Transition-metal oxyhydroxides are attractive catalysts for oxygen evolution reactions(OERs).Further studies for developing transition-metal oxyhydroxide catalysts and understanding their catalytic mechanisms will ben...Transition-metal oxyhydroxides are attractive catalysts for oxygen evolution reactions(OERs).Further studies for developing transition-metal oxyhydroxide catalysts and understanding their catalytic mechanisms will benefit their quick transition to the next catalysts.Herein,Mo-doped CoOOH was designed as a high-performance model electrocatalyst with durability for 20 h at 10 mAcm−2.Additionally,it had an overpotential of 260 mV(glassy carbon)or 215 mV(nickel foam),which was 78 mV lower than that of IrO_(2)(338 mV).In situ,Raman spectroscopy revealed the transformation process of CoOOH.Calculations using the density functional theory showed that during OER,doped Mo increased the spin-up density of states and shrank the spin-down bandgap of the 3d orbits in the reconstructed CoOOH under the electrochemical activation process,which simultaneously optimized the adsorption and electron conduction of oxygen-related intermediates on Co sites and lowered the OER overpotentials.Our research provides new insights into the methodical planning of the creation of transition-metal oxyhydroxide OER catalysts.展开更多
Diagnosis of soil salinity and characterizing its spatial variability both vertically and horizontally are needed to establish control measures in irrigated agriculture. In this regard, it is essential that salinity d...Diagnosis of soil salinity and characterizing its spatial variability both vertically and horizontally are needed to establish control measures in irrigated agriculture. In this regard, it is essential that salinity development in varying soil depths be known temporally and spatially. Apparent soil electrical conductivity, measured by electromagnetic induction instruments, has been widely used as an auxiliary variable to estimate spatial distribution of field soil salinity. The main objectives of this paper were adopted a mobile electromagnetic induction (EMI) system to perform field electromagnetic (EM) survey in different soil layers, to evaluate the uncertainty through Inverse Distance Weighted (IDW) and Ordinary Kriging (OK) methods, and to determine which algorithm is more reliable for the local and spatial uncertainty assessment. Results showed that EM38 data from apparent soil electrical conductivity are highly correlated with salinity, more accurate for estimating salinity from multiple linear regression models, which the correlation coefficient of 0 - 20, 20 - 40, 40 - 60 and 60 - 80 cm were 0.9090, 0.9228, 0.896 and 0.9085 respectively. The comparison showed that the prediction accuracy of two methods also displays good performance for soil salinity, the estimation precision of IDW method (with E = 0.8873, 0.9075, 0.8483 and 0.901, RPD = 9.64, 8.01, 8.17 and 11.23 in 0 - 20, 20 - 40. 40 - 60 and 60 - 80 cm soil layers, respectively) was superior to that of OK (with E = 0.8857, 0.872, 0.8744 and 0.8822, RPD = 9.44, 7.83, 8.52 and 10.88, respectively), but differences of two methods in predictions are not significant. The obtained salinity map was helpful to display the spatial patterns of soil salinity and monitor and evaluate the management of salinity.展开更多
Objective： To detect the activity of tumor cells and tumor blood flow before and after the radiotherapy of implanted pulmonary VX-2 carcinoma in rabbit models by using magnetic resonance diffusion-weighted imaging（M...Objective： To detect the activity of tumor cells and tumor blood flow before and after the radiotherapy of implanted pulmonary VX-2 carcinoma in rabbit models by using magnetic resonance diffusion-weighted imaging（MR-DWI） and magnetic resonance perfusion weighted imaging（MR-PWI）, and to evaluate the effectiveness and safety of the radiotherapy based on the changes in the MR-DWI and MR-PWI parameters at different treatment stages.Methods： A total of 56 rabbit models with implanted pulmonary VX-2 carcinoma were established, and then equally divided into treatment group and control group. MR-DWI and MR-PWI were separately performed using a Philips Acheiva 1.5T MRI machine（Philips, Netherland）. MRI image processing was performed using special perfusion software and the WORKSPACE advanced workstation for MRI. MRDWI was applied for the observation of tumor signals and the measurement of apparent diffusion coefficient（ADC） values; whereas MR-PWI was used for the measurement of wash in rate（WIR）, wash out rate（WOR）, and maximum enhancement rate（MER）. The radiation treatment was performed using Siemens PRIMUS linear accelerator. In the treatment group, the radiotherapy was performed 21 days later on a once weekly dosage of 1,000 c Gy to yield a total dosage of 5,000 c Gy.Results： The ADC parameters in the region of interest on DWI were as follows： on the treatment day for the implanted pulmonary VX-2 carcinoma, the t values at the center and the edge of the lesions were 1.352 and 1.461 in the treatment group and control group（P〉0.05）. During weeks 0-1 after treatment, the t values at the center and the edge of the lesions were 1.336 and 1.137（P〉0.05）. During weeks 1-2, the t values were 1.731 and 1.736（P〈0.05）. During weeks 2-3, the t values were 1.742 and 1.749（P〈0.05）. During weeks 3-4, the t values were 2.050 and 2.127（P〈0.05）. During weeks 4-5, the t values were 2.764 and 2.985（P〈0.05）. The ADC values in the treatment group were significantly higher than in the control group. After the radiotherapy（5,000 c Gy）, the tumors remarkably shrank, along with low signal on DWI, decreased signal on ADC map, and remarkably increased ADC values. As shown on PWI, on the treatment day for the implanted pulmonary VX-2 carcinoma, the t values of the WIR, WOR, and MER at the center of the lesions were 1.05, 1.31, and 1.33 in the treatment group and control group（P〉0.05）; in addition, the t values of the WIR, WOR, and MER at the edge of the lesions were 1.35, 1.07, and 1.51（P〉0.05）. During weeks 0-1 after treatment, the t values of the WIR, WOR, and MER at the center of the lesions were 1.821, 1.856, and 1.931（P〈0.05）; in addition, the t values of the WIR, WOR, and MER at the edge of the lesions were 1.799, 2.016, and 2.137（P〈0.05）. During weeks 1-1 after treatment, the t values of the WIR, WOR, and MER at the center of the lesions were 2.574, 2.156, and 2.059（P〈0.05） and the t values of the WIR, WOR, and MER at the edge of the lesions were 1.869, 2.058, and 2.057（P〈0.05）. During weeks 2-3 after treatment, the t values of the WIR, WOR, and MER at the center of the lesions were 2.461, 2.098, and 2.739（P〈0.05） and the t values of the WIR, WOR, and MER at the edge of the lesions were 2.951, 2.625, and 2.154（P〈0.05）. During weeks 3-4 after treatment, the t values of the WIR, WOR, and MER at the center of the lesions were 2.584, 2.107, and 2.869（P〈0.05） and the t values of the WIR, WOR, and MER at the edge of the lesions were 2.057, 2.637, and 2.951（P〈0.05）. During weeks 4-5 after treatment, the t values of the WIR, WOR, and MER at the center of the lesions were 2.894, 2.827, and 3.285（P〈0.05） and the t values of the WIR, WOR, andMER at the edge of the lesions were 3.45, 3.246, and 3.614（P〈0.05）. After the radiotherapy（500 c Gy）, the tumors shrank on the T1 WI, WIR, WOR, and MER; meanwhile, the PWI parameter gradually decreased and reached its minimum value.Conclusions： MR-DWI and MR-PWI can accurately and directly reflect the inactivation of tumor cells and the tumor hemodynamics in rabbit models with implanted pulmonary VX-2 carcinoma, and thus provide theoretical evidences for judging the clinical effectiveness of radiotherapy for the squamous cell carcinoma of the lung.展开更多
A novel tunable-quality-factor （tunable-Q） contourlet transform for geometric image representation is proposed. The Laplacian pyramid in original contourlet decomposes a signal into channels that have the same bandw...A novel tunable-quality-factor （tunable-Q） contourlet transform for geometric image representation is proposed. The Laplacian pyramid in original contourlet decomposes a signal into channels that have the same bandwidth on a logarithmic scale, and is not suitable for images with different behavior in frequency domain. We employ a new tunable-Q decomposition defined in the frequency domain by which one can flexibly tune the bandwidth of decomposition channels. With an acceptable redundancy, this tunable-Q contourlet is also anti-aliasing and its basis is sharply localized in the desired area of frequency and spatial domain. Our experiments in nonlinear approximation and denoising show that the contourlet using a better-suitable quality factor can achieve a more promising performance and often outperform wavelets and the previous contourlets both in visual quality and in terms of peak signal-to-noise ratio.展开更多
The concept of ＂numerical Green’s functions＂ （NGF or Green’s function database） is developed. The basic idea is： a large seismic fault is divided into subfaults of appropriate size, for which synthetic Green’s...The concept of ＂numerical Green’s functions＂ （NGF or Green’s function database） is developed. The basic idea is： a large seismic fault is divided into subfaults of appropriate size, for which synthetic Green’s functions at the surface （NGF） are calculated and stored. Consequently, ground motions from arbitrary kinematic sources can be simulated, rapidly, for the whole fault or parts of it by superposition. The target fault is a simplified, vertical model of the Newport-Inglewood fault in the Los Angeles basin. This approach and its functionality are illustrated by investigating the variations of ground motions （e.g. peak ground velocity and synthetic seismograms） due to the source complexity. The source complexities are considered with two respects： hypocenter location and slip history. The results show a complex behavior, with dependence of absolute peak ground velocity and their variation on source process directionality, hypocenter location, local structure, and static slip asperity location. We concluded that combining effect due to 3-D structure and finite-source is necessary to quan- tify ground motion characteristics and their variations. Our results will facilitate the earthquake hazard assessment projects.展开更多
Purpose Colorectal cancer is a common malignant tumor worldwide.In China,the ratio of rectal cancer to coloncancer in terms of incidence is close to 1:1.Low rectal cancer accounts for more than half of all cases of re...Purpose Colorectal cancer is a common malignant tumor worldwide.In China,the ratio of rectal cancer to coloncancer in terms of incidence is close to 1:1.Low rectal cancer accounts for more than half of all cases of rectal cancer.In recent years,the proportion of rectal cancer has trended downward,however the incidence of rectal cancer inyounger adults is increasing.The CACA Guidelines for Holistic Integrative Management of Rectal Cancer were editedto help improve the diagnosis and comprehensive treatment in China.Methods This guideline has been prepared by consensuses reached by the CACA Committee of Colorectal CancerSociety,based on a careful review of the latest evidence including China’s studies,and referred to domestic and internationalrelative guidelines,also considered China’s specific national conditions and clinical practice.Results The CACA Guidelines for Holistic Integrative Management of Rectal Cancer include the epidemiology of rectalcancer,prevention and screening,diagnosis,treatment of nonmetastatic and metastatic rectal cancer,follow-up,and whole-course rehabilitation management.Conclusion Committee of Colorectal Cancer Society,Chinese Anti-Cancer Association,standardizes the diagnosisand treatment of rectal cancer in China through the formulation of the CACA Guidelines.展开更多
Hydrogen is a favored alternative to fossil fuels due to the advantages of clean-liness,zero emissions,and high calorific value.Large-scale green hydrogen production can be achieved using proton exchange membrane wate...Hydrogen is a favored alternative to fossil fuels due to the advantages of clean-liness,zero emissions,and high calorific value.Large-scale green hydrogen production can be achieved using proton exchange membrane water electrolyz-ers(PEMWEs)with utilization of renewable energy.The porous transport layer(PTL),positioned between the flow fields and catalyst layers(CLs)in PEMWEs,plays a critical role in facilitating water/gas transport,enabling electrical/thermal conduction,and mechanically supporting CLs and membranes.Superior cor-rosion resistance is essential as PTL operates in acidic media with oxygen saturation and high working potential.This paper covers the development of high-performance titanium-based PTLs for PEMWEs.The heat/electrical con-duction and mass transport mechanisms of PTLs and how they affect the overall performances are reviewed.By carefully designing and controlling substrate microstructure,protective coating,and surface modification,the performance of PTL can be regulated and optimized.The two-phase mass transport char-acteristics can be enhanced by fine-tuning the microstructure and surface wettability of PTL.The addition of a microporous top-layer can effectively improve PTL|CL contact and increase the availability of catalytic sites.The anti-corrosion coatings,which are crucial for chemical stability and conductivity of the PTL,are compared and analyzed in terms of composition,fabrication,and performance.展开更多
To explore advanced cathode materials for lithium ion batteries(LIBs),a nanoarchitectured LiNi_(1/3)Co_(1/3)Mn_(1/3)O_(2)(LNCM)material is developed using a modified carbonate coprecipitation method in combination wit...To explore advanced cathode materials for lithium ion batteries(LIBs),a nanoarchitectured LiNi_(1/3)Co_(1/3)Mn_(1/3)O_(2)(LNCM)material is developed using a modified carbonate coprecipitation method in combination with a vacuum distillation-crystallisation process.Compared with the LNCM materials produced by a traditional carbonate copre-cipitation method,the prepared LNCM material synthesized through this modified method reveals a better hexago-nal layered structure,smaller particle sizes(ca.110.5 nm),and higher specific surface areas.Because of its unique structural characteristics,the as-prepared LNCM material demonstrates excellent electrochemical properties in-cluding high rate capability and good cycleability when it is utilized as a cathode in the lithium ion battery(LIB).展开更多
Objective:Serum tumor markers are seldom considered as diagnostic biomarkers for breast cancer because they lack good sensitivity or specificity.This study aimed to evaluate whether a combination of circulating tumor ...Objective:Serum tumor markers are seldom considered as diagnostic biomarkers for breast cancer because they lack good sensitivity or specificity.This study aimed to evaluate whether a combination of circulating tumor cells(CTCs)and the serum tumor markers carcinoembryonic antigen(CEA),cancer antigen(CA)125,and CA15-3 might improve their diagnostic performance.Methods:We performed a retrospective case-control study of patients with breast cancer or benign breast diseases(BBD)and healthy female donors(HDs)who underwent preoperative CTC detection and serum tumor marker tests between December 2017 and November 2018.CTC detection and serum tumor marker test results were collected from 177 breast cancer patients,64 patients with BBD,and 20 HDs.Correlations between CTC,CEA,CA125,or CA15-3 and participants’clinical characteristics were then analyzed.The diagnostic performances of CTC,CEA,CA125,and CA15-3 were estimated using the area under the receiver operating characteristic curve(AUC).This study was approved by the Institutional Review Board of Sun Yat-sen Memorial Hospital of Sun Yat-sen University,China(approval No.[2018]kuaishendi(75))on May 24,2018.Results:CTC,CEA,and CA15-3 were able to distinguish breast cancer patients from controls(BBD+HDs)(P<0.0001,P=0.0006,and P=0.0086,respectively).CTCs were associated with tumor size(P=0.0275)and lymph node involvement(P=0.0373),while CA15-3 was correlated with cancer stage(P=0.01)and lymph node involvement(P=0.001).The AUCs of CTCs,CEA,CA125,and CA15-3 were 0.845,0.623,0.477,and 0.58,respectively.CA125,with AUC<0.5,was not considered a biomarker for breast cancer.CEA and CA15-3 had low sensitivities(<10%)but high specificities(>98%).Combination with CTC improved the diagnostic performances of CEA and CA15-3 for breast cancer.CTC_CA15-3 had better diagnostic performance than CTC_CEA,with an AUC of 0.874,a sensitivity of 0.757,and a specificity of 0.905.Conclusion:CTCs,CEA,and CA15-3 are potential diagnostic biomarkers for breast cancer.The diagnostic performance of CEA and CA15-3 may be improved by combination with CTCs.展开更多
In the last decade,many researchers have focused on developing fuel-cell flow-field designs that homogeneously distribute reactants with an optimum pressure drop.Most of the previous studies are numerical simulations ...In the last decade,many researchers have focused on developing fuel-cell flow-field designs that homogeneously distribute reactants with an optimum pressure drop.Most of the previous studies are numerical simulations and the few experimental studies conducted have used very simple flow-field geometries due to the limitations of the conventional fabrication techniques.3D printing is an excellent rapid prototyping method for prototyping bipolar plates(BPPs)to perform experiments on new flow-field designs.The present research investigates the applicability of different 3D-printed BPPs for studying fluid-dynamic behaviour.State-of-the-art flow-field designs are fabricated using PolyJet 3D printing,stereolithographic apparatus(SLA)3D printing and laser-cutter technologies,and the pressure-drop and velocity profiles are measured for each plate.The results demonstrate that SLA BPPs have great promise in serving as a screening tool in modifying flow-field design with a small feature size.展开更多
基金The National Natural Science Foundation of China(Grant Nos.52072114 and 51922008)the 111 Project(Grant No.D17007),the Henan Center for Outstanding Overseas Scientists(Grant No.GZS2018003)+2 种基金Xinxiang Major Science and Technology Projects(Grant No.21ZD001)Guangdong Innovative and Entrepreneurial Research Team Program(2016ZT06N500)Guangdong Provincial Key Laboratory of Energy Materials for Electric Power(2018B030322001)all provided financial support for this work.
文摘Transition-metal oxyhydroxides are attractive catalysts for oxygen evolution reactions(OERs).Further studies for developing transition-metal oxyhydroxide catalysts and understanding their catalytic mechanisms will benefit their quick transition to the next catalysts.Herein,Mo-doped CoOOH was designed as a high-performance model electrocatalyst with durability for 20 h at 10 mAcm−2.Additionally,it had an overpotential of 260 mV(glassy carbon)or 215 mV(nickel foam),which was 78 mV lower than that of IrO_(2)(338 mV).In situ,Raman spectroscopy revealed the transformation process of CoOOH.Calculations using the density functional theory showed that during OER,doped Mo increased the spin-up density of states and shrank the spin-down bandgap of the 3d orbits in the reconstructed CoOOH under the electrochemical activation process,which simultaneously optimized the adsorption and electron conduction of oxygen-related intermediates on Co sites and lowered the OER overpotentials.Our research provides new insights into the methodical planning of the creation of transition-metal oxyhydroxide OER catalysts.
文摘Diagnosis of soil salinity and characterizing its spatial variability both vertically and horizontally are needed to establish control measures in irrigated agriculture. In this regard, it is essential that salinity development in varying soil depths be known temporally and spatially. Apparent soil electrical conductivity, measured by electromagnetic induction instruments, has been widely used as an auxiliary variable to estimate spatial distribution of field soil salinity. The main objectives of this paper were adopted a mobile electromagnetic induction (EMI) system to perform field electromagnetic (EM) survey in different soil layers, to evaluate the uncertainty through Inverse Distance Weighted (IDW) and Ordinary Kriging (OK) methods, and to determine which algorithm is more reliable for the local and spatial uncertainty assessment. Results showed that EM38 data from apparent soil electrical conductivity are highly correlated with salinity, more accurate for estimating salinity from multiple linear regression models, which the correlation coefficient of 0 - 20, 20 - 40, 40 - 60 and 60 - 80 cm were 0.9090, 0.9228, 0.896 and 0.9085 respectively. The comparison showed that the prediction accuracy of two methods also displays good performance for soil salinity, the estimation precision of IDW method (with E = 0.8873, 0.9075, 0.8483 and 0.901, RPD = 9.64, 8.01, 8.17 and 11.23 in 0 - 20, 20 - 40. 40 - 60 and 60 - 80 cm soil layers, respectively) was superior to that of OK (with E = 0.8857, 0.872, 0.8744 and 0.8822, RPD = 9.44, 7.83, 8.52 and 10.88, respectively), but differences of two methods in predictions are not significant. The obtained salinity map was helpful to display the spatial patterns of soil salinity and monitor and evaluate the management of salinity.
文摘Objective： To detect the activity of tumor cells and tumor blood flow before and after the radiotherapy of implanted pulmonary VX-2 carcinoma in rabbit models by using magnetic resonance diffusion-weighted imaging（MR-DWI） and magnetic resonance perfusion weighted imaging（MR-PWI）, and to evaluate the effectiveness and safety of the radiotherapy based on the changes in the MR-DWI and MR-PWI parameters at different treatment stages.Methods： A total of 56 rabbit models with implanted pulmonary VX-2 carcinoma were established, and then equally divided into treatment group and control group. MR-DWI and MR-PWI were separately performed using a Philips Acheiva 1.5T MRI machine（Philips, Netherland）. MRI image processing was performed using special perfusion software and the WORKSPACE advanced workstation for MRI. MRDWI was applied for the observation of tumor signals and the measurement of apparent diffusion coefficient（ADC） values; whereas MR-PWI was used for the measurement of wash in rate（WIR）, wash out rate（WOR）, and maximum enhancement rate（MER）. The radiation treatment was performed using Siemens PRIMUS linear accelerator. In the treatment group, the radiotherapy was performed 21 days later on a once weekly dosage of 1,000 c Gy to yield a total dosage of 5,000 c Gy.Results： The ADC parameters in the region of interest on DWI were as follows： on the treatment day for the implanted pulmonary VX-2 carcinoma, the t values at the center and the edge of the lesions were 1.352 and 1.461 in the treatment group and control group（P〉0.05）. During weeks 0-1 after treatment, the t values at the center and the edge of the lesions were 1.336 and 1.137（P〉0.05）. During weeks 1-2, the t values were 1.731 and 1.736（P〈0.05）. During weeks 2-3, the t values were 1.742 and 1.749（P〈0.05）. During weeks 3-4, the t values were 2.050 and 2.127（P〈0.05）. During weeks 4-5, the t values were 2.764 and 2.985（P〈0.05）. The ADC values in the treatment group were significantly higher than in the control group. After the radiotherapy（5,000 c Gy）, the tumors remarkably shrank, along with low signal on DWI, decreased signal on ADC map, and remarkably increased ADC values. As shown on PWI, on the treatment day for the implanted pulmonary VX-2 carcinoma, the t values of the WIR, WOR, and MER at the center of the lesions were 1.05, 1.31, and 1.33 in the treatment group and control group（P〉0.05）; in addition, the t values of the WIR, WOR, and MER at the edge of the lesions were 1.35, 1.07, and 1.51（P〉0.05）. During weeks 0-1 after treatment, the t values of the WIR, WOR, and MER at the center of the lesions were 1.821, 1.856, and 1.931（P〈0.05）; in addition, the t values of the WIR, WOR, and MER at the edge of the lesions were 1.799, 2.016, and 2.137（P〈0.05）. During weeks 1-1 after treatment, the t values of the WIR, WOR, and MER at the center of the lesions were 2.574, 2.156, and 2.059（P〈0.05） and the t values of the WIR, WOR, and MER at the edge of the lesions were 1.869, 2.058, and 2.057（P〈0.05）. During weeks 2-3 after treatment, the t values of the WIR, WOR, and MER at the center of the lesions were 2.461, 2.098, and 2.739（P〈0.05） and the t values of the WIR, WOR, and MER at the edge of the lesions were 2.951, 2.625, and 2.154（P〈0.05）. During weeks 3-4 after treatment, the t values of the WIR, WOR, and MER at the center of the lesions were 2.584, 2.107, and 2.869（P〈0.05） and the t values of the WIR, WOR, and MER at the edge of the lesions were 2.057, 2.637, and 2.951（P〈0.05）. During weeks 4-5 after treatment, the t values of the WIR, WOR, and MER at the center of the lesions were 2.894, 2.827, and 3.285（P〈0.05） and the t values of the WIR, WOR, andMER at the edge of the lesions were 3.45, 3.246, and 3.614（P〈0.05）. After the radiotherapy（500 c Gy）, the tumors shrank on the T1 WI, WIR, WOR, and MER; meanwhile, the PWI parameter gradually decreased and reached its minimum value.Conclusions： MR-DWI and MR-PWI can accurately and directly reflect the inactivation of tumor cells and the tumor hemodynamics in rabbit models with implanted pulmonary VX-2 carcinoma, and thus provide theoretical evidences for judging the clinical effectiveness of radiotherapy for the squamous cell carcinoma of the lung.
基金supported by the National Natural Science Foundation of China(4097117341071188)
文摘A novel tunable-quality-factor （tunable-Q） contourlet transform for geometric image representation is proposed. The Laplacian pyramid in original contourlet decomposes a signal into channels that have the same bandwidth on a logarithmic scale, and is not suitable for images with different behavior in frequency domain. We employ a new tunable-Q decomposition defined in the frequency domain by which one can flexibly tune the bandwidth of decomposition channels. With an acceptable redundancy, this tunable-Q contourlet is also anti-aliasing and its basis is sharply localized in the desired area of frequency and spatial domain. Our experiments in nonlinear approximation and denoising show that the contourlet using a better-suitable quality factor can achieve a more promising performance and often outperform wavelets and the previous contourlets both in visual quality and in terms of peak signal-to-noise ratio.
基金funding from the International Quality Network:Georisk (Ger-man Academic Exchange Service),and the Elite Gradu-ate College THESIS (Bavarian Government)support from the European Hu-man Resources Mobility Program (Research Training Network SPICE)
文摘The concept of ＂numerical Green’s functions＂ （NGF or Green’s function database） is developed. The basic idea is： a large seismic fault is divided into subfaults of appropriate size, for which synthetic Green’s functions at the surface （NGF） are calculated and stored. Consequently, ground motions from arbitrary kinematic sources can be simulated, rapidly, for the whole fault or parts of it by superposition. The target fault is a simplified, vertical model of the Newport-Inglewood fault in the Los Angeles basin. This approach and its functionality are illustrated by investigating the variations of ground motions （e.g. peak ground velocity and synthetic seismograms） due to the source complexity. The source complexities are considered with two respects： hypocenter location and slip history. The results show a complex behavior, with dependence of absolute peak ground velocity and their variation on source process directionality, hypocenter location, local structure, and static slip asperity location. We concluded that combining effect due to 3-D structure and finite-source is necessary to quan- tify ground motion characteristics and their variations. Our results will facilitate the earthquake hazard assessment projects.
文摘Purpose Colorectal cancer is a common malignant tumor worldwide.In China,the ratio of rectal cancer to coloncancer in terms of incidence is close to 1:1.Low rectal cancer accounts for more than half of all cases of rectal cancer.In recent years,the proportion of rectal cancer has trended downward,however the incidence of rectal cancer inyounger adults is increasing.The CACA Guidelines for Holistic Integrative Management of Rectal Cancer were editedto help improve the diagnosis and comprehensive treatment in China.Methods This guideline has been prepared by consensuses reached by the CACA Committee of Colorectal CancerSociety,based on a careful review of the latest evidence including China’s studies,and referred to domestic and internationalrelative guidelines,also considered China’s specific national conditions and clinical practice.Results The CACA Guidelines for Holistic Integrative Management of Rectal Cancer include the epidemiology of rectalcancer,prevention and screening,diagnosis,treatment of nonmetastatic and metastatic rectal cancer,follow-up,and whole-course rehabilitation management.Conclusion Committee of Colorectal Cancer Society,Chinese Anti-Cancer Association,standardizes the diagnosisand treatment of rectal cancer in China through the formulation of the CACA Guidelines.
基金National Natural Science Foundation of China,Grant/Award Numbers:22379098,52072247Basic and Applied Basic Research Foundation of Guangdong Province,Grant/Award Number:2021A1515010735+1 种基金Science,Technology and Innovation Commission of Shenzhen Municipality,Grant/Award Numbers:20220804193203001,GXWD20220811164046002Department of Education of Guangdong Province,Grant/Award Number:2021KTSCX365。
文摘Hydrogen is a favored alternative to fossil fuels due to the advantages of clean-liness,zero emissions,and high calorific value.Large-scale green hydrogen production can be achieved using proton exchange membrane water electrolyz-ers(PEMWEs)with utilization of renewable energy.The porous transport layer(PTL),positioned between the flow fields and catalyst layers(CLs)in PEMWEs,plays a critical role in facilitating water/gas transport,enabling electrical/thermal conduction,and mechanically supporting CLs and membranes.Superior cor-rosion resistance is essential as PTL operates in acidic media with oxygen saturation and high working potential.This paper covers the development of high-performance titanium-based PTLs for PEMWEs.The heat/electrical con-duction and mass transport mechanisms of PTLs and how they affect the overall performances are reviewed.By carefully designing and controlling substrate microstructure,protective coating,and surface modification,the performance of PTL can be regulated and optimized.The two-phase mass transport char-acteristics can be enhanced by fine-tuning the microstructure and surface wettability of PTL.The addition of a microporous top-layer can effectively improve PTL|CL contact and increase the availability of catalytic sites.The anti-corrosion coatings,which are crucial for chemical stability and conductivity of the PTL,are compared and analyzed in terms of composition,fabrication,and performance.
基金supported by the Science and Technology Pillar Program of Sichuan Province(2014GZ0077)the Youth Foundation of Sichuan University(No.2011SCU11081)+1 种基金the Doctoral Program of Higher Education of China(No.20120181120103)the Open Found of National Engineering Center for Phosphorus Chemical Industry(2013LF1012).
文摘To explore advanced cathode materials for lithium ion batteries(LIBs),a nanoarchitectured LiNi_(1/3)Co_(1/3)Mn_(1/3)O_(2)(LNCM)material is developed using a modified carbonate coprecipitation method in combination with a vacuum distillation-crystallisation process.Compared with the LNCM materials produced by a traditional carbonate copre-cipitation method,the prepared LNCM material synthesized through this modified method reveals a better hexago-nal layered structure,smaller particle sizes(ca.110.5 nm),and higher specific surface areas.Because of its unique structural characteristics,the as-prepared LNCM material demonstrates excellent electrochemical properties in-cluding high rate capability and good cycleability when it is utilized as a cathode in the lithium ion battery(LIB).
基金the National Key Program of the Ministry of Science and Technology(No.2020YFC2004505)GuangdongNatural Science Foundation(No.2020A1515011467)Guangzhou Municipal Science and Technology Project(No.202002030149).
文摘Objective:Serum tumor markers are seldom considered as diagnostic biomarkers for breast cancer because they lack good sensitivity or specificity.This study aimed to evaluate whether a combination of circulating tumor cells(CTCs)and the serum tumor markers carcinoembryonic antigen(CEA),cancer antigen(CA)125,and CA15-3 might improve their diagnostic performance.Methods:We performed a retrospective case-control study of patients with breast cancer or benign breast diseases(BBD)and healthy female donors(HDs)who underwent preoperative CTC detection and serum tumor marker tests between December 2017 and November 2018.CTC detection and serum tumor marker test results were collected from 177 breast cancer patients,64 patients with BBD,and 20 HDs.Correlations between CTC,CEA,CA125,or CA15-3 and participants’clinical characteristics were then analyzed.The diagnostic performances of CTC,CEA,CA125,and CA15-3 were estimated using the area under the receiver operating characteristic curve(AUC).This study was approved by the Institutional Review Board of Sun Yat-sen Memorial Hospital of Sun Yat-sen University,China(approval No.[2018]kuaishendi(75))on May 24,2018.Results:CTC,CEA,and CA15-3 were able to distinguish breast cancer patients from controls(BBD+HDs)(P<0.0001,P=0.0006,and P=0.0086,respectively).CTCs were associated with tumor size(P=0.0275)and lymph node involvement(P=0.0373),while CA15-3 was correlated with cancer stage(P=0.01)and lymph node involvement(P=0.001).The AUCs of CTCs,CEA,CA125,and CA15-3 were 0.845,0.623,0.477,and 0.58,respectively.CA125,with AUC<0.5,was not considered a biomarker for breast cancer.CEA and CA15-3 had low sensitivities(<10%)but high specificities(>98%).Combination with CTC improved the diagnostic performances of CEA and CA15-3 for breast cancer.CTC_CA15-3 had better diagnostic performance than CTC_CEA,with an AUC of 0.874,a sensitivity of 0.757,and a specificity of 0.905.Conclusion:CTCs,CEA,and CA15-3 are potential diagnostic biomarkers for breast cancer.The diagnostic performance of CEA and CA15-3 may be improved by combination with CTCs.
基金Financial support to the Collaborative Research and Development project‘PEM fuel cell architecture design’from the National Sciences and Engineering Research Council of Canada(NSERC)and H2E Co.is gratefully acknowledged and appreciated.
文摘In the last decade,many researchers have focused on developing fuel-cell flow-field designs that homogeneously distribute reactants with an optimum pressure drop.Most of the previous studies are numerical simulations and the few experimental studies conducted have used very simple flow-field geometries due to the limitations of the conventional fabrication techniques.3D printing is an excellent rapid prototyping method for prototyping bipolar plates(BPPs)to perform experiments on new flow-field designs.The present research investigates the applicability of different 3D-printed BPPs for studying fluid-dynamic behaviour.State-of-the-art flow-field designs are fabricated using PolyJet 3D printing,stereolithographic apparatus(SLA)3D printing and laser-cutter technologies,and the pressure-drop and velocity profiles are measured for each plate.The results demonstrate that SLA BPPs have great promise in serving as a screening tool in modifying flow-field design with a small feature size.
