This paper expounds upon a novel target detection methodology distinguished by its elevated discriminatory efficacy,specifically tailored for environments characterized by markedly low luminance levels.Conventional me...This paper expounds upon a novel target detection methodology distinguished by its elevated discriminatory efficacy,specifically tailored for environments characterized by markedly low luminance levels.Conventional methodologies struggle with the challenges posed by luminosity fluctuations,especially in settings characterized by diminished radiance,further exacerbated by the utilization of suboptimal imaging instrumentation.The envisioned approach mandates a departure from the conventional YOLOX model,which exhibits inadequacies in mitigating these challenges.To enhance the efficacy of this approach in low-light conditions,the dehazing algorithm undergoes refinement,effecting a discerning regulation of the transmission rate at the pixel level,reducing it to values below 0.5,thereby resulting in an augmentation of image contrast.Subsequently,the coiflet wavelet transform is employed to discern and isolate high-discriminatory attributes by dismantling low-frequency image attributes and extracting high-frequency attributes across divergent axes.The utilization of CycleGAN serves to elevate the features of low-light imagery across an array of stylistic variances.Advanced computational methodologies are then employed to amalgamate and conflate intricate attributes originating from images characterized by distinct stylistic orientations,thereby augmenting the model’s erudition potential.Empirical validation conducted on the PASCAL VOC and MS COCO 2017 datasets substantiates pronounced advancements.The refined low-light enhancement algorithm yields a discernible 5.9%augmentation in the target detection evaluation index when compared to the original imagery.Mean Average Precision(mAP)undergoes enhancements of 9.45%and 0.052%in low-light visual renditions relative to conventional YOLOX outcomes.The envisaged approach presents a myriad of advantages over prevailing benchmark methodologies in the realm of target detection within environments marked by an acute scarcity of luminosity.展开更多
This study aims to improve the performances of the high-pressure water descaling technology used in steel hot rolling processes.In particular,a 2050 mm hot rolling line is considered,and the problem is investigated by...This study aims to improve the performances of the high-pressure water descaling technology used in steel hot rolling processes.In particular,a 2050 mm hot rolling line is considered,and the problem is investigated by means of a fluid–structure interaction(FSI)method by which the descaling effect produced by rolling coils with different section sizes is examined.Assuming a flat fan-shaped nozzle at the entrance of the R1R2 roughing mill,the outflow field characteristics and the velocity distribution curve on the strike line(at a target distance of 30–120 mm)are determined.It is found that the velocity in the center region of the water jet with different target distances is higher than that in the boundary region.As the target distance increases,the velocity of the water jet in the central region decreases.Through comparison with experimental results,it is shown that the simulation model can accurately predict the impact position of the high-pressure water on the impact plate,thereby providing a computational scheme that can be used to optimize the nozzle space layout and improve the slabs’descent effect for different rolling specifications.展开更多
A new proportional navigation(PN) guidance law,called combined proportional navigation(CPN),is proposed.The guidance law is designed to intercept high-speed targets,which is a common case for ballistic targets.The ran...A new proportional navigation(PN) guidance law,called combined proportional navigation(CPN),is proposed.The guidance law is designed to intercept high-speed targets,which is a common case for ballistic targets.The range of target-to-interceptor speed ratio during target interception is derived when guidance laws are applied in high-speed targets interception,and the effectiveness of negative navigation ratio in the PN-based guidance law is proven analytically in some lemmas.Based on the lemmas,the lateral acceleration command of CPN is defined,and the solution to the appearance of singularity in time-varying navigation ratio is given.The simulation results show that CPN can determine headon engagement(as PN) or tail-chase engagement(as RPN) through initial path angle compared with PN and retro proportional navigation(RPN),and can adjust the value of navigation ratio for head-on engagement or tail-chase engagement.Therefore,the capture region of CPN is larger than that of other guidance laws using PN-based methods.展开更多
BACKGROUND Mesenchymal stem cells(MSCs)are a type of stem cells that possess relevant regenerative abilities and can be used to treat many chronic diseases.Diabetes mellitus(DM)is a frequently diagnosed chronic diseas...BACKGROUND Mesenchymal stem cells(MSCs)are a type of stem cells that possess relevant regenerative abilities and can be used to treat many chronic diseases.Diabetes mellitus(DM)is a frequently diagnosed chronic disease characterized by hyperglycemia which initiates many multisystem complications in the long-run.DM patients can benefit from MSCs transplantation to curb down the pathological consequences associated with hyperglycemia persistence and restore the function of damaged tissues.MSCs therapeutic outcomes are found to last for short period of time and ultimately these regenerative cells are eradicated and died in DM disease model.AIM To investigate the impact of high glucose or hyperglycemia on the cellular and molecular characteristics of MSCs.METHODS Human adipose tissue-derived MSCs(hAD-MSCs)were seeded in low(5.6 mmol/L of glucose)and high glucose(25 mmol/L of glucose)for 7 d.Cytotoxicity,viability,mitochondrial dynamics,and apoptosis were deplored using specific kits.Western blotting was performed to measure the protein expression of phosphatidylinositol 3-kinase(PI3K),TSC1,and mammalian target of rapamycin(mTOR)in these cells.RESULTS hAD-MSCs cultured in high glucose for 7 d demonstrated marked decrease in their viability,as shown by a significant increase in lactate dehydrogenase(P<0.01)and a significant decrease in Trypan blue(P<0.05)in these cells compared to low glucose control.Mitochondrial membrane potential,indicated by tetramethylrhodamine ethyl ester(TMRE)fluorescence intensity,and nicotinamide adenine dinucleotide(NAD+)/NADH ratio were significantly dropped(P<0.05 for TMRE and P<0.01 for NAD+/NADH)in high glucose exposed hAD-MSCs,indicating disturbed mitochondrial function.PI3K protein expression significantly decreased in high glucose culture MSCs(P<0.05 compared to low glucose)and it was coupled with significant upregulation in TSC1(P<0.05)and downregulation in mTOR protein expression(P<0.05).Mitochondrial complexes I,IV,and V were downregulated profoundly in high glucose(P<0.05 compared to low glucose).Apoptosis was induced as a result of mitochondrial impairment and explained the poor survival of MSCs in high glucose.CONCLUSION High glucose impaired the mitochondrial dynamics and regulatory proteins in hAD-MSCs ensuing their poor survival and high apoptosis rate in hyperglycemic microenvironment.展开更多
A new guidance law, called biased retro proportional navigation(BRPN), is proposed. The guidance law is designed to intercept high-speed targets with angular constraint, which can be used for ballistic target intercep...A new guidance law, called biased retro proportional navigation(BRPN), is proposed. The guidance law is designed to intercept high-speed targets with angular constraint, which can be used for ballistic target interception. BRPN guidance law is defined, and the exact time-varying bias for a required impact angle is derived. Furthermore, the simulation results(trajectory, variation of navigation ratio, capture region, etc) are compared with those of biased proportional navigation(BPN), proportional navigation and retro-proportional navigation. The results show that,at the cost of a higher intercept time, BRPN demands lower terminal lateral acceleration and has larger capture region compared to BPN.展开更多
A new long term integration algorithm is proposed forhigh-dynamic targets, which can resolve the problems of spectrumspread, frequency walk and pseudorandom noise (PRN)code phase curvature caused by the motion of ta...A new long term integration algorithm is proposed forhigh-dynamic targets, which can resolve the problems of spectrumspread, frequency walk and pseudorandom noise (PRN)code phase curvature caused by the motion of targets. This algorithmfirst applies a keystone transform based improved discretepolynomial-phase transform (KT-IDPT) to estimate the Dopplerchirp rate. Then, based on the estimated Doppler chirp rate,dechirping and envelope translation are performed on the partialcorrelation results to correct the spectrum spread and the codephase curvature. The simulation results demonstrate that the proposedmethod has low integration loss and computational burden.展开更多
This article gives a brief introduction to manufacturers and markets of sputtering targets as well as the manufacturing technology thereof. Then, it analyzes the application of high-purity gold sputtering targets in t...This article gives a brief introduction to manufacturers and markets of sputtering targets as well as the manufacturing technology thereof. Then, it analyzes the application of high-purity gold sputtering targets in the fields of integrated circuit, information storage, flat panel display, etc. Based on the above, the article analyzes the processing development trend for the high-purity gold sputtering targets in aspects of ultra-high purity, manufacturing technology, analysis and testing technologies.展开更多
The summer western North Pacific subtropical high(WNPSH) has large influences on the East Asian summer climate. Many studies have focused on the projected changes in the WNPSH, but little is known about the changes un...The summer western North Pacific subtropical high(WNPSH) has large influences on the East Asian summer climate. Many studies have focused on the projected changes in the WNPSH, but little is known about the changes under different global warming targets, such as 1.5℃ and 2.0℃. This study investigates the changes in the WNPSH under six global warming targets(1.5℃, 2.0℃, 2.5℃,3.0℃, 3.5℃, and 4.0℃) in both the mid-and lower troposphere, using the outputs of CMIP5 model in historical simulations and under Representative Concentration Pathway 8.5. The projected changes in the WNPSH, which is measured by multiple variables, show that it changes little under the 1.5℃ target in the mid-troposphere, but weakens and retreats approximately 2.5° in longitude under the 2.0℃ target. It tends to linearly weaken with warming greater than 2.5℃ and shifts eastward by approximately 6.0° in longitude by the 4.0℃ target. Meanwhile, the WNPSH intensifies and extends westward under the 1.5℃ target in the lower troposphere, but changes little with warming rising from 1.5℃ to 2.0℃. It is projected to extend westward by approximately2.0° in longitude by the 4.0℃ target.展开更多
The paper first discusses shortcomings of classical adjacent-frame difference. Sec ondly, based on the image energy and high order statistic(HOS) theory, background reconstruction constraints are setup. Under the help...The paper first discusses shortcomings of classical adjacent-frame difference. Sec ondly, based on the image energy and high order statistic(HOS) theory, background reconstruction constraints are setup. Under the help of block-processing technology, background is reconstructed quickly. Finally, background difference is used to detect motion regions instead of adjacent frame difference. The DSP based platform tests indicate the background can be recovered losslessly in about one second, and moving regions are not influenced by moving target speeds. The algorithm has important usage both in theory and applications.展开更多
Interaction between high-intensity pulsed ion beam (HIPIB) and a double-layer target with titanium film on top of aluminum substrate was simulated. The two-dimensional nonlinear thermal conduction equations, with th...Interaction between high-intensity pulsed ion beam (HIPIB) and a double-layer target with titanium film on top of aluminum substrate was simulated. The two-dimensional nonlinear thermal conduction equations, with the deposited energy in the target taken as source term, were derived and solved by finite differential method. As a result, the two-dimensional spatial and temporal evolution profiles of temperature were obtained for a titanium/aluminum double-layer target irradiated by a pulse of HIPIB. The effects of ion beam current density on the phase state of the target materials near the film and substrate interface were analyzed. Both titanium and aluminum were melted near the interface after a shot when the ion beam current density fell in the range of 100 A/cm2 to 200 A/cm2.展开更多
目标高分辨一维距离像(High Resolution Range Profile,HRRP)中包含了丰富的目标尺寸、结构等目标特征,是进行空间目标身份识别的有效途径。但由于卫星宽带雷达实测数据获取难度大,前期相关研究多集中于基于HRRP的目标识别算法,结论也...目标高分辨一维距离像(High Resolution Range Profile,HRRP)中包含了丰富的目标尺寸、结构等目标特征,是进行空间目标身份识别的有效途径。但由于卫星宽带雷达实测数据获取难度大,前期相关研究多集中于基于HRRP的目标识别算法,结论也多是基于仿真数据和少量类别(几类)的前提下得到的,与工程应用实际情况有较大差距,工程指导意义有限。为解决这一问题,基于地基雷达获取的30类卫星目标的大量一维距离像实测数据,从识别正确率的角度对目标HRRP及其特征(组合)的可分性和在空间目标个体识别中的应用效果进行了量化分析,分析结果可为后续基于HRRP的空间目标个体识别技术研究和工程应用提供可靠依据。展开更多
以高耐热玉米品种郑单958、低耐热玉米品种先玉335为材料,以正常生长条件为对照,在花期进行高温胁迫,通过miRNA高通量测序筛选玉米花粉中的差异表达miRNA,然后预测其靶基因,并对靶基因的本体特征和代谢通路进行富集分析。结果表明,共筛...以高耐热玉米品种郑单958、低耐热玉米品种先玉335为材料,以正常生长条件为对照,在花期进行高温胁迫,通过miRNA高通量测序筛选玉米花粉中的差异表达miRNA,然后预测其靶基因,并对靶基因的本体特征和代谢通路进行富集分析。结果表明,共筛选到818个miRNA前体序列。在郑单958高温胁迫花粉与对照花粉对比组(HT958 vs CK958)中共筛选到19个显著差异表达miRNA序列,其中15个miRNA序列上调表达,4个下调表达,3个miRNA序列达到极显著水平(P<0.01)。对这19个显著差异表达miRNA的靶基因进行预测,共获得了503个基因转录本,其富集较多的GO生物学过程条目分别为转录调控DNA-模板、微管生物学过程、磷酸化作用、RNA聚合酶Ⅱ正向调控转录过程、甲基化作用等,KEGG富集较显著的代谢通路分别是谷胱甘肽代谢、碳代谢、花生四烯酸代谢、糖酵解/糖异生、叶酸生物合成等。在先玉335高温胁迫花粉与对照花粉对比组(HT335 vs CK335)中共筛选到15个显著差异表达miRNA序列,其中7个miRNA序列上调表达,8个下调表达,1个miRNA序列达到了极显著水平(P<0.01)。对这15个显著差异表达miRNA的靶基因进行预测,共获得了454个基因转录本,其富集较多的GO生物学过程条目分别为转录调控DNA-模板、磷酸化作用、蛋白质磷酸化作用、蛋白质水解、DNA修复等,富集较显著的KEGG代谢通路分别是其他多糖降解、亚油酸代谢、代谢通路、硫胺素代谢、内质网内蛋白质加工过程等。在郑单958高温胁迫花粉与先玉335高温胁迫花粉对比组(HT985 vs HT335)中共筛选到85个显著差异表达miRNA序列,其中35个miRNA序列为上调表达,50个为下调表达,24个miRNA序列达到了极显著水平(P<0.01)。对这85个显著差异表达miRNA的靶基因进行预测,共获得了2 286个基因转录本,其富集较多的GO生物学过程条目分别为转录调控DNA-模板、磷酸化作用、蛋白质磷酸化、蛋白质水解、跨膜转运等,富集较显著的代谢通路分别是鞘脂类代谢、淀粉和蔗糖代谢、其他多糖降解、代谢通路、半胱氨酸及甲硫氨酸代谢等。在HT958 vs CK958与HT335 vs CK335对比组中共筛选到94个显著差异表达miRNA序列,其中(预测全新)PC-3p-10069_1143、(预测全新)PC-3p-18335_646、(玉米)zma-miR164f-5p等28个miRNA序列达到了极显著水平(P<0.01)。对这94个显著差异表达miRNA的靶基因进行预测,共获得了4 569个基因转录本,其富集较多的GO生物学过程条目分别为转录调控DNA-模板、磷酸化作用、蛋白质磷酸化、蛋白质转运、蛋白质水解等,其富集较显著的KEGG代谢通路分别是内质网内蛋白质加工过程、真核生物核糖体生物合成、剪接体、鞘脂类代谢、内吞作用等。展开更多
基金supported by National Sciences Foundation of China Grants(No.61902158).
文摘This paper expounds upon a novel target detection methodology distinguished by its elevated discriminatory efficacy,specifically tailored for environments characterized by markedly low luminance levels.Conventional methodologies struggle with the challenges posed by luminosity fluctuations,especially in settings characterized by diminished radiance,further exacerbated by the utilization of suboptimal imaging instrumentation.The envisioned approach mandates a departure from the conventional YOLOX model,which exhibits inadequacies in mitigating these challenges.To enhance the efficacy of this approach in low-light conditions,the dehazing algorithm undergoes refinement,effecting a discerning regulation of the transmission rate at the pixel level,reducing it to values below 0.5,thereby resulting in an augmentation of image contrast.Subsequently,the coiflet wavelet transform is employed to discern and isolate high-discriminatory attributes by dismantling low-frequency image attributes and extracting high-frequency attributes across divergent axes.The utilization of CycleGAN serves to elevate the features of low-light imagery across an array of stylistic variances.Advanced computational methodologies are then employed to amalgamate and conflate intricate attributes originating from images characterized by distinct stylistic orientations,thereby augmenting the model’s erudition potential.Empirical validation conducted on the PASCAL VOC and MS COCO 2017 datasets substantiates pronounced advancements.The refined low-light enhancement algorithm yields a discernible 5.9%augmentation in the target detection evaluation index when compared to the original imagery.Mean Average Precision(mAP)undergoes enhancements of 9.45%and 0.052%in low-light visual renditions relative to conventional YOLOX outcomes.The envisaged approach presents a myriad of advantages over prevailing benchmark methodologies in the realm of target detection within environments marked by an acute scarcity of luminosity.
基金The research was funded by Science and Technology Project of Hebei Education Department(Project Number:QN2022198).Y.C.received the grant.
文摘This study aims to improve the performances of the high-pressure water descaling technology used in steel hot rolling processes.In particular,a 2050 mm hot rolling line is considered,and the problem is investigated by means of a fluid–structure interaction(FSI)method by which the descaling effect produced by rolling coils with different section sizes is examined.Assuming a flat fan-shaped nozzle at the entrance of the R1R2 roughing mill,the outflow field characteristics and the velocity distribution curve on the strike line(at a target distance of 30–120 mm)are determined.It is found that the velocity in the center region of the water jet with different target distances is higher than that in the boundary region.As the target distance increases,the velocity of the water jet in the central region decreases.Through comparison with experimental results,it is shown that the simulation model can accurately predict the impact position of the high-pressure water on the impact plate,thereby providing a computational scheme that can be used to optimize the nozzle space layout and improve the slabs’descent effect for different rolling specifications.
文摘A new proportional navigation(PN) guidance law,called combined proportional navigation(CPN),is proposed.The guidance law is designed to intercept high-speed targets,which is a common case for ballistic targets.The range of target-to-interceptor speed ratio during target interception is derived when guidance laws are applied in high-speed targets interception,and the effectiveness of negative navigation ratio in the PN-based guidance law is proven analytically in some lemmas.Based on the lemmas,the lateral acceleration command of CPN is defined,and the solution to the appearance of singularity in time-varying navigation ratio is given.The simulation results show that CPN can determine headon engagement(as PN) or tail-chase engagement(as RPN) through initial path angle compared with PN and retro proportional navigation(RPN),and can adjust the value of navigation ratio for head-on engagement or tail-chase engagement.Therefore,the capture region of CPN is larger than that of other guidance laws using PN-based methods.
文摘BACKGROUND Mesenchymal stem cells(MSCs)are a type of stem cells that possess relevant regenerative abilities and can be used to treat many chronic diseases.Diabetes mellitus(DM)is a frequently diagnosed chronic disease characterized by hyperglycemia which initiates many multisystem complications in the long-run.DM patients can benefit from MSCs transplantation to curb down the pathological consequences associated with hyperglycemia persistence and restore the function of damaged tissues.MSCs therapeutic outcomes are found to last for short period of time and ultimately these regenerative cells are eradicated and died in DM disease model.AIM To investigate the impact of high glucose or hyperglycemia on the cellular and molecular characteristics of MSCs.METHODS Human adipose tissue-derived MSCs(hAD-MSCs)were seeded in low(5.6 mmol/L of glucose)and high glucose(25 mmol/L of glucose)for 7 d.Cytotoxicity,viability,mitochondrial dynamics,and apoptosis were deplored using specific kits.Western blotting was performed to measure the protein expression of phosphatidylinositol 3-kinase(PI3K),TSC1,and mammalian target of rapamycin(mTOR)in these cells.RESULTS hAD-MSCs cultured in high glucose for 7 d demonstrated marked decrease in their viability,as shown by a significant increase in lactate dehydrogenase(P<0.01)and a significant decrease in Trypan blue(P<0.05)in these cells compared to low glucose control.Mitochondrial membrane potential,indicated by tetramethylrhodamine ethyl ester(TMRE)fluorescence intensity,and nicotinamide adenine dinucleotide(NAD+)/NADH ratio were significantly dropped(P<0.05 for TMRE and P<0.01 for NAD+/NADH)in high glucose exposed hAD-MSCs,indicating disturbed mitochondrial function.PI3K protein expression significantly decreased in high glucose culture MSCs(P<0.05 compared to low glucose)and it was coupled with significant upregulation in TSC1(P<0.05)and downregulation in mTOR protein expression(P<0.05).Mitochondrial complexes I,IV,and V were downregulated profoundly in high glucose(P<0.05 compared to low glucose).Apoptosis was induced as a result of mitochondrial impairment and explained the poor survival of MSCs in high glucose.CONCLUSION High glucose impaired the mitochondrial dynamics and regulatory proteins in hAD-MSCs ensuing their poor survival and high apoptosis rate in hyperglycemic microenvironment.
文摘A new guidance law, called biased retro proportional navigation(BRPN), is proposed. The guidance law is designed to intercept high-speed targets with angular constraint, which can be used for ballistic target interception. BRPN guidance law is defined, and the exact time-varying bias for a required impact angle is derived. Furthermore, the simulation results(trajectory, variation of navigation ratio, capture region, etc) are compared with those of biased proportional navigation(BPN), proportional navigation and retro-proportional navigation. The results show that,at the cost of a higher intercept time, BRPN demands lower terminal lateral acceleration and has larger capture region compared to BPN.
基金supported by the Beijing Natural Science Foundation(4164097)the Chinese Postdoctoral Science Foundation(2016M591226)
文摘A new long term integration algorithm is proposed forhigh-dynamic targets, which can resolve the problems of spectrumspread, frequency walk and pseudorandom noise (PRN)code phase curvature caused by the motion of targets. This algorithmfirst applies a keystone transform based improved discretepolynomial-phase transform (KT-IDPT) to estimate the Dopplerchirp rate. Then, based on the estimated Doppler chirp rate,dechirping and envelope translation are performed on the partialcorrelation results to correct the spectrum spread and the codephase curvature. The simulation results demonstrate that the proposedmethod has low integration loss and computational burden.
基金National key technology support program(2012BAE06B05)
文摘This article gives a brief introduction to manufacturers and markets of sputtering targets as well as the manufacturing technology thereof. Then, it analyzes the application of high-purity gold sputtering targets in the fields of integrated circuit, information storage, flat panel display, etc. Based on the above, the article analyzes the processing development trend for the high-purity gold sputtering targets in aspects of ultra-high purity, manufacturing technology, analysis and testing technologies.
基金This research was supported by the National Key R&D Program of China[grant number 2017YFA0603802]the Strategic Priority Research Program of the Chinese Academy of Sciences[grant number XDA2006040102]the National Natural Science Foundation of China[grant number 41675084].
文摘The summer western North Pacific subtropical high(WNPSH) has large influences on the East Asian summer climate. Many studies have focused on the projected changes in the WNPSH, but little is known about the changes under different global warming targets, such as 1.5℃ and 2.0℃. This study investigates the changes in the WNPSH under six global warming targets(1.5℃, 2.0℃, 2.5℃,3.0℃, 3.5℃, and 4.0℃) in both the mid-and lower troposphere, using the outputs of CMIP5 model in historical simulations and under Representative Concentration Pathway 8.5. The projected changes in the WNPSH, which is measured by multiple variables, show that it changes little under the 1.5℃ target in the mid-troposphere, but weakens and retreats approximately 2.5° in longitude under the 2.0℃ target. It tends to linearly weaken with warming greater than 2.5℃ and shifts eastward by approximately 6.0° in longitude by the 4.0℃ target. Meanwhile, the WNPSH intensifies and extends westward under the 1.5℃ target in the lower troposphere, but changes little with warming rising from 1.5℃ to 2.0℃. It is projected to extend westward by approximately2.0° in longitude by the 4.0℃ target.
文摘The paper first discusses shortcomings of classical adjacent-frame difference. Sec ondly, based on the image energy and high order statistic(HOS) theory, background reconstruction constraints are setup. Under the help of block-processing technology, background is reconstructed quickly. Finally, background difference is used to detect motion regions instead of adjacent frame difference. The DSP based platform tests indicate the background can be recovered losslessly in about one second, and moving regions are not influenced by moving target speeds. The algorithm has important usage both in theory and applications.
基金supported by National Natural Science Foundation of China (No.10975026)
文摘Interaction between high-intensity pulsed ion beam (HIPIB) and a double-layer target with titanium film on top of aluminum substrate was simulated. The two-dimensional nonlinear thermal conduction equations, with the deposited energy in the target taken as source term, were derived and solved by finite differential method. As a result, the two-dimensional spatial and temporal evolution profiles of temperature were obtained for a titanium/aluminum double-layer target irradiated by a pulse of HIPIB. The effects of ion beam current density on the phase state of the target materials near the film and substrate interface were analyzed. Both titanium and aluminum were melted near the interface after a shot when the ion beam current density fell in the range of 100 A/cm2 to 200 A/cm2.
文摘目标高分辨一维距离像(High Resolution Range Profile,HRRP)中包含了丰富的目标尺寸、结构等目标特征,是进行空间目标身份识别的有效途径。但由于卫星宽带雷达实测数据获取难度大,前期相关研究多集中于基于HRRP的目标识别算法,结论也多是基于仿真数据和少量类别(几类)的前提下得到的,与工程应用实际情况有较大差距,工程指导意义有限。为解决这一问题,基于地基雷达获取的30类卫星目标的大量一维距离像实测数据,从识别正确率的角度对目标HRRP及其特征(组合)的可分性和在空间目标个体识别中的应用效果进行了量化分析,分析结果可为后续基于HRRP的空间目标个体识别技术研究和工程应用提供可靠依据。
文摘以高耐热玉米品种郑单958、低耐热玉米品种先玉335为材料,以正常生长条件为对照,在花期进行高温胁迫,通过miRNA高通量测序筛选玉米花粉中的差异表达miRNA,然后预测其靶基因,并对靶基因的本体特征和代谢通路进行富集分析。结果表明,共筛选到818个miRNA前体序列。在郑单958高温胁迫花粉与对照花粉对比组(HT958 vs CK958)中共筛选到19个显著差异表达miRNA序列,其中15个miRNA序列上调表达,4个下调表达,3个miRNA序列达到极显著水平(P<0.01)。对这19个显著差异表达miRNA的靶基因进行预测,共获得了503个基因转录本,其富集较多的GO生物学过程条目分别为转录调控DNA-模板、微管生物学过程、磷酸化作用、RNA聚合酶Ⅱ正向调控转录过程、甲基化作用等,KEGG富集较显著的代谢通路分别是谷胱甘肽代谢、碳代谢、花生四烯酸代谢、糖酵解/糖异生、叶酸生物合成等。在先玉335高温胁迫花粉与对照花粉对比组(HT335 vs CK335)中共筛选到15个显著差异表达miRNA序列,其中7个miRNA序列上调表达,8个下调表达,1个miRNA序列达到了极显著水平(P<0.01)。对这15个显著差异表达miRNA的靶基因进行预测,共获得了454个基因转录本,其富集较多的GO生物学过程条目分别为转录调控DNA-模板、磷酸化作用、蛋白质磷酸化作用、蛋白质水解、DNA修复等,富集较显著的KEGG代谢通路分别是其他多糖降解、亚油酸代谢、代谢通路、硫胺素代谢、内质网内蛋白质加工过程等。在郑单958高温胁迫花粉与先玉335高温胁迫花粉对比组(HT985 vs HT335)中共筛选到85个显著差异表达miRNA序列,其中35个miRNA序列为上调表达,50个为下调表达,24个miRNA序列达到了极显著水平(P<0.01)。对这85个显著差异表达miRNA的靶基因进行预测,共获得了2 286个基因转录本,其富集较多的GO生物学过程条目分别为转录调控DNA-模板、磷酸化作用、蛋白质磷酸化、蛋白质水解、跨膜转运等,富集较显著的代谢通路分别是鞘脂类代谢、淀粉和蔗糖代谢、其他多糖降解、代谢通路、半胱氨酸及甲硫氨酸代谢等。在HT958 vs CK958与HT335 vs CK335对比组中共筛选到94个显著差异表达miRNA序列,其中(预测全新)PC-3p-10069_1143、(预测全新)PC-3p-18335_646、(玉米)zma-miR164f-5p等28个miRNA序列达到了极显著水平(P<0.01)。对这94个显著差异表达miRNA的靶基因进行预测,共获得了4 569个基因转录本,其富集较多的GO生物学过程条目分别为转录调控DNA-模板、磷酸化作用、蛋白质磷酸化、蛋白质转运、蛋白质水解等,其富集较显著的KEGG代谢通路分别是内质网内蛋白质加工过程、真核生物核糖体生物合成、剪接体、鞘脂类代谢、内吞作用等。