Traditional Chinese medicine(TCM)is a precious treasure of the Chinese nation and has unique advantages in the prevention and treatment of diseases.The holistic view of TCM coincides with the new generation of medical...Traditional Chinese medicine(TCM)is a precious treasure of the Chinese nation and has unique advantages in the prevention and treatment of diseases.The holistic view of TCM coincides with the new generation of medical research paradigm characterized by network and system.TCM gave birth to a new method featuring holistic and systematic"network target",a core theory and method of network pharmacology.TCM is also an important research object of network pharmacology.TCM network pharmacology,which aims to understand the network-based biological basis of complex diseases,TCM syndromes and herb treatments,plays a critical role in the origin and development process of network pharmacology.This review introduces new progresses of TCM network pharmacology in recent years,including predicting herb targets,understanding biological foundation of diseases and syndromes,network regulation mechanisms of herbal formulae,and identifying disease and syndrome biomarkers based on biological network.These studies show a trend of combining computational,experimental and clinical approaches,which is a promising direction of TCM network pharmacology research in the future.Considering that TCM network pharmacology is still a young research field,it is necessary to further standardize the research process and evaluation indicators to promote its healthy development.展开更多
The effects of slope surface material, slope gradient, block shape, and block mass conditions on rockfall rolling velocity were estimated with orthogonal test approach. Visual analysis shows that the importance of the...The effects of slope surface material, slope gradient, block shape, and block mass conditions on rockfall rolling velocity were estimated with orthogonal test approach. Visual analysis shows that the importance of the factors is slope surface material > slope gradient > block shape > block mass. All the factors except block mass have the F value greater than the critical value, suggesting that these three factors are the key factors affecting the rockfall rolling velocity. Factor interaction analysis shows that the effect of the slope gradient relies largely on the slope surface conditions, and the block shape has little influence if the slope gradient is larger than a critical value. An empirical model considering the three key factors is proposed to estimate the rolling velocity, of which the error is limited to 5% of the testing value. This model is validated by 73 field tests, and the prediction shows excellent correlation with the site test. Thus, this analysis can be used as a tool in the rockfall behavior analysis.展开更多
The effect of formulation variables on in-vitro release and permeation properties of carvedilol from transdermal patch was studied by varying one factor at a time as preliminary study.Based on these results,design of ...The effect of formulation variables on in-vitro release and permeation properties of carvedilol from transdermal patch was studied by varying one factor at a time as preliminary study.Based on these results,design of experiments technique was applied followed by regression analysis and response surface methodology to optimize formulation variables.Central Composite IV model design was used with four formulation variables:drug loading,matrix thickness,adhesive layer thickness,and propylene glycol concentration.Nineteen formulations were prepared according to the design;and the effect of formulation variables was studied on in-vitro release and permeation profiles of these formulations.In all cases,the permeation profiles paralleled in-vitro release profiles.The drug released at 7 h and 24 h was used as release response parameters while permeation flux obtained was employed as permeation response parameter.All four formulation variables were found to be significant for release properties and three of these exhibited significant effect on permeation profile of carvedilol across artificial membrane.Constrained optimization,using 47.9%of cumulative carvedilol released at 7 h and 99.8%at 24 h as well as 25.7 mg/cm2/h of permeation flux,was applied to obtain desired release and permeation profiles.Experimentally,carvedilol was observed to release from the optimized formulation with 51.4%drug release at 7 h and 98.5%at 24 h with an observed flux value of 27.4 mg/cm2/h across artificial membrane,which showed an excellent agreement with the predicted values.The results of this investigation show that the quadratic mathematical model developed could be used to further predict formulations with desirable release and permeation properties.展开更多
Soil-water characteristic curve (SWCC) is significant to estimate the site-specific unsaturated soil properties (such as unsaturated shear strength and coefficient of permeability) for geotechnical analyses involving ...Soil-water characteristic curve (SWCC) is significant to estimate the site-specific unsaturated soil properties (such as unsaturated shear strength and coefficient of permeability) for geotechnical analyses involving unsaturated soils. Determining SWCC can be achieved by fitting data points obtained according to the prescribed experimental scheme, which is specified by the number of measuring points and their corresponding values of the control variable. The number of measuring points is limited since direct measurement of SWCC is often costly and time-consuming. Based on the limited number of measuring points, the estimated SWCC is unavoidably associated with uncertainties, which depends on measurement data obtained from the prescribed experimental scheme. Therefore, it is essential to plan the experimental scheme so as to reduce the uncertainty in the estimated SWCC. This study presented a Bayesian approach, called OBEDO, for probabilistic experimental design optimization of measuring SWCC based on the prior knowledge and information of testing apparatus. The uncertainty in estimated SWCC is quantified and the optimal experimental scheme with the maximum expected utility is determined by Subset Simulation optimization (SSO) in candidate experimental scheme space. The proposed approach is illustrated using an experimental design example given prior knowledge and the information of testing apparatus and is verified based on a set of real loess SWCC data, which were used to generate random experimental schemes to mimic the arbitrary arrangement of measuring points during SWCC testing in practice. Results show that the arbitrary arrangement of measuring points of SWCC testing is hardly superior to the optimal scheme obtained from OBEDO in terms of the expected utility. The proposed OBEDO approach provides a rational tool to optimize the arrangement of measuring points of SWCC test so as to obtain SWCC measurement data with relatively high expected utility for uncertainty reduction.展开更多
Due to the dissimilar scaling issues,the conventional experimental method of FOWTs can hardly be used directly to validate the full-scale global dynamic responses accurately.Therefore,it is of absolute necessity to fi...Due to the dissimilar scaling issues,the conventional experimental method of FOWTs can hardly be used directly to validate the full-scale global dynamic responses accurately.Therefore,it is of absolute necessity to find a more accurate,economic and efficient approach,which can be utilized to predict the full-scale global dynamic responses of FOWTs.In this paper,a literature review of experimental-numerical methodologies and challenges for FOWTs is made.Several key challenges in the conventional basin experiment issues are discussed,including scaling issues;coupling effects between aero-hydro and structural dynamic responses;blade pitch control strategies;experimental facilities and calibration methods.Several basin experiments,industrial projects and numerical codes are summarized to demonstrate the progress of hybrid experimental methods.Besides,time delay in hardware-in-the-loop challenges is concluded to emphasize their significant role in real-time hybrid approaches.It is of great use to comprehend these methodologies and challenges,which can help some future researchers to make a footstone for proposing a more efficient and functional hybrid basin experimental and numerical method.展开更多
Piles in a group experience additional displacements in soil due to pile-to-pile interactions apart from those resulting from the external loading.The effect of these interactions determined assuming soil as an elasti...Piles in a group experience additional displacements in soil due to pile-to-pile interactions apart from those resulting from the external loading.The effect of these interactions determined assuming soil as an elastic and/or viscoelastic material on pile head impedance functions of the pile group is studied by relating the group stiffness to the static stiffness of a single pile.However,the prevailing elastic solutions may misestimate the resulting pile group response due to the lack of consideration for either soil(material)and/or soil-pile interface nonlinearities.It is well established that soil behaves nonlinearly under moderate-to-high loading amplitudes,and besides,the soil-pile interface nonlinearity can exist even at small loading amplitudes.This study addresses the effects of these nonlinearities on the vertical impedance functions of a 3×3-pile group using numerical methods by direct analyses and superposition using pile-to-pile interaction factors.The numerical results are validated using scaled model tests under 1 g conditions.The results highlight the overestimation of pile-to-pile interactions in the pile group when assuming elastic soil conditions.The cases either by direct analyses or superposition approach involving soil and soil-pile interface nonlinearities agree well with the experimental pile group responses under close-to-elastic and nonlinear conditions.展开更多
In the version of article originally published in the volume 68,2025 of Sci China Chem(pages 3675-3688),the article was published in subscription format rather than open access format due to an oversight during the pr...In the version of article originally published in the volume 68,2025 of Sci China Chem(pages 3675-3688),the article was published in subscription format rather than open access format due to an oversight during the production stage.The corrected copyright and open access notes are provided below.The original article has been corrected.展开更多
Two land surface schemes, one the standard Biosphere / Atmosphere Transfer Scheme Version ie (BOZ) and the other B1Z based on B0Z and heterogeneously-treated by' combined approach' , were co 'pled to the m...Two land surface schemes, one the standard Biosphere / Atmosphere Transfer Scheme Version ie (BOZ) and the other B1Z based on B0Z and heterogeneously-treated by' combined approach' , were co 'pled to the meso-scale model MM4, respectively. Through the calculations of equations from the companion paper, parameters representing land surface heterogeneity and suitable for the coupling models were found out. Three cases were simulated for heavy rainfalls during 36 hours, and the sensitivity of short-term weather modeling to the land surface heterogeneity was tested. Through the analysis of the simulations of the three heavy rainfalls, it was demonstrated that BIZ, compared with BOZ, could more realistically reflect the features of the land surface heterogeneity, therefore could more realistically reproduce the circulation and precipitation amount in the heavy rainfall processes of the three cases. This shows that even short-term weather is sensitive to the land surface heterogeneity, which is more obvious with time passing, and whose influence is more pronounced in the lower layer and gradually extends to the middle and upper layer. Through the analysis of these simulations with BlZ, it is suggested that the bulk effect of smaller-scale fluxes (i.e., the momentum, water vapor and sensible heat fluxes) near the s ig nificantly-heterogeneous land surface is to change the larger-scale (i.e., meso-scale) circulation, and then to influence the development of the low-level jets and precipitation. And also, the complexity of the land-atmosphere interaction was shown in these simulations.展开更多
A method based on Giorgi (1997a, 1997b) and referred to as ’ combined approach’, which is a combi-nation of mosaic approach and analytical-statistical-dynamical approach, is proposed. Compared with those of other ap...A method based on Giorgi (1997a, 1997b) and referred to as ’ combined approach’, which is a combi-nation of mosaic approach and analytical-statistical-dynamical approach, is proposed. Compared with those of other approaches, the main advantage of the combined approach is that it not only can represent both interpatch and intrapatch variability, but also cost less computational time when the land surface heterogeneity is considered. Because the independent variable of probability density function (PDF) is ex-tended to the single valued function of basic meteorological characteristic quantities, which is much more universal, the analytical expressions of the characteristic quantities (e.g., drag coefficient, snow coverage, leaf surface aerodynamical resistance) affected by roughness length are derived , when the roughness length(and / or the zero plane displacement) heterogeneity has been mainly taken into account with the approach. On the basis of the rule which the PDF parameters should follow, we choose a function y of the roughness length z 0 as the PDF independent variable, and set different values of the two parameters width ratio αn and height ratio γ of PDF (here a linear, symmetric PDF is applied) for sensitivity experiments, from which some conclusions can be drawn, e.g., relevant characteristic terms show different sensitivities to the heterogeneous characteristic (i.e., roughness length), which suggests that we should consider the heterogeneities of the more sensitive terms in our model instead of the heterogeneities of the rest, and which also implies that when the land surface scheme is coupled into the global or regional atmospheric model, sensitivity tests against the distribution of the heterogeneous characteristic are very necessary; when the parameter αn is close to zero, little heterogeneity is represented, and αn differs with cases, which have an upper limit of about 0.6; in the reasonable range of αn, a peak-like distribution of roughness length can be depicted by a small value of γ, etc.. Key words Representation of land surface heterogeneity - “ Combined approach” - Numerical experiment This work was supported by the National Sciences Foundation of China, Grant No.49875005 and the State Key Project (973) G19990434 (03).展开更多
Maximum frost heave of unsaturated frost-susceptible soils,in conjunction with a high water table,is an important consideration for the design of foundations in seasonally frozen regions.Therefore,it is necessary to e...Maximum frost heave of unsaturated frost-susceptible soils,in conjunction with a high water table,is an important consideration for the design of foundations in seasonally frozen regions.Therefore,it is necessary to evaluate accurately and efficiently the maximum frost heave for a given soil.For this purpose,a series of one-sided freezing experiments was conducted on unsaturated silty clay in an open system.Multistage cooling of sufficient duration was applied to the soil sample's top,while constant above-zero temperatures were maintained at the bottom.Then,a simple methodology for calculating maximum frost heave at a given cooling temperature was derived utilizing information obtained within the limited time allotted for each stage.On this basis,an empirical equation for defining maximum frost heave as a function of cooling temperature and overburden pressure was determined.Overall,this study provides a simple and practical procedure that is applicable to the evaluation of maximum frost heave of unsaturated frost-susceptible soils.展开更多
In this paper we present a series of monthly gravity field solutions from Gravity Recovery and Climate Experiment（GRACE） range measurements using modified short arc approach,in which the ambiguity of range measureme...In this paper we present a series of monthly gravity field solutions from Gravity Recovery and Climate Experiment（GRACE） range measurements using modified short arc approach,in which the ambiguity of range measurements is eliminated via differentiating two adjacent range measurements.The data used for developing our monthly gravity field model are same as Tongji-GRACEOl model except that the range measurements are used to replace the range rate measurements,and our model is truncated to degree and order 60,spanning Jan.2004 to Dec.2010 also same as Tongji-GRACE01 model.Based on the comparison results of the C_（2,0）,C_（2,1）,S_（2,1）,and C_（15,15）,S_（15,15）,time series and the global mass change signals as well as the mass change time series in Amazon area of our model with those of Tongji-GRACE01 model,we can conclude that our monthly gravity field model is comparable with Tongji-GRACE01 monthly model.展开更多
Nuclear energy driven magnetic confinement via donut shape device known as Tokamak,a toroidal apparatus,for producing controlled fusion reactions in hot plasma,was originally suggested as a basic yet more promising fu...Nuclear energy driven magnetic confinement via donut shape device known as Tokamak,a toroidal apparatus,for producing controlled fusion reactions in hot plasma,was originally suggested as a basic yet more promising fusion reactor.Today the more innovative version of this apparatus that is known as an ITER(international thermonuclear experimental reactor)shows a way toward MCF(magnetic confinement fusion)of hot plasma goal by satisfying Lawson’s Criteria to some degree of achievement.However,since this fusion driven reactor of hot plasma needs to operate at almost 150 million Celsius,the internal material of this reactor is a matter of concern for scientists that are involved with its fabrication.Uniqueness of nanomaterials from the point of view of physical and chemical properties is suggested as a possible potential application for this special and innovative reactor for a nuclear fusion device.Convergence of nanotechnology in study of new generation of materials of this kind can shape the path for various technological developments and a large variety of disciplines,including MCF driven plasma of hot fusion as well.This short TM(technical memorandum)written by these two authors will cover this aspect of technology in a holistic way and the more granular level is left to the reader of this TM to investigate further.展开更多
A molecular structural mechanics approach combining with finite element analysis(MSM/FEA) was applied to study the microstructure and tensile behaviors of bamboo-like carbon nanotubes(BCNTs). The mathematical model of...A molecular structural mechanics approach combining with finite element analysis(MSM/FEA) was applied to study the microstructure and tensile behaviors of bamboo-like carbon nanotubes(BCNTs). The mathematical model of tensile behaviors of BCNTs was established based on molecular structural mechanics theory. The deformations of BCNTs, with different diameters and compartments set based on the experimental investigation on BCNT structures synthesized by chemical vapor depositon, under tensile load, were analyzed with ANSYS programmed. Results show that the BCNTs have good tensile properties, and those Young's modulus can reach 0.84 Tpa. Through the analysis, it can be found that the Young's modulus of BCNTs depends on the diameters and the length of compartment, which is in good agreement with our experimental tests for the tensile performances of individual BCNT.展开更多
The Gravity Recovery and Climate Experiment（GRACE） mission can significantly improve our knowledge of the temporal variability of the Earth＇s gravity field.We obtained monthly gravity field solutions based on varia...The Gravity Recovery and Climate Experiment（GRACE） mission can significantly improve our knowledge of the temporal variability of the Earth＇s gravity field.We obtained monthly gravity field solutions based on variational equations approach from GPS-derived positions of GRACE satellites and K-band range-rate measurements.The impact of different fixed data weighting ratios in temporal gravity field recovery while combining the two types of data was investigated for the purpose of deriving the best combined solution.The monthly gravity field solution obtained through above procedures was named as the Institute of Geodesy and Geophysics（IGG） temporal gravity field models.IGG temporal gravity field models were compared with GRACE Release05（RL05） products in following aspects：（i） the trend of the mass anomaly in China and its nearby regions within 2005-2010; （ii） the root mean squares of the global mass anomaly during 2005-2010; （iii） time-series changes in the mean water storage in the region of the Amazon Basin and the Sahara Desert between 2005 and 2010.The results showed that IGG solutions were almost consistent with GRACE RL05 products in above aspects（i）-（iii）.Changes in the annual amplitude of mean water storage in the Amazon Basin were 14.7 ± 1.2 cm for IGG,17.1 ± 1.3 cm for the Centre for Space Research（CSR）,16.4 ± 0.9 cm for the GeoForschungsZentrum（GFZ） and 16.9 ± 1.2 cm for the Jet Propulsion Laboratory（JPL） in terms of equivalent water height（EWH）,respectively.The root mean squares of the mean mass anomaly in Sahara were 1.2 cm,0.9 cm,0.9 cm and 1.2 cm for temporal gravity field models of IGG,CSR,GFZ and JPL,respectively.Comparison suggested that IGG temporal gravity field solutions were at the same accuracy level with the latest temporal gravity field solutions published by CSR,GFZ and JPL.展开更多
Real-time 6 Degree-of-Freedom(DoF)pose estimation is of paramount importance for various on-orbit tasks.Benefiting from the development of deep learning,Convolutional Neural Networks(CNNs)in feature extraction has yie...Real-time 6 Degree-of-Freedom(DoF)pose estimation is of paramount importance for various on-orbit tasks.Benefiting from the development of deep learning,Convolutional Neural Networks(CNNs)in feature extraction has yielded impressive achievements for spacecraft pose estimation.To improve the robustness and interpretability of CNNs,this paper proposes a Pose Estimation approach based on Variational Auto-Encoder structure(PE-VAE)and a Feature-Aided pose estimation approach based on Variational Auto-Encoder structure(FA-VAE),which aim to accurately estimate the 6 DoF pose of a target spacecraft.Both methods treat the pose vector as latent variables,employing an encoder-decoder network with a Variational Auto-Encoder(VAE)structure.To enhance the precision of pose estimation,PE-VAE uses the VAE structure to introduce reconstruction mechanism with the whole image.Furthermore,FA-VAE enforces feature shape constraints by exclusively reconstructing the segment of the target spacecraft with the desired shape.Comparative evaluation against leading methods on public datasets reveals similar accuracy with a threefold improvement in processing speed,showcasing the significant contribution of VAE structures to accuracy enhancement,and the additional benefit of incorporating global shape prior features.展开更多
Vehicle sounds are important factors of customer satisfaction and have a decisive influence on the product automobile andits quality impression. It becomes more and more important to connect customer requirements and ...Vehicle sounds are important factors of customer satisfaction and have a decisive influence on the product automobile andits quality impression. It becomes more and more important to connect customer requirements and technical specifications to developa vehicle sound with high quality. The turn indicator sound can be described as one sound, which gives the customer an importantfeedback of correct function performance and can be seen as one of the sounds, which play a role in the customer＇s perception ofvehicle quality. In a laboratory experimental study, the question was investigated, how a turn indicator sound must be designed to beperceived as pleasant and high-quality. A multidimensional approach was chosen to combine subjective customer assessments,objective psychophysiological responses of the study participants and physical parameters of the sounds. In total, 15 different tumindicator sounds were assessed by 48 subjects. The study shows how the connection of subjective and objective parameters cansupport product development. The multi-dimensional approach helps to derive recommendations for action to improve the soundquality of the product automobile. Also, the study shows a possibility to involve the human factor in a highly technical environment.展开更多
As one of the four basic skills of language teaching and an aspect of communicative competence,writing seems to be the weakest one among senior school students in China.Most of teachers have had such experiences that ...As one of the four basic skills of language teaching and an aspect of communicative competence,writing seems to be the weakest one among senior school students in China.Most of teachers have had such experiences that although we spend a lot of time marking on the students'writing,but only to find the corrections and comments ignored.The students pay little attention to responses and regard revision of their writing as a punishment.Starting from the perspectives of modern linguistic theory,the pressing demands of the new curriculum,and the practical needs of student development,the study analyses the prevalent misconceptions about writing.The author proposes an assumption of integrating the teaching materials with Reading-to-Write Approach in the senior school writing teaching.To examine the validity of the Approach,about one-year action research is carried out in an ordinary high school,adopting the methodology of literature survey,questionnaire survey,interview,testing and so on.The results of the experiment showed that the approach had a more positive impact on students'writing attitudes and habits than traditional teaching methods.This approach helped them much more in word usage,longer sentences,content,and text structure or development.Besides,the students'compe?tence of interaction and cooperation were enhanced,Therefore,the approach in writing teaching is effective.展开更多
Companies differ in their motivation to corporate social responsibility(CSR)practices,with some companies taking a genuine,altruistic approach and others preferring an opportunistic approach(and attempting to mi...Companies differ in their motivation to corporate social responsibility(CSR)practices,with some companies taking a genuine,altruistic approach and others preferring an opportunistic approach(and attempting to mimic the former).If consumers can distinguish them,they will eventually reward the altruistic(being willing to pay more)and penalize the opportunistic ones.This paper performs an experimental study to assess whether differences in consumers’willingness to pay are statistically significant for different classifications of CSR activities:(i)proactive or reactive,(ii)environment,employees,or social,(iii)involving more or less expensive products,(iv)being performed by firms facing competition or not.Results show that consumers are willing to reward CSR initiatives that follow a reactive approach;consumers’decisions are more moderate when rewarding initiatives associated with more expensive products;the rewards provided depend on the CSR dimension;a relationship between market structure and consumers’reaction to CSR was not found.展开更多
基金supported by the National Natural Science Foundation of China(Nos.6201101081,81630103 and 81225025)Tsinghua University Spring Breeze Fund(No.2020-Z99CFY040)Beijing National Research Center for Information Science and Technology(Nos.BNR2019TD01020 and BNR2019-RC01012)。
文摘Traditional Chinese medicine(TCM)is a precious treasure of the Chinese nation and has unique advantages in the prevention and treatment of diseases.The holistic view of TCM coincides with the new generation of medical research paradigm characterized by network and system.TCM gave birth to a new method featuring holistic and systematic"network target",a core theory and method of network pharmacology.TCM is also an important research object of network pharmacology.TCM network pharmacology,which aims to understand the network-based biological basis of complex diseases,TCM syndromes and herb treatments,plays a critical role in the origin and development process of network pharmacology.This review introduces new progresses of TCM network pharmacology in recent years,including predicting herb targets,understanding biological foundation of diseases and syndromes,network regulation mechanisms of herbal formulae,and identifying disease and syndrome biomarkers based on biological network.These studies show a trend of combining computational,experimental and clinical approaches,which is a promising direction of TCM network pharmacology research in the future.Considering that TCM network pharmacology is still a young research field,it is necessary to further standardize the research process and evaluation indicators to promote its healthy development.
基金supported by the National Science Foundation of China (Grant No. 41572302)the Funds for Creative Research Groups of China (Grant No. 41521002)
文摘The effects of slope surface material, slope gradient, block shape, and block mass conditions on rockfall rolling velocity were estimated with orthogonal test approach. Visual analysis shows that the importance of the factors is slope surface material > slope gradient > block shape > block mass. All the factors except block mass have the F value greater than the critical value, suggesting that these three factors are the key factors affecting the rockfall rolling velocity. Factor interaction analysis shows that the effect of the slope gradient relies largely on the slope surface conditions, and the block shape has little influence if the slope gradient is larger than a critical value. An empirical model considering the three key factors is proposed to estimate the rolling velocity, of which the error is limited to 5% of the testing value. This model is validated by 73 field tests, and the prediction shows excellent correlation with the site test. Thus, this analysis can be used as a tool in the rockfall behavior analysis.
基金The authors acknowledge financial assistance and research facilities provided by College of Pharmacy and Health Sciences,St.John’s University to carry out this research。
文摘The effect of formulation variables on in-vitro release and permeation properties of carvedilol from transdermal patch was studied by varying one factor at a time as preliminary study.Based on these results,design of experiments technique was applied followed by regression analysis and response surface methodology to optimize formulation variables.Central Composite IV model design was used with four formulation variables:drug loading,matrix thickness,adhesive layer thickness,and propylene glycol concentration.Nineteen formulations were prepared according to the design;and the effect of formulation variables was studied on in-vitro release and permeation profiles of these formulations.In all cases,the permeation profiles paralleled in-vitro release profiles.The drug released at 7 h and 24 h was used as release response parameters while permeation flux obtained was employed as permeation response parameter.All four formulation variables were found to be significant for release properties and three of these exhibited significant effect on permeation profile of carvedilol across artificial membrane.Constrained optimization,using 47.9%of cumulative carvedilol released at 7 h and 99.8%at 24 h as well as 25.7 mg/cm2/h of permeation flux,was applied to obtain desired release and permeation profiles.Experimentally,carvedilol was observed to release from the optimized formulation with 51.4%drug release at 7 h and 98.5%at 24 h with an observed flux value of 27.4 mg/cm2/h across artificial membrane,which showed an excellent agreement with the predicted values.The results of this investigation show that the quadratic mathematical model developed could be used to further predict formulations with desirable release and permeation properties.
文摘Soil-water characteristic curve (SWCC) is significant to estimate the site-specific unsaturated soil properties (such as unsaturated shear strength and coefficient of permeability) for geotechnical analyses involving unsaturated soils. Determining SWCC can be achieved by fitting data points obtained according to the prescribed experimental scheme, which is specified by the number of measuring points and their corresponding values of the control variable. The number of measuring points is limited since direct measurement of SWCC is often costly and time-consuming. Based on the limited number of measuring points, the estimated SWCC is unavoidably associated with uncertainties, which depends on measurement data obtained from the prescribed experimental scheme. Therefore, it is essential to plan the experimental scheme so as to reduce the uncertainty in the estimated SWCC. This study presented a Bayesian approach, called OBEDO, for probabilistic experimental design optimization of measuring SWCC based on the prior knowledge and information of testing apparatus. The uncertainty in estimated SWCC is quantified and the optimal experimental scheme with the maximum expected utility is determined by Subset Simulation optimization (SSO) in candidate experimental scheme space. The proposed approach is illustrated using an experimental design example given prior knowledge and the information of testing apparatus and is verified based on a set of real loess SWCC data, which were used to generate random experimental schemes to mimic the arbitrary arrangement of measuring points during SWCC testing in practice. Results show that the arbitrary arrangement of measuring points of SWCC testing is hardly superior to the optimal scheme obtained from OBEDO in terms of the expected utility. The proposed OBEDO approach provides a rational tool to optimize the arrangement of measuring points of SWCC test so as to obtain SWCC measurement data with relatively high expected utility for uncertainty reduction.
文摘Due to the dissimilar scaling issues,the conventional experimental method of FOWTs can hardly be used directly to validate the full-scale global dynamic responses accurately.Therefore,it is of absolute necessity to find a more accurate,economic and efficient approach,which can be utilized to predict the full-scale global dynamic responses of FOWTs.In this paper,a literature review of experimental-numerical methodologies and challenges for FOWTs is made.Several key challenges in the conventional basin experiment issues are discussed,including scaling issues;coupling effects between aero-hydro and structural dynamic responses;blade pitch control strategies;experimental facilities and calibration methods.Several basin experiments,industrial projects and numerical codes are summarized to demonstrate the progress of hybrid experimental methods.Besides,time delay in hardware-in-the-loop challenges is concluded to emphasize their significant role in real-time hybrid approaches.It is of great use to comprehend these methodologies and challenges,which can help some future researchers to make a footstone for proposing a more efficient and functional hybrid basin experimental and numerical method.
文摘Piles in a group experience additional displacements in soil due to pile-to-pile interactions apart from those resulting from the external loading.The effect of these interactions determined assuming soil as an elastic and/or viscoelastic material on pile head impedance functions of the pile group is studied by relating the group stiffness to the static stiffness of a single pile.However,the prevailing elastic solutions may misestimate the resulting pile group response due to the lack of consideration for either soil(material)and/or soil-pile interface nonlinearities.It is well established that soil behaves nonlinearly under moderate-to-high loading amplitudes,and besides,the soil-pile interface nonlinearity can exist even at small loading amplitudes.This study addresses the effects of these nonlinearities on the vertical impedance functions of a 3×3-pile group using numerical methods by direct analyses and superposition using pile-to-pile interaction factors.The numerical results are validated using scaled model tests under 1 g conditions.The results highlight the overestimation of pile-to-pile interactions in the pile group when assuming elastic soil conditions.The cases either by direct analyses or superposition approach involving soil and soil-pile interface nonlinearities agree well with the experimental pile group responses under close-to-elastic and nonlinear conditions.
文摘In the version of article originally published in the volume 68,2025 of Sci China Chem(pages 3675-3688),the article was published in subscription format rather than open access format due to an oversight during the production stage.The corrected copyright and open access notes are provided below.The original article has been corrected.
基金the NKBRSF Project! G 1999043400 the CNSF Project! 49735180.
文摘Two land surface schemes, one the standard Biosphere / Atmosphere Transfer Scheme Version ie (BOZ) and the other B1Z based on B0Z and heterogeneously-treated by' combined approach' , were co 'pled to the meso-scale model MM4, respectively. Through the calculations of equations from the companion paper, parameters representing land surface heterogeneity and suitable for the coupling models were found out. Three cases were simulated for heavy rainfalls during 36 hours, and the sensitivity of short-term weather modeling to the land surface heterogeneity was tested. Through the analysis of the simulations of the three heavy rainfalls, it was demonstrated that BIZ, compared with BOZ, could more realistically reflect the features of the land surface heterogeneity, therefore could more realistically reproduce the circulation and precipitation amount in the heavy rainfall processes of the three cases. This shows that even short-term weather is sensitive to the land surface heterogeneity, which is more obvious with time passing, and whose influence is more pronounced in the lower layer and gradually extends to the middle and upper layer. Through the analysis of these simulations with BlZ, it is suggested that the bulk effect of smaller-scale fluxes (i.e., the momentum, water vapor and sensible heat fluxes) near the s ig nificantly-heterogeneous land surface is to change the larger-scale (i.e., meso-scale) circulation, and then to influence the development of the low-level jets and precipitation. And also, the complexity of the land-atmosphere interaction was shown in these simulations.
文摘A method based on Giorgi (1997a, 1997b) and referred to as ’ combined approach’, which is a combi-nation of mosaic approach and analytical-statistical-dynamical approach, is proposed. Compared with those of other approaches, the main advantage of the combined approach is that it not only can represent both interpatch and intrapatch variability, but also cost less computational time when the land surface heterogeneity is considered. Because the independent variable of probability density function (PDF) is ex-tended to the single valued function of basic meteorological characteristic quantities, which is much more universal, the analytical expressions of the characteristic quantities (e.g., drag coefficient, snow coverage, leaf surface aerodynamical resistance) affected by roughness length are derived , when the roughness length(and / or the zero plane displacement) heterogeneity has been mainly taken into account with the approach. On the basis of the rule which the PDF parameters should follow, we choose a function y of the roughness length z 0 as the PDF independent variable, and set different values of the two parameters width ratio αn and height ratio γ of PDF (here a linear, symmetric PDF is applied) for sensitivity experiments, from which some conclusions can be drawn, e.g., relevant characteristic terms show different sensitivities to the heterogeneous characteristic (i.e., roughness length), which suggests that we should consider the heterogeneities of the more sensitive terms in our model instead of the heterogeneities of the rest, and which also implies that when the land surface scheme is coupled into the global or regional atmospheric model, sensitivity tests against the distribution of the heterogeneous characteristic are very necessary; when the parameter αn is close to zero, little heterogeneity is represented, and αn differs with cases, which have an upper limit of about 0.6; in the reasonable range of αn, a peak-like distribution of roughness length can be depicted by a small value of γ, etc.. Key words Representation of land surface heterogeneity - “ Combined approach” - Numerical experiment This work was supported by the National Sciences Foundation of China, Grant No.49875005 and the State Key Project (973) G19990434 (03).
基金support for this research from the State Key Program of National Natural Science of China (Grant No. 41430634)the National Natural Science Foundation of China (Grant Nos. 41702382, 51578195, 51378161, and 51308547)+1 种基金the Foundation Project Program 973 of China (No. 2012CB026104)the State Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining & Technology (Grant No. SKLGDUEK1209)
文摘Maximum frost heave of unsaturated frost-susceptible soils,in conjunction with a high water table,is an important consideration for the design of foundations in seasonally frozen regions.Therefore,it is necessary to evaluate accurately and efficiently the maximum frost heave for a given soil.For this purpose,a series of one-sided freezing experiments was conducted on unsaturated silty clay in an open system.Multistage cooling of sufficient duration was applied to the soil sample's top,while constant above-zero temperatures were maintained at the bottom.Then,a simple methodology for calculating maximum frost heave at a given cooling temperature was derived utilizing information obtained within the limited time allotted for each stage.On this basis,an empirical equation for defining maximum frost heave as a function of cooling temperature and overburden pressure was determined.Overall,this study provides a simple and practical procedure that is applicable to the evaluation of maximum frost heave of unsaturated frost-susceptible soils.
基金sponsored by National Natural Science Foundation of China(41474017)National Key Basic Research Program of China(973 Program+3 种基金2012CB957703)sponsored by National Natural Science Foundation of China(41274035)State Key Laboratory of Geodesy and Earth's Dynamics(SKLGED2013-3-2-Z,SKLGED2014-1-3-E)State Key Laboratory of Geo-Information Engineering(SKLGIE2014-M-1-2)
文摘In this paper we present a series of monthly gravity field solutions from Gravity Recovery and Climate Experiment（GRACE） range measurements using modified short arc approach,in which the ambiguity of range measurements is eliminated via differentiating two adjacent range measurements.The data used for developing our monthly gravity field model are same as Tongji-GRACEOl model except that the range measurements are used to replace the range rate measurements,and our model is truncated to degree and order 60,spanning Jan.2004 to Dec.2010 also same as Tongji-GRACE01 model.Based on the comparison results of the C_（2,0）,C_（2,1）,S_（2,1）,and C_（15,15）,S_（15,15）,time series and the global mass change signals as well as the mass change time series in Amazon area of our model with those of Tongji-GRACE01 model,we can conclude that our monthly gravity field model is comparable with Tongji-GRACE01 monthly model.
文摘Nuclear energy driven magnetic confinement via donut shape device known as Tokamak,a toroidal apparatus,for producing controlled fusion reactions in hot plasma,was originally suggested as a basic yet more promising fusion reactor.Today the more innovative version of this apparatus that is known as an ITER(international thermonuclear experimental reactor)shows a way toward MCF(magnetic confinement fusion)of hot plasma goal by satisfying Lawson’s Criteria to some degree of achievement.However,since this fusion driven reactor of hot plasma needs to operate at almost 150 million Celsius,the internal material of this reactor is a matter of concern for scientists that are involved with its fabrication.Uniqueness of nanomaterials from the point of view of physical and chemical properties is suggested as a possible potential application for this special and innovative reactor for a nuclear fusion device.Convergence of nanotechnology in study of new generation of materials of this kind can shape the path for various technological developments and a large variety of disciplines,including MCF driven plasma of hot fusion as well.This short TM(technical memorandum)written by these two authors will cover this aspect of technology in a holistic way and the more granular level is left to the reader of this TM to investigate further.
基金Funded by the National Natural Science Foundation of China(Nos.51472203,51221001,U1435202)
文摘A molecular structural mechanics approach combining with finite element analysis(MSM/FEA) was applied to study the microstructure and tensile behaviors of bamboo-like carbon nanotubes(BCNTs). The mathematical model of tensile behaviors of BCNTs was established based on molecular structural mechanics theory. The deformations of BCNTs, with different diameters and compartments set based on the experimental investigation on BCNT structures synthesized by chemical vapor depositon, under tensile load, were analyzed with ANSYS programmed. Results show that the BCNTs have good tensile properties, and those Young's modulus can reach 0.84 Tpa. Through the analysis, it can be found that the Young's modulus of BCNTs depends on the diameters and the length of compartment, which is in good agreement with our experimental tests for the tensile performances of individual BCNT.
基金funded by the Major National Scientific Research Plan(2013CB733305,2012CB957703)the National Natural Science Foundation of China(41174066,41131067,41374087,41431070)
文摘The Gravity Recovery and Climate Experiment（GRACE） mission can significantly improve our knowledge of the temporal variability of the Earth＇s gravity field.We obtained monthly gravity field solutions based on variational equations approach from GPS-derived positions of GRACE satellites and K-band range-rate measurements.The impact of different fixed data weighting ratios in temporal gravity field recovery while combining the two types of data was investigated for the purpose of deriving the best combined solution.The monthly gravity field solution obtained through above procedures was named as the Institute of Geodesy and Geophysics（IGG） temporal gravity field models.IGG temporal gravity field models were compared with GRACE Release05（RL05） products in following aspects：（i） the trend of the mass anomaly in China and its nearby regions within 2005-2010; （ii） the root mean squares of the global mass anomaly during 2005-2010; （iii） time-series changes in the mean water storage in the region of the Amazon Basin and the Sahara Desert between 2005 and 2010.The results showed that IGG solutions were almost consistent with GRACE RL05 products in above aspects（i）-（iii）.Changes in the annual amplitude of mean water storage in the Amazon Basin were 14.7 ± 1.2 cm for IGG,17.1 ± 1.3 cm for the Centre for Space Research（CSR）,16.4 ± 0.9 cm for the GeoForschungsZentrum（GFZ） and 16.9 ± 1.2 cm for the Jet Propulsion Laboratory（JPL） in terms of equivalent water height（EWH）,respectively.The root mean squares of the mean mass anomaly in Sahara were 1.2 cm,0.9 cm,0.9 cm and 1.2 cm for temporal gravity field models of IGG,CSR,GFZ and JPL,respectively.Comparison suggested that IGG temporal gravity field solutions were at the same accuracy level with the latest temporal gravity field solutions published by CSR,GFZ and JPL.
基金supported by the National Natural Science Foundation of China(No.52272390)the Natural Science Foundation of Heilongjiang Province of China(No.YQ2022A009)the Shanghai Sailing Program,China(No.20YF1417300).
文摘Real-time 6 Degree-of-Freedom(DoF)pose estimation is of paramount importance for various on-orbit tasks.Benefiting from the development of deep learning,Convolutional Neural Networks(CNNs)in feature extraction has yielded impressive achievements for spacecraft pose estimation.To improve the robustness and interpretability of CNNs,this paper proposes a Pose Estimation approach based on Variational Auto-Encoder structure(PE-VAE)and a Feature-Aided pose estimation approach based on Variational Auto-Encoder structure(FA-VAE),which aim to accurately estimate the 6 DoF pose of a target spacecraft.Both methods treat the pose vector as latent variables,employing an encoder-decoder network with a Variational Auto-Encoder(VAE)structure.To enhance the precision of pose estimation,PE-VAE uses the VAE structure to introduce reconstruction mechanism with the whole image.Furthermore,FA-VAE enforces feature shape constraints by exclusively reconstructing the segment of the target spacecraft with the desired shape.Comparative evaluation against leading methods on public datasets reveals similar accuracy with a threefold improvement in processing speed,showcasing the significant contribution of VAE structures to accuracy enhancement,and the additional benefit of incorporating global shape prior features.
文摘Vehicle sounds are important factors of customer satisfaction and have a decisive influence on the product automobile andits quality impression. It becomes more and more important to connect customer requirements and technical specifications to developa vehicle sound with high quality. The turn indicator sound can be described as one sound, which gives the customer an importantfeedback of correct function performance and can be seen as one of the sounds, which play a role in the customer＇s perception ofvehicle quality. In a laboratory experimental study, the question was investigated, how a turn indicator sound must be designed to beperceived as pleasant and high-quality. A multidimensional approach was chosen to combine subjective customer assessments,objective psychophysiological responses of the study participants and physical parameters of the sounds. In total, 15 different tumindicator sounds were assessed by 48 subjects. The study shows how the connection of subjective and objective parameters cansupport product development. The multi-dimensional approach helps to derive recommendations for action to improve the soundquality of the product automobile. Also, the study shows a possibility to involve the human factor in a highly technical environment.
文摘As one of the four basic skills of language teaching and an aspect of communicative competence,writing seems to be the weakest one among senior school students in China.Most of teachers have had such experiences that although we spend a lot of time marking on the students'writing,but only to find the corrections and comments ignored.The students pay little attention to responses and regard revision of their writing as a punishment.Starting from the perspectives of modern linguistic theory,the pressing demands of the new curriculum,and the practical needs of student development,the study analyses the prevalent misconceptions about writing.The author proposes an assumption of integrating the teaching materials with Reading-to-Write Approach in the senior school writing teaching.To examine the validity of the Approach,about one-year action research is carried out in an ordinary high school,adopting the methodology of literature survey,questionnaire survey,interview,testing and so on.The results of the experiment showed that the approach had a more positive impact on students'writing attitudes and habits than traditional teaching methods.This approach helped them much more in word usage,longer sentences,content,and text structure or development.Besides,the students'compe?tence of interaction and cooperation were enhanced,Therefore,the approach in writing teaching is effective.
基金Margarida Catalão-Lopes and Ana S.Costa gratefully acknowledge financial support from Fundação para a Ciência e Tecnologia(FCT),through UIDB/00097/2020.
文摘Companies differ in their motivation to corporate social responsibility(CSR)practices,with some companies taking a genuine,altruistic approach and others preferring an opportunistic approach(and attempting to mimic the former).If consumers can distinguish them,they will eventually reward the altruistic(being willing to pay more)and penalize the opportunistic ones.This paper performs an experimental study to assess whether differences in consumers’willingness to pay are statistically significant for different classifications of CSR activities:(i)proactive or reactive,(ii)environment,employees,or social,(iii)involving more or less expensive products,(iv)being performed by firms facing competition or not.Results show that consumers are willing to reward CSR initiatives that follow a reactive approach;consumers’decisions are more moderate when rewarding initiatives associated with more expensive products;the rewards provided depend on the CSR dimension;a relationship between market structure and consumers’reaction to CSR was not found.
