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高压气体双孔浸没射流振荡频率特性研究

原子能科学技术 2024年第2期58卷 357-364页

作者：尹威凯欧阳勇崔旭阳纪文英谷海峰中广核研究院有限公司广东深圳518000 哈尔滨工程大学核安全与仿真技术国防重点学科实验室黑龙江哈尔滨150001

在沸水堆或小型堆中一般将抑压水池作为气体排放的热阱以实现安全壳压力的有效控制。基于这一背景,本文在不同过冷度下对高压气体双孔浸没射流振荡主频特性进行了一系列实验研究,其中不凝性气体份额为0.0~0.4,孔间距范围为1.5 d~3 d。... 详细信息

在沸水堆或小型堆中一般将抑压水池作为气体排放的热阱以实现安全壳压力的有效控制。基于这一背景,本文在不同过冷度下对高压气体双孔浸没射流振荡主频特性进行了一系列实验研究,其中不凝性气体份额为0.0~0.4,孔间距范围为1.5 d~3 d。实验结果表明,无论是纯蒸汽还是混合气,在双孔射流时两股气羽均表现出向中间汇聚的形态,甚至汇聚到一起形成联合射流,相较单孔射流而言双孔射流气羽尺度增大冷凝时间延长,所以其振荡主频更低。分析射流参数影响发现,纯蒸汽射流振荡主频随过冷度和孔间距的增加而增加。同时本文总结振荡主频影响规律提出了纯蒸汽射流主频的预测关系式,预测精度在-15%~20%之间。混合气体射流时(纯蒸汽+不凝性气体)振荡主频随过冷度和孔间距的增加而增加,与纯蒸汽射流主频变化规律一致。值得注意的是,混合气射流相较纯蒸汽而言振荡主频更低,并且主频随不凝气份额增加而降低。

关键词：混合气体双孔射流压力振荡振荡主频

Molecular evolution of the exon 2 of CHS genes and the possibility of its application to plant phylogenetic analysis

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Chinese Science Bulletin 2000年第19期45卷 1735-1742页

作者： WANG jinling QU Lijia CHEN Jun gu hongya CHEN Zhangliang The National Laboratory of Protein Engineering and Plant Genetic Engineering Peking UniversityBeijing 100871China De Montfort University The GatewayLeicesterLEI 9BHUK

The exon 2 of chalcone synthase (CHS) gene is relatively conserved during evolution. In this study, three exon 2 fragments from two species in gymnosperm (Cycas panzhihuaensis, Ginkgo biloba ) and seven from four species in angiosperm (Magnolia denudata, Salix babylonica, Nymphaea tetragona, Camellia japonica) have been amplified by PCR from genomic DNA and sequenced. Together with other 73 sequences of CHS collected from EMBL database and literature, these sequences, which embrace 19 families of gymnosperm and angiosperm, have been analyzed for their phylogenetic relations by parsimony method. The result indicated that sequences from the same systematic family usually grouped together except those from Theaceae, Magnoliaceae and Nymphaeaceae. The relative rate test revealed the rate heterogeneity of CHS genes among the families. For the nucleotide substitution the sequences from Asteraceae and Solanaceae evolve faster than those from the other families analyzed while the sequences from Poaceae,

关键词： chalcone synthase (CHS) PCR phylogeny molecular evolution.

Artificial intelligence-driven autonomous optical networks: 3S architecture and key technologies

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Science China(Information Sciences) 2020年第6期63卷 7-30页

作者： Yuefeng ji Rentao gu Zeyuan yang jin LI Hui LI Min ZHANG State Key Laboratory of Information Photonics and Optical Communications School of Information and Communication Engineering Beijing University of Posts and Telecommunications State Key Laboratory of Information Photonics and Optical Communications Institute of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications

In the optical networks, the dynamicity, the complexity and the heterogeneity have dramatically increased owing to the deployment of advanced coherent techniques, and the optical cross-connect technologies and diverse network infrastructures pose great challenges in the optical network management and maintenance for the network operators. In this review, we propose a "3 S" architecture for AI-driven autonomous optical network, which can aid the optical networks operated in "self-aware" of network status, "self-adaptive" of network control, and "self-managed" of network operations. To support these functions, a number of artificial intelligence(AI)-driven techniques have been investigated to improve the flexibility and the reliability from the device aspect to network aspect. Adaptative erbium-doped fiber amplifier(EDFA) controlling is an example for the device aspect, which provides a power self-adaptive capability according to the network *** the link aspect, adaptive fiber nonlinearity compensation, optical monitoring performance and quality of transmission estimation are developed to monitor and alleviate the link-dependent signal impairments in an automatic way. From the network aspect, traffic prediction and network state analysis methods provide the self-awareness, while automatic resource allocation and network fault management powered by AI enhance the self-adaptiveness and self-management capabilities. Benefit from the sufficient network management data,powerful data-mining capability and matured computation units, these AI techniques have great potentials to provide autonomous features for optical networks, including the network resource scheduling and the network customization.

关键词： artificial intelligence optical networks self-aware self-adaptive self-managed

可见光氧化还原钴催化立体发散性合成1,4-二烯

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Chinese Journal of Catalysis 2024年第6期61卷 291-300页

作者：任行宇刘佳俊张士启李彦霖崔坤李静顾正洋夏纪宝盐城工学院化学化工学院和纺织服装学院江苏盐城224003 中国科学院兰州化学物理研究所羰基合成与选择氧化国家重点实验室甘肃兰州730000 杭州师范大学材料化学与化工学院教育部有机硅化学与材料技术重点实验室浙江杭州311121

1,4-二烯是一类重要的烯烃化合物,其分子骨架广泛存在于药物和天然产物中.由于1,4-二烯分子在有机合成中具有重要作用,目前其合成方法已被广泛研究,包括1,3-二烯的氢烯基化、炔烃的氢烯丙基化、乙烯基和烯丙基试剂的交叉偶联等.然而,由... 详细信息

1,4-二烯是一类重要的烯烃化合物,其分子骨架广泛存在于药物和天然产物中.由于1,4-二烯分子在有机合成中具有重要作用,目前其合成方法已被广泛研究,包括1,3-二烯的氢烯基化、炔烃的氢烯丙基化、乙烯基和烯丙基试剂的交叉偶联等.然而,由于1,4-二烯的热力学稳定性,现有的合成方法主要倾向于生成E-立体选择性的产物,而Z-异构体的生成则相对困难.值得注意的是,通过同一组底物同时构建1,4-二烯的Z和E异构体的立体发散性合成策略鲜有报道.因此,发展新型催化体系,以同时构建1,4-二烯的Z和E异构体具有十分重要的意义和应用前景.本文报道了一种高效的可见光光致氧化还原/钴协同催化策略,该策略以联烯与炔烃为原料,通过调控反应溶剂即可实现立体发散性地构建Z,E-和E,E-1,4-二烯化合物.该反应在室温下,以2,4,5,6-四(9-咔唑基)-间苯二腈(4CzIPN)作为光敏剂,4,6-双(二苯基膦基)-10H-吩噁嗪为配体,H_(2)O和DIPEA作为氢源,实现了1,4-二烯的高效合成.值得一提的是,通过简单地调控溶剂可以直接控制产物的立体选择性,即以乙腈为溶剂时可得到Z,E-1,4-二烯产物,而使用2-MeTHF作为溶剂时,则得到E,E-1,4-二烯产物.此外,该反应对炔烃底物具有良好的兼容性,包括乙基、硅醚、羟基和环丙基等非对称的芳基烷基内炔,均能与联烯有效偶联,以较高收率得到目标产物.此外,芳基上带有各种富电子和缺电子基团的炔烃也能很好地参与反应.联烯底物研究结果表明,联烯上的酯基对反应效率有显著影响,具有较小酯取代基的联烯,如甲基和乙基,反应活性较低,相应的产物收率较低;而具有较大酯基的联烯,如异丙基、苄基和叔丁基,则能获得更高的产率.此外,当使用苯基、酸酐、二苯基氧化膦或磺酰基等其他官能团取代的联烯时,反应无法发生.通过氘代实验、荧光猝灭实验等一系列控制实验以及密度泛函理论计算,揭示了该反应机制.反应过程涉及五元钴环戊烯中间体的分解,并通过光催化的能量转移过程实现了E,E-1,4-二烯的E→Z异构化,最终实现Z,E-1,4-二烯的立体选择性合成.综上所述,本文提出了一种新的钴催化炔烃-联烯的选择性还原偶联反应.通过结合可见光光致氧化还原与钴协同催化策略,在温和的条件下,以H_(2)O和DIPEA作为氢源,实现了具有良好区域选择性和立体选择性的Z,E-和E,E-1,4-二烯的立体发散性合成.通过控制反应溶剂来实现立体选择性,本研究为立体发散性合成1,4-二烯化合物提供了一种简单有效的新途径.

关键词： 1,4-二烯钴催化光氧化还原还原偶联炔烃联烯

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地氯雷他定的光谱检测方法研究

光谱学与光谱分析 2024年第3期44卷 751-755页

作者：葛学峰时斌唐梦圆籍康张银萍顾敏芬南京师范大学分析测试中心江苏南京210023

地氯雷他定(DL)是一种治疗过敏性鼻炎和慢性荨麻疹的经典抗组胺药,在采用光谱法研究其结构相关的N—H键时,检测结果会受到不同预处理方式及测试方法的影响。采用透射模式傅里叶变换红外法(TR-FTIR)对DL进行检测,常规氯化钾压片法获得的... 详细信息

地氯雷他定(DL)是一种治疗过敏性鼻炎和慢性荨麻疹的经典抗组胺药,在采用光谱法研究其结构相关的N—H键时,检测结果会受到不同预处理方式及测试方法的影响。采用透射模式傅里叶变换红外法(TR-FTIR)对DL进行检测,常规氯化钾压片法获得的光谱在3 325和3 304 cm-1处出现2个较弱的峰高约为1∶1的N—H伸缩特征吸收峰;石蜡糊法没有明显信号;样品先与石蜡混合成糊状再加入氯化钾压片,则会在3 327和3 304 cm-1处出现2个峰高约为1∶2.3的特征吸收峰;采用衰减全反射式傅里叶变换红外光谱法(ATR-FTIR)对DL进行检测,无论是改变ATR晶体类型还是改变仪器的检测器,此区间几乎检测不出特征峰;采用漫反射式傅里叶变换红外光谱法(DRS-FTIR),不需要对样品进行预处理,能检测出3 327和3 304 cm-1处2个峰高比约为1∶5的特征吸收峰。采用傅里叶变换拉曼方法(FT-Raman),无需预处理,信噪比高,能检测出3 327和3 304 cm-1处2个峰高比约为1∶6的特征峰;而分别采用激发波长为532、 633和785 nm的激光拉曼,荧光信号很强,1 700 cm^(-1)以上观察不到任何有用信号。为了进一步研究预处理过程对DL的影响,采用差示扫描量热法(DSC)对不同预处理后的样品进行了熔点测试,结果显示:(1) DL原样熔点为156.4℃, DL进行研磨后的样品熔点为156.6℃, DL与氯化钾进行物理混合后的样品熔点为156.6℃,说明研磨及物理混合对DL的晶型没有造成破坏;(2) DL与氯化钾一起混合研磨的样品,熔点为153.0℃,与石蜡混合后熔点为141.5℃,先石蜡制糊再加入氯化钾研磨的试样,熔点为145.0℃,熔点均比原样明显偏低且熔程变宽,说明这些预处理可能使原样的结构发生了变化。为避免预处理过程引入的不确定性,在对DL进行光谱检测时建议选用DRS-FTIR及FT-Raman方法。

关键词：地氯雷他定红外光谱拉曼光谱热分析

GAMT2 Encodes a Methyltransferase of Gibberellic Acid That is Involved in Seed Maturation and Germination in Arabidopsis

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Journal of Integrative Plant Biology 2007年第3期49卷 368-381页

作者： Shufan Xing Genji Qin Yan Shi Zhangliang Chen hongya gu Li-jia Qu National Laboratory for Protein Engineering and Plant Genetic Engineering Peking-Yale Joint Research Center for Plant Molecular Genetics and AgroBiotechnology College of Life Sciences Peking University Beijing 100871 China National Plant Gene Research Center (Beijing) Beijing 100101 China

Salicylic acid methyltransferase （SAMT）, benzoic acid methyltransferase （BAMT） and theobromine methyltransferase （TH）（henceforth, SABATH） family proteins belong to a unique class of mehtyltransferase that can methylate small molecular compounds Including indole-3-acidic acid （IAA）, salicylic acid （SA） and jasmonic acid （JA）, in plants. Here we report that the GAMT2 protein, which has 34.2% similarity with IAMT1 in the amino acid sequence, can methylate gibberellic acid （GA）. Biolnformatics analysis suggests that GAMT2 may be able to methylate one molecule larger than SA. GAMT2 is predominantly expressed in the developing seed embryo and endosperm in Arabidopsis. During seed germination, the expression of GAMT2 decreases until the cotyledons expand out of the seed coat. Overexpression of GAMT2 in Arabidopsis resulted in multiple phenotypes, including dwarfism, retarded growth, late flowering, and reduced fertility, which are similar to the phenotypes of GA-deficient mutants. Seed germination assay showed that GAMT2 overexpression in plants was hypersensitive to GA biosynthesis inhibitor （ancymidol） and abscisic acid （ABA） treatments, whereas the GAMT2 null mutant （SALK_075450） was slightly Insensitive to such treatments, suggesting that GAMT2 may methylate GA or ABA. Enzyme activity analysis indicated that GAMT2 was able to methylate GA3 into Methyi-GA3 in vitro, but could not methylate ABA. Microarray analysis on GAMT2 overexpression plants suggested that Methyl-GA may be an Inactive form of GA in Arabidopsis. These data suggest that GAMT2 Is Involved in seed maturation and germination by modulating GA activity.

关键词： GAMT2 GA-deficient seed germination seed maturation Me-GA methyl acceptors SABATH methyltransferase

穴位埋线联合阿托伐他汀钙治疗老年人高脂血症的随机对照试验

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中国全科医学 2024年第5期27卷 535-546页

作者：刘美玲赵天易顾吉郭义上海市嘉定区马陆镇社区卫生服务中心中医科 201801 天津中医药大学天津市301617

背景2012年我国成年人血脂异常患病率达40.4%,血脂异常是动脉粥样硬化性心血管疾病(ASCVD)发生的独立危险因素,老年人又是血脂异常和慢性病的高危人群,前期调查结果显示上海市马陆辖区老年人血脂异常患病率达63%,故有效控制血脂异常的... 详细信息

背景2012年我国成年人血脂异常患病率达40.4%,血脂异常是动脉粥样硬化性心血管疾病(ASCVD)发生的独立危险因素,老年人又是血脂异常和慢性病的高危人群,前期调查结果显示上海市马陆辖区老年人血脂异常患病率达63%,故有效控制血脂异常的意义重大。目的探索采用穴位埋线联合阿托伐他汀钙干预马陆辖区老年人高脂血症的协同作用,为防治老年人高脂血症提供依据,指导临床实践。方法本研究为单中心随机对照试验,于2020-05-10—08-04在上海市嘉定区马陆镇社区卫生服务中心门诊招募老年高脂血症患者119例。采用随机简单数字分组方法将患者分为埋线组(n=59)和对照组(n=60)。埋线组采用穴位埋线联合阿托伐他汀钙治疗,埋线每2周1次,4次1个疗程,同时口服10 mg/d阿托伐他汀钙片;对照组仅口服10 mg/d阿托伐他汀钙片,干预周期为8周。主要观察指标为低密度脂蛋白胆固醇达标率和血脂水平改善情况,并探索该治疗方案在不同人群中的效应。结果主要结局指标:两组治疗后低密度脂蛋白胆固醇达标率分别为79.5%(35/44)、71.4%(30/42);两组总胆固醇、三酰甘油、低密度脂蛋白胆固醇、高密度脂蛋白胆固醇治疗前后差值以及随访1个月时水平比较,差异均无统计学意义(P>0.05)。次要结局指标:两组载脂蛋白A、载脂蛋白B、脂蛋白a、空腹血糖和糖化白蛋白治疗前后差值比较,差异均无统计学意义(P>0.05);两组BMI治疗前后差值、治疗后、随访1个月比较,差异均无统计学意义(P>0.05);治疗后埋线组中医证候积分高于对照组(P<0.001)。不良反应:埋线组谷氨酰转移异常升高率低于对照组(P<0.05)。结论穴位埋线联合阿托伐他汀钙可以调节老年人的血脂水平,在改善中医证候积分和减轻阿托伐他汀钙的不良反应方面有优势。

关键词：高脂血症老年人穴位埋线疗法阿托伐他汀钙随机对照试验

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邯郸市大气PM_(2.5)时空分布及季节性潜在源分析

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环境科学学报 2024年第2期44卷 298-309页

作者：纪晓腾马心怡马博健鲍晓磊马文娜田宇婷岳亮牛红亚河北工程大学地球科学与工程学院邯郸056038 河北先进环保产业创新中心有限公司石家庄050000 河北化工医药职业技术学院河北省化工行业挥发性有机物检测与治理技术创新中心石家庄050026 河北省邯郸生态环境监测中心邯郸056001

为研究大气污染防治攻坚战后邯郸最新大气环境污染情况,选取2022年3月—2023年2月邯郸市环境空气污染物浓度数据,借助Kriging插值分析模拟了邯郸市PM_(2.5)浓度的时间和空间变化趋势,并利用HYSPLIT气团后向轨迹模型进行聚类分析,探究邯... 详细信息

为研究大气污染防治攻坚战后邯郸最新大气环境污染情况,选取2022年3月—2023年2月邯郸市环境空气污染物浓度数据,借助Kriging插值分析模拟了邯郸市PM_(2.5)浓度的时间和空间变化趋势,并利用HYSPLIT气团后向轨迹模型进行聚类分析,探究邯郸市不同季节PM_(2.5)污染的传输路径及潜在源区分布.结果表明,邯郸市PM_(2.5)浓度呈现出明显的季节差异性,最高平均浓度出现在冬季(75.13μg·m^(-3)),秋、春次之,最低则出现在夏季(27.64μg·m^(-3)),同时,PM_(2.5)/PM_(10)在秋冬季均高于0.55,说明邯郸市秋冬季主要以细颗粒物污染为主.PM_(2.5)污染年均值空间分布呈现出“东部、中部自北向南高,西部低”的特点,污染高值区PM_(2.5)与PM_(10)、CO、NO_(2)、SO_(2)均呈显著正相关关系,与O_(3)呈负相关关系,邯郸市PM_(2.5)污染以本地排放为主.传输路径分析表明,河北中部及东北部传输路径是邯郸市四季外来PM_(2.5)污染的主要传输路径;潜在源区的分布及贡献存在明显的季节差异,春、秋、冬三季主要贡献源区分布在河北、河南和山东三省交界区域,夏季贡献源区呈条带状贯穿山西省中部地区和河南地区.

关键词： PM_(2.5) 克里金插值传输路径后向轨迹潜在源区邯郸

Over-expression of WOX1 Leads to Defects in Meristem Development and Polyamine Homeostasis in Arabidopsis

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Journal of Integrative Plant Biology 2011年第6期53卷 493-506页

作者： Yanxia Zhang Renhong Wu Genji Qin Zhangliang Chen hongya gu Li-jia Qu State KeyLaboratory for Protein- and Plant 'Gene-I~esearch 'Pe--king-Yale Joi~ Research Center iorl~la-nt Molecular Genetics andAgroBiotechnology College of Life Sciences Peking University Beijing 100871 China The National Plant Gene Research Center (Beijingi Beijing 100101 China

In plants, the meristem has to maintain a separate population of pluripotent cells that serve two main tasks, i.e., self-maintenance and organ initiation, which are separated spatially in meristem. Prior to our study, WUS and *** WOX genes had been reported as essential for the development of the SAM. In this study, the consequences of gain of WOX1 function are described. Here we report the identification of an Arabidopsis gain-of-function mutant woxl-D, in which the expression level of the WOX1 （WUSCHEL HOMEOBOX 1） was elevated and subtle defects in meristem development were observed. The woxl-D mutant phenotype is dwarfed and slightly bushy, with a smaller shoot apex. The woxl-D mutant also produced small and dark green leaves, and exhibited a failure in anther dehiscence and male sterility. Molecular evidences showed that the transcription of the stem cell marker gene CLV3 was down-regulated in the meristem of woxl-D but accumulated in the other regions, i.e., in the root-hypocotyl junction and at the sites for lateral root initiation. The fact that the organ size and cell size in leaves of woxl-D are smaller than those in wild type suggests that cell expansion is possibly affected in order to have partially retarded the development of lateral organs, possibly through alteration of CLV3 expression pattern in the meristem. An S-adenosylmethionine decarboxylase （SAMDC） protein, SAMDC1, was found able to interact with WOX1 by yeast two-hybrid and pull-down assays in vitro. HPLC analysis revealed a significant reduction of polyamine content in woxl-D. Our results suggest that WOX1 plays an important role in meristem development in Arabidopsis, possibly via regulation of SAMDC activity and polyamine homeostasis, and/or by regulating CLV3 expression.

关键词： WOX CLV3 meristems polyamines SAMDC Arabidopsis.