With the rapid growth of China's economic strength,the demand and market share are also constantly increasing.The number ofcars is rapidly increasing,and a large amount of fuel is consumed as a result.The massive ...With the rapid growth of China's economic strength,the demand and market share are also constantly increasing.The number ofcars is rapidly increasing,and a large amount of fuel is consumed as a result.The massive release of vehicle exhaust seriously damages the natural environment,and the environmental crisis is becoming increasingly serious.This article follows the principles of improving fuel efficiency,reducing emissions,andenhancing vehicle performance.Using NX 12.0 software,a three-dimensional model of a certain type of dump truck frame is constructed based on actual parameters.ANSYS Workbench is used to simplify the geometric model,mesh division,and material definition,and a finite element model is constructed.Obtain the structural performance and natural vibration characteristics of the original chassis under four typical working conditions:bending,torsion,lifting,and unloading,through static analysis and modal analysis.On this basis,the dimensions of the components that bear less load on the original frame were optimized,and the topology of the second crossbeam and rear end corner of the subframe that bear less load on the original frame was optimized to obtain a new frame.The new frame of the dump truck underwent secondary static analysis and modal analysis,and it was found that the weight of the new frame decreased by 41.03 kg,successfully reducing the weight of the frame by 4.38%,improving the vehicle's handling and stability,and extending its service life.展开更多
Coordination between the sporophytic tissue and the gametic pollen within anthers is tightly controlled to achieve the optimal pollen fitness. Glucose-6-phosphate/phosphate translocator(GPT) transports glucose-6-phosp...Coordination between the sporophytic tissue and the gametic pollen within anthers is tightly controlled to achieve the optimal pollen fitness. Glucose-6-phosphate/phosphate translocator(GPT) transports glucose-6-phosphate, a key precursor of starch and/or fatty acid biosynthesis, into plastids. Here, we report the functional characterization of Os GPT1 in the rice anther development and pollen fertility. Pollen grains from homozygous osgpt1 mutant plants fail to accumulate starch granules, resulting in pollen sterility. Genetic analyses reveal a sporophytic effect for this mutation. Os GPT1 is highly expressed in the tapetal layer of rice anther. Degeneration of the tapetum, an important process to provide cellular contents to support pollen development, is impeded in osgpt1 plants. In addition, defective intine and exine are observed in the pollen from osgpt1 plants. Expression levels of multiple genes that are important to tapetum degeneration or pollen wall formation are significantly decreased in osgpt1 anthers. Previously, we reported that At GPT1 plays a gametic function in the accumulation of lipid bodies in Arabidopsis pollen. This report highlights a sporophytic role of Os GPT1 in the tapetum degeneration and pollen development. The divergent functions of Os GPT1 and At GPT1 in pollen development might be a result of their independent evolution after monocots and dicots diverged.展开更多
Point cloud completion aims to infer complete point clouds based on partial 3D point cloud inputs.Various previous methods apply coarseto-fine strategy networks for generating complete point clouds.However,such method...Point cloud completion aims to infer complete point clouds based on partial 3D point cloud inputs.Various previous methods apply coarseto-fine strategy networks for generating complete point clouds.However,such methods are not only relatively time-consuming but also cannot provide representative complete shape features based on partial inputs.In this paper,a novel feature alignment fast point cloud completion network(FACNet)is proposed to directly and efficiently generate the detailed shapes of objects.FACNet aligns high-dimensional feature distributions of both partial and complete point clouds to maintain global information about the complete shape.During its decoding process,the local features from the partial point cloud are incorporated along with the maintained global information to ensure complete and time-saving generation of the complete point cloud.Experimental results show that FACNet outperforms the state-of-theart on PCN,Completion3D,and MVP datasets,and achieves competitive performance on ShapeNet-55 and KITTI datasets.Moreover,FACNet and a simplified version,FACNet-slight,achieve a significant speedup of 3–10 times over other state-of-the-art methods.展开更多
The mitotic activity of root apical meristem(RAM)is critical to primary root growth and development.Previous studies have identified the roles of ROOT GROWTH FACTOR 1(RGF1),a peptide ligand,and its receptors,RGF1 INSE...The mitotic activity of root apical meristem(RAM)is critical to primary root growth and development.Previous studies have identified the roles of ROOT GROWTH FACTOR 1(RGF1),a peptide ligand,and its receptors,RGF1 INSENSITIVEs(RGIs),a clade of five leucine-rich-repeat receptor-like kinases,in promoting cell division in the RAM,which determines the primary root length.However,the downstream signaling components remain elusive.In this study,we identify a complete mitogen-activated protein kinase(MAPK or MPK)cascade,composed of YDA,MKK4/MKK5,and MPK3/MPK6,that functions downstream of the RGF1-RGI ligand-receptor pair.Similar to the rgi1/2/3/4/5 quintuple mutant,loss-of-function mutants of MPK3 and MPK6,MKK4 and MKK5,or YDA show a short-root phenotype,which is associated with reduced mitotic activity and lower expression of PLETHORA 1(PLT1)/PLT2 in the RAM.Furthermore,MPK3/MPK6 activation in response to exogenous RGF1 treatment is impaired in the rgi1/2/3/4/5 quintuple,yda single,and mkk4 m kk5 double mutants.Epistatic analyses demonstrated that the expression of constitutively active MKK4,MKK5,or YDA driven by the RGI2 promoter can rescue the short-root phenotype of the rgi1/2/3/4/5 mutant.Taken together,these results suggest that the YDA-MKK4/MKK5-MPK3/MPK6 cascade functions downstream of the RGF1-RGI ligand-receptor pair and upstream of PLT1/PLT2 to modulate the stem cell population and primary root growth in Arabidopsis.展开更多
文摘With the rapid growth of China's economic strength,the demand and market share are also constantly increasing.The number ofcars is rapidly increasing,and a large amount of fuel is consumed as a result.The massive release of vehicle exhaust seriously damages the natural environment,and the environmental crisis is becoming increasingly serious.This article follows the principles of improving fuel efficiency,reducing emissions,andenhancing vehicle performance.Using NX 12.0 software,a three-dimensional model of a certain type of dump truck frame is constructed based on actual parameters.ANSYS Workbench is used to simplify the geometric model,mesh division,and material definition,and a finite element model is constructed.Obtain the structural performance and natural vibration characteristics of the original chassis under four typical working conditions:bending,torsion,lifting,and unloading,through static analysis and modal analysis.On this basis,the dimensions of the components that bear less load on the original frame were optimized,and the topology of the second crossbeam and rear end corner of the subframe that bear less load on the original frame was optimized to obtain a new frame.The new frame of the dump truck underwent secondary static analysis and modal analysis,and it was found that the weight of the new frame decreased by 41.03 kg,successfully reducing the weight of the frame by 4.38%,improving the vehicle's handling and stability,and extending its service life.
基金supported by the grants from National Natural Science Foundation of China (31922005)Zhejiang Provincial Natural Science Foundation of China (LR18C020001)+2 种基金Zhejiang University K.P.Chao’s High Technology Development Foundation (2018RC016)the Young Elite Scientist Sponsorship Program by CAST (2018QNRC001)111 Project (B14027) to J.X。
文摘Coordination between the sporophytic tissue and the gametic pollen within anthers is tightly controlled to achieve the optimal pollen fitness. Glucose-6-phosphate/phosphate translocator(GPT) transports glucose-6-phosphate, a key precursor of starch and/or fatty acid biosynthesis, into plastids. Here, we report the functional characterization of Os GPT1 in the rice anther development and pollen fertility. Pollen grains from homozygous osgpt1 mutant plants fail to accumulate starch granules, resulting in pollen sterility. Genetic analyses reveal a sporophytic effect for this mutation. Os GPT1 is highly expressed in the tapetal layer of rice anther. Degeneration of the tapetum, an important process to provide cellular contents to support pollen development, is impeded in osgpt1 plants. In addition, defective intine and exine are observed in the pollen from osgpt1 plants. Expression levels of multiple genes that are important to tapetum degeneration or pollen wall formation are significantly decreased in osgpt1 anthers. Previously, we reported that At GPT1 plays a gametic function in the accumulation of lipid bodies in Arabidopsis pollen. This report highlights a sporophytic role of Os GPT1 in the tapetum degeneration and pollen development. The divergent functions of Os GPT1 and At GPT1 in pollen development might be a result of their independent evolution after monocots and dicots diverged.
基金supported by the Zhuhai Industry-University-Research Project(No.2220004002411)National Key R&D Program of China(No.2021YFE0205700)+3 种基金Science and Technology Development Fund of Macao(Nos.0070/2020/AMJ,00123/2022/A3,and 0096/2023/RIA2)Zhuhai City Polytechnic Research Project(No.2024KYBS02)Shenzhen Science and Technology Innovation Committee(No.SGDX20220530111001006)the University of Macao under Grants MYRG(Nos.GRG2023-00061-FST UMDF and 2022-00084-FST)。
文摘Point cloud completion aims to infer complete point clouds based on partial 3D point cloud inputs.Various previous methods apply coarseto-fine strategy networks for generating complete point clouds.However,such methods are not only relatively time-consuming but also cannot provide representative complete shape features based on partial inputs.In this paper,a novel feature alignment fast point cloud completion network(FACNet)is proposed to directly and efficiently generate the detailed shapes of objects.FACNet aligns high-dimensional feature distributions of both partial and complete point clouds to maintain global information about the complete shape.During its decoding process,the local features from the partial point cloud are incorporated along with the maintained global information to ensure complete and time-saving generation of the complete point cloud.Experimental results show that FACNet outperforms the state-of-theart on PCN,Completion3D,and MVP datasets,and achieves competitive performance on ShapeNet-55 and KITTI datasets.Moreover,FACNet and a simplified version,FACNet-slight,achieve a significant speedup of 3–10 times over other state-of-the-art methods.
基金grants from the National Natural Science Foundation of China(31922005)the Natural Science Foundation of Zhejiang Province(LR18C020001)+1 种基金the Young Elite Scientist Sponsorship Program of China Association for Science and Technology(CAST)(2018QNRC001)111 Project(B14027)to J.X.
文摘The mitotic activity of root apical meristem(RAM)is critical to primary root growth and development.Previous studies have identified the roles of ROOT GROWTH FACTOR 1(RGF1),a peptide ligand,and its receptors,RGF1 INSENSITIVEs(RGIs),a clade of five leucine-rich-repeat receptor-like kinases,in promoting cell division in the RAM,which determines the primary root length.However,the downstream signaling components remain elusive.In this study,we identify a complete mitogen-activated protein kinase(MAPK or MPK)cascade,composed of YDA,MKK4/MKK5,and MPK3/MPK6,that functions downstream of the RGF1-RGI ligand-receptor pair.Similar to the rgi1/2/3/4/5 quintuple mutant,loss-of-function mutants of MPK3 and MPK6,MKK4 and MKK5,or YDA show a short-root phenotype,which is associated with reduced mitotic activity and lower expression of PLETHORA 1(PLT1)/PLT2 in the RAM.Furthermore,MPK3/MPK6 activation in response to exogenous RGF1 treatment is impaired in the rgi1/2/3/4/5 quintuple,yda single,and mkk4 m kk5 double mutants.Epistatic analyses demonstrated that the expression of constitutively active MKK4,MKK5,or YDA driven by the RGI2 promoter can rescue the short-root phenotype of the rgi1/2/3/4/5 mutant.Taken together,these results suggest that the YDA-MKK4/MKK5-MPK3/MPK6 cascade functions downstream of the RGF1-RGI ligand-receptor pair and upstream of PLT1/PLT2 to modulate the stem cell population and primary root growth in Arabidopsis.
