This essay focused on comparing and contrasts audio lingual method and Task-based language teaching method,demonstrating the strengths and weaknesses of the two methods and discusses how they impact upon both the teac...This essay focused on comparing and contrasts audio lingual method and Task-based language teaching method,demonstrating the strengths and weaknesses of the two methods and discusses how they impact upon both the teachers and the learners.TBLT is the contemporary teaching method with a great number of strong points.It seems that if there is more relatively scientific and effective method,TBLT should give way to it.The ultimate goal is to advocate the comparatively successful teaching method in the field of foreign language education.展开更多
Photoacoustic(PA) imaging has drawn tremendous research interest for various applications in biomedicine and experienced exponential growth over the past decade. Since the scattering effect of biological tissue on ult...Photoacoustic(PA) imaging has drawn tremendous research interest for various applications in biomedicine and experienced exponential growth over the past decade. Since the scattering effect of biological tissue on ultrasound is two-to three-orders magnitude weaker than that of light, photoacoustic imaging can effectively improve the imaging depth.However, as the depth of imaging further increases, the incident light is seriously affected by scattering that the generated photoacoustic signal is very weak and the signal-to-noise ratio(SNR) is quite low. Low SNR signals can reduce imaging quality and even cause imaging failure. In this paper, we proposed a new wavefront shaping and imaging method of low SNR photoacoustic signal using digital micromirror device(DMD) based superpixel method. We combined the superpixel method with DMD to modulate the phase and amplitude of the incident light, and the genetic algorithm(GA) was used as the wavefront shaping algorithm. The enhancement of the photoacoustic signal reached 10.46. Then we performed scanning imaging by moving the absorber with the translation stage. A clear image with contrast of 8.57 was obtained while imaging with original photoacoustic signals could not be achieved. The proposed method opens new perspectives for imaging with weak photoacoustic signals.展开更多
As one of the most exciting inspection and powerful analysis methods in modern materials metallographic examinations, the difference interference contrast (DIC) method has many advantages, including relatively low req...As one of the most exciting inspection and powerful analysis methods in modern materials metallographic examinations, the difference interference contrast (DIC) method has many advantages, including relatively low requirement for specimen preparation, obvious relief senses observed under microscope. Details such as fine structures or defects that are not or barely visible in incident-light bright field, could be easily revealed and thus make materials analysis more reliable. Differential interference contrast produces an image that can be readily manipulated using digital and video imaging techniques to further enhance contrast. But, studies of material metallography based on DIC method have rarely carried out. Based on the fundamental principle of the DIC method combing with the computer image analysis, applications of DIC method in materials metallographic examination were investigated in this study.展开更多
Recent studies indicated that except for the land-sea thermal contrast,there also existed the land-land thermal contrast.The composite analysis and t-test method are used to further study the local thermal contrast va...Recent studies indicated that except for the land-sea thermal contrast,there also existed the land-land thermal contrast.The composite analysis and t-test method are used to further study the local thermal contrast variation over the Asian continent,and to discuss the association of seasonal variation of land thermal state with circulation over East Asia,the early summer and summer monsoon activity,and the precipitation anomaly in China in the decadal scale.Results show that the positive meridional temperature anomaly transports downward from upper tropospheric layers in middle-high latitudes north of 25°N in the positive years.In the zonal direction,the Tibetan Plateau heating in the successive spring acts as a force to influence the atmosphere,leading to the rapid temperature warming over eastern Chinese continent,which could increase the land-sea thermal contrast with the negative SSTA.Accordingly,the monsoon activity in early summer over East Asian establishes earlier and the summer monsoon intensity becomes stronger.The early summer precipitation is more-than-normal over the Yangtze River,and the summer precipitation is more-than-normal over the north China and the southwest China.The situation is contrary in the negative years.展开更多
输电线路的智能巡检视觉任务对电力系统的安全稳定至关重要。尽管深度学习网络在分布一致的训练和测试数据集上表现良好,但实际应用中数据分布的偏差常常会降低模型性能。为了解决这一问题,提出一种基于对比学习的训练方法(TMCL),旨在...输电线路的智能巡检视觉任务对电力系统的安全稳定至关重要。尽管深度学习网络在分布一致的训练和测试数据集上表现良好,但实际应用中数据分布的偏差常常会降低模型性能。为了解决这一问题,提出一种基于对比学习的训练方法(TMCL),旨在增强模型鲁棒性。首先,构建专为输电线路场景设计的基准测试集TLD-C(Transmission Line Dataset-Corruption)用于评估模型在面对图像损坏时的鲁棒性;其次,通过构建对类别特征敏感的正负样本对,提升模型对不同类别特征的区分能力;然后,使用结合对比损失和交叉熵损失的联合优化策略对特征提取过程施加额外约束,以优化特征向量的表征;最后,引入非局部特征去噪网络(NFD)用于提取与类别密切相关的特征。实验结果表明,模型改进后的训练方法在输电线路数据集(TLD)上的平均精度比原始方法高出3.40个百分点,在TLD-C数据集上的相对损坏精度(rCP)比原始方法高出4.69个百分点。展开更多
探讨不同激发方式在右心声学造影(agitated saline contrast echocardiography,ASCE)诊断卵圆孔未闭(patent foramen ovale,PFO)合并右向左分流(right to left shunt,RLS)中的作用。纳入2023年1月—2024年6月于川北医学院附属医院心内...探讨不同激发方式在右心声学造影(agitated saline contrast echocardiography,ASCE)诊断卵圆孔未闭(patent foramen ovale,PFO)合并右向左分流(right to left shunt,RLS)中的作用。纳入2023年1月—2024年6月于川北医学院附属医院心内科就诊的328例疑似PFO患者,采用咳嗽、改良蹲立动作、束臂试验及联合激发,以经食管超声(TEE)为金标准,比较不同方式的诊断效能。结果显示,束臂试验对中-大量RLS的检出率(45.8%)高于咳嗽(28.9%)和改良蹲立动作(35.4%);二阶法中咳嗽+束臂试验的检出率最高(52.1%),三阶法的检出率(54.3%)未显著提升但稳定性更佳;束臂试验及三阶法的AUC分别为0.842和0.891,显著优于单一激发。研究发现,束臂试验及联合激发可提高PFO-RLS检出率,推荐将其作为个体化联合方案以优化诊断效能。展开更多
文摘This essay focused on comparing and contrasts audio lingual method and Task-based language teaching method,demonstrating the strengths and weaknesses of the two methods and discusses how they impact upon both the teachers and the learners.TBLT is the contemporary teaching method with a great number of strong points.It seems that if there is more relatively scientific and effective method,TBLT should give way to it.The ultimate goal is to advocate the comparatively successful teaching method in the field of foreign language education.
基金Project supported by the National Key Research and Development Program of China(Grant No.2017YFB1104500)the Beijing Natural Science Foundation,China(Grant No.7182091)+1 种基金the National Natural Science Foundation of China(Grant No.21627813)the Research Projects on Biomedical Transformation of China–Japan Friendship Hospital(Grant No.PYBZ1801)。
文摘Photoacoustic(PA) imaging has drawn tremendous research interest for various applications in biomedicine and experienced exponential growth over the past decade. Since the scattering effect of biological tissue on ultrasound is two-to three-orders magnitude weaker than that of light, photoacoustic imaging can effectively improve the imaging depth.However, as the depth of imaging further increases, the incident light is seriously affected by scattering that the generated photoacoustic signal is very weak and the signal-to-noise ratio(SNR) is quite low. Low SNR signals can reduce imaging quality and even cause imaging failure. In this paper, we proposed a new wavefront shaping and imaging method of low SNR photoacoustic signal using digital micromirror device(DMD) based superpixel method. We combined the superpixel method with DMD to modulate the phase and amplitude of the incident light, and the genetic algorithm(GA) was used as the wavefront shaping algorithm. The enhancement of the photoacoustic signal reached 10.46. Then we performed scanning imaging by moving the absorber with the translation stage. A clear image with contrast of 8.57 was obtained while imaging with original photoacoustic signals could not be achieved. The proposed method opens new perspectives for imaging with weak photoacoustic signals.
文摘As one of the most exciting inspection and powerful analysis methods in modern materials metallographic examinations, the difference interference contrast (DIC) method has many advantages, including relatively low requirement for specimen preparation, obvious relief senses observed under microscope. Details such as fine structures or defects that are not or barely visible in incident-light bright field, could be easily revealed and thus make materials analysis more reliable. Differential interference contrast produces an image that can be readily manipulated using digital and video imaging techniques to further enhance contrast. But, studies of material metallography based on DIC method have rarely carried out. Based on the fundamental principle of the DIC method combing with the computer image analysis, applications of DIC method in materials metallographic examination were investigated in this study.
基金Natural Science Fund projects of China(40675045,41065004)NSFC-Yunnan Joint Foundation(U0833602)National Public Benefit Research Foundation of China(GYHY201206017)
文摘Recent studies indicated that except for the land-sea thermal contrast,there also existed the land-land thermal contrast.The composite analysis and t-test method are used to further study the local thermal contrast variation over the Asian continent,and to discuss the association of seasonal variation of land thermal state with circulation over East Asia,the early summer and summer monsoon activity,and the precipitation anomaly in China in the decadal scale.Results show that the positive meridional temperature anomaly transports downward from upper tropospheric layers in middle-high latitudes north of 25°N in the positive years.In the zonal direction,the Tibetan Plateau heating in the successive spring acts as a force to influence the atmosphere,leading to the rapid temperature warming over eastern Chinese continent,which could increase the land-sea thermal contrast with the negative SSTA.Accordingly,the monsoon activity in early summer over East Asian establishes earlier and the summer monsoon intensity becomes stronger.The early summer precipitation is more-than-normal over the Yangtze River,and the summer precipitation is more-than-normal over the north China and the southwest China.The situation is contrary in the negative years.
文摘输电线路的智能巡检视觉任务对电力系统的安全稳定至关重要。尽管深度学习网络在分布一致的训练和测试数据集上表现良好,但实际应用中数据分布的偏差常常会降低模型性能。为了解决这一问题,提出一种基于对比学习的训练方法(TMCL),旨在增强模型鲁棒性。首先,构建专为输电线路场景设计的基准测试集TLD-C(Transmission Line Dataset-Corruption)用于评估模型在面对图像损坏时的鲁棒性;其次,通过构建对类别特征敏感的正负样本对,提升模型对不同类别特征的区分能力;然后,使用结合对比损失和交叉熵损失的联合优化策略对特征提取过程施加额外约束,以优化特征向量的表征;最后,引入非局部特征去噪网络(NFD)用于提取与类别密切相关的特征。实验结果表明,模型改进后的训练方法在输电线路数据集(TLD)上的平均精度比原始方法高出3.40个百分点,在TLD-C数据集上的相对损坏精度(rCP)比原始方法高出4.69个百分点。
文摘探讨不同激发方式在右心声学造影(agitated saline contrast echocardiography,ASCE)诊断卵圆孔未闭(patent foramen ovale,PFO)合并右向左分流(right to left shunt,RLS)中的作用。纳入2023年1月—2024年6月于川北医学院附属医院心内科就诊的328例疑似PFO患者,采用咳嗽、改良蹲立动作、束臂试验及联合激发,以经食管超声(TEE)为金标准,比较不同方式的诊断效能。结果显示,束臂试验对中-大量RLS的检出率(45.8%)高于咳嗽(28.9%)和改良蹲立动作(35.4%);二阶法中咳嗽+束臂试验的检出率最高(52.1%),三阶法的检出率(54.3%)未显著提升但稳定性更佳;束臂试验及三阶法的AUC分别为0.842和0.891,显著优于单一激发。研究发现,束臂试验及联合激发可提高PFO-RLS检出率,推荐将其作为个体化联合方案以优化诊断效能。
