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Upconversion hollow nanospheres CeF_(3) co-doped with Yb^(3+) and Tm^(3+) for photocatalytic nitrogen fixation

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Journal of Rare Earths 2022年第4期40卷 586-594,I0003页

作者： Minghui Zhong Zhendong Wang da dai Baozhu Yang Shixiang Zuo Chao Yao Fengqin Wu Xiazhang Li Advanced Catalysis and Green Manufacturing Collaborative Innovation Center Jiangsu Key Laboratory of Advanced Catalytic Materials and TechnologyChangzhou UniversityChangzhou 213164China W.M.Keck Center for Advanced Microscopy and Microanalysis University of DelawareNewarkDE19716USA

Solar driven nitrogen(N_(2))fixation to synthesize ammonia is a potential alternative for the traditional Haber-Bosch approach to meeting industrial demand,but is largely hampered by the difficulties in the harvesting of solar energy and activating inert N_(2).In this work,hollow CeF_(3) nanospheres co-doped with activator Tm^(3+)and sensitizer Yb^(3+)(Yb^(3+):Tm^(3+):CeF_(3))were prepared by microwave hydrothermal *** product was employed as a catalyst for photo-driven N_(2) fixation by adjusting the molar ratio of Ce^(3+):Yb^(3+):Tm^(3+).Results show that the porous hollow structure enhances the light-harvesting by physical scattering and *** addition,heteroatom doping generates abundant fluorine vacancies(F_(V))which provide abundant active sites for adsorption and activation of N_(2).The sample with molar ratio of CeF_(3):Yb^(3+):Tm^(3+)at 178:20:2 demonstrates the highest utilization of solar energy attributed to the strongest upconversion capability of near-infrared(NIR)light to visible and ultraviolet(UV)light,and the NH_(4)+concentration achieves the highest value of 15.06μmol/(gcat∙h)under simulated sunlight while nearly 6.22μmol/(gcat∙h)under NIR *** study offers a promising and sustainable strategy for the fixation of atmospheric N_(2) using full-spectrum solar energy.

关键词： Rare earth CeF_(3) Hollow structure Upconversion Fluorine vacancy Photocatalytic nitrogen fixation

A New Design and Implementation of an Attendance Checking Node for Coal Mines

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Journal of China University of Mining and Technology 2007年第2期17卷 193-196页

作者： XIA Shi-xiong QIAO da-lei CHEN dai ZHOU Yong School of Computer Science ＆ Technology China University of Mining ＆ Technology Xuzhou Jiangsu 221008 China

A novel design and implementation of an attendance checking node for coal mines based on the CAN bus is presented in this paper. Hardware circuits and programming methods for the attendance checking node are discussed,including the single-chip computer with CAN controller AT89C51CC03,the CAN bus transceiver TJA1050,the large capacity dataFlash memory,the real-time clock DS1302,the voice chip ISD2560 and the card-reading circuit in Wie-gand format. All the extended hardware satisfies the requirements for intrinsically safe circuits (GB3836.4-2000) and intrinsically safe authentication promoted by the national explosion-proof institute. Further,the software programming methods for the CAN controller (AT89C51CC03) and the implementation of the CAN communications protocol are presented as well.

关键词： CAN bus attendance checking node wiegand message passing

Microwave hydrothermal synthesis of lanthanum oxyfluoride nanorods for photocatalytic nitrogen fixation:Effect of Pr doping

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Frontiers of Materials Science 2020年第1期14卷 43-51页

作者： Xiangyu Yan da dai Kun Ma Shixiang Zuo Wenjie Liu Xiazhang Li Chao Yao Advanced Catalysis and Green Manufacturing Collaborative Innovation Center Jiangsu Key Laboratory of Advanced Catalytic Materials and TechnologyChangzhou UniversityChangzhou213164China Department of Materials Science and Engineering University of DelawareNewarkDE19716USA

Photocatalytic fixation of nitrogen has been recognized as a green and promising strategy for ammonia synthesis under ambient ***,the efficient reduction of nitrogen remains a challenge due to high activation energy of nitrogen and low utilization of solar ***,lanthanum oxyfluoride with different doping content of Pr3+(LaOF:xPr3+)upconversion nanorods were synthesized by microwave hydrothermal *** indicated that the doping of Pr3+generated considerable defects on the surface of LaOF which acted as the adsorption and activation center for ***,the Pr3+ion narrowed the band gap and broadened the light response range of LaOF because LaOF:Pr3+can upconvert visible light into ultraviolet light,which excite LaOF nanorods and improve the utilization of solar *** doping amount of Pr3+had critical effect on the photocatalytic nitrogen fixation performance which reached as high as 180μmol·L?1·ho1 when the molar ratio of Pr3+to LaOF was optimized to be 2%.

关键词： LaOF defect upconversion photocatalysis nitrogen fixation

Application of intelligent algorithms in Down syndrome screening during second trimester pregnancy

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World Journal of Clinical Cases 2021年第18期9卷 4573-4584页

作者： Hong-Guo Zhang Yu-Ting Jiang Si-da dai Ling Li Xiao-Nan Hu Rui-Zhi Liu Center for Reproductive Medicine and Center for Prenatal Diagnosis First HospitalJilin UniversityChangchun 130021Jilin ProvinceChina College of Communication Engineering Jilin UniversityChangchun 130012Jilin ProvinceChina

BACKGROUND Down syndrome(DS)is one of the most common chromosomal aneuploidy *** screening and diagnostic tests can aid the early diagnosis,appropriate management of these fetuses,and give parents an informed choice about whether or not to terminate a *** recent years,investigations have been conducted to achieve a high detection rate(DR)and reduce the false positive rate(FPR).Hospitals have accumulated large numbers of screened ***,artificial intelligence methods are rarely used in the risk assessment of prenatal screening for *** To use a support vector machine algorithm,classification and regression tree algorithm,and AdaBoost algorithm in machine learning for modeling and analysis of prenatal DS *** The dataset was from the Center for Prenatal Diagnosis at the First Hospital of Jilin *** designed and developed intelligent algorithms based on the synthetic minority over-sampling technique(SMOTE)-Tomek and adaptive synthetic sampling over-sampling techniques to preprocess the dataset of prenatal screening *** machine learning model was then ***,the feasibility of artificial intelligence algorithms in DS screening evaluation is *** The database contained 31 DS diagnosed cases,accounting for 0.03%of all *** dataset showed a large difference between the numbers of DS affected and non-affected cases.A combination of over-sampling and undersampling techniques can greatly increase the performance of the algorithm at processing non-balanced *** the number of iterations increases,the combination of the classification and regression tree algorithm and the SMOTETomek over-sampling technique can obtain a high DR while keeping the FPR to a *** The support vector machine algorithm and the classification and regression tree algorithm achieved good results on the DS screening *** the T21 risk cutoff value was set to 270,machine learning m

关键词： Down syndrome Prenatal screening Algorithms Classification and regression tree Support vector machine Risk cutoff value

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非完备信息系统的启发式特征选择遗传算法

电子学报 2013年第3期41卷 451-455页

作者：戴大蒙慕德俊西北工业大学自动化学院陕西西安710072 温州大学物理与电子信息工程学院浙江温州325035

为了获取非完备信息系统的相对最小特征子集,提出一种基于非完备信息系统的启发式特征选择遗传算法.本文首先构造了适应度函数,并以特征重要度为启发式信息融入特征选择;同时利用特征的相对核对种群初始化,引导染色体的进化,缩小了算法... 详细信息

为了获取非完备信息系统的相对最小特征子集,提出一种基于非完备信息系统的启发式特征选择遗传算法.本文首先构造了适应度函数,并以特征重要度为启发式信息融入特征选择;同时利用特征的相对核对种群初始化,引导染色体的进化,缩小了算法的搜索空间;且在染色体的交叉和变异过程中,对满足条件的染色体及时删除,加快算法的收敛性;实验结果验证了算法的有效性.

关键词：非完备信息系统特征选择遗传算法启发式方法

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基于语料库句法结构分析的动态规划模型

计算机学报 1999年第10期22卷 1019-1024页

作者：王厚峰戴大为中国科学院声学研究所华中师范大学计算机科学系武汉430079 武汉大学软件工程国家重点实验室

语料库方法在词性标注上获得了较大的成功，但句法分析中仍存在许多问题．针对句法分析方法的不足，文中给出了一个基于语料库的动态规划分析模型．其算法按自底向上的方式逐层构造各种句法树．它可以像枚举分析那样，从所有可能的句法... 详细信息

语料库方法在词性标注上获得了较大的成功，但句法分析中仍存在许多问题．针对句法分析方法的不足，文中给出了一个基于语料库的动态规划分析模型．其算法按自底向上的方式逐层构造各种句法树．它可以像枚举分析那样，从所有可能的句法树中选择最合理的句法结构，还可以将复杂度控制在多项式范围内．作为比较，还详细讨论了基于语料库的枚举分析方法。

关键词：动态规划自然语言处理语料库句法结构

微水相中改性Ultrastable-Y分子筛固定化脂肪酶拆分(R,S)-2-辛醇

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高等学校化学学报 2007年第12期28卷 2307-2310页

作者：戴大章夏黎明浙江大学材料与化学工程学院生物工程研究所杭州310027

采用改性Ultrastable-Y分子筛固定化***-03脂肪酶(PEL),利用固定化PEL在微水相中对(R,S)-2-辛醇进行拆分.结果表明,改性Ultrastable-Y分子筛固定化PEL所催化的拆分反应的转化率(c)和对映体过量值(e.e.)以及对映体选择性(E)均得到大幅度... 详细信息

采用改性Ultrastable-Y分子筛固定化***-03脂肪酶(PEL),利用固定化PEL在微水相中对(R,S)-2-辛醇进行拆分.结果表明,改性Ultrastable-Y分子筛固定化PEL所催化的拆分反应的转化率(c)和对映体过量值(e.e.)以及对映体选择性(E)均得到大幅度提高.介质类型和体系含水量对酶促拆分反应有较大的影响.在以正己烷为溶剂,含水量为0.8%的体系中,于50℃反应24 h的转化率(c)可达到理论值的97.68%,对映体过量值(e.e.)可达到98.75%.改性Ultrastable-Y分子筛固定化PEL催化效率高、立体选择性强,且催化性能稳定,在(R,S)-2-辛醇的酶法拆分方面具有良好的应用前景.

关键词：微水相改性Ultrastable-Y分子筛固定化脂肪酶拆分 (R,S)-2-辛醇

改性Ultrastable-Y分子筛固定化对非水相中脂肪酶拆分(R，S)-2-辛醇的影响

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化学学报 2008年第2期66卷 245-250页

作者：戴大章夏黎明浙江大学化学工程与生物工程学系杭州310027

采用改性Ultrastable-Y分子筛固定Penicillium expansum PED-03脂肪酶(PEL),利用固定化PEL在非水相中对(R,S)-2-辛醇进行手性拆分,考察了改性Ultrastable-Y分子筛固定化处理对PEL催化性能的影响.结果表明,与游离PEL及经其它载体固定化的... 详细信息

采用改性Ultrastable-Y分子筛固定Penicillium expansum PED-03脂肪酶(PEL),利用固定化PEL在非水相中对(R,S)-2-辛醇进行手性拆分,考察了改性Ultrastable-Y分子筛固定化处理对PEL催化性能的影响.结果表明,与游离PEL及经其它载体固定化的PEL相比,改性Ultrastable-Y分子筛固定的PEL所催化的拆分反应的转化率(c)和对映体过量值(ee)以及对映体选择性(E)均得到了较大提高.经固定化处理后,PEL的最适反应温度明显升高,适宜反应温度范围变宽,其稳定性也得到了明显改善,而适宜反应pH值则具有"记忆"性.在间歇式反心器中利用Ultrastable-Y分子筛固定化PEL对(R,S)-2-辛醇进行手性拆分,50℃反应24 h转化率(c)可达理论值的97.68%,对映体过量值(ee)可达98.75%.连续8批拆分反应的结果表明:改性Ultrastable-Y分子筛固定化脂肪酶催化效率高、立体选择性强(平均E值>460),且催化性能稳定,显示了该固定化酶在(R,S)-2-辛醇的手性拆分方面具有良好的应用前景.

关键词：改性分子筛固定化脂肪酶拆分 2-辛醇催化性能

扩展青霉脂肪酶的生产及其在外消旋烯丙醇酮拆分上的应用

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高校化学工程学报 2008年第1期22卷 166-171页

作者：戴大章夏黎明浙江大学化学工程与生物工程学系浙江杭州310027

试图应用脂肪酶催化拆分法代替化学法拆分外消旋烯丙醇酮(4-羟基-3-甲基-2-(2-烯丙基)-2-环戊烯-1-酮,allethrolone)。以Rodamine B平板筛选法获得了一株脂肪酶高产菌Penicillium expansum PED-03,并对该菌液态发酵产脂肪酶的主要工艺... 详细信息

试图应用脂肪酶催化拆分法代替化学法拆分外消旋烯丙醇酮(4-羟基-3-甲基-2-(2-烯丙基)-2-环戊烯-1-酮,allethrolone)。以Rodamine B平板筛选法获得了一株脂肪酶高产菌Penicillium expansum PED-03,并对该菌液态发酵产脂肪酶的主要工艺参数进行了优化。确立了0.5%的淀粉和4%的豆饼粉为该菌种的适宜碳源和氮源,最适C/N为0.5。Tween-80对产酶有明显的促进作用,添加0.05%Tween-80后所产酶活力可提高55%。发酵罐产酶试验结果表明,搅拌速度对脂肪酶的产生有明显影响,适宜的搅拌速度为500r·min·1。利用*** PED-03脂肪酶在非水相中对外消旋烯丙醇酮进行手性拆分,反应36h时转化率(C)可达理论值的96%,产物的对映体过量值(eeP)可达99%,显示了该酶在烯丙醇酮的酶法拆分方面具有良好的应用潜力。

关键词：脂肪酶液态发酵酶法拆分烯丙醇酮