Increasing intense human activities have largely changed the coastal landscape and caused many environmental issues.However,whether human-induced activities could change the coastal land use gradient pattern,an import...Increasing intense human activities have largely changed the coastal landscape and caused many environmental issues.However,whether human-induced activities could change the coastal land use gradient pattern,an important coastal zonal characteristic along the sea-land direction,remains unclear.Manila Bay was selected as the study area in this work.According to the distance of the land use and land cover(LULC)to the coastline,we clustered the typical coastal land use sequence patterns(CLUSPs)along the sea-land direction between 1988 and 2016 in Manila Bay and found the following.(1)Four typical CLUSPs,including the natural CLUSP dominated by forest land and grassland,the agricultural CLUSP dominated by dry farm and paddy field,the urbanised CLUSP dominated by construction land and the fishery CLUSP dominated by fishing farm,were mined in 1988.Three typical CLUSPs(a natural CLUSP,an intermediate CLUSP between the agricultural and urbanised CLUSPs,and a fishery CLUSP)were mined in 2016.(2)Affected by the dominant LULC,these typical CLUSPs showed a regular spatial pattern along the sea-land direction.For example,the typical natural CLUSP showed a landward pattern due to the long distance between the forest land and grassland and the coastline.(3)However,influenced by urban and aquaculture expansion,the land intensification of the CLUSP exhibited an obvious increase and caused the decrease of the CLUSP diversity from 1988 to 2016.The increase in the area of LULC coverage showed no obvious correlation with its distance from the coastline(DFC),but the net increase rate of LULC coverage had a significant negative correlation with the DFC.Therefore,human-induced activities have a large impact on the gradient pattern of coastal land use along the sea-land direction.展开更多
Accurate prediction of shield tunneling-induced settlement is a complex problem that requires consideration of many influential parameters.Recent studies reveal that machine learning(ML)algorithms can predict the sett...Accurate prediction of shield tunneling-induced settlement is a complex problem that requires consideration of many influential parameters.Recent studies reveal that machine learning(ML)algorithms can predict the settlement caused by tunneling.However,well-performing ML models are usually less interpretable.Irrelevant input features decrease the performance and interpretability of an ML model.Nonetheless,feature selection,a critical step in the ML pipeline,is usually ignored in most studies that focused on predicting tunneling-induced settlement.This study applies four techniques,i.e.Pearson correlation method,sequential forward selection(SFS),sequential backward selection(SBS)and Boruta algorithm,to investigate the effect of feature selection on the model’s performance when predicting the tunneling-induced maximum surface settlement(S_(max)).The data set used in this study was compiled from two metro tunnel projects excavated in Hangzhou,China using earth pressure balance(EPB)shields and consists of 14 input features and a single output(i.e.S_(max)).The ML model that is trained on features selected from the Boruta algorithm demonstrates the best performance in both the training and testing phases.The relevant features chosen from the Boruta algorithm further indicate that tunneling-induced settlement is affected by parameters related to tunnel geometry,geological conditions and shield operation.The recently proposed Shapley additive explanations(SHAP)method explores how the input features contribute to the output of a complex ML model.It is observed that the larger settlements are induced during shield tunneling in silty clay.Moreover,the SHAP analysis reveals that the low magnitudes of face pressure at the top of the shield increase the model’s output。展开更多
AIM: To compare the short-term outcomes of patients who underwent proximal gastrectomy with jejunal interposition (PGJI) with those undergoing total gastrectomy with Roux-en-Y anastomosis (TGRY).
M13 phage＇is a filamentous bacteriophage containing a circular single-stranded DNA molecular, which is surrounded by approximately 2 800 copies of protein PVIII. In addition, there are five copies of each of proteins...M13 phage＇is a filamentous bacteriophage containing a circular single-stranded DNA molecular, which is surrounded by approximately 2 800 copies of protein PVIII. In addition, there are five copies of each of proteins PVII and PXI in one end, and five copies of each of proteins PVI and PUI on the other. These coat proteins have play an important role in the infection and assembly of M13 phage. With the development of phage display technology, these five coat proteins all can be used in phage display, which plays an increasingly important role in molecular detection and treatment.展开更多
In this paper, a novel signal processing method combining mathematical morphology (MM) and Walsh theory is proposed, which uses Walsh functions to control the structuring element (SE) and MM operators. Based on the Wa...In this paper, a novel signal processing method combining mathematical morphology (MM) and Walsh theory is proposed, which uses Walsh functions to control the structuring element (SE) and MM operators. Based on the Walsh-MM method, a scheme for power quality disturbances detection and classification is developed, which involves three steps: denoising, feature extraction and morphological clustering. First, various evolution rules of Walsh function are used to generate groups of SEs for the multiscale Walsh-ordered morphological operation, so the original signal can be denoised. Next, the fundamental wave of the denoised signal is suppressed by Hadamard matrix;thus, disturbances can be extracted. Finally, the Walsh power spectrum of the waveform extracted in the previous step is calculated, and the parameters of which are taken by morphological clustering to classify the disturbances. Simulation results reveal the proposed scheme can effectively detect and classify disturbances, and the Walsh-MM method is less affected by noise and only involves simple calculation, which has a potential to be implemented in hardware and more suitable for real-time application.展开更多
Soil-pipeline separation due to tunnelling has been certainly substantiated in previous model tests.However,this phenomenon has seldom been considered in current analytical solutions.This study formulates a tensionles...Soil-pipeline separation due to tunnelling has been certainly substantiated in previous model tests.However,this phenomenon has seldom been considered in current analytical solutions.This study formulates a tensionless Winkler solution that could make allowance for gap formation in soil-pipeline interaction analyses.The solution is validated by comparisons with existing experimental measurements and two recognized analytical solutions.Also,its advantage over an existing Winkler solution is addressed.Further parametric studies reveal that the effects of gap formation on the response of a pipeline rely largely on the tunnel volume loss and the pipeline’s bending stiffness and burial depth.In general,a pipeline’s bending moments and subgrade reaction forces are more susceptible than its deflections to the gap formation.展开更多
The emergence of microhemispherical resonant gyroscopes,which integrate the advantages of exceptional stability and long lifetime with miniaturization,has afforded new possibilities for the development of whole-angle ...The emergence of microhemispherical resonant gyroscopes,which integrate the advantages of exceptional stability and long lifetime with miniaturization,has afforded new possibilities for the development of whole-angle gyroscopes.However,existing methods used for manufacturing microhemispherical resonant gyroscopes based on MEMS technology face the primary drawback of intricate and costly processing.Here,we report the design,fabrication,and characterization of the first 3D-printable microhemispherical shell resonator for a Coriolis vibrating gyroscope.We remarkably achieve fabrication in just two steps bypassing the dozen or so steps required in traditional micromachining.By utilizing the intricate shaping capability and ultrahigh precision offered by projection microstereolithography,we fabricate 3D high-aspect-ratio resonant structures and controllable capacitive air gaps,both of which are extremely difficult to obtain via MEMS technology.In addition,the resonance frequency of the fabricated resonators can be tuned by electrostatic forces,and the fabricated resonators exhibit a higher quality factor in air than do typical MEMS microhemispherical resonators.This work demonstrates the feasibility of rapidly batch-manufacturing microhemispherical shell resonators,paving the way for the development of microhemispherical resonator gyroscopes for portable inertial navigation.Moreover,this particular design concept could be further applied to increase uptake of resonator tools in the MEMS community.展开更多
Golden2(G2), a member of the GARP transcription factor superfamily, regulates several biological processes and phytohormone signaling pathways in plants. In this study, we used a rice codon-optimized maize G2 gene(rZm...Golden2(G2), a member of the GARP transcription factor superfamily, regulates several biological processes and phytohormone signaling pathways in plants. In this study, we used a rice codon-optimized maize G2 gene(rZmG2) to improve the regeneration efficiency of rice and maize calli for genetic transformation. We isolated a promoter driving strong and callus-specific expression from rice to drive rZmG2 transcription from a transgene after transformation of two indica and two japonica rice cultivars. The resulting rZmG2 transgenic calli turned green in advance at the differentiation stage, thus significantly raising the regeneration rates of the transgenic indica and japonica rice plants relative to control transformations. Similar effect of this gene on improving maize transformation was also observed. Transcriptome sequencing and RT-qPCR analyses showed that many rice genes related to chloroplast development and phytohormones are upregulated in rZmG2-transgenic calli. These results demonstrate that rZmG2 can promote embryogenic callus differentiation and improve regeneration efficiency by activating chloroplast development and phytohormone pathways. We also established a heat-inducible Cre/loxP-based gene-excision system to remove rZmG2 and the antibiotic selectable gene after obtaining the transgenic plants. This study provides a useful tool for functional genomics work and biotechnology in plants.展开更多
As urbanization accelerates,the metro has become an important means of transportation.Considering the safety problems caused by metro construction,ground settlement needs to be monitored and predicted regularly,especi...As urbanization accelerates,the metro has become an important means of transportation.Considering the safety problems caused by metro construction,ground settlement needs to be monitored and predicted regularly,especially when a new metro line crosses an existing one.In this paper,we propose a settlement-probability prediction model with a Bayesian emulator(BE)based on the Gaussian prior(GP),that is,a GPBE.In addition,considering the distortion characteristics of monitoring data,the data is denoised using wavelet decomposition(WD),so the final prediction model is WD-GPBE.In particular,the effects of different prediction ratios and moving windows on prediction performance are explored,and the optimal number of moving windows is determined.In addition,the predicted value for GPBE based on the original data is compared with the predicted value for WD-GPBE based on the denoised data.One year of settlement-monitoring data collected by a structural health monitoring(SHM)system installed on the Nanjing Metro is used to demonstrate the effectiveness of WDGPBE and GPBE for predicting settlement.展开更多
Land surface temperature(LST),especially day-night LST difference(LSTd-LSTn),is a key variable for the stability of terrestrial ecosystems,affected by vegetation and climate change.Quantifying the contribution and fee...Land surface temperature(LST),especially day-night LST difference(LSTd-LSTn),is a key variable for the stability of terrestrial ecosystems,affected by vegetation and climate change.Quantifying the contribution and feedback of vegetation and climate to LST changes is critical to developing mitigation strategies.Based on LST,Normalized vegetation index(NDVI),land use(LU),air temperature(AT)and precipitation(Pre)from 2003 to 2021,partial correlation was used to analyze the response of LST to vegetation and climate.The feedback and contribution of both to LST were further quantifed by using spatial linear relationships and partial derivatives analysis.The results showed that both interannual LST(LSTy)and LSTd-LSTn responded negatively to vegetation,and vegetation had a negative feedback effect in areas with significantly altered.Vegetation was also a major contributor to the decline of LSTd-LSTn.With the advantage of positive partial correlation area of 94.99%,AT became the main driving factor and contributor to LSTy change trend.Pre contributed negatively to both LSTy and LSTd-LSTn,with contributions of-0.004℃/y and-0.022℃/y,respectively.AT played a decisive role in LST warming of YRB,which was partially mitigated by vegetation and Pre.The present research contributed'to,the,detection,of LST changes and improved understanding of the driving mechanism.展开更多
In recent years,past changes in global and regional land surface temperatures(LST)have been well studied,however,future LST changes have been largely ignored owing to data limitations.In this study,three climate varia...In recent years,past changes in global and regional land surface temperatures(LST)have been well studied,however,future LST changes have been largely ignored owing to data limitations.In this study,three climate variables of CMIP6,namely air temperature(AT),precipitation(Pre),and leaf area index(LAl),were spatially corrected using the Delta downscaling method.On this basis,by combining MODIS LST,elevation,slope and aspect,a random forest(RF)model was built to calculate the LST from 2022 to 2100.The absolute variability(AV)and Mann-Kendall(M-K)tests were used to quantitatively detect interannual and seasonal LST changes in different Shared Socioeconomic Pathways(SSPs)scenarios.The results showed that the AV value increased successively from SSP1-2.6 to SSP2-4.5 and then to SSP5-8.5.Compared with the base period(2003-2021),the increment in interannual,spring,summer and autumn LST during 2022-2100 was mainly between 1 and 2°℃under threescenarios.The interannual and seasonal LST were spatially characterized by significant warming over large areas,and the increasing was the fastest under SSP5-8.5.These results indicate that,in the future,LST will increase further over large areas,especially in winter.展开更多
In this study,a machine learning method,i.e.genetic programming(GP),is employed to obtain a simplified statistical model to describe the variation of soil suction in drying cycles using five selected influential param...In this study,a machine learning method,i.e.genetic programming(GP),is employed to obtain a simplified statistical model to describe the variation of soil suction in drying cycles using five selected influential parameters.The data used for model development was recorded by an in-situ experiment.The image processing technology is used to quantify several tree canopy parameters.Based on four accuracy metrics,i.e.root mean square error(RMSE),mean absolute percentage error(MAPE),coefficient of determination(R2),and relative error,the performance of the proposed GP model was evaluated.The results indicate that the model can give a reasonable estimation for the spatiotemporal variations of soil suction around a tree with acceptable errors.Global sensitivity analysis for the statistical model obtained using limited data of a specific region demonstrates the drying time as the most influential variable and the initial soil suction as the second most influential variable for the soil suction variations.A case study was conducted using a set of assumed input variable values and validated that the simplified GP model can be used to estimate and predict the spatiotemporal variations of soil suction in rooted soil at a certain range.展开更多
Accurate quantitative reverse transcription PCR(q RT-PCR)requires reliable reference genes whose expression does not vary in different tissues and developmental stages.However,few reliable reference genes are availabl...Accurate quantitative reverse transcription PCR(q RT-PCR)requires reliable reference genes whose expression does not vary in different tissues and developmental stages.However,few reliable reference genes are available for q RT-PCR in rice(Oryza sativa).Here,we established an effective strategy for identifying novel reference genes(NRGs)for reliable normalization of q RT-PCR data in various rice organs and developmental stages.We selected candidate NRGs using the Information Commons for Rice Database and confirmed their expression in Rice Expression Profile Database(Rice XPro)data.Genes with low variation(<2.5 cycle quantification)across tissues and developmental stages,and little fluctuation in expression in heatmaps from Rice XPro data were considered stable NRGs.To validate this strategy,we selected 11 candidate NRGs and calculated their expression stability in different spatio-temporal conditions using five programs,and compared these genes with five established reference genes(ERGs).Only one of the ERGs(UBQ5)was reliable and 10 of the candidate NRGs were more stable than the four remaining ERGs.Therefore,public transcriptomic databases are useful for identifying NRGs.We selected two NRGs,UFC1(Homolog of UFM1-Conjugating Enzyme 1)and Fha B(Homolog of Adhesin Fha B)for q RT-PCR analysis in rice;their homologs might be suitable for other monocot plants.展开更多
Surface settlements caused by twin tunneling are a major interest in underground space engineering.Most prevailing studies have investigated the surface settlements observed over twin tunnels constructed in clay.Yet,l...Surface settlements caused by twin tunneling are a major interest in underground space engineering.Most prevailing studies have investigated the surface settlements observed over twin tunnels constructed in clay.Yet,less attention is given to the twin tunnels exca-vated in silty sand,which is the focus of this study.A comprehensive field monitoring scheme was designed in the Hangzhou metro line six project to measure the surface settlements during twin tunneling by adopting earth pressure balance shields.The influence of four shield operational parameters,namely,face pressure,tail grouting pressure,penetration rate,and pitching angle on the surface settle-ments due to twin tunneling are explored.In general,the total settlement profiles observed over twin tunnels follow an inverted bimodal shape.The post-settlement observed over the 1^(st)tunnel due to the 2^(nd)tunnel excavation is non-trivial when the twin tunnels are spaced closely.Low face pressure and tail grouting pressure can induce excessive peak surface settlements during twin tunneling in silty sand.展开更多
Aims Climate warming and agricultural non-point source pollution both resulting from anthropogenic activities have been projected to affect plant reproduction and growth in wetlands worldwide.In order to predict and m...Aims Climate warming and agricultural non-point source pollution both resulting from anthropogenic activities have been projected to affect plant reproduction and growth in wetlands worldwide.In order to predict and mitigate impacts of these anthropogenic activities,it is important to investigate how marsh plants respond to such environmental changes.Methods In this study,Bolboschoenus planiculmis,a tuberous sedge with a wide distribution range in Eurasia,was selected to examine the effect of air temperature changes(15,20 and 25°C over 24 h;20/10 and 30/15°C,day/night)and K supply(0,1,3,9 and 18 mmol/L)on its reproductive and growth traits in climate chambers.Important Findings We found that high constant temperatures(20 and 25°C)were more beneficial for tuberization of B.planiculmis than high alternating temperatures(30/15°C),whereas aboveground biomass and shoot height were generally largest at high temperatures(30/15 and 25°C).Both reproductive and growth traits of B.planiculmis showed hump-shaped relationships with K supply,with an optimum K concentration of around 1–3 mmol/L.The combination of high constant temperatures and optimal K concentrations promoted reproductive traits the most,whereas the combination of higher temperatures(30/15 and 25°C)and K concentrations up to 9 mmol/L increased growth traits only.We therefore conclude that population abundance of B.planiculmis might benefit from global warming and the additional K supply.展开更多
Anchor-based ad-hoc networks utilize hop measurements to generate a virtual coordinate system for topology inference and routing applications.A common problem with such coordinate system is its sensitivity to anchor p...Anchor-based ad-hoc networks utilize hop measurements to generate a virtual coordinate system for topology inference and routing applications.A common problem with such coordinate system is its sensitivity to anchor placement.We present a general formulation to the anchor node selection problem.Then,we relax the optimization problem by deriving an upper-bound of the objective function.We finally propose an iterative algorithm that consists in choosing additional anchor nodes based on the connectivity information provided by the current anchor set.Numerical simulations indicate that our anchor selection method is robust to missing measurements and improves network topology inference and routing performance.展开更多
基金The Innovation Academy of South China Sea Ecology and Environmental Engineering,Chinese Academy of Sciences under contract No.ISEE2020YB06the National Natural Science Foundation of China under contract Nos 41830648 and 41801353+3 种基金the Chongqing Postdoctoral Innovation Fund under contract No.cstc2020jcyj-bshX0103the Grant from the State Key Laboratory of Resources and Environmental Information Systemthe Open Project Programme of the Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions under contract No.GTYR201906the Open Project Programme of Chongqing Key Laboratory of Karst Environment under contract No.Cqk201903.
文摘Increasing intense human activities have largely changed the coastal landscape and caused many environmental issues.However,whether human-induced activities could change the coastal land use gradient pattern,an important coastal zonal characteristic along the sea-land direction,remains unclear.Manila Bay was selected as the study area in this work.According to the distance of the land use and land cover(LULC)to the coastline,we clustered the typical coastal land use sequence patterns(CLUSPs)along the sea-land direction between 1988 and 2016 in Manila Bay and found the following.(1)Four typical CLUSPs,including the natural CLUSP dominated by forest land and grassland,the agricultural CLUSP dominated by dry farm and paddy field,the urbanised CLUSP dominated by construction land and the fishery CLUSP dominated by fishing farm,were mined in 1988.Three typical CLUSPs(a natural CLUSP,an intermediate CLUSP between the agricultural and urbanised CLUSPs,and a fishery CLUSP)were mined in 2016.(2)Affected by the dominant LULC,these typical CLUSPs showed a regular spatial pattern along the sea-land direction.For example,the typical natural CLUSP showed a landward pattern due to the long distance between the forest land and grassland and the coastline.(3)However,influenced by urban and aquaculture expansion,the land intensification of the CLUSP exhibited an obvious increase and caused the decrease of the CLUSP diversity from 1988 to 2016.The increase in the area of LULC coverage showed no obvious correlation with its distance from the coastline(DFC),but the net increase rate of LULC coverage had a significant negative correlation with the DFC.Therefore,human-induced activities have a large impact on the gradient pattern of coastal land use along the sea-land direction.
基金support provided by The Science and Technology Development Fund,Macao SAR,China(File Nos.0057/2020/AGJ and SKL-IOTSC-2021-2023)Science and Technology Program of Guangdong Province,China(Grant No.2021A0505080009).
文摘Accurate prediction of shield tunneling-induced settlement is a complex problem that requires consideration of many influential parameters.Recent studies reveal that machine learning(ML)algorithms can predict the settlement caused by tunneling.However,well-performing ML models are usually less interpretable.Irrelevant input features decrease the performance and interpretability of an ML model.Nonetheless,feature selection,a critical step in the ML pipeline,is usually ignored in most studies that focused on predicting tunneling-induced settlement.This study applies four techniques,i.e.Pearson correlation method,sequential forward selection(SFS),sequential backward selection(SBS)and Boruta algorithm,to investigate the effect of feature selection on the model’s performance when predicting the tunneling-induced maximum surface settlement(S_(max)).The data set used in this study was compiled from two metro tunnel projects excavated in Hangzhou,China using earth pressure balance(EPB)shields and consists of 14 input features and a single output(i.e.S_(max)).The ML model that is trained on features selected from the Boruta algorithm demonstrates the best performance in both the training and testing phases.The relevant features chosen from the Boruta algorithm further indicate that tunneling-induced settlement is affected by parameters related to tunnel geometry,geological conditions and shield operation.The recently proposed Shapley additive explanations(SHAP)method explores how the input features contribute to the output of a complex ML model.It is observed that the larger settlements are induced during shield tunneling in silty clay.Moreover,the SHAP analysis reveals that the low magnitudes of face pressure at the top of the shield increase the model’s output。
文摘AIM: To compare the short-term outcomes of patients who underwent proximal gastrectomy with jejunal interposition (PGJI) with those undergoing total gastrectomy with Roux-en-Y anastomosis (TGRY).
文摘M13 phage＇is a filamentous bacteriophage containing a circular single-stranded DNA molecular, which is surrounded by approximately 2 800 copies of protein PVIII. In addition, there are five copies of each of proteins PVII and PXI in one end, and five copies of each of proteins PVI and PUI on the other. These coat proteins have play an important role in the infection and assembly of M13 phage. With the development of phage display technology, these five coat proteins all can be used in phage display, which plays an increasingly important role in molecular detection and treatment.
基金supported by the National Natural Science Foundation of China(52077081)。
文摘In this paper, a novel signal processing method combining mathematical morphology (MM) and Walsh theory is proposed, which uses Walsh functions to control the structuring element (SE) and MM operators. Based on the Walsh-MM method, a scheme for power quality disturbances detection and classification is developed, which involves three steps: denoising, feature extraction and morphological clustering. First, various evolution rules of Walsh function are used to generate groups of SEs for the multiscale Walsh-ordered morphological operation, so the original signal can be denoised. Next, the fundamental wave of the denoised signal is suppressed by Hadamard matrix;thus, disturbances can be extracted. Finally, the Walsh power spectrum of the waveform extracted in the previous step is calculated, and the parameters of which are taken by morphological clustering to classify the disturbances. Simulation results reveal the proposed scheme can effectively detect and classify disturbances, and the Walsh-MM method is less affected by noise and only involves simple calculation, which has a potential to be implemented in hardware and more suitable for real-time application.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.52174101 and 52208380)the Department of Science and Technology of Guangdong Province,China(Grant No.2021ZT09G087)+4 种基金the Guangdong Basic and Applied Basic Research Foundation,China(Grant Nos.2023A1515030243,2023A1515011634)Zhuhai Basic and Applied Basic Research Foundation,China(Grant No.ZH22017003210005PWC)the open fund project of Key Laboratory of Safe Construction and Intelligent Maintenance for Urban Shield Tunnels of Zhejiang Province,China(Grant No.ZUCC-UST-22-03)General Research and Development Projects of Guangdong Provincial Communications Group Co.,Ltd.,China(Grant No.JT2022YB25)Highway Projects of Guangdong Provincial Development and Reform Commission,China(Grant No.2108-441400-04-01-637272).
文摘Soil-pipeline separation due to tunnelling has been certainly substantiated in previous model tests.However,this phenomenon has seldom been considered in current analytical solutions.This study formulates a tensionless Winkler solution that could make allowance for gap formation in soil-pipeline interaction analyses.The solution is validated by comparisons with existing experimental measurements and two recognized analytical solutions.Also,its advantage over an existing Winkler solution is addressed.Further parametric studies reveal that the effects of gap formation on the response of a pipeline rely largely on the tunnel volume loss and the pipeline’s bending stiffness and burial depth.In general,a pipeline’s bending moments and subgrade reaction forces are more susceptible than its deflections to the gap formation.
基金support provided by the National Natural Science Foundation of China under grant 52027808the High-level Talents Special Support Program of Zhejiang Province(No.2021R52011).
文摘The emergence of microhemispherical resonant gyroscopes,which integrate the advantages of exceptional stability and long lifetime with miniaturization,has afforded new possibilities for the development of whole-angle gyroscopes.However,existing methods used for manufacturing microhemispherical resonant gyroscopes based on MEMS technology face the primary drawback of intricate and costly processing.Here,we report the design,fabrication,and characterization of the first 3D-printable microhemispherical shell resonator for a Coriolis vibrating gyroscope.We remarkably achieve fabrication in just two steps bypassing the dozen or so steps required in traditional micromachining.By utilizing the intricate shaping capability and ultrahigh precision offered by projection microstereolithography,we fabricate 3D high-aspect-ratio resonant structures and controllable capacitive air gaps,both of which are extremely difficult to obtain via MEMS technology.In addition,the resonance frequency of the fabricated resonators can be tuned by electrostatic forces,and the fabricated resonators exhibit a higher quality factor in air than do typical MEMS microhemispherical resonators.This work demonstrates the feasibility of rapidly batch-manufacturing microhemispherical shell resonators,paving the way for the development of microhemispherical resonator gyroscopes for portable inertial navigation.Moreover,this particular design concept could be further applied to increase uptake of resonator tools in the MEMS community.
基金supported by the Major Program of Guangdong Basic and Applied Research(2019B030302006)the Laboratory of Lingnan Modern Agriculture Project(NT2021002)the National Natural Science Foundation of China(31921004)。
文摘Golden2(G2), a member of the GARP transcription factor superfamily, regulates several biological processes and phytohormone signaling pathways in plants. In this study, we used a rice codon-optimized maize G2 gene(rZmG2) to improve the regeneration efficiency of rice and maize calli for genetic transformation. We isolated a promoter driving strong and callus-specific expression from rice to drive rZmG2 transcription from a transgene after transformation of two indica and two japonica rice cultivars. The resulting rZmG2 transgenic calli turned green in advance at the differentiation stage, thus significantly raising the regeneration rates of the transgenic indica and japonica rice plants relative to control transformations. Similar effect of this gene on improving maize transformation was also observed. Transcriptome sequencing and RT-qPCR analyses showed that many rice genes related to chloroplast development and phytohormones are upregulated in rZmG2-transgenic calli. These results demonstrate that rZmG2 can promote embryogenic callus differentiation and improve regeneration efficiency by activating chloroplast development and phytohormone pathways. We also established a heat-inducible Cre/loxP-based gene-excision system to remove rZmG2 and the antibiotic selectable gene after obtaining the transgenic plants. This study provides a useful tool for functional genomics work and biotechnology in plants.
基金the Humanities and Social Sciences Research Project of Ministry of Education of China(No.23YJCZH037)the Educational Science Planning Project of Zhejiang Province(No.2023SCG222)+3 种基金the Foundation of the State Key Laboratory of Mountain Bridge and Tunnel Engi‐neering of China(No.SKLBT-2210)the National Key R&D Program of China(No.2022YFC3802301)the National Natural Science Foundation of China(No.52178306)the Scientific Research Project of Zhejiang Provincial Department of Educa-tion(No.Y202248682),China.
文摘As urbanization accelerates,the metro has become an important means of transportation.Considering the safety problems caused by metro construction,ground settlement needs to be monitored and predicted regularly,especially when a new metro line crosses an existing one.In this paper,we propose a settlement-probability prediction model with a Bayesian emulator(BE)based on the Gaussian prior(GP),that is,a GPBE.In addition,considering the distortion characteristics of monitoring data,the data is denoised using wavelet decomposition(WD),so the final prediction model is WD-GPBE.In particular,the effects of different prediction ratios and moving windows on prediction performance are explored,and the optimal number of moving windows is determined.In addition,the predicted value for GPBE based on the original data is compared with the predicted value for WD-GPBE based on the denoised data.One year of settlement-monitoring data collected by a structural health monitoring(SHM)system installed on the Nanjing Metro is used to demonstrate the effectiveness of WDGPBE and GPBE for predicting settlement.
基金supported by the National key R&D plan[grant no 2022YFF0802101]the National Natural Science Foundation of China[grant no 42171175]+1 种基金the Natural Science Foundation of Chongqing[grant no CSTB2022NSCQ-MSX0753]the Key Project of Innovation LREIS[grant no KPI001].
文摘Land surface temperature(LST),especially day-night LST difference(LSTd-LSTn),is a key variable for the stability of terrestrial ecosystems,affected by vegetation and climate change.Quantifying the contribution and feedback of vegetation and climate to LST changes is critical to developing mitigation strategies.Based on LST,Normalized vegetation index(NDVI),land use(LU),air temperature(AT)and precipitation(Pre)from 2003 to 2021,partial correlation was used to analyze the response of LST to vegetation and climate.The feedback and contribution of both to LST were further quantifed by using spatial linear relationships and partial derivatives analysis.The results showed that both interannual LST(LSTy)and LSTd-LSTn responded negatively to vegetation,and vegetation had a negative feedback effect in areas with significantly altered.Vegetation was also a major contributor to the decline of LSTd-LSTn.With the advantage of positive partial correlation area of 94.99%,AT became the main driving factor and contributor to LSTy change trend.Pre contributed negatively to both LSTy and LSTd-LSTn,with contributions of-0.004℃/y and-0.022℃/y,respectively.AT played a decisive role in LST warming of YRB,which was partially mitigated by vegetation and Pre.The present research contributed'to,the,detection,of LST changes and improved understanding of the driving mechanism.
基金supported by the National Natural Science Foundation of China(U2244216)the National key R&D plan(2022YFF0802101)+1 种基金the Fundamental Research Funds for the Central Universities(SWU-KT22009)the Key Project of Innovation LREIS(KPI001).
文摘In recent years,past changes in global and regional land surface temperatures(LST)have been well studied,however,future LST changes have been largely ignored owing to data limitations.In this study,three climate variables of CMIP6,namely air temperature(AT),precipitation(Pre),and leaf area index(LAl),were spatially corrected using the Delta downscaling method.On this basis,by combining MODIS LST,elevation,slope and aspect,a random forest(RF)model was built to calculate the LST from 2022 to 2100.The absolute variability(AV)and Mann-Kendall(M-K)tests were used to quantitatively detect interannual and seasonal LST changes in different Shared Socioeconomic Pathways(SSPs)scenarios.The results showed that the AV value increased successively from SSP1-2.6 to SSP2-4.5 and then to SSP5-8.5.Compared with the base period(2003-2021),the increment in interannual,spring,summer and autumn LST during 2022-2100 was mainly between 1 and 2°℃under threescenarios.The interannual and seasonal LST were spatially characterized by significant warming over large areas,and the increasing was the fastest under SSP5-8.5.These results indicate that,in the future,LST will increase further over large areas,especially in winter.
基金the National Key R&D Program of China(No.2019YFB1600700)the Science and Technology Development Fund of Macao(Nos.SKL-IOTSC-2018-2020 and 0193/2017/A3)the University of Macao Research Fund(No.MYRG2018-00173-FST),China。
文摘In this study,a machine learning method,i.e.genetic programming(GP),is employed to obtain a simplified statistical model to describe the variation of soil suction in drying cycles using five selected influential parameters.The data used for model development was recorded by an in-situ experiment.The image processing technology is used to quantify several tree canopy parameters.Based on four accuracy metrics,i.e.root mean square error(RMSE),mean absolute percentage error(MAPE),coefficient of determination(R2),and relative error,the performance of the proposed GP model was evaluated.The results indicate that the model can give a reasonable estimation for the spatiotemporal variations of soil suction around a tree with acceptable errors.Global sensitivity analysis for the statistical model obtained using limited data of a specific region demonstrates the drying time as the most influential variable and the initial soil suction as the second most influential variable for the soil suction variations.A case study was conducted using a set of assumed input variable values and validated that the simplified GP model can be used to estimate and predict the spatiotemporal variations of soil suction in rooted soil at a certain range.
基金supported by grants from the National Key Research and Development Program of China(2016YFD0100601)the National Natural Science Foundation of China(31772104,31771739,31600977)
文摘Accurate quantitative reverse transcription PCR(q RT-PCR)requires reliable reference genes whose expression does not vary in different tissues and developmental stages.However,few reliable reference genes are available for q RT-PCR in rice(Oryza sativa).Here,we established an effective strategy for identifying novel reference genes(NRGs)for reliable normalization of q RT-PCR data in various rice organs and developmental stages.We selected candidate NRGs using the Information Commons for Rice Database and confirmed their expression in Rice Expression Profile Database(Rice XPro)data.Genes with low variation(<2.5 cycle quantification)across tissues and developmental stages,and little fluctuation in expression in heatmaps from Rice XPro data were considered stable NRGs.To validate this strategy,we selected 11 candidate NRGs and calculated their expression stability in different spatio-temporal conditions using five programs,and compared these genes with five established reference genes(ERGs).Only one of the ERGs(UBQ5)was reliable and 10 of the candidate NRGs were more stable than the four remaining ERGs.Therefore,public transcriptomic databases are useful for identifying NRGs.We selected two NRGs,UFC1(Homolog of UFM1-Conjugating Enzyme 1)and Fha B(Homolog of Adhesin Fha B)for q RT-PCR analysis in rice;their homologs might be suitable for other monocot plants.
基金the financial support funded by The Science and Technology Development Fund,Macao SAR(File Nos.0057/2020/AGJ,SKLIOTSC-2021-2023)National Natural Science Foundation of China(Grant No.52022001)+2 种基金the University of Macao Research Fund(MYRG2018-00173-FST)Zhejiang Natural Science Foundation(LHZ20E080001)Zhejiang Province Key R&D Program Project(2020C01102).
文摘Surface settlements caused by twin tunneling are a major interest in underground space engineering.Most prevailing studies have investigated the surface settlements observed over twin tunnels constructed in clay.Yet,less attention is given to the twin tunnels exca-vated in silty sand,which is the focus of this study.A comprehensive field monitoring scheme was designed in the Hangzhou metro line six project to measure the surface settlements during twin tunneling by adopting earth pressure balance shields.The influence of four shield operational parameters,namely,face pressure,tail grouting pressure,penetration rate,and pitching angle on the surface settle-ments due to twin tunneling are explored.In general,the total settlement profiles observed over twin tunnels follow an inverted bimodal shape.The post-settlement observed over the 1^(st)tunnel due to the 2^(nd)tunnel excavation is non-trivial when the twin tunnels are spaced closely.Low face pressure and tail grouting pressure can induce excessive peak surface settlements during twin tunneling in silty sand.
基金by National Key Research and Development Program of China(2016YFC0500408)National Science and Technology Planning Project(41771120)+2 种基金Chongqing Innovation Support Plan Fund for Returned Overseas Chinese Scholars(CX2019023)a grant from State Key Laboratory of Resources and Environmental Information SystemAn open project programme of the Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions(GTYR201906).
文摘Aims Climate warming and agricultural non-point source pollution both resulting from anthropogenic activities have been projected to affect plant reproduction and growth in wetlands worldwide.In order to predict and mitigate impacts of these anthropogenic activities,it is important to investigate how marsh plants respond to such environmental changes.Methods In this study,Bolboschoenus planiculmis,a tuberous sedge with a wide distribution range in Eurasia,was selected to examine the effect of air temperature changes(15,20 and 25°C over 24 h;20/10 and 30/15°C,day/night)and K supply(0,1,3,9 and 18 mmol/L)on its reproductive and growth traits in climate chambers.Important Findings We found that high constant temperatures(20 and 25°C)were more beneficial for tuberization of B.planiculmis than high alternating temperatures(30/15°C),whereas aboveground biomass and shoot height were generally largest at high temperatures(30/15 and 25°C).Both reproductive and growth traits of B.planiculmis showed hump-shaped relationships with K supply,with an optimum K concentration of around 1–3 mmol/L.The combination of high constant temperatures and optimal K concentrations promoted reproductive traits the most,whereas the combination of higher temperatures(30/15 and 25°C)and K concentrations up to 9 mmol/L increased growth traits only.We therefore conclude that population abundance of B.planiculmis might benefit from global warming and the additional K supply.
基金This work was supported by National Science Foundation under Grant NSF 2009001.
文摘Anchor-based ad-hoc networks utilize hop measurements to generate a virtual coordinate system for topology inference and routing applications.A common problem with such coordinate system is its sensitivity to anchor placement.We present a general formulation to the anchor node selection problem.Then,we relax the optimization problem by deriving an upper-bound of the objective function.We finally propose an iterative algorithm that consists in choosing additional anchor nodes based on the connectivity information provided by the current anchor set.Numerical simulations indicate that our anchor selection method is robust to missing measurements and improves network topology inference and routing performance.
