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基于不同维度低场核磁共振技术的大豆含油率检测与判别

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农业工程学报 2024年第4期40卷 337-344页

作者：张宇赵亚楠赵健翔宋平沈阳农业大学信息与电气工程学院沈阳110866

大豆含油率的高低直接影响榨油与育种结果。为探究大豆含油率的最佳检测方法与构建含油率高低判别模型,该研究基于不同维度低场核磁共振(low field nuclear magnetic resonance,LF-NMR)技术,以国标法为对照,利用LF-NMR波谱和LF-NMR含油... 详细信息

大豆含油率的高低直接影响榨油与育种结果。为探究大豆含油率的最佳检测方法与构建含油率高低判别模型,该研究基于不同维度低场核磁共振(low field nuclear magnetic resonance,LF-NMR)技术,以国标法为对照,利用LF-NMR波谱和LF-NMR含油含水率软件检测大豆含油率;核磁共振成像(magnetic resonance imaging,MRI)结合深度学习,建立大豆含油率高低判别模型。引入低场二维核磁共振(low field two-dimensional nuclear magnetic resonance,LF-2D-NMR)技术,定性分析一维波谱中信号重叠无法区分组分的问题。试验结果表明,LF-NMR含油含水率软件能快速准确检测大豆含油率,T1-T2二维核磁图谱成功解决了自由水和油信号重叠问题。利用U-net++深度学习模型对MRI成像的矢状面、冠状面、横截面以及三面混合数据集进行训练,其中横截面评价指标与其他数据集相比更优,语义分割部分中平均交并比(mean intersection over union,mIoU)约0.9058,全局准确率0.9980,训练后的模型能够将MRI图像识别并分割,快速判别大豆含油率高低。试验证明,LF-NMR及MRI能够快速无损掌握大豆含油率信息,为大豆的高油育种提供了新思路和技术支持。

关键词：低场核磁共振低场二维核磁共振磁共振成像大豆含油率深度学习

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基于磁编码器和窄带解调的太阳轮故障检测

振动．测试与诊断 2024年第2期44卷 365-371,414页

作者：尹兴超郭瑜李震焘华健翔昆明理工大学机电工程学院昆明650500

绝对式磁编码器具有价格低、安装方便等优势,适合于工程应用,但在低转速工况下其角度信号受测量误差的影响较大,需要对角度信号进行拟合以消除测量误差带来的干扰。传统的分段拟合方法在分段点处易出现不连续现象,角度信号的不连续导致... 详细信息

绝对式磁编码器具有价格低、安装方便等优势,适合于工程应用,但在低转速工况下其角度信号受测量误差的影响较大,需要对角度信号进行拟合以消除测量误差带来的干扰。传统的分段拟合方法在分段点处易出现不连续现象,角度信号的不连续导致由其计算的瞬时角速度(instantaneous angular speed,简称IAS)信号中出现虚假冲击,并对基于IAS信号的故障特征提取造成干扰。针对此问题,提出一种基于绝对式磁编码器IAS估计和窄带解调的太阳轮故障检测方法。首先,为保证IAS信号的连续性与平滑性,提出基于最小二乘拟合与5次Hermite插值的方法,实现了对IAS信号的拟合估计和平滑处理;其次,结合窄带解调技术实现了对行星齿轮减速器太阳轮故障特征的有效提取;最后,通过对正常与故障太阳轮的绝对式磁编码器信号分析对比,验证了所提方法的有效性。

关键词：磁编码器行星齿轮箱瞬时角速度信号窄带解调角域同步平均

First Human Infection with Avian Influenza H9N2—Guangdong Province,China,2020

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China CDC weekly 2020年第29期2卷 545-548页

作者： Qianfang Guo Lirong Zou jianxiang yu Yingchao Song Lijun Liang Xue Zhuang Tie Song Jie Wu Guangdong Provincial Center of Disease Control and Prevention GuangzhouGuangdongChina Southern Medical University School of Public HealthGuangzhouGuangdongChina

A case of avian influenza H9N2 was detected in a human in Zhuhai City,Guangdong Province through routine influenza surveillance on March 30,2020.The patient was a 3-year-old child who developed fever and cough on March 22.A pharyngeal swab was collected on March 23,and the novel coronavirus nucleic acid test was negative.On March 26,the pharyngeal swab was sent to Zhuhai CDC for influenza virus tests and was found to be H9 influenza A positive,and on March 30,Guangdong Provincial CDC reexamined the pharyngeal swabs as positive for influenza A(H9N2).

关键词： Guangdong routine Province,China

Numerical investigation of airborne transmission of respiratory infections on the subway platform

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Geoscience Frontiers 2022年第6期13卷 236-243页

作者： Jianjian Wei Sirui Zhu Feiwu He Qianfang Guo Xinxin Huang jianxiang yu Lirong Zou Tao Jin Jie Wu Institute of Refrigeration and Cryogenics/Key Laboratory of Refrigeration and Cryogenic Technology of Zhejiang Province Zhejiang UniversityHangzhou 310027China Center for Balance Architecture Zhejiang UniversityHangzhou 310000China The Architectural Design&Research Institute of Zhejiang University Co LtdHangzhou 310000China Guangdong Medicine and Food Consulting and Research Center Guangzhou 511430China Guangdong Provincial Center for Disease Control and Prevention Guangzhou 511430China School of Public Health Southern Medical UniversityGuangzhou 510515China

Underground subway platforms are among the world’s busiest public transportation systems,but the airborne transmission mechanism of respiratory infections on these platforms has been rarely studied.Here,computational fluid dynamics(CFD)modeling is used to investigate the airflow patterns and infection risks in an island platform under two common ventilation modes:Mode 1-both sides have air inlets and outlets;Mode 2-air inlets are present at the two sides and outlets are present in the middle.Under the investigated scenario,airflow structure is characterized by the ventilation jet and human thermal plumes.Their interaction with the infector’s breathing jet imposes the front passenger under the highest exposure risk by short-range airborne route,with intake fractions up to 2.57%(oral breathing)or 0.63%(nasal breathing)under Mode 1;oral breathing of the infector may impose higher risks for the front passenger compared with nasal breathing.Pathogen are efficiently diluted as they travel further,in particular to adjacent crowds.The maximum and median value of intake fractions of passengers in adjacent crowds are respectively 0.093%and 0.016%(oral breathing),and 0.073%and 0.014%(nasal breathing)under Mode 1.Compared with Mode 1,the 2nd mode minimizes the interaction of ventilation jet and breathing jet,where the maximum intake fraction is only 0.34%,and the median value in the same crowd and other crowds are reduced by 23–63%.Combining published quanta generation rate data of COVID-19 and influenza infectors,the predicted maximum and median infection risks for passengers in the same crowds are respectively 1.46%–40.23%and 0.038%–1.67%during the 3–10 min waiting period,which are more sensitive to ventilation rate and exposure time compared with return air.This study can provide practical guidance for the prevention of respiratory infections in subway platforms.

关键词： Airborne transmission route Ventilation Thermal plume COVID-19 Influenza

快速合成Cu-SAPO-34分子筛及其甲醇制烯烃催化性能

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中国石油大学学报（自然科学版） 2024年第1期48卷 197-205页

作者：张强周洲李建祥田梦阳于梦云中国石油大学(华东)重质油国家重点实验室山东青岛266580 巩义市泛锐熠辉复合材料有限公司河南巩义451200 江苏洋井石化集团有限公司江苏连云港222000

通过引入含铜分子筛晶种作为铜源、10 h快速合成出Cu-SAPO-34分子筛,并与传统的水热合成法和铜胺络合物引入铜源的方式进行对比,同时利用XRD、SEM、IR、TPD和微反等手段表征样品的结构和甲醇制烯烃(MTO)催化性能。结果表明:与常规合成... 详细信息

通过引入含铜分子筛晶种作为铜源、10 h快速合成出Cu-SAPO-34分子筛,并与传统的水热合成法和铜胺络合物引入铜源的方式进行对比,同时利用XRD、SEM、IR、TPD和微反等手段表征样品的结构和甲醇制烯烃(MTO)催化性能。结果表明:与常规合成方法相比,快速合成法可在10 h制备出结晶度在86.24%,固体收率达到94.65%的Cu-SAPO-34分子筛,其乙烯+丙烯选择之和达到81.26%;与添加铜胺络合物相比,加入含铜分子筛晶种的方式引入铜元素,更合适于快速合成法,避免了铜无法与分子筛骨架结合的问题;通过调整含铜分子筛晶种的性质及加入量,可以快速合成晶粒直径在470 nm的纳米Cu-SAPO-34分子筛,固体收率达到96.72%,乙烯+丙烯选择之和达到86.24%。

关键词：甲醇制烯烃 Cu-SAPO-34分子筛快速合成含铜分子筛晶种

沸石合成后酸位点调控策略及其在VOCs催化氧化中应用进展

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硅酸盐通报 2024年第1期43卷 158-171,182页

作者：王健祥袁建华刘晓杨芸于飞马杰同济大学环境科学与工程学院上海200092 上海宝冶工程技术有限公司上海200941 上海海洋大学海洋生态与环境学院上海201306

挥发性有机化合物(VOCs)是一种常见的工业排放污染源,对人体健康、生态系统有着极强的毒害性。催化氧化是一种节能高效的VOCs去除方法,其关键在于催化剂设计和开发。沸石中酸位点能降低VOCs氧化反应活化能,有效催化VOCs氧化降解,但原始... 详细信息

挥发性有机化合物(VOCs)是一种常见的工业排放污染源,对人体健康、生态系统有着极强的毒害性。催化氧化是一种节能高效的VOCs去除方法,其关键在于催化剂设计和开发。沸石中酸位点能降低VOCs氧化反应活化能,有效催化VOCs氧化降解,但原始沸石的催化性能无法满足VOCs催化需求。通过合成后调控策略,可使沸石中酸位点密度更高,使其分布更有利于VOC分子和催化位点的接触,从而令沸石催化剂具有更加优异的催化性能。本文首先介绍了沸石中酸位点的形成和酸位点密度、类型的表征技术,之后着重介绍了沸石合成后酸位点的调控策略,包括骨架改性和内外表面改性等,最后列举了通过调控策略得到的沸石催化剂对VOCs的催化性能。在以上内容的基础上,展望了沸石合成后酸位点调控策略未来的研究方向,对推动沸石催化剂应用于工业VOCs高效催化氧化有重要意义。

关键词：沸石挥发性有机化合物酸位点调控催化氧化

Further Study of Electric Dust Removal with Transparent Fork Electrodes

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American Journal of Analytical Chemistry 2015年第3期6卷 196-201页

作者： Guangming Wu Dan Li jianxiang yu Tianlan Yin Dongdong Feng Beijing Institute of Petrochemical Technology Beijing China Beijing University of Chemical Technology Beijing China

This study is a continuation of our previous work. In this experiment, transparent tin-doped indium oxide (ITO) fork electrodes with different width and spacing were coated on the glass substrates. The used dust particle size was smaller than 180 mesh. The effects of the electrode width, the electrode spacing, voltage, frequency, waveform, and the duty ratio on the dust removal efficiency were studied. The obtained optimum conditions of dust removal were as follows: voltage was 1500 V, frequency was 15 Hz, square wave, 10% duty ratio, the electrode width was 0.5 mm, electrodes spacing was 1.3 mm. Our previous experimental results show that the dust removal efficiency would be up to 95%. But in this experiment, under the optimum conditions, the dust removal efficiency could be up to 99%.

关键词： Transparent Fork Electrode Dust Removal Efficiency ITO

Bi nanoparticles encapsulated in nitrogen-doped carbon as a long-life anode material for magnesium batteries

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Journal of Magnesium and Alloys 2023年第11期11卷 4181-4188页

作者： Junjun Wang Ruohan yu jianxiang Wang Juncai Long Fan Qiao Lei Zhang Guanjie He Qinyou An Liqiang Mai State Key Laboratory of Advanced Technology for Materials Synthesis and Processing School of Materials Science and EngineeringWuhan University of TechnologyWuhan 430070China Christopher Ingold Laboratory Department of ChemistryUniversity College London20 Gordon StreetLondon WC1H 0AJUnited Kingdom of Great Britain and Northern IrelandUnited Kingdom Hubei Longzhong Laboratory Wuhan University of Technology(Xiangyang Demonstration Zone)Xiangyang 441000China

Bismuth has garnered significant interest as an anode material for magnesium batteries(MBs) because of its high volumetric specific capacity and low working potential. Nonetheless, the limited cycling performance(≤100 cycles) limits the practical application of Bi as anode for MBs. Therefore, the improvement of Bi cycling performance is of great significance to the development of MBs and is also full of challenges. Here, Bi nanoparticles encapsulated in nitrogen-doped carbon with single-atom Bi embedded(Bi@NC) are prepared and reported as an anode material for MBs. Bi@NC demonstrates impressive performance, with a high discharge capacity of 347.5 mAh g^(-1) and good rate capability(206.4 mAh g^(-1)@500 mA g^(-1)) in a fluoride alkyl magnesium salt electrolyte. In addition, Bi@NC exhibits exceptional long-term stability, enduring 400 cycles at 500 mA g^(-1). To the best of our knowledge, among reported Bi and Bi-based compounds for MBs, Bi@NC exhibits the longest cycle life in this work. The magnesium storage mechanism of Bi@NC is deeply studied through X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy. This work provides some guidance for further improving the cycling performance of other alloy anodes in MBs.

关键词： Magnesium batteries Bismuth 3D tomography reconstruction Magnesium alloy Single-atom

A hierarchical vascularized engineered bone inspired by intramembranous ossification for mandibular regeneration

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International Journal of Oral Science 2022年第3期14卷 309-320页

作者： Xin Ye jianxiang He Shaolong Wang Qianglong Han Dongqi You Bin Feng Feiya Zhao Jun Yin Mengfei yu Huiming Wang Huayong Yang Key Laboratory of Oral Biomedical Research of Zhejiang Province Stomatology HospitalSchool of StomatologyZhejiang University School of MedicineZhejiang Provincial Clinical Research Center for Oral DiseasesHangzhouChina The State Key Laboratory of Fluid Power and Mechatronic Systems Key Laboratory of 3D Printing Process and Equipment of Zhejiang ProvinceSchool of Mechanical EngineeringZhejiang UniversityHangzhouChina

Mandibular defects caused by injuries,tumors,and infections are common and can severely affect mandibular function and the patient's appearance.However,mandible reconstruction with a mandibular bionic structure remains challenging.Inspired by the process of intramembranous ossification in mandibular development,a hierarchical vascularized engineered bone consisting of angiogenesis and osteogenesis modules has been produced.Moreover,the hierarchical vascular network and bone structure generated by these hierarchical vascularized engineered bone modules match the particular anatomical structure of the mandible.The ultra-tough polyion complex has been used as the basic scaffold for hierarchical vascularized engineered bone for ensuring better reconstruction of mandible function.According to the results of in vivo experiments,the bone regenerated using hierarchical vascularized engineered bone is similar to the natural mandibular bone in terms of morphology and genomics.The sonic hedgehog signaling pathway is specifically activated in hierarchical vascularized engineered bone,indicating that the new bone in hierarchical vascularized engineered bone underwent a process of intramembranous ossification identical to that of mandible development.Thus,hierarchical vascularized engineered bone has a high potential for clinical application in mandibular defect reconstruction.Moreover,the concept based on developmental processes and bionic structures provides an effective strategy for tissue regeneration.

关键词： A hierarchical vascularized engineered bone inspired by intramembranous ossification for mandibular regeneration