The detailed surface rainfall processes associated with landfalling typhoon Kaemi（2006） are investigated based on hourly data from a two-dimensional cloud-resolving model simulation. The model is integrated for 6 da...The detailed surface rainfall processes associated with landfalling typhoon Kaemi（2006） are investigated based on hourly data from a two-dimensional cloud-resolving model simulation. The model is integrated for 6 days with imposed large-scale vertical velocity, zonal wind, horizontal temperature and vapor advection from National Center for Environmental Prediction （NCEP） / Global Data Assimilation System （GDAS） data. The simulation data are validated with observations in terms of surface rain rate. The Root-Mean-Squared （RMS） difference in surface rain rate between the simulation and the gauge observations is 0.660 mm h^-1, which is smaller than the standard deviations of both the simulated rain rate （0.753 mm h^-1） and the observed rain rate （0.833 mm h^-1）. The simulation data are then used to study the physical causes associated with the detailed surface rainfall processes during the landfall. The results show that time averaged and model domain-mean Ps mainly comes from large-scale convergence （QWVF） and local vapor loss （positive QWVT）. Large underestimation （about 15%） of Ps will occur if QWVT and QCM （cloud source/sink） are not considered as contributors to Ps ,QWVF accounts for the variation of P during most of the integration time, while it is not always a contributor to Ps,Sometimes surface rainfall could occur when divergence is dominant with local vapor loss to be a contributor to Ps - Surface rainfall is a result ofmulti-timescale interactions. QWVE possesses the longest time scale and the lowest frequeney the second and QCM of variation with time and may exert impact on P on longer time scales. QWVF possesses longest time scale and lowest frequency and can explain most of the variation of Ps. QWVT possess shorter time scales and higher frequencies, which can explain more detailed variations in Ps. Partitioning analysis shows that stratiform rainfall is dominant from the morning of 26 July till the late night of 27 July. After that, convective rainfall dominates till about 1000 LST 28 July. Before 28 July, the variations of QWVT in rainfall-free regions contribute less to that of the domain-mean QWVT while after that they contribute much, which is consistent to the corresponding variations in their fractional coverage. The variations of QWVF in rainfall regions are the main contributors to that of the domain-mean QWVF, then the main contributors to the surface rain rate before the afternoon of 28 July.展开更多
A water model and a high-speed video camera were utilized in the 300-t RH equipment to study the effect of steel flow patterns in a vacuum chamber on fast decarburization and a superior flow-pattern map was obtained d...A water model and a high-speed video camera were utilized in the 300-t RH equipment to study the effect of steel flow patterns in a vacuum chamber on fast decarburization and a superior flow-pattern map was obtained during the practical RH process. There are three flow patterns with different bubbling characteristics and steel surface states in the vacuum chamber： boiling pattern（BP）, transition pattern（TP）, and wave pattern（WP）. The effect of the liquid-steel level and the residence time of the steel in the chamber on flow patterns and decarburization reaction were investigated, respectively. The liquid-steel level significantly affected the flow-pattern transition from BP to WP, and the residence time and reaction area were crucial to evaluate the whole decarburization process rather than the circulation flow rate and mixing time. A superior flow-pattern map during the practical RH process showed that the steel flow pattern changed from BP to TP quickly, and then remained as TP until the end of decarburization.展开更多
Short residence time of the sorbent in the gas stream and formation of a dense layer of reaction product surrounding its surface influence the sulfur removal efficiency. A practical means of improving the process perf...Short residence time of the sorbent in the gas stream and formation of a dense layer of reaction product surrounding its surface influence the sulfur removal efficiency. A practical means of improving the process performance is to employ fluidized bed reaction in replacement of entrained bed reaction on normally used in cool side desulfurizaiton. This paper describes cold modeling study of a circulating fluidized bed reactor. Several aspects of the problem are discussed: fluidization behavior of CaO, attrition of the sorbent and solids entrainment from the fluidized bed. Mechanisms and key controlling parameters are identified, and an integral model based on rate of attrition and mass balance is developed for predicting steady state mass flows and particle size distributions of the system. A process flow scheme is finally presented for conducting desulfurization tests in the second stage of the study.展开更多
Droplet phase change is important for energy storage and saving technology.The initial profile of the droplet is extremely important for its vaporization or solidification on a horizontal surface.To understand the eff...Droplet phase change is important for energy storage and saving technology.The initial profile of the droplet is extremely important for its vaporization or solidification on a horizontal surface.To understand the effect of liquid physical properties on droplet profile,a theoretical model was developed in this study,based on the Young-Laplace equation with gravity effect specially considered.After the model was experimentally validated by comparing the geometric shape of water droplets,it was further used for predicting droplet shapes of other materials,and thus analyzing the influence of different physical properties,such as temperature,pressure,surface wettability,etc.Results show that the results of this model agree well with the experimental data.The maximum and average deviations are less than 4.5%and 1.5%,respectively.For all kinds of droplets on the fixed surfaces,when the temperature increases,the droplet contact radius increases and height decreases.The droplets of nitro-gen and carbon dioxide are more sensitive to temperature than ethanol and ethylene glycol droplets.For 20𝜇L droplets on the surface of contact angle 150°,when the temperature changes from 273.15 K to 293.15 K,the droplet contact radiuses increase by 30.6%for carbon dioxide,1.2%for ethanol and 0.67%for ethylene glycol,and the droplet heights decrease by 42.9%,2.5%,1.1%,respectively.Results of this study are meaningful for predicting the phase change process of droplets on the horizontal surface by controlling their initial profiles.展开更多
The North East China Transect (NECT) is an exemplary region of landmass running along the line of 43°30′ North Latitude and caught between 112° and 130°30′ East Longtitude, and is being sampled by the...The North East China Transect (NECT) is an exemplary region of landmass running along the line of 43°30′ North Latitude and caught between 112° and 130°30′ East Longtitude, and is being sampled by the International Geosphere-Biosphere Program (IGBP) for today’s study on global change. So far, it has already been listed in the first set of IGBP-sponsored transects, becoming a key theatre and "hot spot" for probing terrestrial ecosystems. In terms of biota, the nearly 1,600-kilometre-long tract is located in a mid-latitude zone, featuring a vegetational transition from a temperate timberland of evergreen coniferous forests and broadleaved deciduous forests to a mild-temperate steppe. According to the norms of biome types, it consists of three subzones: meadow steppe, typical steppe and desert steppe in a continuous east-to-west spatial sequence. There are four ecological stations supported by a great number of permanent samples, long-term plots and an enormous build-up of experimental data along展开更多
Mo has been widely reported as a conducive element for the corrosion resistance of massive alloy sys-tems.However,the mechanism of Mo optimizing the corrosion resistance is complicated,and in-depth studies are still r...Mo has been widely reported as a conducive element for the corrosion resistance of massive alloy sys-tems.However,the mechanism of Mo optimizing the corrosion resistance is complicated,and in-depth studies are still required.The present work comprehensively and quantitatively studied the critical influ-ences of Mo on the passivation and repassivation behavior of CoCrFeNi HEA based on the dissolution-diffusion-deposition model proposed in our previous work.The experimental results indicated that Mo remarkably eliminated the metastable pitting corrosion,significantly improved the breakdown potential and perfectly protected the CoCrFeNiMo_(0.2)HEA from pitting corrosion.The modelling and X-ray photo-electron spectroscopy(XPS)results both show that in the passivation process,MoO_(2)was the last product to deposit,thereby existing in the outer layer of the passive film.Mo addition increased the Cr content by weakening the deposition of Fe_(2)O_(3)and Fe_(3)O_(4)and also improved the Cr_(2)O_(3)/Cr(OH)3 ratio by promot-ing deprotonation of Cr(OH)_(3),thus enhancing the quality of passive film.Besides,when pitting corrosion occurred,MoO_(2),MoO_(3),and FeMoO_(4)were the first products to deposit and accelerated the repassivation process of HEA by timely covering the matrix in the pit cavity,thereby preventing further corrosion of the matrix.展开更多
Objective:Mathematical modeling and simulation is a useful research method to inform decision-making.This article aims to describe the National Cancer Center(NCC)modeling framework and how well it reproduces observed ...Objective:Mathematical modeling and simulation is a useful research method to inform decision-making.This article aims to describe the National Cancer Center(NCC)modeling framework and how well it reproduces observed empirical data for six major cancers.Methods:We developed the NCC modeling framework for six major cancers in China(lung,liver,stomach,colorectal,esophageal,and breast),which simulates the life-histories represented by states among normal,pre-cancerous lesion,stage-specific invasive cancer,and death for six cancers separately.Each NCC simulation model could be illustrated as an integrated framework of 3 modules:a demography module,natural history module,and screening module.Combined with costs and health utilities data,the models could have many detailed outputs for informing decisions,including the harm of screening(e.g.,false positives,complications,and overdiagnosis),healthcare costs,and benefits(quality-adjusted life years gained,cancer incidence and mortality,and investment returns).We calibrated the models to Chinese population-based observations on cancer incidence,mortality,and stage distribution.All models are validated by comparing model simulated results to data observed from nationwide cancer registration and a large prospective cohort study.Results:The simulated results from the calibrated models consistently match the epidemiological patterns in six major cancer incidence,mortality,and stage distributions in China.Model projected age-specific cancer incidence and mortality were close to the observed data in the national cancer registration.The NCC modeling framework reproduced the cumulative cancer cases and deaths observed in the prospective cohort study at 7.0 and 10.8 years of follow-up.Model estimated net survival rates also consistent with population-based statistics.Conclusion:The NCC modeling framework’s ability to reproduce the observed population-level cancer statistics and the cancer cases in a prospective cohort study suggests its results are reliable to inform decision-making related to six major cancers in China.展开更多
Cholangiocarcinoma(CCA)is a fatal bile duct malignancy.CCA is intrinsically resistant to standard chemotherapy,responds poorly to it,and has a poor prognosis.Effective treatments for cholangiocarcinoma remain elusive,...Cholangiocarcinoma(CCA)is a fatal bile duct malignancy.CCA is intrinsically resistant to standard chemotherapy,responds poorly to it,and has a poor prognosis.Effective treatments for cholangiocarcinoma remain elusive,and a breakthrough in CCA treatment is still awaited.The human epidermal growth factor receptor 2(HER2)plays an oncogenic role by promoting an aggressive cancer phenotype through multiple pathways.While HER2 has shown increasing potential as an effective target for breast and gastric cancers over the last decade,this has not been the case for CCA.This review explores the possibility of targeting HER2 in CCA immunotherapy.Key findings suggest that HER2 alterations have been reported as one of the signatures associated with a poorer prognosis in liver fluke-associated CCA,the most prevalent subtype in Southeast Asia.Furthermore,we assess recent advances in HER2-targeted therapeutic approaches,presenting the current stage,rationale,and evidence supporting the use of HER2 as a promising therapeutic target for cancer immunotherapy in CCA.We also emphasize the crucial role of animal models in developing anticancer therapies.In summary,focusing on HER2 expression could provide alternative strategies for the HER2-altered CCA cluster.展开更多
Evolution of the Arctic sea ice and its snow cover during the SHEBA year were simulated by applying a high-resolution thermodynamic snow/ice model （HIGHTSI）. Attention was paid to the impact of albedo on snow and se...Evolution of the Arctic sea ice and its snow cover during the SHEBA year were simulated by applying a high-resolution thermodynamic snow/ice model （HIGHTSI）. Attention was paid to the impact of albedo on snow and sea ice mass balance, effect of snow on total ice mass balance, and the model vertical resolution. The SHEBA annual simulation was made applying the best possible external forcing data set created by the Sea Ice Model Intercomparison Project. The HIGHTSI control run reasonably reproduced the observed snow and ice thickness. A number of albedo schemes were incorporated into HIGHTSI to study the feedback processes between the albedo and snow and ice thickness. The snow thickness turned out to be an essential variable in the albedo parameterization. Albedo schemes dependent on the surface temperature were liable to excessive positive feedback effects generated by errors in the modelled surface temperature. The superimposed ice formation should be taken into account for the annual Arctic sea ice mass balance.展开更多
The modified shear lag model proposed recently was applied to calculate thermal residual stresses and subsequent stress distributions under tensile and compressive loadings. The expressions for the elastic moduli and ...The modified shear lag model proposed recently was applied to calculate thermal residual stresses and subsequent stress distributions under tensile and compressive loadings. The expressions for the elastic moduli and the yield strengths under tensile and compressive loadings were derived which take account of thermal residual stresses. The asymmetries in the elastic modulus and the yield strength were interpreted using the derived expressions and the obtained results of the stress calculations. The model predictions have exhibited good agreements with the experimental results and also with the other theoretical predictions展开更多
Forest canopy reduces shortwave radiation and increases the incoming longwave radiation to snowpacks beneath forest canopies. Furthermore, the effect of forest canopy may be changed by complex topography. In this pape...Forest canopy reduces shortwave radiation and increases the incoming longwave radiation to snowpacks beneath forest canopies. Furthermore, the effect of forest canopy may be changed by complex topography. In this paper, we measured and simulated the incoming longwave radiation to snow beneath forest at different canopy openness in the west Tianshan Mountains, China(43°16'N, 84°24'E) during spring 2013. A sensitivity study was conducted to explore the way that terrain influenced the incoming longwave radiation to snow beneath forest canopies. In the simulation model, measurement datasets, including air temperature, incoming shortwave radiation above canopy, and longwave radiation enhanced by adjacent terrain, were applied to calculate the incoming longwave radiation to snow beneath forest canopy. The simulation results were consistent with the measurements on hourly scale and daily scale. The effect of longwave radiation enhanced by terrain was important than that of shortwave radiation above forest canopy with different openness except the 20% canopy openness. The longwave radiation enhanced due to adjacent terrain increases with the slope increase and temperature rise. When air temperature(or slope) is relatively low, thelongwave radiation enhanced by adjacent terrain is not sensitive to slope(or air temperature), but the sensitivity increases with the decrease of snow cover area on sunny slope. The effect of longwave radiation is especially sensitive when the snow cover on sunny slope melts completely. The effect of incoming shortwave radiation reflected by adjacent terrain on incoming longwave radiation to snow beneath forest canopies is more slight than that of the enhanced longwave radiation.展开更多
A new series of benzothiazole Schiff bases 3–29 was synthesized and screened for antitumor activity against cervical cancer（Hela） and kidney fibroblast cancer（COS-7） cell lines. Results indicated that compounds 3...A new series of benzothiazole Schiff bases 3–29 was synthesized and screened for antitumor activity against cervical cancer（Hela） and kidney fibroblast cancer（COS-7） cell lines. Results indicated that compounds 3, 14, 19, 27 and 28 have promising activity against Hela cell line with IC50 values of 2.41,3.06, 6.46, 2.22 and 6.25 mmol/L, respectively, in comparison to doxorubicin as a reference antitumor agent（IC50 2.05 mmol/L）. In addition, compound 3 displayed excellent activity against COS-7 cell line with IC50 value of 4.31 mmol/L in comparison to doxorubicin（IC50 3.04 mmol/L）. In the present work,structure based pharmacophore mapping, molecular docking, protein-ligand interaction, fingerprints and binding energy calculations were employed in a virtual screening strategy to identify the interaction between the compounds and the active site of the putative target, EGFR tyrosine kinase. Molecular properties, toxicity, drug-likeness, and drug score profiles of compounds 3, 14, 19, 27, 28 and 29 were also assessed.展开更多
<b>Introduction:</b> Digital models showed promising results for orthodontic diagnosis and treatment planning. Digital models can be obtained from alginate impressions as well as direct intra-oral scanners...<b>Introduction:</b> Digital models showed promising results for orthodontic diagnosis and treatment planning. Digital models can be obtained from alginate impressions as well as direct intra-oral scanners. Studies assessing the accuracy of digital models have shown digital models to be valid, clinically acceptable, and more quickly obtainable. With the advent of new scanners with better scanning technology researches are necessary to evaluate their accuracy and reliability. <b>Aim of Study:</b> To evaluate the diagnostic accuracy of 3D digital models obtained through intraoral and extraoral scanning modalities to the reference gold standard plaster model. <b>Material & Methods:</b> Twenty-four adult male and female subjects were randomly selected for this study. The intraoral scanners evaluated in this study were Sirona (CEREC Omnicam) and 3 shape (TRIOS 3), while the laboratory scanners used were Sirona (inEos X5), and 3 shape (D850). Intra-oral scanning of the subjects and extra-oral scanning of their alginate impressions, plaster models of the alginate impression, rubber base impression, and plaster model of their rubber base impression were done. Linear dental measurements included intermolar width, interpremolar width, intercanine width, mesiodistal width of the 1<sup>st</sup> permanent molar, 1<sup>st</sup> premolar, canine and central incisor and arch width. All data were collected, tabulated and subjected to statistical analysis. <b>Results:</b> Small differences between the plaster and digital models were observed. Intra-observer reliability analysis for 14 out of the 16 measurements showed that all variables exhibited good to excellent reliability. <b>Conclusions: </b>There was no difference between the digitization using the intraoral scanner or the laboratory scanner. The most accurate digitization technique was the 3 Shape laboratory scanner of the cast of the alginate impression. The inEos X5 showed the highest error of digitization of the alginate and rubber base impressions.展开更多
The cross sections of fragments produced in the 140 A MeV58,64Ni＋9 Be projectile fragmentation reactions are calculated by using the antisymmetrized molecular dynamics （AMD） model, the modified statistical abrasion...The cross sections of fragments produced in the 140 A MeV58,64Ni＋9 Be projectile fragmentation reactions are calculated by using the antisymmetrized molecular dynamics （AMD） model, the modified statistical abrasion- ablation （SAA） model, and the empirical EPAX2/EPAX3 formulae. The Gogny-gO interaction is taken as the effective nucleon-nucleon interaction in the AMD calculation, and the decays of fragments obtained from the AMD results are calculated by using the GEMINI code. The calculated cross sections of fragments are compared.展开更多
Vulvodynia is a prevalent form of chronic pain, most com- monly affecting the vaginal vestibule （vestibulodynia） （Pukall et al., 2016）. Women with vulvodynia describe intense pain in response to light touch of the...Vulvodynia is a prevalent form of chronic pain, most com- monly affecting the vaginal vestibule （vestibulodynia） （Pukall et al., 2016）. Women with vulvodynia describe intense pain in response to light touch of the affected region, such that sexual function and other activities can be severely limited. Medical costs associated with vulvodynia are high, exceeding $21 billion annually in the United States （Xie et al., 2012）. The high level of direct medical costs has been linked to high treatment failure rates. Many women with the disorder consult multiple practitioners and undergo multiple courses of treatment with limited benefit.展开更多
The key problem to the calculation and optimization design of the helicopter 'Ground Resonance' is to correctly build up a mechanical model. In the past, the literature was only concerned with the lag modes of...The key problem to the calculation and optimization design of the helicopter 'Ground Resonance' is to correctly build up a mechanical model. In the past, the literature was only concerned with the lag modes of the rotor blade and the flap modes were neglected. But such approaches should be reconsidered now. In order to study the influences of rotating multiblades rotor on the degrees of freedom and also the flap ''Ground Resonance' of a helicopter, it is necessary to consider not only the lag degrees of freedom but also the flap degrees of freedom. Using Lagrangian equation a dynamical equation of the space model for helicopter 'Ground Resonance'is deduced for the first time. Some computation results show that the mechanical model including both lag DOF and flap DOF is more reasonable.展开更多
In order to make the numerical calculation of viscous flows more convenient for the flows in channel with complicated profile governing equations expressed in the arbitrary curvilinear coordinates were derived by mean...In order to make the numerical calculation of viscous flows more convenient for the flows in channel with complicated profile governing equations expressed in the arbitrary curvilinear coordinates were derived by means of Favre density-weighted averaged method, and a turbulent model with effect of curvature modification was also derived. The numerical calculation of laminar and turbulent flown in divergent curved channels was carried out by means of parabolizeil computation method. The calculating results were used to analyze and investigate the aerodynamic performance of talor cascades in compressors preliminarily.展开更多
The innovations actually diffuse among social network nowadays.Individual heterogeneity,interactions between individuals and network topology influence a lot.We established a "double threshold" modified mode...The innovations actually diffuse among social network nowadays.Individual heterogeneity,interactions between individuals and network topology influence a lot.We established a "double threshold" modified model and took the number of neighbors,neighbors' adoption and the cost-benefit parameters as crucial influencing factors.The diffusion of DaLingTong(CDMA450)products in MeiShan city of SiChuan province during 2004 to 2007 has been used to verity the model on Matlab.The validation results fit the actual diffusion pattern of DaLingTong(CDMA450) products very well.The results indicate that there exists a "tipping point(threshold)" in the process of innovation diffusion.If the initial adoption quantity is larger than the tipping point,then the product will spread to a large portion of people,otherwise is will collapse to zero.The model can effectively predict the diffusion of new products,and can influence the diffusion process by changing the value of the parameters.展开更多
Introduction-The cervical spine is subjected to injury frequently,especially among pilots who are usually on the condition of high acceleration.Injuries of the cervical spine will be potential risk of damage to the sp...Introduction-The cervical spine is subjected to injury frequently,especially among pilots who are usually on the condition of high acceleration.Injuries of the cervical spine will be potential risk of damage to the spinal cord,which could be result in life threatening展开更多
The greatest risks to mammalian pregnancy occur during the peri-implantation period (passage through the uterotubal junction, blastulation, zona shedding, embryonic signaling and recognition, blastocyst attachment, po...The greatest risks to mammalian pregnancy occur during the peri-implantation period (passage through the uterotubal junction, blastulation, zona shedding, embryonic signaling and recognition, blastocyst attachment, postattachment events initiating placentation). Conventional markers and screening methods do not provide the means to clarify the relationship between exposure of a reproductively competent woman to a xenobiotic compound and the specific error in the functional expression of an embryogenetic process identified by impairment or deletion of that process. Laboratory models which provide the flexibility of in vitro culture methods and allow integration of cellular and molecular techniques have identified cell-specific, stage-specific markers that could focus on the mechanism of xenobiotic action. In vitro models have been used to define postattachment trophoblast cell differentiation. Trophoblast specific peptide hormones prove to be valid markers of established pregnancy. They provide no assessment of the risk to the embryo during the peri-implantation period. The relationship between developmental time of exposure and risk is discussed in terms of trophoblast differentiation.展开更多
基金National Basic Research Program of China (973 Program) (2009CB421505)National Natural Science Foundation of China (40775036)Knowledge Innovation Program of Chinese Academy of Sciences (IAP07214)
文摘The detailed surface rainfall processes associated with landfalling typhoon Kaemi（2006） are investigated based on hourly data from a two-dimensional cloud-resolving model simulation. The model is integrated for 6 days with imposed large-scale vertical velocity, zonal wind, horizontal temperature and vapor advection from National Center for Environmental Prediction （NCEP） / Global Data Assimilation System （GDAS） data. The simulation data are validated with observations in terms of surface rain rate. The Root-Mean-Squared （RMS） difference in surface rain rate between the simulation and the gauge observations is 0.660 mm h^-1, which is smaller than the standard deviations of both the simulated rain rate （0.753 mm h^-1） and the observed rain rate （0.833 mm h^-1）. The simulation data are then used to study the physical causes associated with the detailed surface rainfall processes during the landfall. The results show that time averaged and model domain-mean Ps mainly comes from large-scale convergence （QWVF） and local vapor loss （positive QWVT）. Large underestimation （about 15%） of Ps will occur if QWVT and QCM （cloud source/sink） are not considered as contributors to Ps ,QWVF accounts for the variation of P during most of the integration time, while it is not always a contributor to Ps,Sometimes surface rainfall could occur when divergence is dominant with local vapor loss to be a contributor to Ps - Surface rainfall is a result ofmulti-timescale interactions. QWVE possesses the longest time scale and the lowest frequeney the second and QCM of variation with time and may exert impact on P on longer time scales. QWVF possesses longest time scale and lowest frequency and can explain most of the variation of Ps. QWVT possess shorter time scales and higher frequencies, which can explain more detailed variations in Ps. Partitioning analysis shows that stratiform rainfall is dominant from the morning of 26 July till the late night of 27 July. After that, convective rainfall dominates till about 1000 LST 28 July. Before 28 July, the variations of QWVT in rainfall-free regions contribute less to that of the domain-mean QWVT while after that they contribute much, which is consistent to the corresponding variations in their fractional coverage. The variations of QWVF in rainfall regions are the main contributors to that of the domain-mean QWVF, then the main contributors to the surface rain rate before the afternoon of 28 July.
基金financially supported by the National Natural Science Foundation of China (No.51704203)the PhD Early Development Program of Taiyuan University of Science and Technology (Nos. 20152008, 20152013, and 20152018)+2 种基金Shanxi Province Science Foundation for Youths (No. 201601D202027)Key Project of Research and Development Plan of Shanxi Province (Nos. 201603D111004 and 201603D121010)NSFC-Shanxi Coal Based Low Carbon Joint Fund (No. U1510131)
文摘A water model and a high-speed video camera were utilized in the 300-t RH equipment to study the effect of steel flow patterns in a vacuum chamber on fast decarburization and a superior flow-pattern map was obtained during the practical RH process. There are three flow patterns with different bubbling characteristics and steel surface states in the vacuum chamber： boiling pattern（BP）, transition pattern（TP）, and wave pattern（WP）. The effect of the liquid-steel level and the residence time of the steel in the chamber on flow patterns and decarburization reaction were investigated, respectively. The liquid-steel level significantly affected the flow-pattern transition from BP to WP, and the residence time and reaction area were crucial to evaluate the whole decarburization process rather than the circulation flow rate and mixing time. A superior flow-pattern map during the practical RH process showed that the steel flow pattern changed from BP to TP quickly, and then remained as TP until the end of decarburization.
文摘Short residence time of the sorbent in the gas stream and formation of a dense layer of reaction product surrounding its surface influence the sulfur removal efficiency. A practical means of improving the process performance is to employ fluidized bed reaction in replacement of entrained bed reaction on normally used in cool side desulfurizaiton. This paper describes cold modeling study of a circulating fluidized bed reactor. Several aspects of the problem are discussed: fluidization behavior of CaO, attrition of the sorbent and solids entrainment from the fluidized bed. Mechanisms and key controlling parameters are identified, and an integral model based on rate of attrition and mass balance is developed for predicting steady state mass flows and particle size distributions of the system. A process flow scheme is finally presented for conducting desulfurization tests in the second stage of the study.
基金the National Nature Science Foundation of China(No.52076013)Discovery Early Career Researcher Award(DECRA)2020+2 种基金Australian Re-search Council(ARC)Australia(No.DE200101747)the CAS Key Laboratory of Cryogenics,TIPC,China(No.CRYO202001).
文摘Droplet phase change is important for energy storage and saving technology.The initial profile of the droplet is extremely important for its vaporization or solidification on a horizontal surface.To understand the effect of liquid physical properties on droplet profile,a theoretical model was developed in this study,based on the Young-Laplace equation with gravity effect specially considered.After the model was experimentally validated by comparing the geometric shape of water droplets,it was further used for predicting droplet shapes of other materials,and thus analyzing the influence of different physical properties,such as temperature,pressure,surface wettability,etc.Results show that the results of this model agree well with the experimental data.The maximum and average deviations are less than 4.5%and 1.5%,respectively.For all kinds of droplets on the fixed surfaces,when the temperature increases,the droplet contact radius increases and height decreases.The droplets of nitro-gen and carbon dioxide are more sensitive to temperature than ethanol and ethylene glycol droplets.For 20𝜇L droplets on the surface of contact angle 150°,when the temperature changes from 273.15 K to 293.15 K,the droplet contact radiuses increase by 30.6%for carbon dioxide,1.2%for ethanol and 0.67%for ethylene glycol,and the droplet heights decrease by 42.9%,2.5%,1.1%,respectively.Results of this study are meaningful for predicting the phase change process of droplets on the horizontal surface by controlling their initial profiles.
基金This research work is jointly subsidied by two research projects entitled"A Predictive Study on the Changing Trend of Life-supporting Environment in China Over the Next 20-50 YearsA Modeling Research on the Responses of China's Terrestrial Ecosys
文摘The North East China Transect (NECT) is an exemplary region of landmass running along the line of 43°30′ North Latitude and caught between 112° and 130°30′ East Longtitude, and is being sampled by the International Geosphere-Biosphere Program (IGBP) for today’s study on global change. So far, it has already been listed in the first set of IGBP-sponsored transects, becoming a key theatre and "hot spot" for probing terrestrial ecosystems. In terms of biota, the nearly 1,600-kilometre-long tract is located in a mid-latitude zone, featuring a vegetational transition from a temperate timberland of evergreen coniferous forests and broadleaved deciduous forests to a mild-temperate steppe. According to the norms of biome types, it consists of three subzones: meadow steppe, typical steppe and desert steppe in a continuous east-to-west spatial sequence. There are four ecological stations supported by a great number of permanent samples, long-term plots and an enormous build-up of experimental data along
基金funded by the National Natural Science Foun-dation of China(Grant Nos.U1960203,52004060,52325406,and 52174308)Science Fund for Distinguished Young Scholars of Liaon-ing Province(Grant No.2023JH6/100500008)Fundamental Re-search Funds for the Central Universities(Grant Nos.N2125017 and N2225031).Special thanks are due to the instrumental analysis from the Analytical and Testing Centre,Northeastern University.
文摘Mo has been widely reported as a conducive element for the corrosion resistance of massive alloy sys-tems.However,the mechanism of Mo optimizing the corrosion resistance is complicated,and in-depth studies are still required.The present work comprehensively and quantitatively studied the critical influ-ences of Mo on the passivation and repassivation behavior of CoCrFeNi HEA based on the dissolution-diffusion-deposition model proposed in our previous work.The experimental results indicated that Mo remarkably eliminated the metastable pitting corrosion,significantly improved the breakdown potential and perfectly protected the CoCrFeNiMo_(0.2)HEA from pitting corrosion.The modelling and X-ray photo-electron spectroscopy(XPS)results both show that in the passivation process,MoO_(2)was the last product to deposit,thereby existing in the outer layer of the passive film.Mo addition increased the Cr content by weakening the deposition of Fe_(2)O_(3)and Fe_(3)O_(4)and also improved the Cr_(2)O_(3)/Cr(OH)3 ratio by promot-ing deprotonation of Cr(OH)_(3),thus enhancing the quality of passive film.Besides,when pitting corrosion occurred,MoO_(2),MoO_(3),and FeMoO_(4)were the first products to deposit and accelerated the repassivation process of HEA by timely covering the matrix in the pit cavity,thereby preventing further corrosion of the matrix.
基金funded by the Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences(grant number:2021-I2M-1-033)the Jing-jin-ji Special Project for Basic Research Cooperation(grant number:J200017)the National Natural Science Foundation of China(grant number:82273721).
文摘Objective:Mathematical modeling and simulation is a useful research method to inform decision-making.This article aims to describe the National Cancer Center(NCC)modeling framework and how well it reproduces observed empirical data for six major cancers.Methods:We developed the NCC modeling framework for six major cancers in China(lung,liver,stomach,colorectal,esophageal,and breast),which simulates the life-histories represented by states among normal,pre-cancerous lesion,stage-specific invasive cancer,and death for six cancers separately.Each NCC simulation model could be illustrated as an integrated framework of 3 modules:a demography module,natural history module,and screening module.Combined with costs and health utilities data,the models could have many detailed outputs for informing decisions,including the harm of screening(e.g.,false positives,complications,and overdiagnosis),healthcare costs,and benefits(quality-adjusted life years gained,cancer incidence and mortality,and investment returns).We calibrated the models to Chinese population-based observations on cancer incidence,mortality,and stage distribution.All models are validated by comparing model simulated results to data observed from nationwide cancer registration and a large prospective cohort study.Results:The simulated results from the calibrated models consistently match the epidemiological patterns in six major cancer incidence,mortality,and stage distributions in China.Model projected age-specific cancer incidence and mortality were close to the observed data in the national cancer registration.The NCC modeling framework reproduced the cumulative cancer cases and deaths observed in the prospective cohort study at 7.0 and 10.8 years of follow-up.Model estimated net survival rates also consistent with population-based statistics.Conclusion:The NCC modeling framework’s ability to reproduce the observed population-level cancer statistics and the cancer cases in a prospective cohort study suggests its results are reliable to inform decision-making related to six major cancers in China.
基金supported in part by the e-ASIA Joint Research Program from the Japan Agency for Medical Research and Development(AMED)(grant number:21jm0210062h0004).
文摘Cholangiocarcinoma(CCA)is a fatal bile duct malignancy.CCA is intrinsically resistant to standard chemotherapy,responds poorly to it,and has a poor prognosis.Effective treatments for cholangiocarcinoma remain elusive,and a breakthrough in CCA treatment is still awaited.The human epidermal growth factor receptor 2(HER2)plays an oncogenic role by promoting an aggressive cancer phenotype through multiple pathways.While HER2 has shown increasing potential as an effective target for breast and gastric cancers over the last decade,this has not been the case for CCA.This review explores the possibility of targeting HER2 in CCA immunotherapy.Key findings suggest that HER2 alterations have been reported as one of the signatures associated with a poorer prognosis in liver fluke-associated CCA,the most prevalent subtype in Southeast Asia.Furthermore,we assess recent advances in HER2-targeted therapeutic approaches,presenting the current stage,rationale,and evidence supporting the use of HER2 as a promising therapeutic target for cancer immunotherapy in CCA.We also emphasize the crucial role of animal models in developing anticancer therapies.In summary,focusing on HER2 expression could provide alternative strategies for the HER2-altered CCA cluster.
基金supported by the EC-funded project DAMOCLES (grant 18509)which is part of the Sixth Framework Program of DFG(grant LU 818/1-1)Natural Science Foundation of China(grants No.40233032,40376006).
文摘Evolution of the Arctic sea ice and its snow cover during the SHEBA year were simulated by applying a high-resolution thermodynamic snow/ice model （HIGHTSI）. Attention was paid to the impact of albedo on snow and sea ice mass balance, effect of snow on total ice mass balance, and the model vertical resolution. The SHEBA annual simulation was made applying the best possible external forcing data set created by the Sea Ice Model Intercomparison Project. The HIGHTSI control run reasonably reproduced the observed snow and ice thickness. A number of albedo schemes were incorporated into HIGHTSI to study the feedback processes between the albedo and snow and ice thickness. The snow thickness turned out to be an essential variable in the albedo parameterization. Albedo schemes dependent on the surface temperature were liable to excessive positive feedback effects generated by errors in the modelled surface temperature. The superimposed ice formation should be taken into account for the annual Arctic sea ice mass balance.
文摘The modified shear lag model proposed recently was applied to calculate thermal residual stresses and subsequent stress distributions under tensile and compressive loadings. The expressions for the elastic moduli and the yield strengths under tensile and compressive loadings were derived which take account of thermal residual stresses. The asymmetries in the elastic modulus and the yield strength were interpreted using the derived expressions and the obtained results of the stress calculations. The model predictions have exhibited good agreements with the experimental results and also with the other theoretical predictions
基金funded by National Key Technology Research and Development Program of the Ministry of Science and Technology of China(Grant No.2012BAC23B01)National Natural Science Foundation of China(Grant Nos.41271098,41171066)China Special Fund for Meteorological Research in the Public Interest(GYHY201206026)
文摘Forest canopy reduces shortwave radiation and increases the incoming longwave radiation to snowpacks beneath forest canopies. Furthermore, the effect of forest canopy may be changed by complex topography. In this paper, we measured and simulated the incoming longwave radiation to snow beneath forest at different canopy openness in the west Tianshan Mountains, China(43°16'N, 84°24'E) during spring 2013. A sensitivity study was conducted to explore the way that terrain influenced the incoming longwave radiation to snow beneath forest canopies. In the simulation model, measurement datasets, including air temperature, incoming shortwave radiation above canopy, and longwave radiation enhanced by adjacent terrain, were applied to calculate the incoming longwave radiation to snow beneath forest canopy. The simulation results were consistent with the measurements on hourly scale and daily scale. The effect of longwave radiation enhanced by terrain was important than that of shortwave radiation above forest canopy with different openness except the 20% canopy openness. The longwave radiation enhanced due to adjacent terrain increases with the slope increase and temperature rise. When air temperature(or slope) is relatively low, thelongwave radiation enhanced by adjacent terrain is not sensitive to slope(or air temperature), but the sensitivity increases with the decrease of snow cover area on sunny slope. The effect of longwave radiation is especially sensitive when the snow cover on sunny slope melts completely. The effect of incoming shortwave radiation reflected by adjacent terrain on incoming longwave radiation to snow beneath forest canopies is more slight than that of the enhanced longwave radiation.
文摘A new series of benzothiazole Schiff bases 3–29 was synthesized and screened for antitumor activity against cervical cancer（Hela） and kidney fibroblast cancer（COS-7） cell lines. Results indicated that compounds 3, 14, 19, 27 and 28 have promising activity against Hela cell line with IC50 values of 2.41,3.06, 6.46, 2.22 and 6.25 mmol/L, respectively, in comparison to doxorubicin as a reference antitumor agent（IC50 2.05 mmol/L）. In addition, compound 3 displayed excellent activity against COS-7 cell line with IC50 value of 4.31 mmol/L in comparison to doxorubicin（IC50 3.04 mmol/L）. In the present work,structure based pharmacophore mapping, molecular docking, protein-ligand interaction, fingerprints and binding energy calculations were employed in a virtual screening strategy to identify the interaction between the compounds and the active site of the putative target, EGFR tyrosine kinase. Molecular properties, toxicity, drug-likeness, and drug score profiles of compounds 3, 14, 19, 27, 28 and 29 were also assessed.
文摘<b>Introduction:</b> Digital models showed promising results for orthodontic diagnosis and treatment planning. Digital models can be obtained from alginate impressions as well as direct intra-oral scanners. Studies assessing the accuracy of digital models have shown digital models to be valid, clinically acceptable, and more quickly obtainable. With the advent of new scanners with better scanning technology researches are necessary to evaluate their accuracy and reliability. <b>Aim of Study:</b> To evaluate the diagnostic accuracy of 3D digital models obtained through intraoral and extraoral scanning modalities to the reference gold standard plaster model. <b>Material & Methods:</b> Twenty-four adult male and female subjects were randomly selected for this study. The intraoral scanners evaluated in this study were Sirona (CEREC Omnicam) and 3 shape (TRIOS 3), while the laboratory scanners used were Sirona (inEos X5), and 3 shape (D850). Intra-oral scanning of the subjects and extra-oral scanning of their alginate impressions, plaster models of the alginate impression, rubber base impression, and plaster model of their rubber base impression were done. Linear dental measurements included intermolar width, interpremolar width, intercanine width, mesiodistal width of the 1<sup>st</sup> permanent molar, 1<sup>st</sup> premolar, canine and central incisor and arch width. All data were collected, tabulated and subjected to statistical analysis. <b>Results:</b> Small differences between the plaster and digital models were observed. Intra-observer reliability analysis for 14 out of the 16 measurements showed that all variables exhibited good to excellent reliability. <b>Conclusions: </b>There was no difference between the digitization using the intraoral scanner or the laboratory scanner. The most accurate digitization technique was the 3 Shape laboratory scanner of the cast of the alginate impression. The inEos X5 showed the highest error of digitization of the alginate and rubber base impressions.
基金Supported by the Program for Science and Technology Innovation Talents in Universities of Henan Province under Grant No13HASTIT046
文摘The cross sections of fragments produced in the 140 A MeV58,64Ni＋9 Be projectile fragmentation reactions are calculated by using the antisymmetrized molecular dynamics （AMD） model, the modified statistical abrasion- ablation （SAA） model, and the empirical EPAX2/EPAX3 formulae. The Gogny-gO interaction is taken as the effective nucleon-nucleon interaction in the AMD calculation, and the decays of fragments obtained from the AMD results are calculated by using the GEMINI code. The calculated cross sections of fragments are compared.
基金A project described in this work regarding innervation changes in the murine vagina in response to inflammation was supported by a grant from the Centre for Neuroscience,Flinders University,Australia
文摘Vulvodynia is a prevalent form of chronic pain, most com- monly affecting the vaginal vestibule （vestibulodynia） （Pukall et al., 2016）. Women with vulvodynia describe intense pain in response to light touch of the affected region, such that sexual function and other activities can be severely limited. Medical costs associated with vulvodynia are high, exceeding $21 billion annually in the United States （Xie et al., 2012）. The high level of direct medical costs has been linked to high treatment failure rates. Many women with the disorder consult multiple practitioners and undergo multiple courses of treatment with limited benefit.
文摘The key problem to the calculation and optimization design of the helicopter 'Ground Resonance' is to correctly build up a mechanical model. In the past, the literature was only concerned with the lag modes of the rotor blade and the flap modes were neglected. But such approaches should be reconsidered now. In order to study the influences of rotating multiblades rotor on the degrees of freedom and also the flap ''Ground Resonance' of a helicopter, it is necessary to consider not only the lag degrees of freedom but also the flap degrees of freedom. Using Lagrangian equation a dynamical equation of the space model for helicopter 'Ground Resonance'is deduced for the first time. Some computation results show that the mechanical model including both lag DOF and flap DOF is more reasonable.
文摘In order to make the numerical calculation of viscous flows more convenient for the flows in channel with complicated profile governing equations expressed in the arbitrary curvilinear coordinates were derived by means of Favre density-weighted averaged method, and a turbulent model with effect of curvature modification was also derived. The numerical calculation of laminar and turbulent flown in divergent curved channels was carried out by means of parabolizeil computation method. The calculating results were used to analyze and investigate the aerodynamic performance of talor cascades in compressors preliminarily.
基金ACKNOWLEDGEMENTS Project supported by the National Social Science Foundation of China （Grant No. 11BGL041）, Ministry of Education Humanities and Social Sciences General Project （12YJA630166）.
文摘The innovations actually diffuse among social network nowadays.Individual heterogeneity,interactions between individuals and network topology influence a lot.We established a "double threshold" modified model and took the number of neighbors,neighbors' adoption and the cost-benefit parameters as crucial influencing factors.The diffusion of DaLingTong(CDMA450)products in MeiShan city of SiChuan province during 2004 to 2007 has been used to verity the model on Matlab.The validation results fit the actual diffusion pattern of DaLingTong(CDMA450) products very well.The results indicate that there exists a "tipping point(threshold)" in the process of innovation diffusion.If the initial adoption quantity is larger than the tipping point,then the product will spread to a large portion of people,otherwise is will collapse to zero.The model can effectively predict the diffusion of new products,and can influence the diffusion process by changing the value of the parameters.
文摘Introduction-The cervical spine is subjected to injury frequently,especially among pilots who are usually on the condition of high acceleration.Injuries of the cervical spine will be potential risk of damage to the spinal cord,which could be result in life threatening
基金Support for these studies was provided by grants from the National Institutes of Health (HD-22785,HD-25189, HD-07495).
文摘The greatest risks to mammalian pregnancy occur during the peri-implantation period (passage through the uterotubal junction, blastulation, zona shedding, embryonic signaling and recognition, blastocyst attachment, postattachment events initiating placentation). Conventional markers and screening methods do not provide the means to clarify the relationship between exposure of a reproductively competent woman to a xenobiotic compound and the specific error in the functional expression of an embryogenetic process identified by impairment or deletion of that process. Laboratory models which provide the flexibility of in vitro culture methods and allow integration of cellular and molecular techniques have identified cell-specific, stage-specific markers that could focus on the mechanism of xenobiotic action. In vitro models have been used to define postattachment trophoblast cell differentiation. Trophoblast specific peptide hormones prove to be valid markers of established pregnancy. They provide no assessment of the risk to the embryo during the peri-implantation period. The relationship between developmental time of exposure and risk is discussed in terms of trophoblast differentiation.
