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Traveling Waves for Nonlocal and Non-monotone Delayed Reaction-difusion Equations

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Acta Mathematica Sinica,English Series 2013年第11期29卷 2159-2180页

作者： Zhi Ting XU pei xuan WENG School of Mathematical Sciences South China Normal University

We study the existence of traveling wave solutions for a nonlocal and non-monotone delayed reaction-diffusion equation. Based on the construction of two associated auxiliary reaction diffusion equations with monotonicity and by using the traveling wavefronts of the auxiliary equations, the existence of the positive traveling wave solutions for c 〉 c. is obtained. Also, the exponential asymptotic behavior in the negative infinity was established. Moreover, we apply our results to some reactiondiffusion equations with spatio-temporal delay to obtain the existence of traveling waves. These results cover, complement and/or improve some existing ones in the literature.

关键词： Nonlocal non-monotone delayed reaction-diffusion equation traveling wave solutions auxiliary equation

汉语作为方法:从早期文字记录看汉语诗学的当代价值

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河北学刊 2025年第1期45卷 67-73页

作者：张晶刘璇中国传媒大学辽宁师范大学文学院

汉语兼具“文”与“言”的双重属性,与以“言”为主的印欧语相区别。语法与逻辑的同根同源使印欧语在理论表述中陷入了概念与经验的争执,而汉语贯通形而上与形而下的特质使汉语表述本身即构成一种方法。作为“道”之文的载体,中国早期... 详细信息

汉语兼具“文”与“言”的双重属性,与以“言”为主的印欧语相区别。语法与逻辑的同根同源使印欧语在理论表述中陷入了概念与经验的争执,而汉语贯通形而上与形而下的特质使汉语表述本身即构成一种方法。作为“道”之文的载体,中国早期记录及其文法结构提供了关键信息,甲骨卜辞的体例制式为“易”类文献的结构提供了可追溯的原型,也为探索“论出于易”对汉语诗学功能的塑造提供了重要线索。其中,干支配伍的宇宙纪日为“以时系事”的话语表述提供了超线性时空结构;“正反对贞”以对言的形式表现语义的动态平衡与赋形必变的道理;“主题+阐释”的体例结构以逐层累积的文本层次为断言的疑难提供了积极的方案。汉语文法能够在表述判断的同时保持对“变”的关切,这为建构既能规范描述艺术经验又能直面人类自身处境的理论话语提供了时代价值。

关键词：汉语早期文字记录文法结构汉语诗学当代价值

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基于反应气混合物的ICP-MS/MS测定原油中的钒和镍

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光谱学与光谱分析 2025年第1期45卷 101-106页

作者：蔡松韬黄莹秀袁亮代宇宣莫垚坤黄建华湖南工学院材料科学与工程学院湖南衡阳421002 湖南省中医药研究院中药研究所湖南长沙410013

原油中金属元素钒和镍(V和Ni)的含量和比值可为深入了解原油的沉积环境特征和有机质类型发挥重要作用。在原油炼制过程中,V和Ni作为原油催化裂化过程中的有害金属元素,会降低催化剂的活性,严重时会导致催化剂中毒,会严重腐蚀设备,在精... 详细信息

原油中金属元素钒和镍(V和Ni)的含量和比值可为深入了解原油的沉积环境特征和有机质类型发挥重要作用。在原油炼制过程中,V和Ni作为原油催化裂化过程中的有害金属元素,会降低催化剂的活性,严重时会导致催化剂中毒,会严重腐蚀设备,在精炼之前必须对原油中的V和Ni进行脱除处理。V和Ni具有致突变性和致癌性,识别或监测原油中V和Ni进入环境的潜在危险变得越来越重要,对原油中V和Ni的含量进行高灵敏精准测定具有重要意义。采用电感耦合等离子体串联质谱(ICP-MS/MS)测定原油中V和Ni的新策略。原油样品经航空煤油简单稀释后直接采用ICP-MS/MS进行分析,针对V和Ni受到的质谱干扰,在MS/MS模式下,采用由NH_(3)/He(He为缓冲气)和H_(2)组成的反应气混合物(NH_(3)/He/H_(2))作为反应气,基于V^(+)与NH_(3)/He/H_(2)不发生反应,而V^(+)的干扰离子与NH_(3)/He/H_(2)发生反应,采用原位质量法消除干扰,选择V^(+)进行测定;基于Ni^(+)与NH_(3)/He/H_(2)发生反应,采用质量转移法消除干扰,选择无干扰团簇离子Ni(NH_(3))_(3)^(+)进行测定。通过与NH_(3)/He反应模式进行对比研究发现,对于V的测定,加入H_(2)为反应气能快速去除氩基离子的干扰,并能协同NH_(3)消除氧化物离子的干扰;对于Ni的测定,加入H_(2)为反应气能促进全氢加合物(-NH_(3))的形成,从而提高生成Ni(NH_(3))_(3)^(+)的产率。在NH_(3)/He/H_(2)反应模式下,V和Ni的背景等效浓度(BEC)更低,Ni的灵敏度更高,V和Ni的检出限(LOD)分别低至0.83和3.76 ng·kg^(-1),定量限(LOQ)分别为2.77和12.5 ng·kg^(-1)。通过分析标准参考物质NIST SRM 1634c并进行加标回收实验评价方法的准确度和精密度,结果显示,方法的测定结果与标准参考物质的认证值基本一致,V和Ni的加标回收率分别为97.7%和103%,相对标准偏差(RSD)分别为1.8%和1.9%。所建立的分析方法避免了繁琐的样品预处理过程,具有操作简单快速、灵敏度高、准确度和精密度好的特点,适用于原油中V和Ni的检测,能为原油深加工中V和Ni的脱除提供理论依据。

关键词：原油电感耦合等离子体串联质谱钒(V) 镍(Ni) 氨气/氦气/氢气(NH_(3)/He/H_(2))

Visible light-mediated C—P bond formation reactions

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Science Bulletin 2019年第5期64卷 337-350页

作者： Bao-Gui cai Jun xuan Wen-Jing Xiao Anhui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials College of Chemistry & Chemical Engineering Anhui University Key Laboratory of Pesticide & Chemical Biology Ministry of Education College of Chemistry Central China Normal University

Organophosphorus compounds have attracted continuous attention in materials science, agrochemical and pharmaceutical fields due to their unique bioactivities. Thus, the development of novel and robust manners for the construction new C—P bond has therefore gained great interests in synthetic organic chemistry. Because of their intrinsic sustainability and green chemistry character, visible light-induced photoredox catalysis has been widely applied in the construction of new chemical bonds, including the formation of C—P bond. In this review, we summarized recent achievements in C—P bond formation reactions initiated by visible light-induced photoredox catalysis, which mainly focusing on the discussion of reaction design and the mechanism.

关键词： C-P bond formation Organophosphorus compounds Photoredox catalysis Visible light

Association of stent thrombectomy and conventional treatment with neuroprotection, complications, anxiety, and depression in acute ischemic stroke patients

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World Journal of Psychiatry 2025年第1期15卷 72-82页

作者： Kai-Jie Yang Jia-Jian Huang cai-Xia xuan Department of Neurology Qinzhou Second People's HospitalQinzhou 535000Guangxi Zhuang Autonomous RegionChina

BACKGROUND Acute ischemic stroke(AIS)is an abrupt blood flow cessation to a specific brain region within a vascular zone,causing a subsequent decline in neurological *** thrombectomy is a recently established technique for treating *** provides the benefits of being a relatively simple and safe procedure,capable of partially enhancing a patient’s ***,some patients may experience endothelial damage and recurrent thrombosis,with clinical outcomes that are not always ***,the efficacy of this method remains *** To survey the association of stent thrombectomy vs standard treatment with neurological function protection,complications,and short-term prognosis in patients diagnosed with *** This study assigned 90 patients with AIS to the observation and control groups(n=45 patients)from December 2020 to December *** thrombectomy was conducted in the observation group,whereas routine treatment was provided to the control *** study assessed the therapeutic outcomes of two groups,including a comparison of their neurological function,living ability,anxiety and depression status,plaque area,serum inflammatory factors,serum Smur100βprotein,neuron-specific enolase(NSE),homocysteine(Hcy),and vascular endo-thelial ***,the incidence of complications was calculated and analyzed for each *** The total effective rate of treatment was 77.78%and 95.56%in the control and observation groups,*** 8 weeks of treatment,the scores on the National Institutes of Health Stroke Scale,Hamilton Anxiety Scale,and Hamilton Depression Scale decreased remarkably;the Barthel index increased remarkably,with better improvement effects of the scores in the observation group(P<0.05);total cholesterol,triglyceride,C-reactive protein,and plaque area lessened remarkably,with fewer patients in the observation group(P<0.05);S-100βprotein,NSE,and Hcy levels lessened remarkably,with fewer patients in

关键词： Stent thrombectomy Acute ischemic stroke Neurological function Complications Short-term prognosis

A Deep Generative Model with Multiscale Features Enabled Industrial Internet of Things for Intelligent Fault Diagnosis of Bearings

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Research 2023年第3期2023卷 57-68页

作者： He-xuan Hu Yicheng cai Qiang Hu Ye Zhang Key Laboratory of Water Big Data Technology of Ministry of Water Resources Hohai UniversityNanjing 211100P.R.China College of Computer and Information Hohai UniversityNanjing 211100P.R.China

Effective condition monitoring and fault diagnosis of bearings can not only maximize the life of rolling bearings and prevent unexpected shutdowns caused by equipment failures but also eliminate unnecessary costs and waste caused by excessive ***,the existing deep-learning-based bearing fault diagnosis models have the following *** of all,these models have a large demand for fault ***,the previous models only consider that single-scale features are generally less effective in diagnosing bearing ***,we designed a bearing fault data collection platform based on the Industrial Internet of Things,which is used to collect bearing status data from sensors in real time and feed it back into the diagnostic *** the basis of this platform,we propose a bearing fault diagnosis model based on deep generative models with multiscale features(DGMMFs)to solve the above *** DGMMF model is a multiclassification model,which can directly output the abnormal type of the ***,the DGMMF model uses 4 different variational autoencoder models to augment the bearing data and integrates features of different *** with single-scale features,these multiscale features contain more information and can perform ***,we conducted a large number of related experiments on the real bearing fault datasets and verified the effectiveness of the DGMMF model using multiple evaluation *** DGMMF model has achieved the highest value under all metrics,among which the value of precision is 0.926,the value of recall is 0.924,the value of accuracy is 0.926,and the value of F1 score is 0.925.

关键词： fault bearings diagnosis

Novel Catalytic Hydrodechlorination of CCl_2F_2 over Supported PdCl_2-(n-C_4H_9)_4N^+Cl^- Molten salts

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Chinese Chemical Letters 2001年第6期12卷 533-536页

作者： Yu cai CAO xuan Zhen JIANG Department of Chemistry Zhejiang UniversityHangzhou 310027

A novel supported liquid phase film catalyst: Supported PdCl2-(n-C4H9),N+Cl- molten salts was found to be an effective catalyst with good stability for selective hydrodechlorination of CCl2F2 (CFC-12) to its alternatives CH2F2 and CHClF2. Addition of CoCl2, GaCl3 and CuCl2 to PdCl2-(n-C4H9),N+Cl- modifies the catalytic performance of supported molten salts.

关键词： Liquid film catalyst palladium chloride tetrabutylammonium chloride molten salts CFC-12 hydrodechlorination HFC-32 HCFC-22

Miocene paleoenvironmental evolution based on benthic foraminiferal assemblages in the Lufeng Sag, northern South China Sea

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Acta Oceanologica Sinica 2019年第3期38卷 124-137页

作者： Liyuan Xue xuan Ding Renjie pei Xiaoqiao Wan School of Ocean Sciences China University of Geosciences School of Earth Sciences and Resources China University of Geosciences

The Miocene epoch marks the most crucial period during the Cenozoic cooling trend, characterized by the Middle Miocene Climatic Optimum(MMCO) and a series of short–lived cooling events(Miocene isotope events).To understand the paleoenvironmental evolution along the shallow water shelf in the South China Sea during the Miocene, the benthic foraminiferal assemblage and total organic carbon content(TOC) were analyzed at Hole LF14 located in the Lufeng Sag, northern South China Sea. Three benthic foraminiferal assemblages(e.g., the Uvigerina spp. assemblage, the Cibicides spp. assemblage, and the Cibicidoides spp. assemblage), corresponding to different watermass conditions, were recognized based on Q–mode factor analysis. Early studies suggested that Hole LF14 was deposited under semienclosed bay, middle to outer shelf or even upper bathyal environment during ～18.7–4.53 Ma. The dominant Uvigerina spp. assemblage was characterized by low diversity and shallow infaunal to infaunal species, indicating a warm, low–oxygenation and eutrophic conditions since the Early Miocene to MMCO(～18.7–14.24 Ma). An abrupt sea level drop and significant faunal changes were recorded during 14.24–13.41 Ma, suggesting development of the East Antarctic Ice Sheets, which resulted in a drop of sea level and change in benthic foraminiferal assemblages along the shallow water shelf. Beyond the Uvigerina ***, the Cibicides spp. assemblage became important during the middle–late Middle Miocene(14.24–11.54 Ma). This assemblage was dominated by epifaunal species with relative high diversity, suggesting high–energy, high–oxygenation and oligotrophic conditions with episodic supply of organic food. The dominant Cibicidoides spp. assemblage with high diversity, indicates a mesotrophic conditions with relative high–oxygen content during the Late Miocene to Pliocene(11.54–4.53 Ma). The appearance and continuous occurrence of Ammonia spp. and Pseudorotalia spp. since 10.02 Ma, may reflect the i

关键词： South China Sea Lufeng Sag Miocene benthic foraminiferal assemblage total organic carbon shelf paleoenvironment

Discussing the development of domestic and foreign fire protection technical regulation and fire protection technical standard systems

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Journal of Safety Science and Resilience 2023年第1期4卷 26-29页

作者： xuan Sun Na cai Wei Zhang CABR Fire Safety Science&Technology Co. LtdBeijing 100013China

This paper reviews the composition, development, and operation mechanism of domestic and foreign fire protection technical regulations and standards. Considering the development and problems of China's fire protection standard system and fire protection technical standards, this paper recommends fire safety professional engineering design specialization, suggests key research fields pertaining to fire protection technical standards, and elucidates how a performance-based fire protection technical standard system can be established.

关键词： Fire protection standard Standard system Specialization of fire safety design