholonomic multi-agent systems with a desired trajectory constraint, where only the leaders can acquire information about the desired trajectory. Input the fixed time-varying formation template to the leader and start executing, this process also needs to track the desired trajectory, and the follower needs to converge to the convex hull that the leader crosses. Firstly, the dynamic models of nonholonomic systems are linearized to second-order dynamics. Then, based on the desired trajectory and formation template, the FC control protocols are proposed. Sufficient conditions to achieve FC are introduced and an algorithm is proposed to resolve the control parameters by solving an algebraic Riccati equation. The system is demonstrated to achieve FC, with the average position and velocity of the leaders converging asymptotically to the desired trajectory. Finally, the theoretical achievements are verified in simulations by a multi-agent system composed of virtual human individuals.展开更多
The carbon dioxide(CO_(2))reduction process involves complex protonation,making the resulting product often unpredictable.To achieve the desired product,it is crucial to manipulate the reaction steps.Herein,we build t...The carbon dioxide(CO_(2))reduction process involves complex protonation,making the resulting product often unpredictable.To achieve the desired product,it is crucial to manipulate the reaction steps.Herein,we build the metal atom pair sites for selective CO_(2)photoreduction into methane.As a prototype,Ni atom pair sites loaded on the Mo S_(2)nanosheets were synthesized and verified by highresolution transmission electron microscopy(HRTEM),X-ray photoelectron spectroscopy(XPS)and X-rayabsorption near edge structure spectra(XANES).In-situ Fourier transform infrared spectroscopy(FTIR)monitors the*CHO group,a crucial intermediate in CH_(4)production,during CO_(2)photoreduction on the Ni-Mo S_(2)nanosheets,whereas this monitoring is not observed for the Mo S_(2)nanosheets.Also,theoretical calculations disclose that over the Ni-Mo S_(2)nanosheet slab,the formation energy of*CHO intermediates is determined to be lower(0.585 e V)than the desorption energy of*CO intermediates for CO production(0.64 e V),implying the higher selectivity of CH_(4)production.展开更多
Chinese materia medica(CMM) compatibility is one core content in the theory of Traditional Chinese Medicine(TCM), and elaborating the scientific connotation of CMM compatibility is of great significance to promote the...Chinese materia medica(CMM) compatibility is one core content in the theory of Traditional Chinese Medicine(TCM), and elaborating the scientific connotation of CMM compatibility is of great significance to promote the modernization of TCM. Self-assembly is the combination of active ingredients into aggregates through noncovalent bonds, such as hydrogen bonding, electrostatic interactions, ionic interactions, and hydrophobic interactions. The complex properties and special structures of CMM components create the basis for selfassembly. The self-assembled materials formed after CMM compatibility is an important part of the material basis for the efficacy of TCM, which can help explain the scientific connotations of CMM compatibility. This review summarizes the self-assembly phenomenon from the perspective of drug pair combinations in recent decades and explains the scientific connotation of CMM compatibility about the material basis, pharmacodynamic changes, and mechanism of action, providing new ideas and methods for the study of TCM.展开更多
Dear Editor,This letter presents a novel Udwadia-Kalaba(U-K)approach for the trajectory tracking control of a quad-rotor unmanned aerial vehicle(UAV).Compared to conventional control approaches,the desired trajectorie...Dear Editor,This letter presents a novel Udwadia-Kalaba(U-K)approach for the trajectory tracking control of a quad-rotor unmanned aerial vehicle(UAV).Compared to conventional control approaches,the desired trajectories are treated as trajectory tracking constraints in this approach.展开更多
Plant derived natural fibers have been widely investigated as alternatives to synthetic fibers in reinforcing polymers.Researchers over the years have explored many plant fibers using different extraction processes to...Plant derived natural fibers have been widely investigated as alternatives to synthetic fibers in reinforcing polymers.Researchers over the years have explored many plant fibers using different extraction processes to study their physical,chemical,and mechanical properties.In this context,the present study relates to the extraction,characterization,and optimization of Typha angustata L.stem fibers.For this purpose,desirability functions and response surface methodology were applied to simultaneously optimize the diameter(D),linear density(LD);yield(Y),lignin fraction(L),and tenacity(T)of Typha stem fibers.Typha stems have been subjected to both alkali(NaOH)and enzymatic(pectinex ultra-SPL)treatments.Three levels of process variables including enzyme concentration(10,15,and 20 ml/L)and treatment duration(10,15,and 20 days)were used to design the experiments according to the factorial design.Experimental results were examined by analysis of variance and fitted to second order polynomial model using multiple regression analysis.The Derringer’s desirability function released that the values of process variables generating optimized diameter,linear density,yield,lignin ratio and tenacity are 20 ml/L and 20 days for concentration of pectinex ultra-SPL enzyme and treatment duration,respectively.Confirmation was performed and high degree of correlation was found between the experimental and statistical values.Moreover,the morphological structure has been investigated by the scanning electron microscope,showing a crenelated structure of ultimate fiber bundles of cellulose composing the Typha fiber.Compared to Typha stem non-treated fibers(TSNTF),Typha stem combined treated fibers(TSCTF),brings to improve mechanical properties.This change in mechanical properties is affected by modifying the fiber structure showing alpha cellulose of(66.86%)and lignin ratio of(10.83%)with a crystallinity index of(58.47%).展开更多
Gas turbines play core roles in clean energy supply and the construction of comprehensive energy systems.The control performance of primary frequency modulation of gas turbines has a great impact on the frequency cont...Gas turbines play core roles in clean energy supply and the construction of comprehensive energy systems.The control performance of primary frequency modulation of gas turbines has a great impact on the frequency control of the power grid.However,there are some control difficulties in the primary frequency modulation control of gas turbines,such as the coupling effect of the fuel control loop and speed control loop,slow tracking speed,and so on.To relieve the abovementioned difficulties,a control strategy based on the desired dynamic equation proportional integral(DDE-PI)is proposed in this paper.Based on the parameter stability region,a parameter tuning procedure is summarized.Simulation is carried out to address the ease of use and simplicity of the proposed tuning method.Finally,DDE-PI is applied to the primary frequency modulation system of an MS6001B heavy-duty gas turbine.The simulation results indicate that the gas turbine with the proposed strategy can obtain the best control performance with a strong ability to deal with system uncertainties.The proposed method shows good engineering application potential.展开更多
In 2023, Latin America was confronted with increased domestic and international challenges, resulting in a stronger public desire for change. New social ideologies are continuing to emerge, and transformation through ...In 2023, Latin America was confronted with increased domestic and international challenges, resulting in a stronger public desire for change. New social ideologies are continuing to emerge, and transformation through reform has become a broad consensus. However, during the complicated reshaping of Latin America's political ecology, the swing of the political pendulum and the change of regimes are accelerating.展开更多
Dear Editor,This letter investigates the level curve tracking problem of unknown scalar fields using an unmanned aerial vehicle(UAV)and presents a robust reinforcement learning(RL)-guided model predictive control(MPC)...Dear Editor,This letter investigates the level curve tracking problem of unknown scalar fields using an unmanned aerial vehicle(UAV)and presents a robust reinforcement learning(RL)-guided model predictive control(MPC)scheme for the UAV.Specifically,we formulate the MPC trajectory tracking problem,wherein an RL-based trajectory planning algorithm provides the reference trajectory to guide the UAV towards the desired concentration.展开更多
文摘The objective of this study was to identify determinants of fertility desires in HIV positive women living in the Western Highlands Province, Papua New Guinea, a male-dominated, patrimonial society. A cross-sectional study was conducted to collect data in February, 2010. Two hundred and ninety one HIV-infected women participated in personal interviews using a structured questionnaire. Sixty-six percent of the respondents were in polygamous relationships. Thirty-four percent of the participants desired a child in the future. Chi-square tests revealed that variables associated with desire for a child were age, marital status, number of children, current co-habitation with a partner, duration of time with a partner, receipt of the bride price, domestic physical violence, sexual activity in the previous three months, partner’s desire for a child, and current contraceptive use. Using multiple logistic regression, a partner’s positive desire for a child was the strongest predictor, with an odds ratio of 13.04 (95% CI = 5.6 -29.91). Fertility desires were largely influenced by dominant culturally sensitive issues and the family-oriented culture. The integration of effective counseling and reproductive healthcare service into HIV clinics is recommended. Holistic, culturally-relevant and family-oriented reproductive health counseling should provide more positive outcomes for both HIV-infected women and their children.
文摘The Popu lation Research Instit ute of the University of Tibet conduct-ed a survey in 1995 on the fertility intentions and atti-tude towards family planning anong m arried Tibetan women of childbearing age in urban and rural Tibet.Women aged 2034 made up 59.2%of the 857 women su1veyed.
文摘To analyze the morality loss of Carrie,the social context and Carrie's own desires are taken in to consideration.At theend of the paper,the analysis of several the metaphorical images is provided to help the reads understand the spiritual consolationof Carrie.
文摘From international student to professor,Tripathi Mani shares his thoughts on Chinese and Indian cultures and the beneficial exchanges between them.TRIPATHI Vivek Mani first learned about China from bedtime stories told by his father,a Sanskrit teacher in rural Bihar,a state in east India.Many of the stories were about the Chinese monk Xuanzang’s adventures during his long journey to India to find Buddhist scriptures.They kindled the young boy’s interest in China and the desire to visit it one day.
基金National Natural Science Foundation of China under Grant No.12005062(SS).National Natural Science Foundation of China under Grant No.11974366(HF).National Natural Science Foundation of China under Grant No.U1632135(HY)Fundamental Research Funds for the Central Universities,China(HF)。
文摘Suppressing the coffee ring effect(CRE)of an aqueous suspension through manipulation without affecting the remaining deposit is highly desirable for practical applications;however,this is extremely challenging.Here,we demonstrate CRE suppression with undetectable disturbance of the deposit on carbon-based surfaces.This was achieved by adding ammonium bicarbonate(NH4HCO_(3)),which benefits from the dissociation of NH_(4)HCO_(3) to produce NH_(4)^(+),as well as its decomposition into NH_(3) and CO_(2) molecules.Surprisingly,NH_(4)^(+) can also function as Na^(+)/K^(+)to suppress the CRE through cation interactions,although its hydrate state is only partially positively charged.Moreover,we successfully applied this approach to enhance the morphology,resistance,and color uniformity of deposits of graphene oxide quantum dots,conductive inks,and organic dyes,respectively.This study provides a practical strategy for improving the performance of fabricated devices and paves the way for the development of high-accuracy manufacturing techniques in diverse industries.
基金Funded by the Deep Underground National Science&Technology Major Project gram of China(No.2024ZD1003704)the National Natural Science Foundation of China(Nos.51834001 and 52374111)。
文摘The multi-objective optimization of backfill effect based on response surface methodology and desirability function(RSM-DF)was conducted.Firstly,the test results show that the uniaxial compressive strength(UCS)increases with cement sand ratio(CSR),slurry concentration(SC),and curing age(CA),while flow resistance(FR)increases with SC and backfill flow rate(BFR),and decreases with CSR.Then the regression models of UCS and FR as response values were established through RSM.Multi-factor interaction found that CSR-CA impacted UCS most,while SC-BFR impacted FR most.By introducing the desirability function,the optimal backfill parameters were obtained based on RSM-DF(CSR is 1:6.25,SC is 69%,CA is 11.5 d,and BFR is 90 m^(3)/h),showing close results of Design Expert and high reliability for optimization.For a copper mine in China,RSM-DF optimization will reduce cement consumption by 4758 t per year,increase tailings consumption by about 6700 t,and reduce CO_(2)emission by about 4758 t.Thus,RSM-DF provides a new approach for backfill parameters optimization,which has important theoretical and practical values.
基金supported by the Guangdong Education Science Planning Project(2024GXJK612).
文摘This study examined how social desirability responses confound the relationship between gender and social media addiction.A total of 496 college student social media users(females=310,62.5%,mean age=20.15,SD=1.26)completed an online questionnaire on Social Media Addiction and Social Desirability.Mediation analysis revealed that females were at higher risk for social media addiction.On the other hand,the indirect effect of gender on social media addiction via social desirability is associated with lower social media addiction,which suggests that social desirability had a suppression effect on social media addiction associated with gender.ANOVA results showed that females reported higher social media addiction scores than males in the low social desirability group;in the high group,gender differences were insignificant.This study’s unique contribution is to suggest that females are at higher risk than males for developing addictive social media behaviors.Based on this finding,student social media safety interventions should be gender sensitive to the social desirability effect on females who may hide their true addiction as a result.
文摘Cashew processing in Côte d’Ivoire focuses only on the cashew nut, to the detriment of the apple. Only a very small proportion of the apple is processed into juice. The aim of this work is to enhance the value of cashew apples by transforming them into jam. Specifically, the aim was first to characterize the sensory properties of cashew apple jam formulations using baobab powder as a source of pectin and then to optimise the formulations. A Box-Behken design with pH, Sugar, and Baobab as factors was used to model and characterize the jam sensory descriptors, and a multivariate analysis with SensomineR was used to characterize the jam formulations. The desirability function was used to optimise the formulations. The results show globally significant regressions at the 0.05 threshold for the sensory descriptors Gelling, Brilliance, Smell, Sweetness, and (-)Astringency, with the exception of (-)Salinity. The R2 coefficients are greater than 80%. The factors studied could have effects on the sensory descriptors of cashew jam formulations. The Baobab had the main effect on the gelling, smell, and astringency of the jams. Brilliance depended on the added sugar. A product effect (p < 0.001) was observed for the descriptors Smell, Gelling, Brilliance, and Sweetness, as these allowed the panelists to find differences between the formulations. Optimum jam formulation can be achieved with 51.56% sugar and 2.12% Baobab at a pH of 3.15. Cashew apple jam using Baobab offers opportunities to add value to apples that have long been abandoned in the field. It would be important to find conditions for prolonged storage of this jam.
基金supported by the National Youth Top-notch Talent Support Program of China(Grant No.00389335)the National Natural Science Foundation of China(Grant No.52378392)the“Foal Eagle Program”Youth Top-notch Talent Project of Fujian Province(Grant No.00387088).
文摘In situ recycling is one of the most effective methods to dispose of earth pressure balance(EPB)shield waste muck with residual foaming agents with high moisture content.In this context,response surface methodology(RSM)was employed to quantify the effects of independent variables,including flocculant dosage,defoamer dosage,and muck drying mass(MDM)and their interactions on defoaming-flocculation-dewatering indices.The polymeric aluminum chloride(PACL)and hydroxy silicone oil-glycerol polypropylene ether(H-G)were selected as the flocculant and defoamer.The contents of surfactants and foam stabilizers in residual foaming agents were determined using the proposed empirical equation.The defoaming ratio,antifoaming ratio,turbidity,moisture content,filtration loss ratio,and fall cone penetration depth were considered as dependent variables.The accuracy of developed RSM models was verified by the analysis results of variance,residuals,and paired t-test.Combined with the desirability approach,an optimal mixing ratio of 0.078 wt%PACL,0.016 wt%H-G,and 27.882 wt%MDM was recommended,leading to a defoaming ratio of 98.34 vol%for residual foams and a moisture content of 56.72 wt%for pressure-filtration cakes.Our findings were demonstrated to be able to provide useful guidance for prediction and optimization of the in situ recycling indicators of EPB shield waste muck in metro tunnel construction sites.
文摘This paper addresses the time-varying formation-containment(FC) problem for nonholonomic multi-agent systems with a desired trajectory constraint, where only the leaders can acquire information about the desired trajectory. Input the fixed time-varying formation template to the leader and start executing, this process also needs to track the desired trajectory, and the follower needs to converge to the convex hull that the leader crosses. Firstly, the dynamic models of nonholonomic systems are linearized to second-order dynamics. Then, based on the desired trajectory and formation template, the FC control protocols are proposed. Sufficient conditions to achieve FC are introduced and an algorithm is proposed to resolve the control parameters by solving an algebraic Riccati equation. The system is demonstrated to achieve FC, with the average position and velocity of the leaders converging asymptotically to the desired trajectory. Finally, the theoretical achievements are verified in simulations by a multi-agent system composed of virtual human individuals.
基金supported by the National Key R&D Program of China(No.2022YFA1502904)the National Natural Science Foundation of China(Nos.22275178 and 22002148)the Fundamental Research Funds for the Central Universities(Nos.JUSRP123013 and JUSRP123015)。
文摘The carbon dioxide(CO_(2))reduction process involves complex protonation,making the resulting product often unpredictable.To achieve the desired product,it is crucial to manipulate the reaction steps.Herein,we build the metal atom pair sites for selective CO_(2)photoreduction into methane.As a prototype,Ni atom pair sites loaded on the Mo S_(2)nanosheets were synthesized and verified by highresolution transmission electron microscopy(HRTEM),X-ray photoelectron spectroscopy(XPS)and X-rayabsorption near edge structure spectra(XANES).In-situ Fourier transform infrared spectroscopy(FTIR)monitors the*CHO group,a crucial intermediate in CH_(4)production,during CO_(2)photoreduction on the Ni-Mo S_(2)nanosheets,whereas this monitoring is not observed for the Mo S_(2)nanosheets.Also,theoretical calculations disclose that over the Ni-Mo S_(2)nanosheet slab,the formation energy of*CHO intermediates is determined to be lower(0.585 e V)than the desorption energy of*CO intermediates for CO production(0.64 e V),implying the higher selectivity of CH_(4)production.
基金the Science and Technology Innovation Project of the China Academy of Chinese Medical Sciences:Establishment of Research Methods for Protein Supramolecular Components in Chinese Medicine decoctionC12021A00108Independent Selection Project of Institute of Basic Theory of Chinese Medicine,China Academy of Chinese Medical Sciences:Exploration and Case Study of the Research Model of"Theory and Experiment"on the Compatibility of Traditional Chinese Medicine,YZ-202109。
文摘Chinese materia medica(CMM) compatibility is one core content in the theory of Traditional Chinese Medicine(TCM), and elaborating the scientific connotation of CMM compatibility is of great significance to promote the modernization of TCM. Self-assembly is the combination of active ingredients into aggregates through noncovalent bonds, such as hydrogen bonding, electrostatic interactions, ionic interactions, and hydrophobic interactions. The complex properties and special structures of CMM components create the basis for selfassembly. The self-assembled materials formed after CMM compatibility is an important part of the material basis for the efficacy of TCM, which can help explain the scientific connotations of CMM compatibility. This review summarizes the self-assembly phenomenon from the perspective of drug pair combinations in recent decades and explains the scientific connotation of CMM compatibility about the material basis, pharmacodynamic changes, and mechanism of action, providing new ideas and methods for the study of TCM.
基金supported by the Fundamental Research Funds for Central Universities of China (23GH020222)the Basic Research Program of Taicang City (TC2023JC06)。
文摘Dear Editor,This letter presents a novel Udwadia-Kalaba(U-K)approach for the trajectory tracking control of a quad-rotor unmanned aerial vehicle(UAV).Compared to conventional control approaches,the desired trajectories are treated as trajectory tracking constraints in this approach.
文摘Plant derived natural fibers have been widely investigated as alternatives to synthetic fibers in reinforcing polymers.Researchers over the years have explored many plant fibers using different extraction processes to study their physical,chemical,and mechanical properties.In this context,the present study relates to the extraction,characterization,and optimization of Typha angustata L.stem fibers.For this purpose,desirability functions and response surface methodology were applied to simultaneously optimize the diameter(D),linear density(LD);yield(Y),lignin fraction(L),and tenacity(T)of Typha stem fibers.Typha stems have been subjected to both alkali(NaOH)and enzymatic(pectinex ultra-SPL)treatments.Three levels of process variables including enzyme concentration(10,15,and 20 ml/L)and treatment duration(10,15,and 20 days)were used to design the experiments according to the factorial design.Experimental results were examined by analysis of variance and fitted to second order polynomial model using multiple regression analysis.The Derringer’s desirability function released that the values of process variables generating optimized diameter,linear density,yield,lignin ratio and tenacity are 20 ml/L and 20 days for concentration of pectinex ultra-SPL enzyme and treatment duration,respectively.Confirmation was performed and high degree of correlation was found between the experimental and statistical values.Moreover,the morphological structure has been investigated by the scanning electron microscope,showing a crenelated structure of ultimate fiber bundles of cellulose composing the Typha fiber.Compared to Typha stem non-treated fibers(TSNTF),Typha stem combined treated fibers(TSCTF),brings to improve mechanical properties.This change in mechanical properties is affected by modifying the fiber structure showing alpha cellulose of(66.86%)and lignin ratio of(10.83%)with a crystallinity index of(58.47%).
基金supported by Science and Technology Project of Jiangsu Frontier Electric Technology Co.,Ltd. (Grant Number KJ202004),Gao A.M. (author who received the grant).
文摘Gas turbines play core roles in clean energy supply and the construction of comprehensive energy systems.The control performance of primary frequency modulation of gas turbines has a great impact on the frequency control of the power grid.However,there are some control difficulties in the primary frequency modulation control of gas turbines,such as the coupling effect of the fuel control loop and speed control loop,slow tracking speed,and so on.To relieve the abovementioned difficulties,a control strategy based on the desired dynamic equation proportional integral(DDE-PI)is proposed in this paper.Based on the parameter stability region,a parameter tuning procedure is summarized.Simulation is carried out to address the ease of use and simplicity of the proposed tuning method.Finally,DDE-PI is applied to the primary frequency modulation system of an MS6001B heavy-duty gas turbine.The simulation results indicate that the gas turbine with the proposed strategy can obtain the best control performance with a strong ability to deal with system uncertainties.The proposed method shows good engineering application potential.
文摘In 2023, Latin America was confronted with increased domestic and international challenges, resulting in a stronger public desire for change. New social ideologies are continuing to emerge, and transformation through reform has become a broad consensus. However, during the complicated reshaping of Latin America's political ecology, the swing of the political pendulum and the change of regimes are accelerating.
基金supported by the National Science and Technology Major Project(2022ZD0119302)the National Natural Science Foundation of China(62173034,U23B 2059,62088101,62303054)。
文摘Dear Editor,This letter investigates the level curve tracking problem of unknown scalar fields using an unmanned aerial vehicle(UAV)and presents a robust reinforcement learning(RL)-guided model predictive control(MPC)scheme for the UAV.Specifically,we formulate the MPC trajectory tracking problem,wherein an RL-based trajectory planning algorithm provides the reference trajectory to guide the UAV towards the desired concentration.
