期刊文献+
共找到158篇文章
< 1 2 8 >
每页显示 20 50 100
正弦交流电絮凝处理含锌电镀废水的研究
1
作者 周益辉 易师 +1 位作者 雷细平 徐涛 《电镀与涂饰》 CAS 北大核心 2024年第1期136-143,共8页
[目的]电镀废水中的Zn^(2+)污染控制是当前重要的工业水环境技术问题。[方法]采用正弦交流电絮凝技术和自制的电絮凝装置从废水中除去Zn^(2+)。采用数值模拟的研究方法对电絮凝装置进行了流场分析,并通过实验研究了溶液初始pH、电流密... [目的]电镀废水中的Zn^(2+)污染控制是当前重要的工业水环境技术问题。[方法]采用正弦交流电絮凝技术和自制的电絮凝装置从废水中除去Zn^(2+)。采用数值模拟的研究方法对电絮凝装置进行了流场分析,并通过实验研究了溶液初始pH、电流密度、初始锌离子浓度、反应时间等因素对去除Zn^(2+)的影响,使用响应面优化方案的Box-Behnken设计获得Zn^(2+)最高去除效率的最佳工艺参数。[结果]钛篮孔板大于3层有利于实现电絮凝装置流场均匀分布;在pH=9、含120 mg/dm^(3)Zn^(2+)的模拟废水溶液中,施加电流密度为0.31 A/m2、频率为50 Hz正弦交流电,通电21.3 min,Zn^(2+)的去除率可达到98.80%。[结论]响应面优化可用于正弦交流电絮凝处理含Zn^(2+)废水的过程。 展开更多
关键词 含锌电镀废水 正弦交流电絮凝 响应面优化 装置 数值模拟
下载PDF
Morphological disruption and visual tuning alterations in the primary visual cortex in glaucoma(DBA/2J)mice
2
作者 yin Yang Zhaoxi Yang +9 位作者 Maoxia Lv Ang Jia Junjun Li Baitao Liao Jing’an Chen Zhengzheng Wu yi shi Yang Xia Dezhong Yao Ke Chen 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第1期220-225,共6页
Glaucoma is a leading cause of irreve rsible blindness wo rldwide,and previous studies have shown that,in addition to affecting the eyes,it also causes abnormalities in the brain.However,it is not yet clear how the pr... Glaucoma is a leading cause of irreve rsible blindness wo rldwide,and previous studies have shown that,in addition to affecting the eyes,it also causes abnormalities in the brain.However,it is not yet clear how the primary visual cortex(V1)is altered in glaucoma.This study used DBA/2J mice as a model for spontaneous secondary glaucoma.The aim of the study was to compare the electrophysiological and histomorphological chara cteristics of neurons in the V1between 9-month-old DBA/2J mice and age-matched C57BL/6J mice.We conducted single-unit recordings in the V1 of light-anesthetized mice to measure the visually induced responses,including single-unit spiking and gamma band oscillations.The morphology of layerⅡ/Ⅲneurons was determined by neuronal nuclear antigen staining and Nissl staining of brain tissue sections.Eighty-seven neurons from eight DBA/2J mice and eighty-one neurons from eight C57BL/6J mice were examined.Compared with the C57BL/6J group,V1 neurons in the DBA/2J group exhibited weaker visual tuning and impaired spatial summation.Moreove r,fewer neuro ns were observed in the V1 of DBA/2J mice compared with C57BL/6J mice.These findings suggest that DBA/2J mice have fewer neurons in the VI compared with C57BL/6J mice,and that these neurons have impaired visual tuning.Our findings provide a better understanding of the pathological changes that occur in V1 neuron function and morphology in the DBA/2J mouse model.This study might offer some innovative perspectives regarding the treatment of glaucoma. 展开更多
关键词 DBA/2J DEGENERATION gamma band oscillations GLAUCOMA primary visual cortex(V1) RETINA single-unit recording tuning curve
下载PDF
大型船舶制造涂装废气治理组合工艺和装备设计
3
作者 易师 周益辉 +1 位作者 雷细平 何曦 《电镀与涂饰》 CAS 北大核心 2024年第3期157-162,共6页
[目的]大型船舶制造涂装废气成分复杂、污染物浓度高、排放风量大,同时含有漆雾、粉尘和挥发性有机物(VOCs)。[方法]根据大型船舶制造涂装废气的排放特征,提出了一套“分级分质漆雾净化+沸石分子筛转筒+蓄热式热力氧化”的组合式治理工... [目的]大型船舶制造涂装废气成分复杂、污染物浓度高、排放风量大,同时含有漆雾、粉尘和挥发性有机物(VOCs)。[方法]根据大型船舶制造涂装废气的排放特征,提出了一套“分级分质漆雾净化+沸石分子筛转筒+蓄热式热力氧化”的组合式治理工艺,分别阐述了各主要部分的设计原理、结构组成、关键参数和工程应用。[结果]该工艺可实现涂装废气中污染物的高效分离净化,废气在处理后能连续稳定地达到排放标准。[结论]单一处理方法无法实现大型船舶制造涂装废气的有效治理,经济高效的组合工艺和装备可有效降低处理成本,提高治理效率。 展开更多
关键词 船舶制造 涂装 废气 挥发性有机物 预处理 沸石分子筛转筒 蓄热式热力氧化
下载PDF
基于融合式PC-ORB的异源图像配准算法
4
作者 伍朗 易诗 +1 位作者 陈梦婷 李立 《红外技术》 CSCD 北大核心 2024年第4期419-426,共8页
异源图像配准中,由于图像的成像机理差异,图像像素强度关联和旋转畸变是不可避免的两大问题,针对图像像素强度关联问题,提出了基于辐射不变特征变换(radiation-variation insensitive feature transform,RIFT)的图像配准算法,对图像间... 异源图像配准中,由于图像的成像机理差异,图像像素强度关联和旋转畸变是不可避免的两大问题,针对图像像素强度关联问题,提出了基于辐射不变特征变换(radiation-variation insensitive feature transform,RIFT)的图像配准算法,对图像间像素关联差异小的图像对配准有良好的精度,但对旋转畸变图像会产生较多错误匹配。对于旋转畸变问题,传统的ORB(oriented fast and rotated brief)算法,对旋转图像的配准有一定的稳定性,但对于强度变化不明显的图像对,特征点检测质量较低,配准精度不理想。因此本文将相位一致性(phase consistency,PC)融合进ORB算法,利用相位信息代替传统的图像强度信息,再构造旋转不变性BRIEF特征描述子,对图像像素强度变化和旋转畸变均具有鲁棒性。用图像像素强度关联不明显的红外图像和可见光图像进行配准实验,本文算法针对不同旋转幅度的图像的配准精度较高,RMSE稳定在1.7~2.1,优于RIFT算法,在特征点检测数量、配准精度和效率等性能上均有良好性能。 展开更多
关键词 图像配准 特征匹配 相位一致性 旋转不变性 ORB算法
下载PDF
Construction and validation of a neovascular glaucoma nomogram in patients with diabetic retinopathy after pars plana vitrectomy
5
作者 yi shi Yan-Xin Zhang +4 位作者 Ming-Fei Jiao Xin-Jun Ren Bo-Jie Hu Ai-Hua Liu Xiao-Rong Li 《World Journal of Diabetes》 SCIE 2024年第4期654-663,共10页
BACKGROUND Neovascular glaucoma(NVG)is likely to occur after pars plana vitrectomy(PPV)for diabetic retinopathy(DR)in some patients,thus reducing the expected benefit.Understanding the risk factors for NVG occurrence ... BACKGROUND Neovascular glaucoma(NVG)is likely to occur after pars plana vitrectomy(PPV)for diabetic retinopathy(DR)in some patients,thus reducing the expected benefit.Understanding the risk factors for NVG occurrence and building effective risk prediction models are currently required for clinical research.AIM To develop a visual risk profile model to explore factors influencing DR after surgery.METHODS We retrospectively selected 151 patients with DR undergoing PPV.The patients were divided into the NVG(NVG occurrence)and No-NVG(No NVG occurrence)groups according to the occurrence of NVG within 6 months after surgery.Independent risk factors for postoperative NVG were screened by logistic regression.A nomogram prediction model was established using R software,and the model’s prediction accuracy was verified internally and externally,involving the receiver operator characteristic curve and correction curve.RESULTS After importing the data into a logistic regression model,we concluded that a posterior capsular defect,preoperative vascular endothelial growth factor≥302.90 pg/mL,glycosylated hemoglobin≥9.05%,aqueous fluid interleukin 6(IL-6)≥53.27 pg/mL,and aqueous fluid IL-10≥9.11 pg/mL were independent risk factors for postoperative NVG in patients with DR(P<0.05).A nomogram model was established based on the aforementioned independent risk factors,and a computer simulation repeated sampling method was used to internally and externally verify the nomogram model.The area under the curve(AUC),sensitivity,and specificity of the model were 0.962[95%confidence interval(95%CI):0.932-0.991],91.5%,and 82.3%,respectively.The AUC,sensitivity,and specificity of the external validation were 0.878(95%CI:0.746-0.982),66.7%,and 95.7%,respectively.CONCLUSION A nomogram constructed based on the risk factors for postoperative NVG in patients with DR has a high prediction accuracy.This study can help formulate relevant preventive and treatment measures. 展开更多
关键词 Diabetic retinopathy RETINOPATHY NEOVASCULAR GLAUCOMA Risk factors NOMOGRAM
下载PDF
Study on physical and mechanical properties of cement asphalt emulsified mortar under track slab
6
作者 Tao Wang Shaoliang Wu +5 位作者 Hengqiong Jia Shanqing Peng Haiyan Li Piyan Shao Zhao Wei yi shi 《Railway Sciences》 2024年第2期227-238,共12页
Purpose–During the construction process of the China Railway Track System(CRTS)I type filling layer,the nonwoven fabric bags have been used as grouting templates for cement asphalt(CA)emulsified mortar.The porous str... Purpose–During the construction process of the China Railway Track System(CRTS)I type filling layer,the nonwoven fabric bags have been used as grouting templates for cement asphalt(CA)emulsified mortar.The porous structure of nonwoven fabrics endowed the templates with breathability and water permeability.The standard requires that the volume expansion rate of CA mortar must be controlled within 1%–3%,which can generate expansion pressure to ensure that the cavities under track slabs are filled fully.However,the expansion pressure caused some of the water to seep out from the periphery of the filling bag,and it would affect the actual mix proportion of CA mortar.The differences in physical and mechanical properties between the CA mortar under track slabs and the CA mortar formed in the laboratory were studied in this paper.The relevant results could provide important methods for the research of filling layer materials for CRTS I type and other types of ballastless tracks in China.Design/methodology/approach–During the inspection of filling layer,the samples of CA mortar from different working conditions and raw materials were taken by uncovering the track slabs and drilling cores.The physical and mechanical properties of CA mortar under the filling layer of the slab were systematically analyzed by testing the electrical flux,compressive strength and density of mortar in different parts of the filling layer.Findings–In this paper,the electric flux,the physical properties and mechanical properties of different parts of CA mortar under the track slab were investigated.The results showed that the density,electric flux and compressive strength of CA mortar were affected by the composition of raw materials for dry powders and different parts of the filling layer.In addition,the electrical flux of CA mortar gradually decreased within 90 days’age.The electrical flux of samples with the thickness of 54 mm was lower than 500 C.Therefore,the impermeability and durability of CA mortar could be improved by increasing the thickness of filling layer.Besides,the results showed that the compressive strength of CA mortar increased,while the density and electric flux decreased gradually,with the prolongation of hardening time.Originality/value–During 90 days’age,the electrical flux of the CA mortar gradually decreased with the increase of specimen thickness and the electrical flux of the specimens with the thickness of 54 mm was lower than 500 C.The impermeability and durability of the CA mortar could be improved by increasing the thickness of filling layer.The proposed method can provide reference for the further development and improvement of CRTS I and CRTS II type ballastless track in China. 展开更多
关键词 CA mortar Electric flux Compressive strength DENSITY
下载PDF
Analysis of Traffic Accidents Based on the Integration Model
7
作者 Yanshun Ma yi shi +2 位作者 yihang Song Chenxiao Wu Yuanzhi Liu 《Journal of Electronic Research and Application》 2024年第1期51-59,共9页
To enhance the safety of road traffic operations,this paper proposed a model based on stacking integrated learning utilizing American road traffic accident statistics.Initially,the process involved data cleaning,trans... To enhance the safety of road traffic operations,this paper proposed a model based on stacking integrated learning utilizing American road traffic accident statistics.Initially,the process involved data cleaning,transformation,and normalization.Subsequently,various classification models were constructed,including logistic regression,k-nearest neighbors,gradient boosting,decision trees,AdaBoost,and extra trees models.Evaluation metrics such as accuracy,precision,recall,F1 score,and Hamming loss were employed.Upon analysis,the passive-aggressive classifier model exhibited superior comprehensive indices compared to other models.Based on the model’s output results,an in-depth examination of the factors influencing traffic accidents was conducted.Additionally,measures and suggestions aimed at reducing the incidence of severe traffic accidents were presented.These findings served as a valuable reference for mitigating the occurrence of traffic accidents. 展开更多
关键词 Stacking integrated learning Data analysis Traffic safety
下载PDF
Supplementation with yak (Bos grunniens) bone collagen hydrolysate altered the structure of gut microbiota and elevated short-chain fatty acid production in mice 被引量:1
8
作者 Zitao Guo Dalong yi +9 位作者 Bo Hu Lingyu Zhu Ji Zhang Yuliang Yang Chunyu Liu yi shi Zhenghua Gu Yu Xin Huaigao Liu Liang Zhang 《Food Science and Human Wellness》 SCIE CSCD 2023年第5期1637-1645,共9页
In this study, yak bone collagen hydrolysate(YBCH)was produced by mixed proteases and provided to standard-diet mice at a different dose(low dose(LD), medium dose(MD), and high dose(HD))to investigate its effects on t... In this study, yak bone collagen hydrolysate(YBCH)was produced by mixed proteases and provided to standard-diet mice at a different dose(low dose(LD), medium dose(MD), and high dose(HD))to investigate its effects on the composition of gut microbiota and short-chain fatty acids(SCFA)production. It was found that YBCH was mainly composed of small molecular peptides whose molecular weight below 2 000 Da. Notably, supplementation with different doses of YBCH could significantly downregulate the ratio of Firmicutes to Bacteroidetes in the fecal microbiota. At the family level, the Lachnospiraceae abundance was significantly reduced in the YBCH gavage groups(mean reduction ratio 41.7 %, 35.2%, and 36.4% for LD, MD, and HD group, respectively). The predicted functions of gut microbes in the MD group were significantly increased at “lipid metabolism” and “glycan biosynthesis and metabolism”. Moreover, the SCFA production in the YBCH groups was elevated. Especially, the concentration of acetic acid, propionic acid, and butyric acid in the MD group was separately increased 79.7%, 89.2%, and 78.8% than that in the NC group. These results indicated that YBCH might be applied in the development of functional food for intestinal microecological regulation. 展开更多
关键词 Yak bone collagen hydrolysate PEPTIDES Gut microbiota Short-chain fatty acid Lachnospiraceae
下载PDF
基于轻量级CNN-Transformer混合网络的梯田图像语义分割
9
作者 刘茜 易诗 +2 位作者 李立 程兴豪 王铖 《农业工程学报》 EI CAS CSCD 北大核心 2023年第13期171-181,共11页
梯田是一种传统的农业种植方式,具有稳定作物生产与水土保持的作用。快速、准确地对梯田区域分布信息进行采集,对提高粮食产量、治理水土流失以及规划区域生态等具有重要的作用与意义。无人机图像梯田道路边界模糊、具有较长的带状结构... 梯田是一种传统的农业种植方式,具有稳定作物生产与水土保持的作用。快速、准确地对梯田区域分布信息进行采集,对提高粮食产量、治理水土流失以及规划区域生态等具有重要的作用与意义。无人机图像梯田道路边界模糊、具有较长的带状结构,为了更准确地获取梯田的边缘信息,受MobileVit启发,该研究在MobileViT block中引入了轴向注意力机制(axial attention),并采用编码器-解码器结构,提出了基于轻量级CNN-Transformer混合构架网络模型。模型编码器部分由改进的MobileViT block、融入了条形池化的逆残差模块和空洞空间金字塔池化模块构成,再通过有效设计摆放各模块的位置顺序来实现局部与全局的视觉表征信息交互,得到完整的全局特征表达;利用解码器对编码器提取到的多尺度特征图进行采样和卷积操作得到语义分割结果图。选取PSPNet、LiteSeg、BisNetv2、Deeplabv3Plus、MobileViT在相同测试集上进行对比试验,结果表明,该研究所提模型在精度与速度方面均具有一定的优势,其像素精度可达95.79%,频权交并比可达94.86%,模型参数量为8.32 M,实现了使用较少的参数和简单的方法对复杂无规则的无人机图像梯田区域较为准确的分割,将其部署到无人机上可以进一步获取梯田的形状、位置、轮廓等信息,可为预防和修护加固梯田提供重要的依据,同时有助于梯田区域种植面积和范围的统计,为梯田和旱作区农业建设的发展提供参考。 展开更多
关键词 图像处理 语义分割 轻量化模型 轴向注意力 梯田数据集
下载PDF
涂装废气漆雾分离的流场模拟与试验研究
10
作者 周益辉 易师 +1 位作者 雷细平 何曦 《电镀与涂饰》 CAS 北大核心 2023年第24期75-83,共9页
在处理含有大量漆雾、挥发性有机物等有害物质的喷漆废气时,干式过滤法与湿式净化技术相比更经济有效,但容易产生堵塞问题。本文分析了漆雾的特性及干式过滤器堵塞的机理,提出了拦截-过滤耦合工艺和自制了实验装置。首先采用流体动力学... 在处理含有大量漆雾、挥发性有机物等有害物质的喷漆废气时,干式过滤法与湿式净化技术相比更经济有效,但容易产生堵塞问题。本文分析了漆雾的特性及干式过滤器堵塞的机理,提出了拦截-过滤耦合工艺和自制了实验装置。首先采用流体动力学的计算方法建立数值模型,优化了折流板拦截装置的结构和运行参数。数值模拟研究的结果表明:在板间距20 mm、折角90°、入口气流速度8 m/s的条件下,折流板拦截装置的压降为220.2 Pa,对直径15μm的漆雾的分离效率为84.7%。在上述优化条件下进行了试验验证,实测折流板拦截装置的压降和漆雾分离效率分别为303.3Pa和78.34%,整个拦截-过滤耦合装置的漆雾分离效率达到96.38%。 展开更多
关键词 喷漆 废气 漆雾 分离 拦截 过滤 数值模拟
下载PDF
Remodeling the tumor immune microenvironment via siRNA therapy for precision cancer treatment
11
作者 Lingxi Jiang Yao Qi +8 位作者 Lei Yang Yangbao Miao Weiming Ren Hongmei Liu yi Huang Shan Huang shiyin Chen yi shi Lulu Cai 《Asian Journal of Pharmaceutical Sciences》 SCIE CAS 2023年第5期51-76,共26页
How to effectively transform the pro-oncogenic tumor microenvironments(TME)surrounding a tumor into an anti-tumoral never fails to attract people to study.Small interfering RNA(siRNA)is considered one of the most note... How to effectively transform the pro-oncogenic tumor microenvironments(TME)surrounding a tumor into an anti-tumoral never fails to attract people to study.Small interfering RNA(siRNA)is considered one of the most noteworthy research directions that can regulate gene expression following a process known as RNA interference(RNAi).The research about siRNA delivery targeting tumor cells and TME has been on the rise in recent years.Using siRNA drugs to silence critical proteins in TME was one of the most efficient solutions.However,the manufacture of a siRNA delivery system faces three major obstacles,i.e.,appropriate cargo protection,accurately targeted delivery,and site-specific cargo release.In the following review,we summarized the pharmacological actions of siRNA drugs in remolding TME.In addition,the delivery strategies of siRNA drugs and combination therapy with siRNA drugs to remodel TME are thoroughly discussed.In the meanwhile,the most recent advancements in the development of all clinically investigated and commercialized siRNA delivery technologies are also presented.Ultimately,we propose that nanoparticle drug delivery siRNA may be the future research focus of oncogene therapy.This summary offers a thorough analysis and roadmap for general readers working in the field. 展开更多
关键词 Small interfering RNA Tumor microenvironment siRNA delivery Cancer therapy CO-DELIVERY
下载PDF
Intrinsic Electronic Properties of BN-Encapsulated,van der Waals Contacted MoSe_(2)Field-Effect Transistors
12
作者 邵印江 周健 +5 位作者 徐宁 陈健 渡邊賢司 谷口尚 施毅 黎松林 《Chinese Physics Letters》 SCIE EI CAS CSCD 2023年第6期98-103,共6页
Two-dimensional(2D)semiconductors have attracted considerable interest for their unique physical properties.Here,we report the intrinsic cryogenic electronic transport properties in few-layer MoSe_(2)field-effect tran... Two-dimensional(2D)semiconductors have attracted considerable interest for their unique physical properties.Here,we report the intrinsic cryogenic electronic transport properties in few-layer MoSe_(2)field-effect transistors(FETs)that are fully encapsulated in ultraclean hexagonal boron nitride dielectrics and are simultaneously van der Waals contacted with gold electrodes.The FETs exhibit electronically favorable channel/dielectric interfaces with low densities of interfacial traps(<1010cm^(-2)),which lead to outstanding device characteristics at room temperature,including near-Boltzmann-limit subthreshold swings(65 mV/dec),high carrier mobilities(53–68 cm^(2)·V-1·s^(-1)),and negligible scanning hystereses(<15 mV).The dependence of various contact-related parameters with temperature and carrier density is also systematically characterized to understand the van der Waals contacts between gold and MoSe_(2).The results provide insightful information about the device physics in van der Waals contacted and encapsulated 2D FETs. 展开更多
关键词 HEXAGONAL BORON dielectric
原文传递
Self-Oscillated Growth Formation of Standing Ultrathin Nanosheets out of Uniform Ge/Si Superlattice Nanowires
13
作者 甘鑫 安钧洋 +5 位作者 王军转 刘宗光 徐骏 施毅 陈坤基 余林蔚 《Chinese Physics Letters》 SCIE EI CAS CSCD 2023年第6期27-32,共6页
Self-oscillation is an intriguing and omnipresent phenomenon that governs a broad range of growth dynamics and formation of nanoscale periodic and delicate heterostructures.A self-oscillating growth phenomenon of cata... Self-oscillation is an intriguing and omnipresent phenomenon that governs a broad range of growth dynamics and formation of nanoscale periodic and delicate heterostructures.A self-oscillating growth phenomenon of catalyst droplets,consuming surface-coating a-Si/a-Ge bilayer,is exploited to accomplish a high-frequency alternating growth of ultrathin crystalline Si and Ge(c-Si/c-Ge)nano-slates,with Ge-rich layer thickness of 14–19 nm,embedded within a superlattice nanowire structure,with pre-known position and uniform channel diameter.A subsequent selective etching of the Ge-rich segments leaves a chain of ultrafine standing c-Si nanosheets down to~6 nm thick,without the use of any expensive high-resolution lithography and growth modulation control.A ternary-phase-competition model has been established to explain the underlying formation mechanism of this nanoscale self-oscillating growth dynamics.It is also suggested that these ultrathin nanosheets could help to produce ultrathin fin-channels for advanced electronics,or provide size-specified trapping sites to capture and position hetero nanoparticle for high-precision labelling or light emission. 展开更多
关键词 OSCILLATING consuming sheets
原文传递
Enhancement of Carrier Mobility in Semiconductor Nanostructures by Carrier Distribution Engineering
14
作者 梁斌熙 刘陆豪 +3 位作者 唐家晨 陈健 施毅 黎松林 《Chinese Physics Letters》 SCIE EI CAS CSCD 2023年第5期115-121,共7页
Two-dimensional(2D)van der Waals semiconductors are appealing for low-power transistors.Here,we show the feasibility in enhancing carrier mobility in 2D semiconductors through engineering the vertical distribution of ... Two-dimensional(2D)van der Waals semiconductors are appealing for low-power transistors.Here,we show the feasibility in enhancing carrier mobility in 2D semiconductors through engineering the vertical distribution of carriers confined inside ultrathin channels via symmetrizing gate configuration or increasing channel thickness.Through self-consistently solving the Schr¨odinger–Poisson equations,the shapes of electron envelope functions are extensively investigated by clarifying their relationship with gate configuration,channel thickness,dielectric permittivity,and electron density.The impacts of electron distribution variation on various carrier scattering matrix elements and overall carrier mobility are insightfully clarified.It is found that the carrier mobility can be generally enhanced in the dual-gated configuration due to the centralization of carrier redistribution in the nanometer-thick semiconductor channels and the rate of increase reaches up to 23%in Hf O2 dual-gated 10-layer MoS_(2) channels.This finding represents a viable strategy for performance optimization in transistors consisting of 2D semiconductors. 展开更多
关键词 DENSITY SEMICONDUCTORS CONFIGURATION
原文传递
Analysis of Investigation on Ebian Spotted Cattle and Suggestions
15
作者 Zhaohua LI yi shi +7 位作者 Fang HE Min CHEN Jun yi Jia GAN Donghui FANG Yueda AGUO Xiaodong DENG Wei WANG 《Agricultural Biotechnology》 CAS 2023年第3期58-60,共3页
Ebian spotted cattle has the ability to adapt to the local natural ecological environment,and is one of the excellent local cattle breeds in Sichuan.Ebian spotted cattle is a breed of cattle for both service and meat ... Ebian spotted cattle has the ability to adapt to the local natural ecological environment,and is one of the excellent local cattle breeds in Sichuan.Ebian spotted cattle is a breed of cattle for both service and meat use and formed through long-term natural selection and artificial selection.Because of the weak development and utilization of this breed,the economic benefits of excellent breeds have not been fully brought into play,and farmers'enthusiasm in breeding is poor,so that the number of Ebian spotted cattle has reduced year by year.In order to strengthen the protection,development and utilization of Ebian spotted cattle as a local excellent breed,combined with the third national survey of livestock and poultry genetic resources in 2021,Ebian spotted cattle was investigated,and a comprehensive,scientific and objective analysis of its population numbers was conducted.Besides,reasonable suggestions were put forward. 展开更多
关键词 Ebian Ebian spotted cattle Local fine varieties Quantity ANALYSIS Suggestions
下载PDF
Gender Differences in the Incidence and Related Factors of Low Social Support among Adolescents with Subthreshold Depression
16
作者 yi shi Fangfang Shangguan Jing Xiao 《International Journal of Mental Health Promotion》 2023年第12期1257-1263,共7页
Background:Social support is related to depression,but the gender differences and related factors that contribute to low social support among adolescents with subthreshold depression remain to be elucidated.This study... Background:Social support is related to depression,but the gender differences and related factors that contribute to low social support among adolescents with subthreshold depression remain to be elucidated.This study explores the relationship between social support and depression,in addition to the gender difference in the incidence of low social support among adolescents with subthreshold depression and its related factors.Methods:A total of 371 Chinese adolescents with subthreshold depression were recruited.All subjects were rated on the Social Support Scale for Adolescents,the Response Style Scale,the Self-Perception Profile for Children,the Individualism-collectivism scale.Results:Binary logistic regression indicated that the stability dimension of cognitive style,the generality dimension of the Cognitive Style Questionnaire,and the social acceptance dimension of the Self-Perception Profile for Children scale were significantly correlated with social support level in male adolescents with subthreshold depression.In contrast,the total score of the Self-Perception Profile for Children scale,the social acceptance of the Self-Perception Profile for Children scale,total individualism,and total collectivism were significantly correlated with social support level in female adolescents with subthreshold depression.Limitations:This study is a cross-sectional study,and its effectiveness in explaining factors that influence levels of social support is limited.Conclusions:The gender difference between low social support among adolescents with subthreshold depression is related to cognitive style,self-perception,and collectivism–individualism. 展开更多
关键词 Gender difference subthreshold depression social support SELF-PERCEPTION cognitive style
下载PDF
Influences of cement asphalt emulsified mortar construction on track slab geometry status
17
作者 Tao Wang Shaoliang Wu +5 位作者 Hengqiong Jia Zhao Wei Haiyan Li Piyan Shao Shanqing Peng yi shi 《Railway Sciences》 2023年第4期447-458,共12页
Purpose–The construction of cement asphalt(CA)emulsified mortar can obviously disturb the slab status after the fine adjustment.To decrease or eliminate the influence of CA mortar grouting on track slab geometry stat... Purpose–The construction of cement asphalt(CA)emulsified mortar can obviously disturb the slab status after the fine adjustment.To decrease or eliminate the influence of CA mortar grouting on track slab geometry status,the effects of grouting funnel,slab pressing method,mortar expansion ratio,seepage ratio and grouting area on China Railway Track System Type(CRTS I)track slab geometry status were discussed in this paper.Design/methodology/approach–Combined with engineering practice,this paper studied the expansion law of filling layer mortar,the liquid level height of the filling funnel,the pressure plate device and the amount of exudation water and systematically analyzed the influence of filling layer mortar construction on the state of track slab.Relevant precautions and countermeasures were put forward.Findings–The results showed that the track slab floating values of four corners were different with the CA mortar grouting and the track slab corner near CA mortar grouting hole had the maximum floating values.The anti-floating effect of“7”shaped slab pressing device was more efficient than fixed-joint angle iron,and the slab floating value could be further decreased by increasing the amount of“7”shaped slab pressing devices.After CA mortar grouting,the track slab floating pattern had a close correlation with the expansion rate and water seepage rate of CA mortar over time and the expansion and water seepage rate of the mortar were faster when the temperature was high.Furthermore,the use of strip CA mortar filling under the rail bearing platform on bothsides could effectively reduce the float under the track slab,and it could also save mortar consumption and reduce costs.Originality/value–This study plays an important role in controlling the floating values,CA mortar dosage and the building cost of projects by grouting CA mortar at two flanks of filling space.The research results have guiding significance for the design and construction of China’s CRTS I,CRTS II and CRTS III track slab. 展开更多
关键词 Ballastless track Track slab CA mortar Geometry status
下载PDF
基于淋巴管系统在免疫调节中的作用探讨新冠病毒致肺损伤的机制及中药干预作用 被引量:6
18
作者 梁倩倩 陈伟 +11 位作者 徐浩 王腾腾 黄怡 石怡 陈锦漫 陈绍华 姚妙恩 鲍嘉敏 庄紫欣 李雪菲 施杞 王拥军 《世界科学技术-中医药现代化》 CSCD 北大核心 2020年第2期270-277,共8页
新型冠状病毒肺炎所产生的炎性渗出,炎症风暴导致急性肺损伤,大量免疫细胞和组织液聚集肺脏,造成患者通气功能障碍,呼吸窘迫,甚至呼吸衰竭而死亡。调节免疫反应和减少肺组织渗出对控制该病的进展及促进后期康复至关重要。淋巴管系统具... 新型冠状病毒肺炎所产生的炎性渗出,炎症风暴导致急性肺损伤,大量免疫细胞和组织液聚集肺脏,造成患者通气功能障碍,呼吸窘迫,甚至呼吸衰竭而死亡。调节免疫反应和减少肺组织渗出对控制该病的进展及促进后期康复至关重要。淋巴管系统具有免疫监视、免疫捕获和维持组织间液平衡的作用,在急性炎症反应过程发挥重要作用。本文综述淋巴管系统在肺部的分布、生理功能及其在急性肺损伤过程中的作用,结合本团队研究成果,探讨淋巴管系统在新型冠状病毒肺炎病理进程中的作用和机制,以及中医药疗法机制,为临床新型冠状病毒肺炎的治疗提供新思路和潜在治疗方案。 展开更多
关键词 新型冠状病毒肺炎 淋巴管系统 急性免疫反应 急性肺损伤 中医药治疗
下载PDF
基于红外热成像与改进YOLOV3的夜间野兔监测方法 被引量:18
19
作者 易诗 李欣荣 +2 位作者 吴志娟 朱竞铭 袁学松 《农业工程学报》 EI CAS CSCD 北大核心 2019年第19期223-229,共7页
随生态改善,野兔数量增多,对农田与林地的危害日益加重。野兔活动多为夜间,目标小,运动速度快,且出现环境较复杂,监控兔害,需要一种高效智能化的方法。针对野兔活动习性,该文提出了使用红外热成像实时监控,结合改进的YOLOV3目标检测方... 随生态改善,野兔数量增多,对农田与林地的危害日益加重。野兔活动多为夜间,目标小,运动速度快,且出现环境较复杂,监控兔害,需要一种高效智能化的方法。针对野兔活动习性,该文提出了使用红外热成像实时监控,结合改进的YOLOV3目标检测方法对夜间野兔进行检测。根据YOLOV3目标检测网络基本结构提出了一种针对红外图像中野兔的实时检测的网络(infrared rabbit detection YOLO,IR-YOLO),该网络特征提取部分压缩YOLOV3特征提取网络深度,利用浅层卷积层特征以提高低分辨率红外小目标检测精度,降低运算量,网络检测部分使用基于CenterNet结构的检测方式以提高检测速度。使用热成像野外实时采集的夜间野兔图像作为数据集,包括不同距离,尺度,出现环境不同的野兔共计6000幅红外图像制作训练集与测试集,比例为5:1。试验结果表明,IR-YOLO在红外热成像视频中复杂环境下出现的野兔检测率达75%,平均检测速度51帧/s,相对改进前YOLOV3检测率提高15个百分点,相对改进前YOLOV3检测速度提高5帧/s。相比其他目标检测算法各项检测指标更为优良,检测率方面相对Faster-RCNN与RFCN-RESNET101分别提高45个百分点与20个百分点,检测速度方面相对Faster-RCNN与RFCN-RESNET101分别提高30和与45帧/s。该方法可高效快速地对夜间复杂环境下出现的野兔进行检测,也可广泛应用于夜间对其他类型农业害兽的检测。 展开更多
关键词 红外热成像 图像处理 野兔 检测 IR-YOLO CENTER Net检测结构 小目标检测
下载PDF
基于增强型Tiny-YOLOV3模型的野鸡识别方法 被引量:10
20
作者 易诗 沈练 +2 位作者 周思尧 朱竞铭 袁学松 《农业工程学报》 EI CAS CSCD 北大核心 2020年第13期141-147,共7页
智慧农业病虫害检测技术发展迅猛,而对农作物具有危害的鸟类检测技术尚处于起步阶段,近年来由于生态改善,野鸡繁殖数量激增,其喜食小麦、玉米、红薯等农作物的种子与幼苗,对农业造成一定危害。该研究提出了一种适宜于嵌入式系统部署的... 智慧农业病虫害检测技术发展迅猛,而对农作物具有危害的鸟类检测技术尚处于起步阶段,近年来由于生态改善,野鸡繁殖数量激增,其喜食小麦、玉米、红薯等农作物的种子与幼苗,对农业造成一定危害。该研究提出了一种适宜于嵌入式系统部署的人工智能野鸡识别方法。由于在野外环境下移动平台上部署,需采用轻量级网络,同时保证检测精度与实时性,因此,根据Tiny-YOLOV3轻量级目标检测网络基本结构,提出了一种针对野外复杂环境中出现野鸡的实时检测网络-增强型轻量级目标检测网络(EnhancedTiny-YOLO,ET-YOLO),该网络特征提取部分加深Tiny-YOLOV3特征提取网络深度,增加检测尺度以提高原网络目标检测精度,网络检测层使用基于CenterNet结构的检测方式以进一步提高检测精度与检测速度。使用野外实地采集各种环境下出现的野鸡图像作为数据集,包括不同距离、角度、环境出现的野鸡共计6000幅高清图像制作数据集。试验结果表明,ET-YOLO在视频中复杂环境下出现的野鸡平均检测精度达86.5%,平均检测速度62帧/s,相对改进前Tiny-YOLOV3平均检测精度提高15个百分点,平均检测速度相对改进前Tiny-YOLOV3提高2帧/s,相对YOLOV3、Faster-RCNN与SSD_MobileNetV2主流代表性目标检测算法,平均检测精度分别提高1.5、1.1与18个百分点,平均检测速度分别提高38、47与1帧/s。可高效实时地对复杂环境下出现的野鸡进行识别,并且检测模型大小为56 MB,适宜于在农业机器人,智能农机所搭载的嵌入式系统上部署。 展开更多
关键词 农业 人工智能 嵌入式系统 野鸡识别 ET-YOLO CenterNet检测结构
下载PDF
上一页 1 2 8 下一页 到第
使用帮助 返回顶部