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基于表征学习的离线强化学习方法研究综述

自动化学报 2024年第6期50卷 1104-1128页

作者：王雪松王荣荣程玉虎中国矿业大学信息与控制工程学院徐州221116

强化学习(Reinforcement learning,RL)通过智能体与环境在线交互来学习最优策略,近年来已成为解决复杂环境下感知决策问题的重要手段.然而,在线收集数据的方式可能会引发安全、时间或成本等问题,极大限制了强化学习在实际中的应用.与此... 详细信息

强化学习(Reinforcement learning,RL)通过智能体与环境在线交互来学习最优策略,近年来已成为解决复杂环境下感知决策问题的重要手段.然而,在线收集数据的方式可能会引发安全、时间或成本等问题,极大限制了强化学习在实际中的应用.与此同时,原始数据的维度高且结构复杂,解决复杂高维数据输入问题也是强化学习面临的一大挑战.幸运的是,基于表征学习的离线强化学习能够仅从历史经验数据中学习策略,而无需与环境产生交互.它利用表征学习技术将离线数据集中的特征表示为低维向量,然后利用这些向量来训练离线强化学习模型.这种数据驱动的方式为实现通用人工智能提供了新契机.为此,对近期基于表征学习的离线强化学习方法进行全面综述.首先给出离线强化学习的形式化描述,然后从方法、基准数据集、离线策略评估与超参数选择3个层面对现有技术进行归纳整理,进一步介绍离线强化学习在工业、推荐系统、智能驾驶等领域中的研究动态.最后,对全文进行总结,并探讨基于表征学习的离线强化学习未来所面临的关键挑战与发展趋势,以期为后续的研究提供有益参考.

关键词：强化学习离线强化学习表征学习历史经验数据分布偏移

维普期刊数据库博看期刊

不同参数电针对内源性阿片肽系统调节的量效关系

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World Journal of Acupuncture-Moxibustion 2024年第1期34卷 9-15页

作者：陈平徐红张仁田雪松上海中医药大学科技实验中心上海201203 上海中医药大学附属龙华医院针灸科上海201203 上海中医文献馆上海200025

Endogenous opioid peptides(EOP)are the neurochemical basis of the anesthetic and analgesic effects of acupuncture,and the quantity of acupuncture stimulus can be controlled accurately by using electroacupuncture(EA).The present study explores the dose-effect relationship between EA with different parameters and the regulation of EOP system.In this paper,the intervention effects of EA on EOP system were specially discussed in terms of the single factor and the different combinations of the frequency,waveform and current intensity.This study shows that EOP system presents a frequency-response specificity.The low frequency of EA promotes the release of enkephalin,β-endorphin and endomorphin,the high one activates the dynorphin system selectively,and the intermediate frequency works on promoting the release of enkephalin andβ-endorphin,as well as dynorphin.Sparse-dense wave of EA may induce the release of enkephalin,β-endorphin,endomorphin and dynorphin,presenting a synergistic effect.However,the waveform of EA should be selected flexibly in clinical practice.Sometimes the better therapeutic effect can also be obtained with the continuous wave of EA.EOP system is involved in mediating appropriate intensity of EA,while the acupuncture effect generated by an extra strong EA stimulation refers to a kind of stress response of non-opioid mechanism.The different combinations of EA parameters result in various effects.The combination of EA parameters should be optimized in accordance with different diseases,which is valuable for guiding clinical practice and the development of EA therapy.

关键词： Electroacupuncture Endogenous opioid system Stimulus parameters Dose-effect relationship

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一类三阶积分边值问题的奇数个正解

山西大学学报(自然科学版) 2024年第3期47卷 555-563页

作者：李丝雨杨赟瑞宋雪兰州交通大学数理学院

为了发展并完善常微分方程非局部问题的基本理论，本文利用Guo-Krasnoselskill不动点定理建立了一类三阶积分边值问题奇数个正解的存在性。首先，通过研究相应线性积分边值问题的格林函数得到解的形式，并讨论格林函数的性质和解的非负... 详细信息

为了发展并完善常微分方程非局部问题的基本理论，本文利用Guo-Krasnoselskill不动点定理建立了一类三阶积分边值问题奇数个正解的存在性。首先，通过研究相应线性积分边值问题的格林函数得到解的形式，并讨论格林函数的性质和解的非负性、单调性等性质。其次，将三阶积分边值问题解的存在性转化为锥上算子的不动点问题，并验证该算子的全连续性。接下来，借助Guo-Krasnoselskill不动点定理证明非线性项满足特定增长性条件下该算子存在奇数个不动点，从而得到三阶积分边值问题奇数个正解的存在性。最后，给出具体的例子说明了研究结果的合理性。基于此，本文在方法上将常用于建立正解以及至少两个正解存在性的Guo-Krasnoselskill不动点定理运用到无穷多（奇数）个正解的存在性研究，推广并完善了三阶边值问题正解的研究结果，丰富了常微分方程边值问题的研究内容，为常微分方程非局部问题在应用数学、物理学领域的广泛应用提供了理论依据。

关键词：积分边值问题不动点定理正解

来源：博看期刊

R_(SC3)K of soybean cv. Kefeng No.1 confers resistance to soybean mosaic virus by interacting with the viral protein P3

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Journal of Integrative Plant Biology 2023年第3期65卷 838-853页

作者： Tongtong Jin Jinlong Yin Tao Wang song xue Bowen Li Tingxuan Zong Yunhua Yang Hui Liu Mengzhuo Liu Kai Xu Liqun Wang Guangnan Xing Haijian Zhi Kai Li National Key L aboratory for Crop Genetics and Germplasm Enhancement Key Laboratory of Biology and Genetic Improvement of Soybean-Ministry of AgricultureNational Center for Soybean ImprovementNanjing Agricultural UniversityNanjing 210095China Jiangsu Key Laboratory for Microbes and Functional Genomics College of Life SciencesNanjing Normal UniversityNanjing 210023China

Soybean mosaic virus(SMV) is one of the most devastating viral pathogens of soybean(Glycine max(L.) Merr). In total, 22 Chinese SMV strains(SC1–SC22) have been classified based on the responses of 10 soybean cultivars to these pathogens. However, although several SMVresistance loci in soybean have been identified, no gene conferring SMV resistance in the resistant soybean cultivar(cv.) Kefeng No.1 has been cloned and verified. Here, using F_(2)-derived F_(3)(F_(2:3)) and recombinant inbred line(RIL) populations from a cross between Kefeng No.1 and susceptible soybean cv. Nannong 1138-2, we localized the gene in Kefeng No.1 that mediated resistance to SMV-SC3 strain to a 90-kb interval on chromosome 2. To study the functions of candidate genes in this interval, we performed Bean pod mottle virus(BPMV)-induced gene silencing(VIGS). We identified a recombinant gene(which we named R_(SC3)K) harboring an internal deletion of a genomic DNA fragment partially flanking the LOC100526921 and LOC100812666 reference genes as the SMV-SC3 resistance gene.By shuffling genes between infectious SMV DNA clones based on the avirulent isolate SC3 and virulent isolate 1129, we determined that the viral protein P3 is the avirulence determinant mediating SMV-SC3 resistance on Kefeng No.1. P3 interacts with RNase proteins encoded by R_(SC3)K, LOC100526921, and LOC100812666. The recombinant R_(SC3)K conveys much higher anti-SMV activity than LOC100526921 and LOC100812666, although those two genes also encode proteins that inhibit SMV accumulation, as revealed by gene silencing in a susceptible cultivar and by overexpression in Nicotiana benthamiana. These findings demonstrate that R_(SC3)K mediates the resistance of Kefeng No.1 to SMV-SC3 and that SMV resistance of soybean is determined by the antiviral activity of RNase proteins.

关键词： recombination resistance gene soybean mosaic virus virulence determinant

高中体育教学中冰雪项目课程的开发和实施策略研究

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冰雪体育创新研究 2024年第3期 127-129页

作者：薛松启东市汇龙中学江苏启东226200

随着教育制度的持续改革创新,高中体育教学更重视对学生综合素养的培育和提升。在高中体育的教学过程中,冰雪体育教学占据十分重要的位置。冰雪项目是一种比较特殊的体育运动方法,既能提升学生的团队合作能力,又能培养学生奋发向上的精... 详细信息

随着教育制度的持续改革创新,高中体育教学更重视对学生综合素养的培育和提升。在高中体育的教学过程中,冰雪体育教学占据十分重要的位置。冰雪项目是一种比较特殊的体育运动方法,既能提升学生的团队合作能力,又能培养学生奋发向上的精神,能够很好地提升学生的能动性,在高中体育教学中具有十分重要的作用,对国内高中体育教学意义深远。在高中体育教学中,全力开展冰雪项目课程内容,是促进高中体育教学改革创新、丰富课程内容的重要环节。

关键词：冰雪项目高中体育体育教学科学研究

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The small and large subunits of carbamoyl-phosphate synthase exhibit diverse contributions to pathogenicity in Xanthomonas citri subsp.citri

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Journal of Integrative Agriculture 2015年第7期14卷 1338-1347页

作者： GUO Jing song xue ZOU Li-fang ZOU Hua-song CHEN Gong-you School of Agriculture and Biology Shanghai Jiao Tong University

Carbamoyl-phosphate synthase plays a vital role in the carbon and nitrogen metabolism cycles. In Xanthomonas citrisubsp. citri, carA and carB encode the small and large subunits of carbamoyl-phosphate synthase, respectively. The deletion mutation of the coding regions revealed that carA did not affect any of the phenotypes, while carB played multiple roles in pathogenicity. The deletion of carB rendered the loss of pathogenicity in host plants and the ability to induce a hyper- sensitive reaction in the non-hosts. Quantitative reverse transcription-PCR assays indicated that 11 hrp genes coding the type Ill secretion system were suppressed when interacting with citrus plants. The mutation in carB also affected bacterial utilization of several carbon and nitrogen resources in minimal medium MMX and extracellular enzyme activities. These data demonstrated that only the large subunit of carbamoyl-phosphate synthase was essential for canker development by X. citri subsp, citri.

关键词： Xanthomonas citri subsp citri carbamoyl-phosphate synthase pathogenicity citrus canker hrp gene

基于Biomek i7自动化工作站筛选高效固碳脱羧酶突变体的方法

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微生物学通报 2024年第3期51卷 792-800页

作者：蒋昕珊范雁刘霖薛松大连理工大学生物工程学院辽宁大连116023 仲恺农业工程学院轻工食品学院广东广州510225

【背景】2,3-二羟基苯甲酸脱羧酶(2,3-dihydroxybenzoic acid decarboxylase,2,3-DHBD)能够催化CO_(2)与酚类化合物羧化生成芳香羧酸,为固定CO_(2)合成增值化学品提供一种新的策略。由于目前转化效率低,限制了其应用。【目的】提高酶的... 详细信息

【背景】2,3-二羟基苯甲酸脱羧酶(2,3-dihydroxybenzoic acid decarboxylase,2,3-DHBD)能够催化CO_(2)与酚类化合物羧化生成芳香羧酸,为固定CO_(2)合成增值化学品提供一种新的策略。由于目前转化效率低,限制了其应用。【目的】提高酶的催化效率,建立基于Biomek i7自动化工作站的高通量筛选方法以期实现高效筛选高羧化活性的苯甲酸脱羧酶的突变体,并建立一个从突变体构建到其酶活筛选的标准方法。【方法】基于Biomek i7自动化工作站对来源于米曲霉(Aspergillus oryzae)的2,3-DHBD(2,3-DHBD_Ao)进行突变体定点半饱和突变、克隆挑选、培养及酶活检测,实现508个克隆的两轮筛选,并利用HPLC评估高通量筛选方法的准确性。【结果】确定了高通量筛选粗酶催化的脱羧及羧化反应体系和Biomek i7自动化工作站筛选流程,对508个克隆进行两轮筛选,得到13个正向突变,HPLC检测最终确定3个正向突变体,构建的文库阳性突变率为0.6%,获得羧化活性最高的突变体是野生型2,3-DHBD_Ao的120%。【结论】利用Biomek i7自动化工作站建立了高通量筛选高羧化活性脱羧酶的方法,首次将自动化高通量设备与突变体筛选结合,提供了筛选时评价指标的确定思路,经过175 h即可完成508个克隆的两轮筛选工作,相较于人工筛选,该方法缩短了筛选周期,具有快速、准确和高效的特点。

关键词：高通量筛选 2,3-二羟基苯甲酸脱羧酶酶的进化羧化

具有非局部效应的时滞SEIR系统的周期行波解

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数学物理学报（A辑） 2024年第1期44卷 140-159页

作者：张广新杨赟瑞宋雪兰州交通大学数理学院兰州730070

该文研究了一类具有非局部效应和非线性发生率的时滞SEIR系统的周期行波解.首先,定义基本再生数R0并构造适当的上下解,将周期行波解的存在性转化为闭凸集上非单调算子的不动点问题,利用Schauder不动点定理结合极限理论建立该系统周期行... 详细信息

该文研究了一类具有非局部效应和非线性发生率的时滞SEIR系统的周期行波解.首先,定义基本再生数R0并构造适当的上下解,将周期行波解的存在性转化为闭凸集上非单调算子的不动点问题,利用Schauder不动点定理结合极限理论建立该系统周期行波解的存在性.其次,利用反证法结合比较原理,建立当基本再生数R0<1时该系统周期行波解的不存在性.

关键词：周期行波解不动点定理存在性

Highly efficient catalytic valorization of biomass-derived hexoses and furfuryl alcohol in the presence of polymer-based catalysts

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Green Energy & Environment 2019年第4期4卷 424-431页

作者： Yangyang Zhang Xinli Tong Linhao Yu Lingwu Meng Pengfei Guo song xue Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion School of Chemistry and Chemical Engineering Tianjin University of Technology

The catalytic transformation of furfuryl alcohol and hexose into value-added chemicals have been investigated with a series of polymer-based catalysts including poly(styrenesulfonic acid)(PSS),graphite oxide-doped poly(styrenesulfonic acid)(PSS-GO),and graphite-doped poly(-styrenesulfonic acid)(PSS-C).It is found that the selective conversion of furfuryl alcohol to methyl levulinate(MLE)was successfully performed with PSS as the catalyst,in which a 96.4%yield is attained in methanol solvent.Moreover,the efficient dehydration of D-fructose to produce 5-hydroxymethylfurfural(HMF)has also been achieved using PSS-GO as the catalyst,where a 76.5%yield of HMF was obtained in Nmethylpyrrodinone solvent.The effects of reaction temperature,time and solvent were investigated.Furthermore,the used catalysts have been respectively characterized by XRD,TG,FTIR,SEM and TEM techniques to reveal the physical properties and structures of these polymeric catalytic materials.

关键词： Catalysis Furfuryl alcohol Fructose 5-Hydroxymethylfurfural Biomass transformation