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空间特性光谱反演及对户外光谱修正的可行性研究

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光谱学与光谱分析 2024年第2期44卷 336-346页

作者：高峰徐嘉翊罗华平塔里木大学机械电气化工程学院新疆阿拉尔843300 自治区教育厅普通高等学校现代农业工程重点实验室新疆阿拉尔843300

户外高光谱探测可以快速获取样品的光谱信息,但受环境光线和样品二向反射特性的影响,采集到的光谱并不能准确反映样品的真实信息,对户外探测精度有一定影响。为了提高户外高光谱探测精度,提出了一种使用空间特性光谱对户外光谱进行修正... 详细信息

户外高光谱探测可以快速获取样品的光谱信息,但受环境光线和样品二向反射特性的影响,采集到的光谱并不能准确反映样品的真实信息,对户外探测精度有一定影响。为了提高户外高光谱探测精度,提出了一种使用空间特性光谱对户外光谱进行修正的方法,以冬枣、红提、小白杏为研究对象,使用Walthall、Shibayama、Ross-li、Roujean与Rahman这5种BRDF模型反演3种果品的空间特性光谱,利用反演的空间特性光谱对户外光谱进行修正,之后分别建立暗室光谱、户外光谱与修正光谱的品质预测模型。反演结果表明:3种果品的空间特性光谱均有较好的反演效果,反演误差从低到高依次为冬枣、小白杏、红提,平均决定系数R2分别为0.957、0.947、0.927,平均误差分别为3.56%、4.90%、8.23%;5种BRDF模型中,Walthall模型的反演效果最佳,平均决定系数R2与误差分别为0.949、5.33%,Ross-li模型的反演效果最差,平均决定系数与误差分别为0.934、6.05%。户外光谱修正结果表明:户外光谱经过修正后噪声减少,光谱更为平滑,且光谱趋势与暗室光谱一致,受反演效果影响,冬枣光谱的修正效果最佳,而红提与小白杏的修正光谱中噪声较多。品质预测模型结果表明:3种果品的品质预测模型预测效果差异较大,从高到低依次为冬枣、小白杏、红提,可能与3种果品的品质不同有关;5种BRDF模型得到的修正光谱所建立的模型预测效果不同,但无显著差异;预测模型中,使用暗室光谱建立的预测模型最优,修正光谱建立的模型预测能力优于户外光谱建立的模型,表明户外光谱经过修正后模型预测能力得到提升。BRDF模型能够较好地反演果品的空间特性光谱,修正后的光谱与暗室光谱较为接近,修正光谱建立的模型优于户外光谱建立的模型,表明使用空间特性光谱对户外光谱进行修正的方法是可行的,可为提高户外无损检测的精度提供一种新的思路。

关键词：二向反射分布函数空间特性光谱光谱反演修正可行性研究

我国数字鸿沟研究热点与发展趋势——基于CiteSpace知识图谱可视化分析

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西安文理学院学报(自然科学版) 2024年第3期27卷 45-55页

作者：董江苹徐华安徽大学社会与政治学院

随着互联网的加速发展，以信息化为特征的新技术不断推动我国数字化经济发展，但由于数字技术运用规模差异，带来了明显的数字不平等.基于此，本文筛选出中国知网(CNKI)803篇中文期刊文献，通过CiteSpace软件进行知识图谱分析，发现我... 详细信息

随着互联网的加速发展，以信息化为特征的新技术不断推动我国数字化经济发展，但由于数字技术运用规模差异，带来了明显的数字不平等.基于此，本文筛选出中国知网(CNKI)803篇中文期刊文献，通过CiteSpace软件进行知识图谱分析，发现我国数字鸿沟研究主要特征是聚焦社会边缘性群体，研究方法多元化但研究力量尚未形成核心集群.未来数字鸿沟将在数字中国战略、弥合教育鸿沟促进教育公平和数字反哺下老年人数字鸿沟的弥合上保持热度.

关键词：数字鸿沟 CiteSpace 数字不平等可视化

Highly Hydrolysis-Resistant Polyimide Fibers Prepared by Thermal Crosslinking with Inherent Carboxyl Groups

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Chinese Journal of Polymer Science 2024年第2期42卷 247-255,I0010页

作者： Can-Can Zhang Jun-Long Yang Ya-Jiang huang Guang-Xian Li College of Polymer Science and Engineering State Key Laboratory of Polymer Materials Engineering of ChinaSichuan UniversityChengdu610065China

Easy hydrolysis in alkaline environments limits the use of polyimide fibers in environmental protection. The hydrolysis resistance levels of polyimide fibers can be improved by crosslinking of the macromolecular chains. In this work, crosslinked polyimide fibers(CPI fibers) were produced by intrinsic carboxyl decarboxylation for the first time. The thermal stability of the polyimide fibers containing the intrinsic carboxyl groups(PIC fibers) was studied, and the temperature of the decarboxylation-crosslinking reaction was determined to be 450 ℃. The PIC fibers were hotdrawn to initiate thermal crosslinking of the carboxyl groups and molecular chain orientation at high temperature. The CPI fibers had high tensile strengths(0.72-1.46 GPa) and compressive strengths(401-604 MPa). The oriented macromolecules and chemically crosslinked structure improved the tightness of the molecular chains and endowed the CPI fibers with excellent hydrolytic resistance. The CPI-50 fiber did not dissolve in a 0.5 wt% NaOH solution during heating at 90 ℃ for 10 h, and the tensile strength retention reached 87% when treated in 0.5 wt% NaOH solutions at 90 ℃ for 1 h, providing a guarantee for its application in alkaline corrosive environments.

关键词： Polyimide Carboxyl group Crosslinking Hydrolysis-resistance

基于可靠度的单层网壳结构临界稳定承载力计算方法

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建筑结构学报 2024年第1期45卷 76-84页

作者：徐军王皓贺拥军董华湖南大学土木工程学院湖南长沙430074 建筑安全与节能教育部重点实验室湖南长沙430074 中建三局一公司钢结构分公司湖北武汉430040

为研究基于可靠度的单层网壳结构临界稳定承载力计算方法,选取并改进随机缺陷模态叠加法,作为单层网壳结构初始几何缺陷模拟方法;结合混合阶容积公式,高效准确地计算结构稳定承载力的前四阶统计矩,进一步采用移位广义对数正态分布重构... 详细信息

为研究基于可靠度的单层网壳结构临界稳定承载力计算方法,选取并改进随机缺陷模态叠加法,作为单层网壳结构初始几何缺陷模拟方法;结合混合阶容积公式,高效准确地计算结构稳定承载力的前四阶统计矩,进一步采用移位广义对数正态分布重构结构稳定承载力概率密度函数;并在给定目标可靠指标或失稳概率下确定单层网壳结构稳定承载力。分别采用六角星网壳模型和K8单层球面网壳结构验证了基于可靠度的临界稳定承载力计算方法的有效性,计算结果表明:采用前四阶屈曲模态叠加所获得的稳定承载力概率分布离散性更大,稳定承载力下降规律与一致模态缺陷法结果基本一致,且现行规范缺陷幅值取跨度的1/300较为保守。

关键词：单层网壳初始几何缺陷稳定承载力统计矩概率密度函数

Recombinant adeno-associated virus 8-mediated inhibition of microRNA let-7a ameliorates sclerosing cholangitis in a clinically relevant mouse model

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World Journal of Gastroenterology 2024年第5期30卷 471-484页

作者： Hui hua Qian-Qian Zhao Miriam Nkesichi Kalagbor Guo-Zhi Yu Man Liu Zheng-Rui Bian Bei-Bei Zhang Qian Yu Yin-Hai xu Ren-Xian Tang Kui-Yang Zheng Chao Yan Jiangsu Key Laboratory of Immunity and Metabolism Department of Pathogenic Biology and ImmunologyNational Demonstration Center for Experimental Basic Medical Science EducationLaboratory of Infection and ImmunityXuzhou Medical UniversityXuzhou 221004Jiangsu ProvinceChina Department of Laboratory Medicine The Affiliated Hospital of Xuzhou Medical UniversityXuzhou 221002Jiangsu ProvinceChina

BACKGROUND Primary sclerosing cholangitis(PSC)is characterized by chronic inflammation and it predisposes to cholangiocarcinoma due to lack of effective treatment *** adeno-associated virus(rAAV)provides a promising platform for gene therapy on such kinds of diseases.A microRNA(miRNA)let-7a has been reported to be associated with the progress of PSC but the potential therapeutic implication of inhibition of let-7a on PSC has not been *** To investigate the therapeutic effects of inhibition of a miRNA let-7a transferred by recombinant adeno-associated virus 8(rAAV8)on a xenobiotic-induced mouse model of sclerosing *** A xenobiotic-induced mouse model of sclerosing cholangitis was induced by 0.1% 3,5-Diethoxycarbonyl-1,4-Dihydrocollidine(DDC)feeding for 2 wk or 6 wk.A single dose of rAAV8-mediated anti-let-7a-5p sponges or scramble control was injected in vivo into mice onset of DDC *** sacrifice,the liver and the serum were collected from each *** hepatobiliary injuries,hepatic inflammation and fibrosis were *** targets of let-7a-5p and downstream molecule NF-κB were detected using Western *** rAAV8-mediated anti-let-7a-5p sponges can depress the expression of let-7a-5p in mice after DDC feeding for 2 wk or 6 *** reduced expression of let-7a-5p can alleviate hepato-biliary injuries indicated by serum markers,and prevent the proliferation of cholangiocytes and biliary ***,inhibition of let-7a mediated by rAAV8 can increase the expression of potential target molecules such as suppressor of cytokine signaling 1 and Dectin1,which consequently inhibit of NF-κB-mediated hepatic *** Our study demonstrates that a rAAV8 vector designed for liver-specific inhibition of let-7a-5p can potently ameliorate symptoms in a xenobiotic-induced mouse model of sclerosing cholangitis,which provides a possible clinical translation of PSC of human.

关键词： Primary sclerosing cholangitis Recombinant adeno-associated virus 8 Let-7a-5p Therapeutic effects Inflammation

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基于连续可微采样的无人机多向视点规划

计算机集成制造系统 2024年第3期30卷 1161-1170页

作者：吴华徐肖顺白晓静华北电力大学控制与计算机工程学院电力智能机器人工程技术研究中心北京102206

无人机在各种工业基础设施的自主巡检中,需要为大型复杂待巡检对象设计大量的数据采集航点,以获取高质量的全覆盖影像数据。逐点飞行作业能耗高采集效率低,限制了无人机大规模的工业应用。为了优化飞行作业模式,有效提升巡检效率,针对... 详细信息

无人机在各种工业基础设施的自主巡检中,需要为大型复杂待巡检对象设计大量的数据采集航点,以获取高质量的全覆盖影像数据。逐点飞行作业能耗高采集效率低,限制了无人机大规模的工业应用。为了优化飞行作业模式,有效提升巡检效率,针对已知待巡检复杂设备结构提出一种全新的多向视点规划算法——连续可微采样的无人机多向视点规划算法(MD-VPP)。该方法在满足全面覆盖巡视目标以及数据采集质量要求的前提下,大幅减少航点数量。首先,将云台俯仰角、偏航角和相机成像面积作为约束条件,构建视点采集连续可微的视图质量目标函数,优化求解候选视点集;然后利用贪心算法求解全覆盖待巡检对象的航点位姿。通过实验对比分析了针对不同巡检对象的航点数量和航点数减少率,相比领域内其他优秀方法,所提方法在确保全覆盖的前提下航点数量至少降低77%,极大地提升了无人机单次作业的数据采集效率。

关键词：多视角视点规划全覆盖无人机巡检

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数字人民币在医疗行业的应用前景与挑战

NiO@Ni nanoparticles embedded in N-doped carbon for efficient photothermal CO_(2) methanation coupled with H_(2)O splitting

科学与信息化 2024年第9期 153-155页

作者：许正华盐城大丰人民医院江苏盐城 224000

随着全球数字经济的蓬勃发展和区块链技术的成熟应用,数字货币已经逐渐成为金融领域和实体经济的关注焦点.数字人民币在医疗行业有着广阔的应用前景.它可以提升支付效率和便捷性,促进医疗信息共享和安全,提供更好的监管手段.然而,数字... 详细信息

随着全球数字经济的蓬勃发展和区块链技术的成熟应用,数字货币已经逐渐成为金融领域和实体经济的关注焦点.数字人民币在医疗行业有着广阔的应用前景.它可以提升支付效率和便捷性,促进医疗信息共享和安全,提供更好的监管手段.然而,数字人民币在技术、数字鸿沟和政策方面也面临挑战,基于此,本文针对数字人民币在医疗行业的应用前景与挑战展开论述,以供参考.

关键词：数字人民币医疗行业应用前景应用挑战

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Nano Research 2024年第4期17卷 2283-2290页

作者： Yun Zhou Peng Zheng Fang Wang Fangna Gu Wenqing xu Qinyang Lu Tingyu Zhu Ziyi Zhong Guangwen xu Fabing Su Institute of Process Engineering Chinese Academy of SciencesBeijing 100190China Key Laboratory on Resources Chemicals and Materials of Ministry of Education Shenyang University of Chemical TechnologyShenyang 110142China Institute of Industrial Chemistry and Energy Technology Shenyang University of Chemical TechnologyShenyang 110142China School of Ecology and Environment Beijing Technology and Business UniversityBeijing 100048China Beijing Key Laboratory of Enze Biomass Fine Chemicals College of New Materials and Chemical EngineeringBeijing Institute of Petrochemical TechnologyBeijing 102617China International School of Beijing 10 An hua Street Shunyi DistrictBeijing 100048China Department of Chemical Engineering Guangdong Technion Israel Institute of Technology(GTIIT)Shantou 515063China Technion Israel Institute of Technology(IIT) Haifa32000Israel

Photothermal carbon dioxide(CO_(2))methanation has attracted increasing interest in solar fuel synthesis,which employs the advantages of photocatalytic H_(2)O splitting as a hydrogen source and photothermal catalytic CO_(2) *** work prepared three-dimensional(3D)honeycomb N-doped carbon(NC)loaded with core–shell NiO@Ni nanoparticles generated in situ at 500℃(NiO@Ni/NC-500).Under the photothermal catalysis(200℃,1.5 W/cm^(2)),the CH_(4) evolution rate of NiO@Ni/NC-500 reached 5.5 mmol/(g·h),which is much higher than that of the photocatalysis(0.8 mmol/(g·h))and the thermal catalysis(3.7 mmol/(g·h)).It is found that the generated localized surface plasmon resonance enhances the injection of hot electrons from Ni to NiO,while thermal heating accelerates the thermal motion of radicals,thus generating a strong photo-thermal synergistic effect on the *** CO_(2) reduction to CH_(4) follows the*OCH *** work demonstrates the synergistic effect of NiO@Ni and NC can enhance the catalytic performance of photothermal CO_(2) reduction reaction coupled with water splitting reaction.

关键词： Ni localized surface plasmon resonance photothermal methanation

New insights into the effects of APP gene dose on synapse in Down syndrome

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Neural Regeneration Research 2024年第5期19卷 961-962页

作者： xu-Qiao Chen Xinxin Zuo Department of Neurosciences University of California San DiegoLa JollaCAUSA

Synaptic dysfunction:Alzheimer’s disease(AD)is a prevalent form of dementia,affecting over 35 million people worldwide(Tzioras et al.,2023).A synapse serves as the connection point between neurons,facilitating the transmission of information from one neuron to *** alterations in synapses,known as synaptic plasticity,play a pivotal role in cognitive processes such as learning and *** loss has been identified as a key contributor to cognitive decline in AD *** have shown that the soluble forms of amyloid-beta(Aβ)and tau proteins are toxic to synapses,leading to cognitive impairment in animal models(Spires-Jones and Hyman,2014).Additionally,the formation of oligomers of tau and Aβcan spread pathology through synaptic connections in the brain,emphasizing the vital role of synapses in disease progression.

关键词： alterations Aβ tau