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Cu含量和热处理工艺对Al-Si-Mg-Mn-xCu铸造铝合金显微组织和力学性能的影响
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作者 贾志宏 周广文 +5 位作者 周宏宇 刘飞 丁立鹏 翁瑶瑶 向开云 赵海东 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2024年第3期737-754,共18页
采用三维X射线显微镜、光学显微镜、扫描电子显微镜、透射电子显微镜及硬度测试系统研究Cu含量及热处理工艺对真空压铸Al-Si-Mg-Mn-xCu合金显微组织和力学性能的影响。研究发现,虽然Cu含量增加会提高铸锭中气孔的密度和尺寸,但是Cu添加... 采用三维X射线显微镜、光学显微镜、扫描电子显微镜、透射电子显微镜及硬度测试系统研究Cu含量及热处理工艺对真空压铸Al-Si-Mg-Mn-xCu合金显微组织和力学性能的影响。研究发现,虽然Cu含量增加会提高铸锭中气孔的密度和尺寸,但是Cu添加将促进凝固过程中含Cu初生相(Q-Al_(5)Cu_(2)Mg_(8)Si_(6)和θ-Al_(2)Cu)的形成,从而提高合金性能。合金中形成5种不同结构的初生相,包括共晶Si、α-Al(Fe,Mn)Si、β-Mg_(2)Si、Q-Al_(5)Cu_(2)Mg_(8)Si_(6)和θ-Al_(2)Cu相。随着Cu含量增加,θ相的面积分数迅速增加,α-Al(Fe,Mn)Si相面积分数首先降低,随后缓慢增加,而Q相的变化趋势与α-Al(Fe,Mn)Si相相反。这些初生相在热处理过程中会出现不同的演变规律。在随后的时效处理过程中,Q'和θ'相的协同析出能显著提高合金的时效硬化潜力。 展开更多
关键词 铝硅铸造合金 真空压铸 热处理 显微组织 力学性能 初生相
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Ascending phase of solar cycle 25 tilts the current El Nino-Southern oscillation transition
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作者 Wenjuan Huo Ziniu Xiao +1 位作者 Liang Zhao fei liu 《Atmospheric and Oceanic Science Letters》 CSCD 2024年第1期34-38,共5页
自2020年初夏,赤道太平洋地区出现拉尼娜现象并持续两年半多(以下简称2020拉尼娜),对其未来演变的预测引起了很多关注,考虑到11年太阳周期活动对热带太平洋SST异常可能存在锁相影响,本研究分析了当前太阳活动周(即第25太阳周(SC25))对... 自2020年初夏,赤道太平洋地区出现拉尼娜现象并持续两年半多(以下简称2020拉尼娜),对其未来演变的预测引起了很多关注,考虑到11年太阳周期活动对热带太平洋SST异常可能存在锁相影响,本研究分析了当前太阳活动周(即第25太阳周(SC25))对目前热带太平洋ENSO现象未来演变的调节作用,基于历史太阳周的统计特征,作者对第25太阳周达到其最大值的时间提出三种可能的情景,并讨论了不同情景下的太阳活动对未来两年ENSO演变的可能影响,第25太阳周的持续上升阶段在一定程度上抑制了当前2023厄尔尼诺现象发展为超级事件. 展开更多
关键词 厄尔尼诺-南方涛动 太阳活动 热带太平洋 位相转变 预测 三重拉尼娜现象
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Southern Hemisphere Volcanism Triggered Multi-year La Niñas during the Last Millennium
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作者 Shangrong ZHOU fei liu 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第4期587-592,共6页
To explain the recent three-year La Niña event from 2020 to 2022,which has caused catastrophic weather events worldwide,Fasullo et al.(2023)demonstrated that the increase in biomass aerosol resulting from the 201... To explain the recent three-year La Niña event from 2020 to 2022,which has caused catastrophic weather events worldwide,Fasullo et al.(2023)demonstrated that the increase in biomass aerosol resulting from the 2019-20 Australian wildfire season could have triggered this multi-year La Niña.Here,we present compelling evidence from paleo-proxies,utilizing a substantial sample size of 26 volcanic eruptions in the Southern Hemisphere(SH),to support the hypothesis that ocean cooling in the SH can lead to a multi-year La Niña event.This research highlights the importance of focusing on the Southern Ocean,as current climate models struggle to accurately simulate the Pacific response driven by the Southern Ocean. 展开更多
关键词 volcanic eruptions multi-year La Niñas Australian wildfire southern ocean cooling
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Differences in spring precipitation over southern China associated with multiyear La Ni?a events
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作者 Guangliang Li Licheng Feng +3 位作者 Wei Zhuang fei liu Ronghua Zhang Cuijuan Sui 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2024年第2期1-10,共10页
Composite analyses were performed in this study to reveal the difference in spring precipitation over southern China during multiyear La Ni?a events during 1901 to 2015. It was found that there is significantly below-... Composite analyses were performed in this study to reveal the difference in spring precipitation over southern China during multiyear La Ni?a events during 1901 to 2015. It was found that there is significantly below-normal precipitation during the first boreal spring, but above-normal precipitation during the second year. The difference in spring precipitation over southern China is correlative to the variation in western North Pacific anomalous cyclone(WNPC), which can in turn be attributed to the different sea surface temperature anomaly(SSTA) over the Tropical Pacific. The remote forcing of negative SSTA in the equatorial central and eastern Pacific and the local air-sea interaction in the western North Pacific are the usual causes of WNPC formation and maintenance.SSTA in the first spring is stronger than those in the second spring. As a result, the intensity of WNPC in the first year is stronger, which is more likely to reduce the moisture in southern China by changing the moisture transport, leading to prolonged precipitation deficits over southern China. However, the tropical SSTA signals in the second year are too weak to induce the formation and maintenance of WNPC and the below-normal precipitation over southern China. Thus, the variation in tropical SSTA signals between two consecutive springs during multiyear La Ni?a events leads to obvious differences in the spatial pattern of precipitation anomaly in southern China by causing the different WNPC response. 展开更多
关键词 multiyear La Nina precipitation anomaly anomalous western North Pacific cyclone southern China
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Colonoscopy plays an important role in detecting colorectal neoplasms in patients with gastric neoplasms
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作者 Xu-Rui liu Ze-Lin Wen +4 位作者 fei liu Zi-Wei Li Xiao-Yu liu Wei Zhang Dong Peng 《World Journal of Gastrointestinal Oncology》 SCIE 2024年第1期133-143,共11页
BACKGROUND Gastric cancer(GC)and colorectal cancer(CRC)are the fifth and third most common cancer worldwide,respectively.Nowadays,GC is reported to have a potential predictive value for CRC,especially for advanced CRC... BACKGROUND Gastric cancer(GC)and colorectal cancer(CRC)are the fifth and third most common cancer worldwide,respectively.Nowadays,GC is reported to have a potential predictive value for CRC,especially for advanced CRC.AIM To evaluate the necessity of colonoscopy for gastric neoplasm(GN)patients.METHODS Four databases,including PubMed,EMBASE,the Cochrane Library,and Ovid,were used to perform the search strategy on May 2,2023.The prevalence of colorectal neoplasms(CRN)and baseline characteristics were compared between the neoplasm group and the control group.Continuous variables are expressed as the mean difference and standard deviation.Relationships of categorical variables in the two groups are expressed as odds ratios(OR)and 95%confidence intervals(95%CIs).Subgroup analysis according to different kinds of GNs was conducted for more in-depth analysis.The results of this study are represented by forest plots.Publication bias was evaluated by a funnel plot.All data analyses were performed by STATA SE 16.0 software.RESULTS A total of 3018 patients with GNs and 3905 healthy controls(age and sex matched)were enrolled for analysis.After comparing the prevalence of CRNs between the two groups,CRNs were detected significantly more frequently in GN patients than in controls(OR=1.69,95%CI=1.28 to 2.23,I^(2)=85.12%,P=0.00),especially in patients with GC(OR=1.80,95%CI=1.49 to 2.18,I^(2)=25.55%,P<0.1).Moreover,other risk factors including age(OR=1.08,95%CI=1.00 to 1.17,I^(2)=90.13%,P=0.00)and male sex(OR=2.31,95%CI=1.26 to 4.22,I^(2)=87.35%,P=0.00),were related to the prevalence of CRNs.For patients in the GN group,body mass index(BMI,OR=0.88,95%CI=0.80 to 0.98,I^(2)=0.00%,P=0.92)and smoking(OR=1.03,95%CI=1.01 to 1.05,I^(2)=0.00%,P=0.57)were protective and risk factors for CRNs,respectively.CONCLUSION Patients are recommended to undergo colonoscopy when diagnosed with GNs,especially GC patients with a low BMI and a history of smoking. 展开更多
关键词 Gastric neoplasm Gastric cancer Colorectal neoplasm COLONOSCOPY
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Poor oral health was associated with higher risk of gastric cancer: Evidence from 1431677 participants
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作者 fei liu Shi-Jun Tang +4 位作者 Zi-Wei Li Xu-Rui liu Quan Lv Wei Zhang Dong Peng 《World Journal of Gastrointestinal Surgery》 SCIE 2024年第2期585-595,共11页
BACKGROUND In recent years,the association between oral health and the risk of gastric cancer(GC)has gradually attracted increased interest.However,in terms of GC incidence,the association between oral health and GC i... BACKGROUND In recent years,the association between oral health and the risk of gastric cancer(GC)has gradually attracted increased interest.However,in terms of GC incidence,the association between oral health and GC incidence remains contro-versial.Periodontitis is reported to increase the risk of GC.However,some studies have shown that periodontitis has no effect on the risk of GC.Therefore,the present study aimed to assess whether there is a relationship between oral health and the risk of GC.AIM To assess whether there was a relationship between oral health and the risk of GC.METHODS Five databases were searched to find eligible studies from inception to April 10,2023.Newcastle-Ottawa Scale score was used to assess the quality of included studies.The quality of cohort studies and case-control studies were evaluated separately in this study.Incidence of GC were described by odds ratio(OR)and 95%confidence interval(CI).Funnel plot was used to represent the publication bias of included studies.We performed the data analysis by StataSE 16.RESULTS A total of 1431677 patients from twelve included studies were enrolled for data analysis in this study.According to our analysis,we found that the poor oral health was associated with higher risk of GC(OR=1.15,95%CI:1.02-1.29;I2=59.47%,P=0.00<0.01).Moreover,after subgroup analysis,the outcomes showed that whether tooth loss(OR=1.12,95%CI:0.94-1.29;I2=6.01%,P>0.01),gingivitis(OR=1.19,95%CI:0.71-1.67;I2=0.00%,P>0.01),dentures(OR=1.27,95%CI:0.63-1.19;I2=68.79%,P>0.01),or tooth brushing(OR=1.25,95%CI:0.78-1.71;I2=88.87%,P>0.01)had no influence on the risk of GC.However,patients with periodontitis(OR=1.13,95%CI:1.04-1.23;I2=0.00%,P<0.01)had a higher risk of GC.CONCLUSION Patients with poor oral health,especially periodontitis,had a higher risk of GC.Patients should be concerned about their oral health.Improving oral health might reduce the risk of GC. 展开更多
关键词 Oral health Tooth loss PERIODONTITIS Gastric cancer Risk factor
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含硒氮杂中环的光化学合成、分析及表征综合实验设计
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作者 刘菲 赵冬阳 +2 位作者 孙凯 于婷婷 王薪 《大学化学》 CAS 2024年第3期369-375,共7页
化学综合实验在大学化学教学中处于基础核心地位。作者结合团队最新研究成果,设计了一个可见光诱导合成含硒七元氮杂中环的综合实验。通过底物设计制备→可见光催化合成→结构表征分析等环节,对学生连续多步合成操作、过程分析和结构解... 化学综合实验在大学化学教学中处于基础核心地位。作者结合团队最新研究成果,设计了一个可见光诱导合成含硒七元氮杂中环的综合实验。通过底物设计制备→可见光催化合成→结构表征分析等环节,对学生连续多步合成操作、过程分析和结构解析等技能进行系统训练,培养学生学习的系统性、全面性。在此基础上,学生可以充分了解光化学反应的前沿和优势,培养学生绿色化学意识。 展开更多
关键词 光化学 氮杂环 有机硒
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Data-driven polarimetric imaging: a review
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作者 Kui Yang fei liu +8 位作者 Shiyang Liang Meng Xiang Pingli Han Jinpeng liu Xue Dong Yi Wei Bingjian Wang Koichi Shimizu Xiaopeng Shao 《Opto-Electronic Science》 2024年第2期1-44,共44页
This study reviews the recent advances in data-driven polarimetric imaging technologies based on a wide range of practical applications.The widespread international research and activity in polarimetric imaging techni... This study reviews the recent advances in data-driven polarimetric imaging technologies based on a wide range of practical applications.The widespread international research and activity in polarimetric imaging techniques demonstrate their broad applications and interest.Polarization information is increasingly incorporated into convolutional neural networks(CNN)as a supplemental feature of objects to improve performance in computer vision task applications.Polarimetric imaging and deep learning can extract abundant information to address various challenges.Therefore,this article briefly reviews recent developments in data-driven polarimetric imaging,including polarimetric descattering,3D imaging,reflection removal,target detection,and biomedical imaging.Furthermore,we synthetically analyze the input,datasets,and loss functions and list the existing datasets and loss functions with an evaluation of their advantages and disadvantages.We also highlight the significance of data-driven polarimetric imaging in future research and development. 展开更多
关键词 deep learning polarimetric imaging image processing
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Epidemiological Investigation of Brucellosis Spondylitis and Optimal Selection of Clinical Drug Compatibility, Treatment Course and Treatment Plan
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作者 Xinming Yang fei liu Yanlin Yin 《Open Journal of Preventive Medicine》 CAS 2023年第5期129-138,共10页
Background: Brucellosis is a zoonotic endemic disease, the main source of infection is infected cattle, sheep, pigs and their products. In recent years, the global incidence of brucellosis spondylitis has increased ye... Background: Brucellosis is a zoonotic endemic disease, the main source of infection is infected cattle, sheep, pigs and their products. In recent years, the global incidence of brucellosis spondylitis has increased year by year, and it has spread from pastoral areas to semi-agricultural and semi-pastoral areas, agricultural areas and cities. It has changed from a mainly occupational disease to a mainly food-borne disease, and it is also a zoonotic specific spinal infectious disease that WHO and governments around the world pay great attention to. Due to the low cure rate and high recurrence rate of traditional drug therapy regimen. Therefore, to carry out epidemiological investigation and Related research on clinical drug therapy of brucellosis spondylitis has practical significance for improving diagnosis rate, cure rate and reducing recurrence rate. Objective: To analyze the epidemiological characteristics of Brucellosis spondylitis and explore the choice of drugs and the best drug treatment plan, so as to provide scientific basis for improving the prevention and control of the disease and treatment effect. Methods: Clinical epidemiodogical materials were collected from 113 patients with brucellar spondylitis. All these patients were divided into 5 different groups according to 5 kinds of drugs adopted respectively, and then the patients were given different course of treatment. Results: In the 113 patients, brucellar spondylitis morbility of female patients were higher than that of male ones, and the morbility of Bashang were higher than that of Baxia. These patients were infected mainly through browsing and breeding beasts. Lumbars were the major focus of infection. It was very comnlon that two adjacent lumbars were involved in concurrently. L4 was the most common infection location and its demolishment was most serious. The curative effect of group treated with doxycycline was better than that of group treated without doxycycline. If the course of treatment Was increased, the curative effect Was not increased obviously. Conclusions: There are characteristic features in clinical epidemiology of brucell spondylitis. Doxycycline + Rifampicin + Sulfamethoxazole was used as the preferred antibiotic. Using antibiotics adequately and jointly by two courses of treatment for a long time is the most reasonable way to treat the disease and prevent the disease from recurrence. 展开更多
关键词 BRUCELLOSIS SPONDYLITIS EPIDEMIOLOGY Drug Compatibility Treatment Course PHARMACOTHERAPY Optimize Treatment
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Clinical Study on Treatment of Type II/III Lumbar Brucellar Spondylitis by Unilateral Biportal Endoscopy
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作者 Xinming Yang Yongli Jia +2 位作者 fei liu Zhe Zhang Peinan Zhang 《Surgical Science》 2023年第5期321-330,共10页
Objective: Explore the feasibility and clinical efficacy of using unilateral biportal endoscopy for the treatment of Type II/III lumbar brucellar spondylitis. Methods: A retrospective study of the clinical data of 20 ... Objective: Explore the feasibility and clinical efficacy of using unilateral biportal endoscopy for the treatment of Type II/III lumbar brucellar spondylitis. Methods: A retrospective study of the clinical data of 20 patients with Type II/III lumbar brucellar spondylitis admitted to the First Affiliated Hospital of Hebei North University from January 2020 to May 2022, including 15 males and 5 females, aged 41 - 60 years old, average age (48.11 ± 7.28) years old. After admission, the patient can isolate brucella through metagenomic Next-Generation Sequencing (mNGS), meeting the tertiary diagnostic criteria. Preoperative conventional drug treatment, unilateral biportal endoscopic minimally invasive surgery was performed when nutrition was improved, perioperative control of various indexes was stable, and erythrocyte sedimentation was declining. It was completed under an endoscope. The lesion was cleared, spinal nerve compression was relieved, interbody fusion was performed, and the spine was fixed by a percutaneous pedicle screw. Erythrocyte Sedimentation Rate (ESR), C-Reactive Protein (CRP), Visual Analogue Scale (VAS), Japanese Orthopedic Association (JOA) score and Oswestry Disability Index (ODI) were analyzed at 1 month, 3 months, 6 months and the last follow-up. At the final follow-up of all patients, the clinical efficacy criteria and the Bridwell grading criteria were used to evaluate the recovery and intervertebral bone graft fusion, respectively. Results: All patients’ lower back and leg pain was relieved the next day after surgery. At a follow-up of one month after surgery, both systemic and local symptoms significantly improved. At the last follow-up, clinical symptoms disappeared and there was no tenderness or percussion pain in the local area. With the passage of time, 1 month, 3 months, 6 months after the operation, and the last follow-up are all evaluation indicators compared with those before the operation. No matter VAS, JOA, ODI score, or ESR, CRP is significantly improved compared with preoperative (P All 20 cases in this group reached the BS clinical cure standard, and the excellent rate of intervertebral bone graft fusion was 95%. Conclusion: On the basis of . 展开更多
关键词 Brucellar Spondylitis Minimally Invasive Surgery Unilateral Biportal Endoscopy Clinical Efficacy
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全基因组重测序解析秦川牛保种群遗传多样性和遗传结构 被引量:1
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作者 马钧 樊安平 +7 位作者 王武生 张金川 江晓军 马瑞军 贾社强 刘飞 雷初朝 黄永震 《遗传》 CAS CSCD 北大核心 2023年第7期602-616,共15页
在畜禽资源保护中,群体遗传多样性和遗传结构是决定保种效果的重要因素。本研究采用全基因组重测序技术检测100头秦川牛(30头公牛、70头母牛)的基因组变异,通过分析群体遗传多样性、连续纯合片段(runs of homozygosity,ROH)分布特征、... 在畜禽资源保护中,群体遗传多样性和遗传结构是决定保种效果的重要因素。本研究采用全基因组重测序技术检测100头秦川牛(30头公牛、70头母牛)的基因组变异,通过分析群体遗传多样性、连续纯合片段(runs of homozygosity,ROH)分布特征、亲缘关系和家系结构,对秦川牛的保种效果进行了综合评估。结果显示,100头秦川牛共检测到20,968,017个高质量SNPs位点,平均最小等位基因频率为0.191±0.124,平均多态信息含量为0.279±0.131,平均观察杂合度为0.275±0.131,平均期望杂合度为0.279±0.131,表明秦川保种群遗传多样性较为丰富。秦川牛保种群体平均状态同源(identity by state,IBS)遗传距离为0.243±0.020,其中公牛为0.242±0.021,亲缘关系G矩阵结果与IBS距离矩阵结果一致,均显示秦川牛保种群部分个体间亲缘关系较近。100头秦川牛个体共检测到8258个基因组ROH,ROH总长度为9.64 GB,平均ROH长度为1.167±1.203 Mb,69.35%的ROH是长度为0.5~1 Mb的短ROH。个体平均ROH总长度为96.40 Mb。基于ROH的平均近交系数为0.039±0.039,其中30头秦川公牛的平均近交系数为0.044±0.035,表明部分公牛个体存在一定程度的近交积累。进化树结果显示,秦川牛保种群所测个体可分为8个家系,包括7个含公牛家系和1个不含公牛家系。本研究表明,秦川牛保种群的遗传多样性较为丰富,未出现较大程度近交积累,但部分个体间存在近交风险,应强化选配以确保秦川牛资源的可持续发展。 展开更多
关键词 秦川牛 全基因组重测序 遗传多样性 遗传结构 亲缘关系
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无金属、卤素、硫等杂元素的聚甲基丙烯酸甲酯纳米微球的合成 被引量:1
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作者 刘志 刘飞 +2 位作者 淡宜 黄云 江龙 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2023年第3期1-7,15,共8页
聚合物纳米微球可用于多孔催化剂的制备,但是来源于乳化剂、引发剂等的硫、卤素、碱金属等容易导致催化剂中毒。因此,文中以十二烷基二甲基氧化胺为乳化剂,过氧化氢/抗坏血酸氧化还原体系为引发剂,通过甲基丙烯酸甲酯乳液聚合,合成了仅... 聚合物纳米微球可用于多孔催化剂的制备,但是来源于乳化剂、引发剂等的硫、卤素、碱金属等容易导致催化剂中毒。因此,文中以十二烷基二甲基氧化胺为乳化剂,过氧化氢/抗坏血酸氧化还原体系为引发剂,通过甲基丙烯酸甲酯乳液聚合,合成了仅含碳、氢、氧、氮4种元素的聚甲基丙烯酸甲酯纳米微球。研究了聚合工艺、引发剂用量与配比、乳化剂用量及单体浓度对单体转化率和微球粒径的影响。结果表明,搅拌速率、温度、引发剂配比及乳化剂用量对单体转化率的影响较大;微球粒径受聚合工艺、引发剂用量及配比的影响较小,微球粒径主要受乳化剂用量和单体浓度控制。 展开更多
关键词 乳液聚合 杂元素 过氧化氢 抗坏血酸 十二烷基二甲基氧化胺
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Analysis of Chinese Citizens’Perception and Its Differences of City Spirit:A Case Study of Hefei City
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作者 Zhiguo Yao fei liu Min Xiang 《Journal of Geographical Research》 2022年第3期41-48,共8页
City spirit is the soul of the city.The spread of city spirit not only could establish a civilized specimen for citizens,but also create a good cultural atmosphere for the city.Hefei residents’perception of city spir... City spirit is the soul of the city.The spread of city spirit not only could establish a civilized specimen for citizens,but also create a good cultural atmosphere for the city.Hefei residents’perception of city spirit is extensive,and most of Hefei citizens consider the expression words of city spirit are very appropriate,which is enlightened,open-minded,actual and innovate.Great majority of Hefei citizens willing to support the propaganda and promotion of the city spirit,and they think the promotion of the city spirit plays a key role in the way of city’s development.In addition,significant differences in the perception of urban spirituality emerge among residents with different economic and social characteristics.There are four aspects about how to enhance the public perception of city spirit,which including increasing dissemination channels and means,strengthening guidance according to the difference of residents,encouraging participation of community residents,and building good atmosphere depending on the city’s advantages. 展开更多
关键词 City spirit Hefei City PERCEPTION
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Structure and Properties of PLA Composite Enhanced with Biomass Fillers from Herbaceous Plants 被引量:2
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作者 Haining Na Juncheng Huang +5 位作者 Hongguang Xu fei liu Liangke Xie Baoqing Zhu Jiuchen Wang Jin Zhu 《Journal of Renewable Materials》 SCIE EI 2023年第2期491-503,共13页
PLA composites containing biomass fillers from the three herbaceous plants such as reed,wheat stalk,and coco-nut fiber with length and diameter at the scale of several millimeters were prepared without using additives... PLA composites containing biomass fillers from the three herbaceous plants such as reed,wheat stalk,and coco-nut fiber with length and diameter at the scale of several millimeters were prepared without using additives.The reinforcement effect on the properties of PLA/biomass filler composites is investigated.The research results show that the PLA/biomass filler composites exhibit good stiffness,flexural strength,and impact toughness.Among the three kinds of biomass fillers,reed reinforced PLA composites show optimal mechanical properties.When filled with 40%–50%reed,the flexural moduli of the composites are over 7000 MPa.Flexural strength retains at the same level of pure PLA.The notch impact strength reaches to 4.50±0.73 kJ/m^(2),which is 2.06 times higher than that of pure PLA.Furthermore,the introduction of biomass fillers increases the crystallization ability of PLA and does not increase the water absorption of the composites.This research demonstrated that PLA composites prepared with biomass fillers from the herbaceous plants(namely herb plastic composites,HPCs)is a material with good comprehensive mechanical properties while retaining the intrinsic particularity of biological sources. 展开更多
关键词 PLA biomass filler herb plastic composites
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Effects of substrate on burrowing behavior,feeding physiology,and energy budget of undulated surf clam Paphia undulata
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作者 Pengfei ZHANG Edwine YONGO +5 位作者 fei liu Shuai PAN Anfu SUN Long ZHOU Zhiqiang GUO Caihuan KE 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2023年第5期1795-1808,共14页
Substrate is an important abiotic factor for burrowing shellfish,as it not only provides them with shelter,but also impose significant effect on their physiological metabolism.However,the physiological responses of bu... Substrate is an important abiotic factor for burrowing shellfish,as it not only provides them with shelter,but also impose significant effect on their physiological metabolism.However,the physiological responses of burrowing clams within various substrates get less attention due to difficulty in carrying out physiological tests in buried conditions.Consequently,this study investigated the burrowing behavior,feeding physiology and energy budget of Paphia undulata,which is an important aquaculture bivalve species in south China.The clams were exposed to mud and sand substrates with variable physical properties in the laboratory,to determine the suitable substrate conditions for this species.The results showed that the percentage of burrowing clams,digging index,burrowing time,burrowing depth and scope for growth(SFG)were higher in mud substrates with≥40%water content.Likewise,burrowing percentage,digging index,and burrowing depths were higher in substrates with≤40%sand content.Moreover,the burrowing depth had significant effect on the feeding physiology and SFG of P.undulata as clams burrowed at 6.3±1.8 cm had higher clearance rates and SFG as compared to other buried depths.This study further revealed that low water content in the sediment inhibited physiological performances of P.undulata by impairing feeding or absorption,hence reducing the SFG.In conclusion,mud substrate with≥40%water content or with≤40%sand content is suitable for proper burrowing and growth of P.undulata.Our findings therefore provide fundamental knowledge that will be applicable in the improvement of bottom aquaculture and conservation of P.undulata. 展开更多
关键词 Paphia undulata SUBSTRATE feeding physiology scope for growth
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Estimation of the unfrozen water content of saturated sandstones by ultrasonic velocity
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作者 Shibing Huang fei liu +1 位作者 Gang liu Shilin Yu 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2023年第6期733-746,共14页
The unfrozen water content(UWC)of rocks at low temperature is an important index for evaluating the stability of the rock engineering in cold regions and artificial freezing engineering.This study addresses a new meth... The unfrozen water content(UWC)of rocks at low temperature is an important index for evaluating the stability of the rock engineering in cold regions and artificial freezing engineering.This study addresses a new method to estimate the UWC of saturated sandstones at low temperature by using the ultrasonic velocity.Ultrasonic velocity variations can be divided into the normal temperature stage(20 to 0℃),quick phase transition stage(0 to-5℃)and slow phase transition stage(-5 to-25℃).Most increment of ultrasonic velocity is completed in the quick phase transition stage and then turns to be almost a constant in the slow phase transition stage.In addition,the UWC is also measured by using nuclear magnetic resonance(NMR)technology.It is validated that the ultrasonic velocity and UWC have a similar change law against freezing and thawing temperatures.The WE(weighted equation)model is appropriate to estimate the UWC of saturated sandstones,in which the parameters have been accurately determined rather than by data fitting.In addition,a linear relationship between UWC and ultrasonic velocity is built based on pore ice crystallization theory.It is evidenced that this linear function can be adopted to estimate the UWC at any freezing temperature by using P-wave velocity,which is simple,practical,and accurate enough compared with the WE model. 展开更多
关键词 Ultrasonic velocity Freeze-thaw cycles Unfrozen water content Prediction function Hysteresis effect
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Ferroelectricity of hafnium oxide-based materials:Current status and future prospects from physical mechanisms to device applications
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作者 Wanwang Yang Chenxi Yu +9 位作者 Haolin Li Mengqi Fan Xujin Song Haili Ma Zheng Zhou Pengying Chang Peng Huang fei liu Xiaoyan liu Jinfeng Kang 《Journal of Semiconductors》 EI CAS CSCD 2023年第5期78-121,共44页
The finding of the robust ferroelectricity in HfO_(2)-based thin films is fantastic from the view point of both the fundamentals and the applications.In this review article,the current research status of the future pr... The finding of the robust ferroelectricity in HfO_(2)-based thin films is fantastic from the view point of both the fundamentals and the applications.In this review article,the current research status of the future prospects for the ferroelectric HfO_(2)-based thin films and devices are presented from fundamentals to applications.The related issues are discussed,which include:1)The ferroelectric characteristics observed in HfO_(2)-based films and devices associated with the factors of dopant,strain,interface,thickness,defect,fabrication condition,and more;2)physical understanding on the observed ferroelectric behaviors by the density functional theory(DFT)-based theory calculations;3)the characterizations of microscopic and macroscopic features by transmission electron microscopes-based and electrical properties-based techniques;4)modeling and simulations,5)the performance optimizations,and 6)the applications of some ferroelectric-based devices such as ferroelectric random access memory,ferroelectric-based field effect transistors,and the ferroelectric tunnel junction for the novel information processing systems. 展开更多
关键词 FERROELECTRICITY HfO_(2)-based thin films physical mechanism characterization modeling and simulation applications
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Adaptive saturated tracking control for solid launch vehicles in ascending based on differential inclusion stabilization
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作者 fei liu Song-yan Wang +1 位作者 Tao Chao Ming Yang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第8期157-179,共23页
The large-range uncertainties of specific impulse,mass flow per second,aerodynamic coefficients and atmospheric density during rapid turning in solid launch vehicles(SLVs) ascending leads to the deviation of the actua... The large-range uncertainties of specific impulse,mass flow per second,aerodynamic coefficients and atmospheric density during rapid turning in solid launch vehicles(SLVs) ascending leads to the deviation of the actual trajectory from the reference one.One of the traditional trajectory tracking methods is to observe the uncertainties by Extended State Observer(ESO) and then modify the control commands.However,ESO cannot accurately estimate the uncertainties when the uncertainty ranges are large,which reduces the guidance accuracy.This paper introduces differential inclusion(DI) and designs a controller to solve the large-range parameter uncertainties problem.When above uncertainties have large ranges,it can be combined with the ascent dynamic equation and described as a DI system in the mathematical form of a set.If the DI system is stabilized,all the subsets are stabilized.Different from the traditional controllers,the parameters of the designed controller are calculated by the uncertain boundaries.Therefore,the controller can solve the problem of large-range parameter uncertainties of in ascending.Firstly,the ascent deviation system is obtained by linearization along the reference trajectory.The trajectory tracking system with engine parameters and aerodynamic uncertainties is described as an ascent DI system with respect to state deviation,which is called DI system.A DI adaptive saturation tracking controller(DIAST) is proposed to stabilize the DI system.Secondly,an improved barrier Lyapunov function(named time-varying tangent-log barrier Lyapunov function) is proposed to constrain the state deviations.Compared with traditional barrier Lyapunov function,it can dynamically adjust the boundary of deviation convergence,which improve the convergence rate and accuracy of altitude,velocity and LTIA deviation.In addition,the correction amplitudes of angle of attack(AOA) and angle of sideslip(AOS) need to be limited in order to guarantee that the overload constraint is not violated during actual flight.In this paper,a fixed time adaptive saturation compensation auxiliary system is designed to shorten the saturation time and accelerate the convergence rate,which eliminates the adverse effects caused by the saturation.Finally,it is proved that the state deviations are ultimately uniformly bounded under the action of DIAST controller.Simulation results show that the DI ascent tracking system is stabilized within the given uncertainty boundary values.The feasible bounds of uncertainty is broadened compared with Integrated Guidance and Control algorithm.Compared with Robust Gain-Scheduling Control method,the robustness to the engine parameters are greatly improved and the control variable is smoother. 展开更多
关键词 Solid launch vehicles Trajectory tracking Adaptive controller Differential inclusion
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KIF15, a key regulator of nasopharyngeal carcinoma development mediated by the P53 pathway
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作者 YONGLIWANG SHENHONG QU +3 位作者 YONG YANG YING QIN fei liu GUANGWU HUANG 《BIOCELL》 SCIE 2023年第3期533-545,共13页
Background:Kinesin family member 15(KIF15)is a protein that regulates cell mitosis and plays an important role in the development and progression of several types of human cancers.However,the role of KIF15 in the deve... Background:Kinesin family member 15(KIF15)is a protein that regulates cell mitosis and plays an important role in the development and progression of several types of human cancers.However,the role of KIF15 in the development of nasopharyngeal cancer(NPC)is still unclear.Methods:The differential expression of KIF15 in NPC and para-carcinoma tissues was evaluated based on data collected from Gene Expression Omnibus(GEO)database and immunohistochemical analysis of clinical specimens collected from a patient cohort.Cell lines 5-8F and CNE-2Z were selected for the construction of KIF15‑knockdown cell models.CCK8 assay,flow cytometry,wound healing,Transwell and clone formation assays were used to detect the proliferation,apoptosis,migration,invasion and colony formation of NPC cells in vitro.A mouse xenograft model and the tail intravenous mouse distant transfer model were constructed for in vivo study.Furthermore,the potential molecular mechanisms underlying the effects of KIF15 were explored through western blot analysis,and several in vitro and in vivo functional assays were performed to explore its role in NPC.Results:The results revealed significantly higher expression of KIF15 in NPC tissues compared to para-carcinoma tissues.High levels of KIF15 expression were also associated with short overall survival(OS)and progression-free survival(PFS).Knockdown of the KIF15 gene led to a cell cycle arrest in the growth 2(G2)phase,inhibition of cell proliferation,migration,invasion,colony formation,and enhanced cell apoptosis.The in vivo murine xenograft experiments showed that down-regulation of the KIF15 gene could inhibit tumor growth and reduce the risk of liver and lung metastasis in NPC.Moreover,the evaluation of the molecular pathway showed that the mitogen-activated protein kinase/P53 pathways might be involved in the KIF15-induced regulation of NPC.Rescue assays indicated that Pifithrin-αcould counteract the pro-proliferative and pro-apoptotic effects mediated by KIF15.Conclusion:This work indicated that KIF15 overexpression accelerated the progression of NPC and promoted the development of distant metastases.Therefore,KIF15 may have an important role as a prognostic indicator and a potential drug target for the treatment of NPC. 展开更多
关键词 KIF15 APOPTOTIC METASTASES P53 Nasopharyngeal carcinoma
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Improved High Order Model-Free Adaptive Iterative Learning Control with Disturbance Compensation and Enhanced Convergence
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作者 Zhiguo Wang Fangqing Gao fei liu 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第1期343-355,共13页
In this paper,an improved high-order model-free adaptive iterative control(IHOMFAILC)method for a class of nonlinear discrete-time systems is proposed based on the compact format dynamic linearization method.This meth... In this paper,an improved high-order model-free adaptive iterative control(IHOMFAILC)method for a class of nonlinear discrete-time systems is proposed based on the compact format dynamic linearization method.This method adds the differential of tracking error in the criteria function to compensate for the effect of the random disturbance.Meanwhile,a high-order estimation algorithmis used to estimate the value of pseudo partial derivative(PPD),that is,the current value of PPD is updated by that of previous iterations.Thus the rapid convergence of the maximumtracking error is not limited by the initial value of PPD.The convergence of the maximumtracking error is deduced in detail.This method can track the desired output with enhanced convergence and improved tracking performance.Two examples are used to verify the convergence and effectiveness of the proposed method. 展开更多
关键词 Pseudo partial derivative enhanced convergence tracking error disturbance compensation
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