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注塑产业离散制造智能感知与控制关键技术及应用
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作者 陈猛 董岱 +3 位作者 逄鹏博 梁健民 胡颖瑜 李松晶 《塑料工业》 CAS CSCD 北大核心 2024年第2期86-90,共5页
在全面推进制造业信息化和智能化的背景下,针对注塑产业离散制造现状,开展注塑离散制造过程的自主感知与控制关键技术研究。本文对注塑装备各功能模块的工艺结构进行升级改造,研究大数据运行过程关键数据的自主感知、缺陷在线采集和智... 在全面推进制造业信息化和智能化的背景下,针对注塑产业离散制造现状,开展注塑离散制造过程的自主感知与控制关键技术研究。本文对注塑装备各功能模块的工艺结构进行升级改造,研究大数据运行过程关键数据的自主感知、缺陷在线采集和智能识别、生产任务自组织调度、装备智能控制策略自适应调整和装备上云智能化管理平台,实现生产过程智能化监控、管理、服务和维护的注塑全新工艺,助力大型企业注塑车间无人化作业实现,提高下游产业注塑产品质量,实现塑机装备产品的智能化提升。 展开更多
关键词 注塑产业 离散制造 智能感知 数据分析和优化 智能控制
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Effect of liquid surface depression size on discharge characteristics and chemical distribution in the plasma-liquid anode system
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作者 Yun LING dong dai +1 位作者 Jiaxin CHANG Buang WANG 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第9期17-31,共15页
Atmospheric pressure plasma-liquid interactions exist in a variety of applications,including wastewater treatment,wound sterilization,and disinfection.In practice,the phenomenon of liquid surface depression will inevi... Atmospheric pressure plasma-liquid interactions exist in a variety of applications,including wastewater treatment,wound sterilization,and disinfection.In practice,the phenomenon of liquid surface depression will inevitably appear.The applied gas will cause a depression on the liquid surface,which will undoubtedly affect the plasma generation and further affect the application performance.However,the effect of liquid surface deformation on the plasma is still unclear.In this work,numerical models are developed to reveal the mechanism of liquid surface depressions affecting plasma discharge characteristics and the consequential distribution of plasma species,and further study the influence of liquid surface depressions of different sizes generated by different helium flow rates on the plasma.Results show that the liquid surface deformation changes the initial spatial electric field,resulting in the rearrangement of electrons on the liquid surface.The charges deposited on the liquid surface further increase the degree of distortion of the electric field.Moreover,the electric field and electron distribution affected by the liquid surface depression significantly influence the generation and distribution of active species,which determines the practical effectiveness of the relevant applications.This work explores the phenomenon of liquid surface depression,which has been neglected in previous related work,and contributes to further understanding of plasma-liquid interactions,providing better theoretical guidance for related applications and technologies. 展开更多
关键词 plasma-liquid interaction deformation of the liquid surface liquid anode species fluxes
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Nonlinear change of ion-induced secondary electron emission in theκ-Al_(2)O_(3) surface charging from first-principle modelling
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作者 Zhicheng JIAO Mingrui ZHU +2 位作者 dong dai Tao SHAO Buang WANG 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第9期40-50,共11页
Secondary electron emission(SEE)induced by the positive ion is an essential physical process to influence the dynamics of gas discharge which relies on the specific surface material.Surface charging has a significant ... Secondary electron emission(SEE)induced by the positive ion is an essential physical process to influence the dynamics of gas discharge which relies on the specific surface material.Surface charging has a significant impact on the material properties,thereby affecting the SEE in the plasma-surface interactions.However,it does not attract enough attention in the previous studies.In this paper,SEE dependent on the charged surface of specific materials is described with the computational method combining a density functional theory(DFT)model from the first-principle theory and the theory of Auger neutralization.The effect ofκ-Al2O3 surface charge,as an example,on the ion-induced secondary electron emission coefficient(SEEC)is investigated by analyzing the defect energy level and band structure on the charged surface.Simulation results indicate that,with the surface charge from negative to positive,the SEEC of a part of low ionization energy ions(such as Ei=12.6 eV)increases first and then decreases,exhibiting a nonlinear changing trend.This is quite different from the monotonic decreasing tendency observed in the previous model which simplifies the electronic structure.This irregular increase of the SEEC can be attributed to the lower escaped probability of orbital energy.The results further illustrate that the excessive charge could cause the bottom of the conduction band close to the valence band,thus leading to the decrease of the orbital energy occupied by the excited electrons.The nonlinear change of SEEC demonstrates a more realistic situation of how the electronic structure of material surface influences the SEE process.This work provides an accurate method of calculating SEEC from specific materials,which is urgent in widespread physical scenarios sensitive to surface materials,such as increasingly growing practical applications concerning plasma-surface interactions. 展开更多
关键词 secondary electron emission charged surface density functional theory defect energy level
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Dietary organic acids ameliorate high stocking density stress-induced intestinal inflammation through the restoration of intestinal microbiota in broilers 被引量:5
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作者 dong dai Guanghai Qi +5 位作者 Jing Wang Haijun Zhang Kai Qiu Yanming Han Yuanyuan Wu Shugeng Wu 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2023年第2期745-759,共15页
Background:High stocking density(HSD)stress has detrimental effects on growth performance,intestinal barrier function,and intestinal microbiota in intensive animal production.Organic acids(OA)are widely used as feed a... Background:High stocking density(HSD)stress has detrimental effects on growth performance,intestinal barrier function,and intestinal microbiota in intensive animal production.Organic acids(OA)are widely used as feed addi-tives for their ability to improve growth performance and intestinal health in poultry.However,whether dietary OA can ameliorate HSD stress-induced impaired intestinal barrier in broilers remains elusive.In this study,a total of 528 one-day-old male Arbor Acres broilers were randomly allocated into 3 treatments with 12 replicates per treatment including 10 birds for normal stocking density and 17 birds for HSD.The dietary treatments were as follows:1)Normal stocking density+basal diet;2)HSD+basal diets;3)HSD+OA.Results:HSD stress can induce increased levels of serum corticosterone,lipopolysaccharides,interleukin-1β,tumor necrosis factor-α,and down-regulated mRNA expression of ZO-1,resulting in compromised growth performance of broilers(P<0.05).Dietary OA could significantly reduce levels of serum corticosterone,lipopolysaccharides,interleukin-1β,and tumor necrosis factor-α,which were accompanied by up-regulated interleukin-10,mRNA expres-sion of ZO-1,and growth performance(P<0.05).Moreover,OA could down-regulate the mRNA expression of TLR4 and MyD88 to inhibit the NF-κB signaling pathway(P<0.05).Additionally,HSD stress significantly decreased the abundance of Bacteroidetes and disturbed the balance of microbial ecosystems,whereas OA significantly increased the abundance of Bacteroidetes and restored the disordered gut microbiota by reducing competitive and exploita-tive interactions in microbial communities(P<0.05).Meanwhile,OA significantly increased the content of acetic and butyric acids,which showed significant correlations with intestinal inflammation indicators(P<0.05).Conclusions:Dietary OA ameliorated intestinal inflammation and growth performance of broilers through restor-ing the disordered gut microbial compositions and interactions induced by HSD and elevating short-chain fatty acid production to inhibit the TLR4/NF-κB signaling pathway.These findings demonstrated the critical role of intestinal microbiota in mediating the HSD-induced inflammatory responses,contributing to exploring nutritional strategies to alleviate HSD-induced stress in animals. 展开更多
关键词 BROILER High stocking density Intestinal inflammation Intestinal microbiota Organic acid Short-chain fatty acid
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烧结台车车轮润滑油自动加注装置设计及试验 被引量:3
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作者 董岱 方实年 +3 位作者 卫卫 杜预 方田 叶学农 《液压与气动》 北大核心 2021年第1期146-151,共6页
针对现有烧结台车车轮润滑缺乏成熟的润滑油自动化加注设备的问题,提出一种新型烧结台车车轮润滑油自动加注装置。对该装置的随动装置、车轮捕捉装置、自动加油枪、移动平台等部件和气动系统进行了设计分析。基于双偏心自动调整机构设... 针对现有烧结台车车轮润滑缺乏成熟的润滑油自动化加注设备的问题,提出一种新型烧结台车车轮润滑油自动加注装置。对该装置的随动装置、车轮捕捉装置、自动加油枪、移动平台等部件和气动系统进行了设计分析。基于双偏心自动调整机构设计了浮动式加油枪,并对其工作原理进行理论分析。根据结构设计制造了试验样机,样机试验结果表明,所研制的烧结台车车轮润滑油自动加注装置能够实现烧结台车车轮的在线自动加油,单次加油循环用时15 s,加油量40 mL。该装置的研制为烧结生产智能化提供了核心技术和装备保障。 展开更多
关键词 烧结台车 车轮润滑 润滑油自动加注 双偏心环机构 随动装置 车轮捕捉装置 气动系统
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家庭社会经济地位对青少年抑郁的影响:自尊的中介作用和心理韧性的调节作用 被引量:18
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作者 殷华敏 牛小倩 +2 位作者 董黛 牛更枫 孙丽君 《心理研究》 2018年第5期465-471,共7页
为探讨家庭社会经济地位、自尊、心理韧性对青少年抑郁的影响及其作用机制,采用家庭富裕量表、Connor–Davidsonx心理韧性量表、Rosenberg自尊量表和流调中心用抑郁量表对467名中学生进行施测,结果表明:(1)家庭社会经济地位与抑郁呈显... 为探讨家庭社会经济地位、自尊、心理韧性对青少年抑郁的影响及其作用机制,采用家庭富裕量表、Connor–Davidsonx心理韧性量表、Rosenberg自尊量表和流调中心用抑郁量表对467名中学生进行施测,结果表明:(1)家庭社会经济地位与抑郁呈显著负相关,与自尊和心理韧性呈显著正相关,自尊与心理韧性和抑郁呈显著负相关;(2)自尊在家庭社会经济地位对抑郁的影响中起中介作用;(3)家庭经济地位对抑郁影响的直接效应以及自尊的中介作用均受到心理韧性的调节,且随着心理韧性水平的提高,这两种效应均呈下降趋势。本研究结果对青少年抑郁的预防干预具有一定的理论价值和实践指导意义。 展开更多
关键词 家庭社会经济地位 自尊 心理韧性 抑郁 青少年
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Dihydromyricetin alleviates carbon tetrachloride-induced acute liver injury via JNK-dependent mechanism in mice 被引量:18
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作者 Jun Xie Jie Liu +7 位作者 Tu-Ming Chen Qing Lan Qing-Yu Zhang Bin Liu dong dai Wei-dong Zhang Li-Ping Hu Run-Zhi Zhu 《World Journal of Gastroenterology》 SCIE CAS 2015年第18期5473-5481,共9页
AIM: To assess the effects of dihydromyricetin(DHM) as a hepatoprotective candidate in reducing hepatic injury and accelerating hepatocyte proliferation after carbon tetrachloride(CCl4) treatment.METHODS: C57 BL/6 mic... AIM: To assess the effects of dihydromyricetin(DHM) as a hepatoprotective candidate in reducing hepatic injury and accelerating hepatocyte proliferation after carbon tetrachloride(CCl4) treatment.METHODS: C57 BL/6 mice were used in this study. Mice were orally administered with DHM(150 mg/kg) for 4 d after CCl4 treatment. Serum and liver tissue samples were collected on days 1, 2, 3, 5 and 7 after CCl4 treatment. The anti-inflammatory effect of DHM was assessed directly by hepatic histology detection and indirectly by serum levels of aspartate aminotransferase(AST), alanine aminotransferase(ALT), albumin, and superoxide dismutase(SOD). Inflammatory cytokines, such as interleukin(IL)-1β, IL-6 and tumor necrosis factor-α(TNF-α), were detected using ELISA kits. Proliferating cell nuclear antigen(PCNA) staining was used to evaluate the role of DHM in promoting hepatocyte proliferation. Hepatocyte apoptosis wasmeasured by TUNEL assay.Furthermore,apoptosis proteins Caspases-3,6,8,and 9 were detected by Western blot.SP600125 were used to confirm whether DHM regulated liver regeneration through JNK/TNF-αpathways.RESULTS:DHM showed a strong anti-inflammatory effect on CCl4-induced liver injury in mice.DHM could significantly decrease serum ALT,AST,IL-1β,IL-6 and TNF-αand increase serum albumin,SOD and liver SOD compared to the control group after CCl4 treatment(P<0.05).PCNA results indicated that DHM could significantly increase the number of PCNA positive cells compared to the control(348.9±56.0 vs 107.1±31.4,P<0.01).TUNEL assay showed that DHM dramatically reduced the number of apoptotic cells after CCl4 treatment compared to the control(365.4±99.4 vs 90.5±13.8,P<0.01).Caspase activity detection showed that DHM could reduce the activities of Caspases-8,3,6 and 9 compared to the control(P<0.05).The results of Western blot showed that DHM increased the expression of JNK and decreased TNF-αexpression.However,DHM could not affect TNF-αexpression after SP600125 treatment.Furthermore,DHM could significantly improve the survival rate of acute liver failure(ALF)mice(73.3%vs 20.0%,P<0.0001),and SP600125 could inhibit the effect of DHM.CONCLUSION:These findings demonstrate that DHM alleviates CCl4-induced liver injury,suggesting that DHM is a promising candidate for reversing liver injury and ALF. 展开更多
关键词 DIHYDROMYRICETIN Liver REGENERATION TUMOR NECROSIS factor-α
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Dynamic alterations in early intestinal development,microbiota and metabolome induced by in ovo feeding of L-arginine in a layer chick model 被引量:9
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作者 dong dai Shu-geng Wu +2 位作者 Hai-jun Zhang Guang-hai Qi Jing Wang 《Journal of Animal Science and Biotechnology》 CAS CSCD 2020年第3期896-911,共16页
Background:Prenatal nutrition is crucial for embryonic development and neonatal growth,and has the potential to be a main determinant of life-long health.In the present study,we used a layer chick model to investigate... Background:Prenatal nutrition is crucial for embryonic development and neonatal growth,and has the potential to be a main determinant of life-long health.In the present study,we used a layer chick model to investigate the effects of in ovo feeding(IOF)of L-arginine(Arg)on growth,intestinal development,intestinal microbiota and metabolism.The treatments included the non-injected control,saline-injected control,and saline containing 2,6,or 10 mg Arg groups.Results:IOF Arg increased early intestinal index and villus height,and enhanced uptake of residual yolk lipid,contributing to subsequent improvement in the early growth performance of chicks.Prenatal Arg supplementation also increased the early microbialα-diversity,the relative abundance of Lactobacillales and Clostridiales,and decreased the relative abundance of Proteobacteria of cecum in chicks.Furthermore,the shift of cecal microbiota composition and the colonization of potential probiotics were accelerated by IOF of Arg.Simultaneously,metabolomics showed that metabolisms of galactose,taurine-conjugated bile acids and lipids were modulated to direct more energy and nutrients towards rapid growth of intestine at the beginning of post-hatch when embryos received IOF of Arg.Conclusions:Prenatal Arg supplementation showed beneficial effects on the early intestinal development,cecal microbiota and host metabolism of layer chicks,contributing to subsequent improvement in the early growth performance.These findings provide new insight into the role of IOF of Arg in the establishment of the gut microbiota of newly-hatched layer chicks,and can expand our fundamental knowledge about prenatal nutrition,early bacterial colonization and intestinal development in neonate. 展开更多
关键词 Development In ovo feeding Intestinal microbiota L-ARGININE Layer chick Metabolomics
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^(18)F-Fluorodeoxyglucose positron emission tomography/computed tomography comparison of gastric lymphoma and gastric carcinoma 被引量:5
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作者 Xiao-Feng Li Qiang Fu +5 位作者 You-Wen dong Jian-Jing Liu Xiu-Yu Song dong dai Cong Zuo Wen-Gui Xu 《World Journal of Gastroenterology》 SCIE CAS 2016年第34期7787-7796,共10页
AIM To compare ^(18)F-fluorodeoxyglucose positron emission tomography/computed tomography(^(18)F-FDG PET/CT) features in gastric lymphoma and gastric carcinoma.METHODS Patients with newly diagnosed gastric lymphoma or... AIM To compare ^(18)F-fluorodeoxyglucose positron emission tomography/computed tomography(^(18)F-FDG PET/CT) features in gastric lymphoma and gastric carcinoma.METHODS Patients with newly diagnosed gastric lymphoma or gastric carcinoma who underwent ^(18)F-FDG PET/CT prior to treatment were included in this study. We reviewed and analyzed the PET/CT features of gastric wall lesions,including FDG avidity,pattern(focal/diffuse),and intensity [maximal standard uptake value:(SUVmax)]. The correlation of SUVmax with gastricclinicopathological variables was investigated by χ~2 test,and receiver-operating characteristic(ROC) curve analysis was performed to determine the differential diagnostic value of SUVmax-associated parameters in gastric lymphoma and gastric carcinoma. RESULTS Fifty-two patients with gastric lymphoma and 73 with gastric carcinoma were included in this study. Abnormal gastric FDG accumulation was found in 49 patients(94.23%) with gastric lymphoma and 65 patients(89.04%) with gastric carcinoma. Gastric lymphoma patients predominantly presented with type Ⅰ and type Ⅱ lesions,whereas gastric carcinoma patients mainly had type Ⅲ lesions. The SUVmax(13.39 ± 9.24 vs 8.35 ± 5.80,P < 0.001) and SUVmax/THKmax(maximal thickness)(7.96 ± 4.02 vs 4.88 ± 3.32,P < 0.001) were both higher in patients with gastric lymphoma compared with gastric carcinoma. ROC curve analysis suggested a better performance of SUVmax/THKmax in the evaluation of gastric lesions between gastric lymphoma and gastric carcinoma in comparison with that of SUVmax alone.CONCLUSION PET/CT features differ between gastric lymphoma and carcinoma,which can improve PET/CT evaluation of gastric wall lesions and help differentiate gastric lymphoma from gastric carcinoma. 展开更多
关键词 GASTRIC LYMPHOMAS GASTRIC CARCINOMAS 18F-FLUORODEOXYGLUCOSE positron emission tomography/ computed TOMOGRAPHY MAXIMAL standard uptake value MAXIMAL thickness Differential diagnosis
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Influence of nitrogen impurities on the characteristics of a patterned helium dielectric barrier discharge at atmospheric pressure 被引量:4
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作者 Yuhui ZHANG Wenjun NING +1 位作者 dong dai Qiao WANG 《Plasma Science and Technology》 SCIE EI CAS CSCD 2019年第7期23-37,共15页
In this paper, a two-dimensional axisymmetric fluid model was established to investigate the influence of nitrogen impurity content on the discharge pattern and the relevant discharge characteristics in an atmosphere ... In this paper, a two-dimensional axisymmetric fluid model was established to investigate the influence of nitrogen impurity content on the discharge pattern and the relevant discharge characteristics in an atmosphere pressure helium dielectric barrier discharge(DBD). The results indicated that when the nitrogen content was increased from 1 to 100 ppm, the discharge pattern evolved from a concentric-ring pattern into a uniform pattern, and then returned to the concentricring pattern. In this process, the discharge mode at the current peak moment transformed from glow mode into Townsend mode, and then returned to glow mode. Further analyses revealed that with the increase of impurity level, the rate of Penning ionization at the pre-ionization stage increased at first and decreased afterwards, resulting in a similar evolution pattern of seed electron level. This evolution trend was believed to be resulted from the competition between the N2 partial pressure and the consumption rate of metastable species. Moreover, the discharge uniformity was found positively correlated with the spatial uniformity of seed electron density as well as the seed electron level. The reason for this correlation was explained by the reduction of radial electric field strength and the promotion of seed electron uniformity as pre-ionization level increases. The results obtained in this work may help better understand the pattern formation mechanism of atmospheric helium DBD under the variation of N2 impurity level, thereby providing a possible means of regulating the discharge performance in practical application scenarios. 展开更多
关键词 pattern dielectric barrier DISCHARGE IMPURITIES Penning IONIZATION DISCHARGE uniformity seed electron
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A Smart Wearable Ring Device for Sensing Hand Tremor of Parkinson’s Patients 被引量:2
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作者 Haixia Yang Yixian Shen +3 位作者 Wei Zhuang Chunming Gao dong dai Weigong Zhang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2021年第3期1217-1238,共22页
Parkinson’s disease(PD)is a very common neurodegenerative disease that occurs mostly in the elderly.There are many main clinical manifestations of PD,such as tremor,bradykinesia,muscle rigidity,etc.Based on the curre... Parkinson’s disease(PD)is a very common neurodegenerative disease that occurs mostly in the elderly.There are many main clinical manifestations of PD,such as tremor,bradykinesia,muscle rigidity,etc.Based on the current research on PD,the accurate and convenient detection of early symptoms is the key to detect PD.With the development of microelectronic and sensor technology,it is much easier to measure the barely noticeable tremor in just one hand for the early detection of Parkinson’s disease.In this paper,we present a smart wearable device for detecting hand tremor,in which MPU6050(MIDI Processing Unit)consisting of a 3-axis gyroscope and a 3-axis accelerometer is used to collect acceleration and angular velocity of fingers.By analyzing the time of specific finger movements,we successfully recognized the tremor signals with high accuracy.Meanwhile,with Bluetooth 4.0(Bluetooth Low Energy,BLE)and networking terminal ability,tremor data can be transferred to a monitoring device in real time with extremely lowenergy consumption.The experimental results have shown that the proposed device(smart ring)is convenient for long-term tremor detection which is vital for early detection and treatment for Parkinson’s disease. 展开更多
关键词 Parkinson’s disease tremor detection IMU sensor MPU6050 BLE
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Development of a Novel Parallel-spool Pilot Operated High-pressure Solenoid Valve with High Flow Rate and High Speed 被引量:6
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作者 dong dai LI Xiaoning 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2015年第2期369-378,共10页
High-pressure solenoid valve with high flow rate and high speed is a key component in an underwater driving system.However,traditional single spool pilot operated valve cannot meet the demands of both high flow rate a... High-pressure solenoid valve with high flow rate and high speed is a key component in an underwater driving system.However,traditional single spool pilot operated valve cannot meet the demands of both high flow rate and high speed simultaneously.A new structure for a high pressure solenoid valve is needed to meet the demand of the underwater driving system.A novel parallel-spool pilot operated high-pressure solenoid valve is proposed to overcome the drawback of the current single spool design.Mathematical models of the opening process and flow rate of the valve are established.Opening response time of the valve is subdivided into 4 parts to analyze the properties of the opening response.Corresponding formulas to solve 4 parts of the response time are derived.Key factors that influence the opening response time are analyzed.According to the mathematical model of the valve,a simulation of the opening process is carried out by MATLAB.Parameters are chosen based on theoretical analysis to design the test prototype of the new type of valve.Opening response time of the designed valve is tested by verifying response of the current in the coil and displacement of the main valve spool.The experimental results are in agreement with the simulated results,therefore the validity of the theoretical analysis is verified.Experimental opening response time of the valve is 48.3 ms at working pressure of 10 MPa.The flow capacity test shows that the largest effective area is 126 mm2 and the largest air flow rate is 2320 L/s.According to the result of the load driving test,the valve can meet the demands of the driving system.The proposed valve with parallel spools provides a new method for the design of a high-pressure valve with fast response and large flow rate. 展开更多
关键词 high-pressure pneumatic solenoid valve parallel-spool high flow rate high speed opening response time
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基于深度学习的图像超分辨率重建方法浅析 被引量:1
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作者 江曙 王俊英 +2 位作者 董岱 陈晗晗 任肖月 《长江信息通信》 2022年第12期28-30,34,共4页
图像超分辨率是图像处理中一个经典问题,从低分辨率图像中恢复高分辨率图像的不确定性给问题的求解带来了极大的挑战。作为一个热门的应用领域,从问题提出至今,研究者们提出了许多的解决方法。随着科技进步和深度学习的发展,基于卷积神... 图像超分辨率是图像处理中一个经典问题,从低分辨率图像中恢复高分辨率图像的不确定性给问题的求解带来了极大的挑战。作为一个热门的应用领域,从问题提出至今,研究者们提出了许多的解决方法。随着科技进步和深度学习的发展,基于卷积神经网络等的深度学习方法应用于图像超分辨率重建,使得重建图像的质量得到了极大的提高。文章对基于深度学习的图像超分辨率重建的一些较为经典的方法进行了总结与探讨,分析了其中的优势与不足,并指出了目前方法中存在的问题和今后研究可以努力的方向。 展开更多
关键词 深度学习 图像超分辨率重建 卷积神经网络 残差学习
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Multiple current peaks and spatial characteristics of atmospheric helium dielectric barrier discharges with repetitive unipolar narrow pulse excitation 被引量:1
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作者 Xiangyu ZHOU Qiao WANG +1 位作者 dong dai Zeen HUANG 《Plasma Science and Technology》 SCIE EI CAS CSCD 2021年第6期21-29,共9页
Atmospheric dielectric barrier discharges driven by repetitive unipolar narrow pulse excitation are investigated numerically by using one-dimensional fluid models.The one-dimensional simulation focuses on the effects ... Atmospheric dielectric barrier discharges driven by repetitive unipolar narrow pulse excitation are investigated numerically by using one-dimensional fluid models.The one-dimensional simulation focuses on the effects of applied voltage amplitude,pulse repetition frequency,gap width andγcoefficient on the multiple-current-pulse(MCP)discharge.The results indicate that the MCP behavior will lead to the stratification of electron density distribution in axial direction.Traditional MCP manipulating methods,such as reducing the applied voltage amplitude,increasing the applied voltage frequency,adjusting the gap width,cannot regulate MCPs exhibiting in this work.Further analyses reveal that the increasing electric field of the cathode fall region is the basis for the emergence of MCP behavior. 展开更多
关键词 dielectric barrier discharges narrow pulse excitation multiple-current-pulse discharge electric field cathode fall region
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Nonlinear phenomena in dielectric barrier discharges: pattern, striation and chaos 被引量:1
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作者 Jiting OUYANG Ben LI +1 位作者 Feng HE dong dai 《Plasma Science and Technology》 SCIE EI CAS CSCD 2018年第10期23-50,共28页
The nonlinear phenomenon is very popular in dielectric barrier discharge (DBD) plasmas. There are at least three kinds of spatial and temporal nonlinear phenomena appearing synchronously or asynchronously in DBDs, i... The nonlinear phenomenon is very popular in dielectric barrier discharge (DBD) plasmas. There are at least three kinds of spatial and temporal nonlinear phenomena appearing synchronously or asynchronously in DBDs, i.e. self-organized patterns, striations and chaos. This paper describes the recent research and progress in understanding the nature of these nonlinear phenomena. Patterns are macroscopic structures with certain spatial and/or temporal periodicities generated through self- organization of microscopic parameters. The physics of patterns in DBDs is mainly associated with lateral dynamic behaviors or the lateral non-local effect of charged particles resulting in the lateral development or non-uniformity of discharge. Striations are ionization waves with unique properties determined by transport phenomena, ionization processes and electron kinetics in current-carrying plasmas. The physics of striations in DBDs is mainly associated with the advances in non-local electron kinetics in spatially inhomogeneous plasmas. Chaos is a kind of random and non-periodic phenomenon occunfng in a determined dynamic system, following a series of certain rules while exhibiting random locomotion, and is regarded as an intrinsic and ubiquitous phenomenon in a nonlinear dynamic system. An evolution trajectory including period-doubling bifurcation to chaos was observed in DBDs or DBD-derived plasmas. In a common sense, it is believed that the formation of all the three nonlinear phenomena in a DBD system should be related to the non-local transversal and/or longitudinal dynamics of space charges (i.e. non-local effect) or the localized electric field interaction. Future work is still needed on the underlying physics and should be directed to pursuing the unification of these nonlinear phenomena in DBD. 展开更多
关键词 nonlinear phenomenon dielectric barrier discharge PATTERN STRIATION CHAOS
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多芯片组件电路封装的频域分析和仿真 被引量:2
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作者 畅艺峰 邹旭军 +2 位作者 董戴 李智荣 雷群龙 《通信技术》 2019年第2期482-484,共3页
改进数字显示电路的技术控制单元,采用多芯片组件技术,利用APD(Advanced PackageDesigner)软件,对数字显示电路进行MCM封装,以实现更高的封装密度和工作频率。多芯片组件(MCM)封装模拟仿真结果表明,MCM封装后电路的响应时间可以满足设... 改进数字显示电路的技术控制单元,采用多芯片组件技术,利用APD(Advanced PackageDesigner)软件,对数字显示电路进行MCM封装,以实现更高的封装密度和工作频率。多芯片组件(MCM)封装模拟仿真结果表明,MCM封装后电路的响应时间可以满足设计要求。Spectra计算结果表明,采用改进方法和MCM封装技术,可明显改善信号的延时和电磁干扰强度,分析与计算结果一致。 展开更多
关键词 多芯片组件 布局布线 频域 仿真
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摄影测量与激光扫描融合技术研究
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作者 许广宏 董岱 《上海汽车》 2021年第2期31-35,共5页
基于提高激光扫描和摄影测量在三维建模和信息提取上优势互补效果的目的,采用了一种激光扫描技术在摄影建模基础上进行平差融合的方法,通过对建筑物进行摄影测量和地面摆站激光扫描相结合的数据处理试验,得出了通过两者技术融合在统一... 基于提高激光扫描和摄影测量在三维建模和信息提取上优势互补效果的目的,采用了一种激光扫描技术在摄影建模基础上进行平差融合的方法,通过对建筑物进行摄影测量和地面摆站激光扫描相结合的数据处理试验,得出了通过两者技术融合在统一坐标系点云构建具备可行性的结论,并在试验结论中提出了进一步研究的意见。 展开更多
关键词 摄影测量 激光扫描 空间反解 点云融合
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On the chronological understanding of the homogeneous dielectric barrier discharge 被引量:1
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作者 Xinpei Lu Zhi Fang +6 位作者 dong dai Tao Shao Feng Liu Cheng Zhang Dawei Liu Lanlan Nie Chunqi Jiang 《High Voltage》 SCIE EI CSCD 2023年第6期1132-1150,共19页
Dielectric barrier discharges(DBD)are widely utilised non‐equilibrium atmospheric pressure plasmas with a diverse range of applications,such as material processing,surface treatment,light sources,pollution control,an... Dielectric barrier discharges(DBD)are widely utilised non‐equilibrium atmospheric pressure plasmas with a diverse range of applications,such as material processing,surface treatment,light sources,pollution control,and medicine.Over the course of several decades,extensive research has been dedicated to the generation of homogeneous DBD(H‐DBD),focussing on understanding the transition from H‐DBD to filamentary DBD and exploring strategies to create and sustain H‐DBD.This paper first discusses the in-fluence of various parameters on DBD,including gas flow,dielectric material,surface conductivity,and mesh electrode.Secondly,a chronological literature review is presented,highlighting the development of H‐DBD and the associated understanding of its un-derlying mechanisms.This encompasses the generation of H‐DBD in helium,nitrogen,and air.Lastly,the paper provides a brief overview of multiple‐current‐pulse(MCP)behaviours in H‐DBD.The objective of this article is to provide a chronological un-derstanding of homogeneous dielectric barrier discharge(DBD).This understanding will aid in the design of new experiments aimed at better comprehending the mechanisms behind H‐DBD generation and ultimately assist in achieving large‐volume H‐DBD in an air environment. 展开更多
关键词 DIELECTRIC BARRIER POLLUTION
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Design and performance analysis of indoor calibration device for the forcemeasuring system of the tractor three-point hitch
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作者 dong dai Du Chen +4 位作者 Xu Mao Yawei Zhang Yutong Li Shumao Wang Bin Zhang 《International Journal of Agricultural and Biological Engineering》 SCIE 2023年第3期47-54,共8页
The real-time monitoring of the load in farming by the sensor installed on the tractor's three-point hitch can effectively improve the farming efficiency and force-position combined control,reduce the compaction r... The real-time monitoring of the load in farming by the sensor installed on the tractor's three-point hitch can effectively improve the farming efficiency and force-position combined control,reduce the compaction risk of the wheel on the soil and reduce the fuel consumption in farming process.However,the measurement and quantification of the loads on the three-point hitch have some problems remaining unresolved:testing the accuracy and reliability of a load measuring system is hard when the tractor works in a field,the mathematical model of spatial forces usually lacks a practical and effective validation,and the calibration process of the measurement system is inconvenient and incomplete while easily causing a low accuracy.Specifically,this paper builds a new spatial-force mathematical model based on the geometry of a three-point hitch.To eliminate the discrepancy of the geometric model with the actual structure and to refine the mathematical model,a calibration process is conducted by developing a calibration bench,which is equipped with a data acquisition system and a multi-parameter monitoring interface.The three-point hitch installed on this calibration bench is subject to steady-state loading.The loading force,angle of the lower drawbar,and three-component forces(three shaft pin sensors’forces)of the three-point hitch are well measured.With applying for the measured data to calibrate the theoretical mathematic model eventually derives the resultant force from all the three-component forces,a dynamical loading bench was developed to test the calculated resultant force for the three-point hitch during the sinusoidal and randomly variant dynamical loadings tests.A hitch force measurement system is also developed to collect real-time data and calculate the resultant force of measured three-component forces through the calibrated mathematical model.The results of the dynamical loading tests show that the average relative error MRE=1.09%with an average force measurement time delay beingΔt=0.5 s,the root mean square error RMSE=59.3 N,and the coefficient of determination R2=0.9903.As observed,the shape and the trend of the generated resultant force curve are basically the dynamical loading force.The dynamical loading test proves the high efficacy and reliability of the proposed indoor calibration method for calculating the load based on the three-component forces as measured on the three-point hitch.Besides,the preliminary study of the proposed method on the hitch load provides great potential to improve the indoor six-component measurement and quantification of both the force and momentum acting on the three-point hitch. 展开更多
关键词 TRACTOR three-point hitch hitch force calibration bench hitch force measurement system dynamic loading verification method
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植物群落稀有种维持机制与土壤反馈的研究进展 被引量:7
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作者 戴冬 邢华 +3 位作者 杨佳绒 刘雅静 蔡焕满 刘宇 《生物多样性》 CAS CSCD 北大核心 2021年第12期1687-1699,共13页
自Janzen-Connell(J-C)假说提出后半个世纪以来,生态学家在热带及亚热带森林对该假说开展的大量实证研究表明,由专性天敌导致的J-C效应所引起的负密度制约是维持森林多样性和决定群落组成的重要驱动力,该假说成功地解释了热带及亚热带... 自Janzen-Connell(J-C)假说提出后半个世纪以来,生态学家在热带及亚热带森林对该假说开展的大量实证研究表明,由专性天敌导致的J-C效应所引起的负密度制约是维持森林多样性和决定群落组成的重要驱动力,该假说成功地解释了热带及亚热带森林的丰富多样性。土壤病原真菌所引起的植物–土壤负反馈是J-C效应最主要的表现形式。然而,对于植物–土壤负反馈是否能够维持森林群落中的大量稀有种仍然存在许多争议。基于当代物种共存理论的"稀有种优势"假说认为,只有在满足"可入侵准则"(即物种在稀有时具有种群增加的趋势)的前提下,稀有种才能在群落中与其他物种长期共存。然而,当前基于土壤反馈的实验结果与该理论预测相悖,因此在稀有种的维持机制方面仍存在较大的分歧。本文通过介绍植物–土壤反馈理论,整合了可能对稀有种维持有较大影响的因素,包括共生菌根真菌、土壤养分以及植物细根性状等在影响土壤负反馈方面的相关研究,并对这些因素如何影响群落中物种多度和稀有种在群落中的维持进行了探讨。最后,我们也从其他角度探讨了一些对稀有种维持的研究。我们认为在未来对稀有种的研究中,探讨使其长期存续的"优势"和制约其种群扩大的"限制"同等重要,将当代物种共存理论与新技术、新方法相结合对于探究稀有种的维持机制具有重要的意义,可为稀有种保护提供理论依据。 展开更多
关键词 同种负密度制约 森林群落 入侵准则 Janzen-Connell假说 植物–土壤反馈 稀有种 物种多度
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