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基于电力大数据的钢铁企业大气污染物排放核算模型构建及应用
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作者 周卫青 杨俊琦 +4 位作者 宁亮 吴华成 薄宇 张强 田贺忠 《环境科学研究》 CAS CSCD 北大核心 2024年第2期299-307,共9页
近年来,各级生态环境部门与国家电网公司积极签署战略合作协议,促进电力大数据在生态环境管理信息化平台的应用.本研究通过梳理电力大数据在大气污染防治中的应用,以唐山市钢铁行业为例构建基于电力大数据的大气污染物高时间精度排放核... 近年来,各级生态环境部门与国家电网公司积极签署战略合作协议,促进电力大数据在生态环境管理信息化平台的应用.本研究通过梳理电力大数据在大气污染防治中的应用,以唐山市钢铁行业为例构建基于电力大数据的大气污染物高时间精度排放核算模型,进一步挖掘电力大数据在大气污染排放控制中的应用潜力.结果表明:①模型核算的2019年唐山市17家钢铁企业的大气污染物排放量与2019年唐山市大气污染物排放清单(简称“城市清单”)结果一致性较好,SO_(2)、NOx和PM_(2.5)排放量分别为1017.90、2047.75、1141.81t,误差介于-0.46%~4.27%之间.②基于工序而言,以PM_(2.5)为例,模型预测结果与城市清单结果的相对误差在-17.34%~10.60%之间.③唐山某钢铁企业2022年SO_(2)、NOx、PM_(2.5)月排放量受钢铁市场价格影响较大,1月和6月分别为最高和最低污染物排放月,而其日排放受行业特征影响较为平稳,小时排放可能受电价波动影响较大.研究显示,基于电力大数据的大气污染物核算模型阐明了电力大数据和污染排放的动态响应关系,一定程度上提升了排放核算的时间精细度,实证了基于电力大数据核算大气污染物排放的研究意义和可行性. 展开更多
关键词 电力大数据 应用现状 大气污染物排放核算模型 高时间精度
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腹腔镜下远端胃癌切除后消化道不同重建方式对患者预后影响分析
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作者 李龙 柏宇 +1 位作者 欧均斌 周强 《川北医学院学报》 CAS 2024年第4期548-550,共3页
目的:探究腹腔镜下远端胃癌切除后消化道不同重建方式对患者预后的影响。方法:回顾性分析107例腹腔镜下远端胃癌切除后消化道重建患者的临床资料,术后均随访1年。根据患者消化道重建方式不同分为Ⅰ组(n=30)、II组(n=28)和R组(n=49),Ⅰ... 目的:探究腹腔镜下远端胃癌切除后消化道不同重建方式对患者预后的影响。方法:回顾性分析107例腹腔镜下远端胃癌切除后消化道重建患者的临床资料,术后均随访1年。根据患者消化道重建方式不同分为Ⅰ组(n=30)、II组(n=28)和R组(n=49),Ⅰ组采取Billroth-Ⅰ式吻合;Ⅱ组患者采取Billroth-Ⅱ式联合布朗吻合;R组患者采取Roux-en-Y吻合。探究各组围术期情况,比较各组术后3周内及术后1年时并发症发生情况。结果:Ⅰ组患者手术时间低于Ⅱ组及R组(P<0.05);各组患者术后3周内并发症发生率比较,差异均无统计学意义(P>0.05);术后1年,R组患者胆汁反流、反流性胃炎发生率低于Ⅰ组及Ⅱ组(P<0.05)。结论:Billroth-Ⅰ式吻合有助于缩短手术时间,但Roux-en-Y吻合在术后远期效果更具优势。 展开更多
关键词 远端胃癌 腹腔镜 消化道重建 预后 并发症
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Prediction and driving factors of forest fire occurrence in Jilin Province,China
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作者 bo Gao Yanlong Shan +4 位作者 Xiangyu Liu Sainan Yin bo yu Chenxi Cui Lili Cao 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第1期58-71,共14页
Forest fires are natural disasters that can occur suddenly and can be very damaging,burning thousands of square kilometers.Prevention is better than suppression and prediction models of forest fire occurrence have dev... Forest fires are natural disasters that can occur suddenly and can be very damaging,burning thousands of square kilometers.Prevention is better than suppression and prediction models of forest fire occurrence have developed from the logistic regression model,the geographical weighted logistic regression model,the Lasso regression model,the random forest model,and the support vector machine model based on historical forest fire data from 2000 to 2019 in Jilin Province.The models,along with a distribution map are presented in this paper to provide a theoretical basis for forest fire management in this area.Existing studies show that the prediction accuracies of the two machine learning models are higher than those of the three generalized linear regression models.The accuracies of the random forest model,the support vector machine model,geographical weighted logistic regression model,the Lasso regression model,and logistic model were 88.7%,87.7%,86.0%,85.0%and 84.6%,respectively.Weather is the main factor affecting forest fires,while the impacts of topography factors,human and social-economic factors on fire occurrence were similar. 展开更多
关键词 Forest fire Occurrence prediction Forest fire driving factors Generalized linear regression models Machine learning models
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Advancements in machine learning for material design and process optimization in the field of additive manufacturing
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作者 Hao-ran Zhou Hao Yang +8 位作者 Huai-qian Li Ying-chun Ma Sen yu Jian shi Jing-chang Cheng Peng Gao bo yu Zhi-quan Miao Yan-peng Wei 《China Foundry》 SCIE EI CAS CSCD 2024年第2期101-115,共15页
Additive manufacturing technology is highly regarded due to its advantages,such as high precision and the ability to address complex geometric challenges.However,the development of additive manufacturing process is co... Additive manufacturing technology is highly regarded due to its advantages,such as high precision and the ability to address complex geometric challenges.However,the development of additive manufacturing process is constrained by issues like unclear fundamental principles,complex experimental cycles,and high costs.Machine learning,as a novel artificial intelligence technology,has the potential to deeply engage in the development of additive manufacturing process,assisting engineers in learning and developing new techniques.This paper provides a comprehensive overview of the research and applications of machine learning in the field of additive manufacturing,particularly in model design and process development.Firstly,it introduces the background and significance of machine learning-assisted design in additive manufacturing process.It then further delves into the application of machine learning in additive manufacturing,focusing on model design and process guidance.Finally,it concludes by summarizing and forecasting the development trends of machine learning technology in the field of additive manufacturing. 展开更多
关键词 additive manufacturing machine learning material design process optimization intersection of disciplines embedded machine learning
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Effects of conductive agent type on lithium extraction from salt lake brine with LiFePO_(4)electrodes
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作者 Zhen Zhang Pan Luo +7 位作者 Yan Zhang yuhan Wang Li Liao bo yu Mingshan Wang Junchen Chen Bingshu Guo Xing Li 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第4期678-687,共10页
Electrochemical lithium extraction from salt lakes is an effective strategy for obtaining lithium at a low cost.Nevertheless,the elevated Mg:Li ratio and the presence of numerous coexisting ions in salt lake brines gi... Electrochemical lithium extraction from salt lakes is an effective strategy for obtaining lithium at a low cost.Nevertheless,the elevated Mg:Li ratio and the presence of numerous coexisting ions in salt lake brines give rise to challenges,such as prolonged lithium extraction periods,diminished lithium extraction efficiency,and considerable environmental pollution.In this work,Li FePO4(LFP)served as the electrode material for electrochemical lithium extraction.The conductive network in the LFP electrode was optimized by adjusting the type of conductive agent.This approach resulted in high lithium extraction efficiency and extended cycle life.When the single conductive agent of acetylene black(AB)or multiwalled carbon nanotubes(MWCNTs)was replaced with the mixed conductive agent of AB/MWCNTs,the average diffusion coefficient of Li+in the electrode increased from 2.35×10^(-9)or 1.77×10^(-9)to 4.21×10^(-9)cm^(2)·s^(-1).At the current density of 20 mA·g^(-1),the average lithium extraction capacity per gram of LFP electrode increased from 30.36 mg with the single conductive agent(AB)to 35.62 mg with the mixed conductive agent(AB/MWCNTs).When the mixed conductive agent was used,the capacity retention of the electrode after 30 cycles reached 82.9%,which was considerably higher than the capacity retention of 65.8%obtained when the single AB was utilized.Meanwhile,the electrode with mixed conductive agent of AB/MWCNTs provided good cycling performance.When the conductive agent content decreased or the loading capacity increased,the electrode containing the mixed conductive agent continued to show excellent electrochemical performance.Furthermore,a self-designed,highly efficient,continuous lithium extraction device was constructed.The electrode utilizing the AB/MWCNT mixed conductive agent maintained excellent adsorption capacity and cycling performance in this device.This work provides a new perspective for the electrochemical extraction of lithium using LFP electrodes. 展开更多
关键词 salt lake brine lithium extraction electrochemical lithium extraction conductive agent extraction efficiency adsorption capacity
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Cu和Zr元素取代对Sm_(2)Co_(7)快淬带磁性能的影响
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作者 侯永杰 左建华 +4 位作者 李敏敏 薄宇 章明 董福海 白锁 《稀有金属与硬质合金》 CAS CSCD 北大核心 2024年第2期50-54,共5页
采用感应熔炼和熔体快淬技术制备了Sm_(2)Co_(7-x)R_(x)(R=Cu、Zr;x=0、0.1、0.2、0.3、0.4)快淬带,研究了取代元素、取代量和快淬速度对快淬带磁性能、晶粒间相互作用和不可逆翻转场的影响规律。磁性能测试结果表明,Cu和Zr取代在快淬... 采用感应熔炼和熔体快淬技术制备了Sm_(2)Co_(7-x)R_(x)(R=Cu、Zr;x=0、0.1、0.2、0.3、0.4)快淬带,研究了取代元素、取代量和快淬速度对快淬带磁性能、晶粒间相互作用和不可逆翻转场的影响规律。磁性能测试结果表明,Cu和Zr取代在快淬带内引起了强烈的钉扎效应,有助于提升快淬带的矫顽力,且均在x=0.3时获得最大矫顽力;Cu取代量x=0.1、0.2、0.4时快淬带的剩磁与最大磁能积随快淬速度逐渐降低,取代量x=0.3时表现为逐渐升高;Zr取代量x=0.1~0.4时快淬带的剩磁与最大磁能积均随快淬速度的增加先升高后降低。Henkel曲线测试结果表明,对于Cu元素和Zr元素取代,δM值均在x=0.3时达到最大,表明此时快淬带晶粒间的交换耦合作用最强;Sm_(2)(Co, Cu)_(7)和Sm_(2)(Co, Zr)_(7)快淬带的最大δM值分别为1.48和1.04。适量Cu、Zr元素取代可以提高Sm_(2)Co_(7)磁体在反磁化过程中的不可逆翻转场H_(n)。 展开更多
关键词 Sm_(2)Co_7 快淬带 Cu和Zr取代 快淬速度 磁性能 交换耦合 不可逆翻转场
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Postoperative pneumocranium after endoscopic transnasal optic canal decompression
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作者 Sheng-Jian Lu bo yu Wen-Can Wu 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第5期973-975,共3页
Dear Editor,We present the first time,a case of a patient developed cerebrospinal fluid(CSF)leak and pneumocranium following optic canal decompression(OCD).INTRODUCTION Indirect traumatic optic neuropathy(ITON)impairs... Dear Editor,We present the first time,a case of a patient developed cerebrospinal fluid(CSF)leak and pneumocranium following optic canal decompression(OCD).INTRODUCTION Indirect traumatic optic neuropathy(ITON)impairs visual functions and quality of life.Endoscopic transnasal optic canal decompression(ETOCD)is one of the standard treatment strategies for the ITON.During the ETOCD,the optic nerve sheath are usually incised for sufficient decompression of optic nerve after removal of optic canal,which is associated with complications like CSF leakage,ophthalmic artery injury,and optic nerve injury[1].Generally,the mild CSF leak is common and can heal spontaneously using conventional treatment,the severe CSF leak requires surgical repair[2]. 展开更多
关键词 DECOMPRESSION NASAL TRAUMATIC
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富锌在脂多糖、地塞米松诱导小鼠腭裂中的作用
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作者 何映瑶 王倩 +5 位作者 柏宇 唐璟 姚涛 王芳 何苇 宋庆高 《遵义医科大学学报》 2024年第4期344-354,共11页
目的 研究富锌在脂多糖、地塞米松诱导小鼠腭裂中的作用,并初步探索其发生的可能机制。方法 将120只孕鼠随机分为6组:常锌对照组(C)、脂多糖组(LPS)、地塞米松组(DEX)、富锌组(Zn)、富锌+脂多糖组(ZLPS)、富锌+地塞米松组(ZDEX),胚胎(ED... 目的 研究富锌在脂多糖、地塞米松诱导小鼠腭裂中的作用,并初步探索其发生的可能机制。方法 将120只孕鼠随机分为6组:常锌对照组(C)、脂多糖组(LPS)、地塞米松组(DEX)、富锌组(Zn)、富锌+脂多糖组(ZLPS)、富锌+地塞米松组(ZDEX),胚胎(ED) 0.5 d开始,前3组给予常锌饲料30 mg/kg,后3组给予富锌饲料100 mg/kg;LPS组、ZLPS组ED 8.5 d颈部注射脂多糖0.15 mg/kg,DEX组、ZDEX组ED 10.5 d开始连续3 d同一时间腹腔注射地塞米松6 mg/kg。孕鼠在ED 13.5 d、ED 14.5 d、ED 15.5 d麻醉后脱颈处死,显微镜下观察胎鼠腭部,统计腭裂发生率;HE染色观察腭突的发育状况,免疫组织化学染色检测腭突Sp5、Wiz表达情况;RT-qPCR和WB方法检测腭突Sp5、Wiz、Ptch1、Gli3表达情况。结果 孕鼠暴露于LPS和DEX均会产生腭裂,且DEX处理后发生率更高;ED 13.5 d时,与C组相比,LPS组腭突Sp5阳性表达平均光密度值及Sp5蛋白表达升高(P<0.05),Zn组腭突Sp5、Wiz阳性表达平均光密度值及Sp5蛋白表达下降(P<0.05),而Wiz mRNA升高(P<0.05)。ZLPS组较LPS组腭突Sp5、Wiz阳性表达平均光密度值、Sp5 mRNA及Sp5蛋白表达显著降低(P<0.05),而ZDEX组较DEX组结果则相反(P<0.05);与C组相比,LPS组、Zn组Ptch1 mRNA及Ptch1蛋白表达均升高(P<0.05),但是LPS组Gli3 mRNA表达降低(P<0.05),Zn组Gli3 mRNA表达升高(P<0.05);ZDEX组较DEX组Ptch1 mRNA及其蛋白表达明显增加(P<0.05),Gli3 mRNA表达降低(P<0.05);ZLPS组较LPS组Ptch1 mRNA及其蛋白表达下降(P<0.05)。结论 富锌饮食对孕鼠暴露在LPS引起的腭裂有一定的拮抗作用,可能与调节Sp5、Wiz的表达相关,但对暴露于DEX诱发的腭裂未见明显的拮抗效果。 展开更多
关键词 腭裂 预防 脂多糖 地塞米松 锌指蛋白
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Long-term follow-up of antithrombotic management patterns in patients with acute coronary syndrome in China 被引量:1
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作者 Xiao-Ning HAN Shu-Bin QIAO +6 位作者 Jun-bo GE Ya-Ling HAN Ji-Yan CHEN Zu-Yi yuAN bo yu Jie JIANG Yong HUO 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2020年第5期246-255,I0002-I0004,共13页
Objective To describe the long-term antithrombotic management patterns(AMPs)and clinical outcomes of Chinese patients with acute coronary syndrome(ACS).Methods This was an observational,multicenter,longitudinal cohort... Objective To describe the long-term antithrombotic management patterns(AMPs)and clinical outcomes of Chinese patients with acute coronary syndrome(ACS).Methods This was an observational,multicenter,longitudinal cohort extension study of Chinese patients who had completed the EPICOR Asia 2-year follow-up study post-hospitalization for an ACS event.Changes in AMP and clinical outcomes for up to 5 years post-ACS event were evaluated.Results Overall,2334 patients with ACS were enrolled at 49 sites.The mean age was 61.6 years and 76.3%were men.By study end,2093 patients completed the 3-year follow-up.At baseline(2 years post-ACS event),72.4%of patents received one antiplatelet(AP)medication,with aspirin being the preferred one.A small proportion of patients(21.5%)was treated with two or more APs(2+AP),and even fewer patients(6.1%)did not receive any AP medication at baseline.Upon study completion,the proportion of patients without AP therapy increased to 13.6%,while the percentage of patients on one AP and 2+AP decreased to 69.3%and 17.1%,respectively.Numerically,a higher incidence of clinical events(composite of all-cause mortality,myocardial infarction,stroke)was observed for the 2+AP(13.2%)subgroup than for the no AP(10.5%)and one AP(8.6%)subgroups.Furthermore,the 2+AP subgroup exhibited the greatest number of bleeding events,outpatient visits,and hospitalization rates.Unlike myocardial infarction or stroke,bleeding events prompted an adjustment in AMP.Conclusion Most patients in China received at least one AP medication up to 5 years after an ACS event. 展开更多
关键词 Acute coronary syndrome Antithrombotic agents Antithrombotic management patterns Observational study Real-world
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多因素影响下黏土比热容变化规律及预测模型
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作者 雷华阳 薄钰 +2 位作者 马长远 王磊 章纬地 《岩土力学》 EI CAS CSCD 北大核心 2023年第S01期1-11,共11页
在“双碳”目标背景下,土体比热容作为重要的热物理性质参数之一,在能源地下结构、地铁通风计算、地埋管线、核废料处置、冻结法施工、农耕灌溉等众多领域有着重要的意义。对不同初始干密度、初始含水率的黏土试样,在不同温度条件下开... 在“双碳”目标背景下,土体比热容作为重要的热物理性质参数之一,在能源地下结构、地铁通风计算、地埋管线、核废料处置、冻结法施工、农耕灌溉等众多领域有着重要的意义。对不同初始干密度、初始含水率的黏土试样,在不同温度条件下开展了比热容测试分析,探讨了其变化规律及机制。试验结果表明:黏土比热容随初始干密度、初始含水率的增加而线性增加,且与温度的三次方呈正比。比热容变化机制与黏土三相比例变化、固相晶格振动、水冰相变等因素有关。建立了考虑多因素的黏土比热容预测模型,与反向传播神经网络(BP-ANN)预测模型、简化理论预测模型、其他经验预测模型的交叉验证结果显示,该模型在适用范围、预测性能等方面都具有较优的表现,可为理论计算、数值仿真、工程实践中黏土比热容的取值和计算提供可靠参考。 展开更多
关键词 黏土 比热容 预测模型 多影响因素 热物理性质
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Numerical simulation of fracture propagation in Russia carbonate reservoirs during refracturing
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作者 Dao-Bing Wang Fu-Jian Zhou +7 位作者 Yi-Peng Li bo yu Dmitriy Martyushev Xiong-Fei Liu Meng Wang Chun-Ming He Dong-Xu Han Dong-Liang Sun 《Petroleum Science》 SCIE CAS CSCD 2022年第6期2781-2795,共15页
Refracturing treatment is often performed on Russian carbonate reservoirs because of the quick production decline of reservoirs.The traditional refracturing model assumes that a refracture initiates in the normal dire... Refracturing treatment is often performed on Russian carbonate reservoirs because of the quick production decline of reservoirs.The traditional refracturing model assumes that a refracture initiates in the normal direction relative to the initial hydro-fracture.This assumption is inconsistent with oilfield measurements of refracture propagation trajectories.Indeed,the existing model is not based on an indepth understanding of initiation and propagation mechanisms of the second hydraulic fractures during refracturing.In this study,we use the extended finite element method to investigate refracture propagation paths at different initiation angles.Both the enriched function approach and phantom mode technique are incorporated into the refracturing model,thereby ensuring that the refracture can freely extend on the structured mesh without any refinement near the crack tips.Key factors including production time,stress anisotropy and initiation angle,and the propped mechanical effect are analyzed in detail.This study provides new insight into the mechanism of refracture propagation in unconventional reservoirs. 展开更多
关键词 REFRACTURING Stress reorientation Extended finite element method Carbonate reservoir Fracture diversion
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Loss of KDM4B impairs osteogenic differentiation of OMSCs and promotes oral bone aging
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作者 Peng Deng Insoon Chang +4 位作者 Jiongke Wang Amr A.Badreldin Xiyao Li bo yu Cun-yu Wang 《International Journal of Oral Science》 SCIE CAS CSCD 2022年第2期145-155,共11页
Aging of craniofacial skeleton significantly impairs the repair and regeneration of trauma-induced bony defects,and complicates dental treatment outcomes.Age-related alveolar bone loss could be attributed to decreased... Aging of craniofacial skeleton significantly impairs the repair and regeneration of trauma-induced bony defects,and complicates dental treatment outcomes.Age-related alveolar bone loss could be attributed to decreased progenitor pool through senescence,imbalance in bone metabolism and bone-fat ratio.Mesenchymal stem cells isolated from oral bones(OMSCs)have distinct lineage propensities and characteristics compared to MSCs from long bones,and are more suited for craniofacial regeneration.However,the effect of epigenetic modifications regulating OMSC differentiation and senescence in aging has not yet been investigated.In this study,we found that the histone demethylase KDM4B plays an essential role in regulating the osteogenesis of OMSCs and oral bone aging.Loss of KDM4B in OMSCs leads to inhibition of osteogenesis.Moreover,KDM4B loss promoted adipogenesis and OMSC senescence which further impairs bone-fat balance in the mandible.Together,our data suggest that KDM4B may underpin the molecular mechanisms of OMSC fate determination and alveolar bone homeostasis in skeletal aging,and present as a promising therapeutic target for addressing craniofacial skeletal defects associated with age-related deteriorations. 展开更多
关键词 METABOLISM HOMEOSTASIS AGING
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京津冀协同推进碳达峰碳中和路径研究 被引量:7
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作者 黄昱杰 刘贵贤 +4 位作者 薄宇 王洁 曹明悦 鲁玺 贺克斌 《中国工程科学》 CSCD 北大核心 2023年第2期160-172,共13页
京津冀地区是我国能源消耗、碳排放的集聚区,研究区域内碳达峰、碳中和的推进举措,对实现高质量的区域协同发展至关重要。本文构建了考虑京津冀地区特征的长期能源替代规划系统模型(LEAP-BTH),设置了基准情景、低碳情景、协同情景等主... 京津冀地区是我国能源消耗、碳排放的集聚区,研究区域内碳达峰、碳中和的推进举措,对实现高质量的区域协同发展至关重要。本文构建了考虑京津冀地区特征的长期能源替代规划系统模型(LEAP-BTH),设置了基准情景、低碳情景、协同情景等主要情景以及8个子情景,完成了2021—2060年京津冀地区相应发展路径的预测分析。结果表明:在基准情景下,京津冀地区能源需求将持续增长,2060年北京市、天津市、河北省的碳排放量分别下降为2020年的41%、40%、53%,实现碳中和目标面临较大挑战;在低碳情景下,2060年北京市、天津市、河北省的碳排放量分别下降为2020年的20%、26%、46%,相比碳中和目标仍有一定差距;在协同情景下,2060年北京市、天津市、河北省的碳排放量分别下降为2020年的13%、15%、21%,能够基本实现碳中和目标。研究建议,京津冀三省市需针对各自的重点减排部门和路径,提出更明确、更严格的应对措施,如北京市重点推动交通、建筑部门的低碳转型,天津市、河北省着力开展可再生能源替代与工业绿色升级;优化顶层设计,挖掘区域内工业、能源、交通等部门的协同发展潜力,重点推动产业协同升级和能源协同发展,据此支撑京津冀地区的“双碳”工作和高质量发展。 展开更多
关键词 京津冀协同发展 LEAP-BTH模型 能源需求 “双碳”目标
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基于复合LSTM模型的PM_(2.5)浓度预测 被引量:2
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作者 顾阔 焦瑞莉 +2 位作者 薄宇 刘帅强 王立志 《中国环境监测》 CAS CSCD 北大核心 2023年第1期170-180,共11页
在对淄博市19个空气质量监测站点监测数据进行分析后,提出了一种基于机器学习的复合模型——灰色关联度分析(GRA)-改进的完备总体经验模态分解(ICEEMD)-长短期记忆网络(LSTM)模型。通过分析淄博市2019年大气污染物和气象数据,选用LSTM... 在对淄博市19个空气质量监测站点监测数据进行分析后,提出了一种基于机器学习的复合模型——灰色关联度分析(GRA)-改进的完备总体经验模态分解(ICEEMD)-长短期记忆网络(LSTM)模型。通过分析淄博市2019年大气污染物和气象数据,选用LSTM模型预测PM_(2.5)浓度。由于传统单一模块机器学习模型具有训练时间较长和预测精度较低的问题,提出了复合LSTM模型。该模型由3部分组成:GRA,用于PM_(2.5)浓度影响因素变量筛选;ICEEMD,用于PM_(2.5)分解、分量筛选和原始大气污染物及气象数据处理;LSTM,用于PM_(2.5)浓度预测。预测结果表明:淄博市中部丘陵地带PM_(2.5)浓度高于南部山区和北部平原,东部高于西部;淄博市逐月PM_(2.5)浓度呈“U”形分布,1月最高,8月最低;淄博市PM_(2.5)浓度受PM_(10)和CO影响较大,受湿度和温度影响较小。对比单一LSTM模型和GRA-LSTM模型,GRA-ICEEMD-LSTM模型能有效提升运算效率,减少训练时长,提升预测精度,具有良好的应用效果。 展开更多
关键词 PM_(2.5)浓度 灰色关联度分析(GRA) 改进的完备总体经验模态分解(ICEEMD) 长短期记忆网络(LSTM)
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Hydrogen Bond Effect in Nonlinear Optical Properties of Azobenzene Derivatives
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作者 Da-qiao Hu Wen-jun Wang +2 位作者 Rong-rong Wang bo Yang bo yu 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2015年第5期-,共5页
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可见光催化二氧化碳参与非活化烯烃1,3-双羧基化反应
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作者 肖汉至 于博 +6 位作者 颜思顺 章炜 李茜茜 鲍莹 罗书平 叶剑衡 余达刚 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2023年第7期222-228,共7页
二氧化碳(CO_(2))具有储量丰富、廉价易得、无毒可再生的特点,是一种理想的碳一合成子.在CO_(2)参与的众多转化中,合成应用广泛、易于衍生的羧酸化学品具有较高的研究价值.其中,有机二元羧酸是一种重要的化学品,广泛应用于材料加工、有... 二氧化碳(CO_(2))具有储量丰富、廉价易得、无毒可再生的特点,是一种理想的碳一合成子.在CO_(2)参与的众多转化中,合成应用广泛、易于衍生的羧酸化学品具有较高的研究价值.其中,有机二元羧酸是一种重要的化学品,广泛应用于材料加工、有机合成和生物医药等领域.尽管目前CO_(2)参与的单羧基化反应研究取得了较大进展,但CO_(2)参与构建的区域选择性二羧基化反应方法仍然亟待发展.近年来,可见光化学因其具有绿色温和、官能团兼容性较好等特点已成为利用CO_(2)构建二羧基化反应的有力策略.目前虽已发展了不同策略实现了烯烃1,1-, 1,2-, 1,6-和1,7-双羧基化等不同的区域选择性,但现有策略还未能完成烯烃1,3-双羧基化的区域选择性.另外,现有策略仅能构建两个C–C键.本文利用可见光催化策略,基于1,2-芳基迁移过程,在温和条件下实现了CO_(2)参与非活化烯烃1,3-双羧基化反应,实现了双羧基化领域尚未实现的区域选择性.反应过程涉及一个C–C单键断裂和三个C–C单键形成,可合成一系列新型戊二酸类产物,并且产物易于衍生为杂环结构.一系列给电子、吸电子取代基以及杂芳环取代基均能兼容于反应体系.机理实验结果表明,反应中可原位产生二氧化碳自由基阴离子(CO_(2)^(-)),随后经历自由基加成、1,2-芳基迁移、单电子还原和亲核进攻CO_(2)等过程产生二元羧酸产物.综上,本文为可见光催化CO_(2)参与二羧基化反应方法提供了重要的区域选择性补充,并可同时构建多个C–C键,具有应用前景. 展开更多
关键词 二氧化碳 可见光催化 1 3-双羧基化 非活化烯烃 1 2-芳基迁移
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CO_(2)高温电解技术助力化工产业碳中和 被引量:1
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作者 李一枫 张龙贵 +2 位作者 于波 朱建新 吴长江 《Engineering》 SCIE EI CAS CSCD 2023年第2期101-114,M0005,共15页
化学工业是我国主要的CO_(2)排放源,为了实现我国的碳中和目标,必须重点关注化学工业的碳排放情况。基于固体氧化物电解池(SOEC)的CO_(2)高温电解技术,对于中国实现碳减排、碳达峰和碳中和目标具有重要意义。此外,该技术可以实现CO_(2)... 化学工业是我国主要的CO_(2)排放源,为了实现我国的碳中和目标,必须重点关注化学工业的碳排放情况。基于固体氧化物电解池(SOEC)的CO_(2)高温电解技术,对于中国实现碳减排、碳达峰和碳中和目标具有重要意义。此外,该技术可以实现CO_(2)的资源化利用,从而产生可观的环境效益和潜在的经济效益。目前,CO_(2)高温电解技术已经在实验室和中试阶段取得了很大进展,但该技术的大规模工业应用还需要进一步探索。本文综述了高温CO_(2)电解池材料的最新研究进展,讨论了SOEC技术的未来发展方向,并提出了SOEC技术与化工合成耦合实现碳中和目标的方法。 展开更多
关键词 碳中和 化工产业 电解池 碳减排 最新研究进展 环境效益 碳排放 排放源
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Endoscopic dacryocystorhinostomy with bicanalicular silicone tube intubation for treating chronic dacryocystitis secondary to nasolacrimal duct stent incarceration 被引量:1
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作者 Shan Lan Jin-Qiang yu +3 位作者 Feng Ke De-Kun Li bo yu Zhen-Kai Liu 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2023年第8期1218-1223,共6页
AIM:To investigate the feasibility of endoscopic dacryocystorhinostomy(En-DCR)with bicanalicular silicone tube intubation for treating chronic dacryocystitis secondary to nasolacrimal duct stent(NDS)incarceration.METH... AIM:To investigate the feasibility of endoscopic dacryocystorhinostomy(En-DCR)with bicanalicular silicone tube intubation for treating chronic dacryocystitis secondary to nasolacrimal duct stent(NDS)incarceration.METHODS:En-DCRs were performed on 44 chronic dacryocystitis patients(46 eyes)secondary to NDS incarceration from April 2016 to October 2022.The granuloma and scar tissues were separated,and the removal of NDS incarceration was achieved during the surgery;the flap of the lacrimal sac was trimmed and anastomosed with nasal mucosal,a bicanalicular silicone tube was implanted,and lacrimal size and condition were assessed.The tube was removed 3mo after surgery.During the final follow-up of 12mo when the surgery was completed,the complications and the rates of surgical success were assessed.RESULTS:This study covered 40 patients(42 eyes).Intraoperatively,it was found that the lacrimal sac became small,and the sac wall had granulation and scar tissue attached to the incarcerated NDS in all eyes.At 12mo after surgery completed,the rates of the functional and anatomical success reached 80.95%(34/42)and 83.33%(35/42),respectively.Under the effect of intranasal ostial closure,seven eyes failed to achieve anatomical success.No serious complications(e.g.,visual impairment,sinusitis,and orbital fat prolapse)was observed.CONCLUSION:With the success rate over 80%and no serious complications,En-DCR with bicanalicular silicone tube implantation is effective in treating chronic dacryocystitis secondary to NDS incarceration. 展开更多
关键词 endoscopic dacryocystorhinostomy bicanalicular silicone tube nasolacrimal duct stent INCARCERATION
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基于DTWKNN的电力缺失数据补全方法
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作者 李富柏 焦瑞莉 +1 位作者 薄宇 李朋 《北京信息科技大学学报(自然科学版)》 2023年第5期32-38,共7页
电力数据是电力负荷预测工作的基础,但是由于智能电表故障、传输信道异常等原因导致的电力数据缺失现象,直接影响电力负荷预测的准确性。针对此问题,提出了一种动态时间规整k最近邻(dynamic time warping k-nearest neighbor, DTWKNN)... 电力数据是电力负荷预测工作的基础,但是由于智能电表故障、传输信道异常等原因导致的电力数据缺失现象,直接影响电力负荷预测的准确性。针对此问题,提出了一种动态时间规整k最近邻(dynamic time warping k-nearest neighbor, DTWKNN)的电力缺失数据补全方法。在传统k最近邻(KNN)方法的基础上,用动态时间规整距离取代欧式距离,参考主成分分析方法计算属性相关性影响参数,该参数调整了近邻点权重并用于补全数据,最终对所有缺失点依次补全。以某市实际用电数据进行补全实验,与KNN补全方法对比,基于DTWKNN方法的缺失数据补全效果更好。此外,经补全后的电力数据在负荷预测实验中误差更低,具备良好的电力负荷预测应用性。 展开更多
关键词 电力数据 数据补全 动态时间规整 k最近邻
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Experimental study of the temporary plugging capability of diverters to block hydraulic fractures in high-temperature geothermal reservoirs
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作者 Dao-Bing Wang Hao Qin +3 位作者 Yong-Liang Wang Jian-Qiao Hu Dong-Liang Sun bo yu 《Petroleum Science》 SCIE EI CAS CSCD 2023年第6期3687-3699,共13页
The effective plugging of artificial fractures is key to the success of temporary plugging and diverting fracturing technology,which is one of the most promising ways to improve the heat recovery efficiency of hot dry... The effective plugging of artificial fractures is key to the success of temporary plugging and diverting fracturing technology,which is one of the most promising ways to improve the heat recovery efficiency of hot dry rock.At present,how temporary plugging agents plug artificial fractures under high temperature remains unclear.In this paper,by establishing an improved experimental system for the evaluation of temporary plugging performance at high temperature,we clarified the effects of high temperature,injection rate,and fracture width on the pressure response and plugging efficiency of the fracture.The results revealed that the temporary plugging process of artificial fractures in hot dry rock can be divided into four main stages:the initial stage of temporary plugging,the bridging stage of the particles,the plugging formation stage,and the high-pressure dense plugging stage.As the temperature increases,the distribution distance of the temporary plugging agent,the number of pressure fluctuations,and the time required for crack plugging increases.Particularly,when the temperature increases by 100℃,the complete plugging time increases by 90.7%. 展开更多
关键词 High temperature Diverter material Fracture plugging capability Hydraulic fracturing Experimental study
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