检索结果-南通市图书馆

Asymmetric syntheses of (8R,8aS)- and (8R,8aR)-8-hydroxy-5-indolizidinones:Two promising oxygenated indolizidine building blocks

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2011年第4期54卷 737-744页

作者： zhang hongkui LI Xin HUANG Huang HUANG PeiQiang Department of Chemistry and Key Laboratory for Chemical Biology of Fujian Province College of Chemistry and Chemical EngineeringXiamen UniversityXiamen. China

Starting from the oxygenated piperidine building block 20,two synthetic approaches to new building blocks (8R,8aS)-and (8R,8aR)-8-hydroxy-5-indolizidinones 19a/19b and 15a/15b have been developed,respectively. The first one is based on the trans-diastereoselective reductive alkylation (dr = 93:7),followed by a four-step procedure; and the second one called for the RCM reaction on the N,O-acetal derived from a vinylation,which was followed by a pyrrole formation,and a stereocontrolled cis-selective (dr = 91:9) catalytic hydrogenation. Reduction of the diastereomer 15a produced (8R,8aR)-8-indolizidinol (18).

关键词： indolizidines building blocks diastereoselective synthesis RCM reaction catalytic hydrogenation

同方期刊数据库

In situ phosphonium-containing Lewis basecatalyzed 1,6-cyanation reaction:a facile way to obtainα-diaryl andα-triaryl acetonitriles

在线全文

学校读者我要写书评

暂无评论

Organic Chemistry Frontiers 2022年第1期9卷 156-162页

作者： Jian-Ping Tan Yuan Chen Xiaoyu Ren Yumeng Guo Bing Yi hongkui zhang Guowei Gao Tianli Wang Hunan Province Key Laboratory of Environmental Catalysis and Waste Recycling College of Materials and Chemical EngineeringHunan Institute of EngineeringXiangtan411104P.R.China Key Laboratory of Green Chemistry&Technology of Ministry of Education College of ChemistrySichuan University 29 Wangjiang RoadChengdu 610064P.R.China

We present a phosphonium-containing catalyst generated in situ from phosphine and tert-butyl acrylate that serves as an unusual Lewis base *** was applied for the promotion of a remote 1,6-cyanation reaction of p-quinone methides and fuchsones employing trimethylsilyl cyanide as the cyanide source.A diverse range ofα-diaryl andα-triaryl acetonitriles was obtained in high yields under mild reaction conditions with low catalyst loading(5 mol%).The practicality and utility of this protocol were demonstrated via the gram-scale preparation and facile elaboration of *** investigations(in situ NMR and ESI-MS analysis)were employed to characterize the active zwitterionic phosphonium intermediate,which was the“true”active catalyst.

关键词： catalyst facile acetonitrile

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

故障诊断技术在热电厂转动设备运行中的应用

振动工程学报 2004年第Z1期17卷 379-382页

作者：张洪奎大庆石化公司热电厂机动科大庆163714

介绍故障诊断的方法和步骤,应用故障诊断技术来解决生产中的实际问题,采用HG-3528数据采集器来分析诊断热电厂转动设备的振动原因及处理方法,论述应用故障诊断技术是提高设备维修现代化水平、确保设备可靠的必要性.

关键词：故障诊断状态监测设备的可靠性频谱分析

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

韵书发展史和山东

东岳论丛 2005年第6期26卷 124-128页

作者：张鸿魁山东社会科学院语言文学研究所山东济南250002

韵书的历史大致可以分为四个阶段。1.起源阶段,最早的韵书应该是山东任城吕静的《韵集》,现存最早最有影响的韵书《切韵》,颜之推、萧该等山东人对其成书起了关键的作用;2.归并韵部编纂韵略阶段,得风气之先的仍然是山东籍学人;3.等韵学... 详细信息

韵书的历史大致可以分为四个阶段。1.起源阶段,最早的韵书应该是山东任城吕静的《韵集》,现存最早最有影响的韵书《切韵》,颜之推、萧该等山东人对其成书起了关键的作用;2.归并韵部编纂韵略阶段,得风气之先的仍然是山东籍学人;3.等韵学阶段,等韵学导源于经咒对译,创建梵汉对音体系的三人中唯一的中国僧人是山东人义净;4.等韵化韵书阶段,山东人不仅对《韵略易通》的传播起了重要作用,而且编纂出数十种等韵化韵书。

关键词：音义书韵书早期等韵韵图山东人

北斗定位技术在管道地质灾害监测与预警中的应用

在线全文

学校读者我要写书评

暂无评论

油气储运 2020年第7期39卷 813-820页

作者：张洪奎中国石化销售股份有限公司华中分公司湖北省武汉市430023

利用北斗定位技术实现油气管道沿线地质灾害的监测与预警,以期减少地质灾害对油气管道造成的威胁与破坏。以华中成品油管道江西处、抚州处、湖南处的成品油管道区段为研究区,利用国产高分遥感影像对地质灾害风险点进行高精度自动识别,... 详细信息

利用北斗定位技术实现油气管道沿线地质灾害的监测与预警,以期减少地质灾害对油气管道造成的威胁与破坏。以华中成品油管道江西处、抚州处、湖南处的成品油管道区段为研究区,利用国产高分遥感影像对地质灾害风险点进行高精度自动识别,并辅以人工目视解译方法进行纠正,将识别结果作为现场调查的基础资料。基于北斗定位技术设计了微位移监测装置,结合高精度定位数据处理技术方法,对地质灾害风险点的坡体位移进行实时监测。结合研究区前期有效降雨量与预报降雨量建立了地质灾害预警模型,通过手机预警APP按输油处、输油站分级分权限推送红、橙、黄、蓝4个等级的预警信息。研究结果可为油气管道地质灾害实时监测与预警的智能化应用提供参考。(图5,表2,参29)

关键词：地质灾害监测预警北斗定位成品油管道高分遥感

35kV煤矿电网高压断路器三相电机操动机构控制技术

在线全文

学校读者我要写书评

暂无评论

煤矿安全 2016年第9期47卷 106-109页

作者：张红奎煤科集团沈阳研究院有限公司辽宁抚顺113122

为了提高35 k V煤矿电网开关设备可控性,实现高压断路器分/合闸操作的智能化,提出一种三相电机操动机构控制技术。针对40.5 k V高压断路器操作要求,设计电机操动机构控制系统,包括桥式驱动逆变电路、三相绕组电流检测电路、电机转子位... 详细信息

为了提高35 k V煤矿电网开关设备可控性,实现高压断路器分/合闸操作的智能化,提出一种三相电机操动机构控制技术。针对40.5 k V高压断路器操作要求,设计电机操动机构控制系统,包括桥式驱动逆变电路、三相绕组电流检测电路、电机转子位置检测电路等,并编写相应的软件程序。将控制系统与煤矿高压断路器三相电机操动机构联机试验,结果表明:控制系统能够对三相电机操动机构动作过程进行有效控制,满足煤矿高压断路器分/合闸操作要求。

关键词：煤矿供电 35 kV电网断路器操动机构控制系统

在线全文

学校读者我要写书评

暂无评论

矿用隔离开关分断能力试验技术研究

煤矿机械 2020年第2期41卷 68-70页

作者：张红奎煤科集团沈阳研究院有限公司辽宁抚顺113122 煤矿安全技术国家重点实验室辽宁抚顺113122

为了提高矿用隔离开关分断试验技术水平,开展分断能力检测检验技术研究。在分析煤矿行业发展趋势和矿用隔离开关在煤矿安全生产中的作用基础上,研究了分断检验过程电弧产生过程和交流电弧熄灭条件,设计分断检验试验系统整体结构,详细设... 详细信息

为了提高矿用隔离开关分断试验技术水平,开展分断能力检测检验技术研究。在分析煤矿行业发展趋势和矿用隔离开关在煤矿安全生产中的作用基础上,研究了分断检验过程电弧产生过程和交流电弧熄灭条件,设计分断检验试验系统整体结构,详细设计了试验线路、控制系统、数据采集系统,试验结果表明:试验系统能够完成矿用隔离开关产品检测检验。

关键词：矿用隔离开关分断机理试验技术

Impending HRT wave precursors to the Wenchuan M_s8.0 earthquake and methods of earthquake impending prediction by using HRT wave

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2009年第10期52卷 1572-1584页

作者： QIAN FuYe ZHAO BiRu QIAN Wei ZHAO Jian HE ShiGen zhang hongkui LI ShiYu LI ShaoKun YAN GuLiang WANG ChengMin SUN ZhenKai zhang DongNing LU Jun zhang Ping YANG GuoJun SUN JiaLin GUO ChunSheng TANG YuXiong XU JianMing XIA KunTao JU Hang YIN BangHong LI Ming YANG DongSheng QI WeiLuo HE TaiMing GUAN HuaPing ZHAO YuLin Institute of Geophysics China Earthquake AdministrationBeijing 100081China Tianjin Hi-tech Development Co.Ltd Tianjin 300201China Department of Physics University of TorontoL6C1V9Canada College of Disaster Prevention Techniques Yanjiao 065201China Earthquake Administration of Beijing Municipality Beijing 100080China Earthquake Administration of Sichuan Province Chengdu 610041China Committee of National Development and Reformation Beijing 100824China Institute of Earthquake Science China Earthquake AdministrationBeijing 100036China China Earthquake Network Center Beijing 100036China Earthquake Administration of Yunnan Province Kunming 650041China Earthquake Administration of Tianjin Municipality Tianjin 300201China Earthquake Administration of Inner Mongolia Autonomous Region Huhhot 010010China The Gucheng District Bureau Lijiang674100China

We deployed four geo-electric monitoring stations in Sichuan and Yunnan provinces from 2004, using the new generation of equipment (PS-100) and technologies to capture the HRT wave earthquake precursor. Before the Wenchuan Ms8.0 earthquake, we recorded the HRT wave precursor at the only operating station in Hongge (HG, Δ=465 km) and found that significant impending signal had been recorded at the station in the early morning ( 0―5 am) of 12th of May, 2008. The precursor for this earthquake is consistent with precursors recorded for other strong earthquakes. The measured physical properties (geo-resistivity and telluric-current) show tidal wave period oscillations from several days to several months before the earthquakes and the amplitude of such HT oscillation increases significantly towards the occurrence of an earthquake. These HT and RT waves from the epicenter have a causal relationship with the earthquakes that happened several days later. The arrival time of two RT waves is proportional to the distance from the station to the epicenter. The estimated natural decay of the amplitude is correlated with the natural period (T0) of the earthquake fault, which is proportional to the fault length. From this relationship, we can predict the earthquake magnitude. For magnitude 6―9 earthquakes, the natural period is about 1―6 hours. Such oscillation comes from the epicenter area and they can propagate several thousand kilometers in the Earth's crust. Before a strong earthquake in the shallow crust, the conductive pore fluid will experience major changes before the fault rapture. Such fluid change will emit an oscillation in the pore fluid pressure. This is the mechanism for the HRT wave generation. Since the China Earthquake Administration funded the HRT wave short-term earth-quake prediction project in 2003, the first record of HRT precursor wave has been recorded from the 2004-12-26 Sumatra Mw9.0 earthquake with the largest epicentre distance Δ=2900 km. Thereafter, we

关键词： Wenchuan Ms8.0 earthquake HRT wave (mechanism) model PS-100 geo-resistivity meter HRT wave precursor precursor consistency feasibility of short-term and impending earthquake prediction

在线全文

学校读者我要写书评

暂无评论

聊斋俚曲的方音特点

蒲松龄研究 2005年第4期 155-175页

作者：张鸿魁山东社会科学院语言文学所山东济南250000

本文论述了聊斋俚曲语音材料的考察、选择和利用方法,并从四个方面论述了聊斋俚曲的方音特点：1、声调分阴阳上去四类；2、韵部的分合特点(哥戈、车遮不分,蟹摄二等喉牙音字属皆来,大灰微韵的独立)；3、古入声字的分派特点(归韵特点有... 详细信息

本文论述了聊斋俚曲语音材料的考察、选择和利用方法,并从四个方面论述了聊斋俚曲的方音特点：1、声调分阴阳上去四类；2、韵部的分合特点(哥戈、车遮不分,蟹摄二等喉牙音字属皆来,大灰微韵的独立)；3、古入声字的分派特点(归韵特点有：基本不派入皆来,梗曾摄一二等派入灰微,江宕摄派入哥戈车遮,“没”归鱼模,“缚”归歌戈车遮。归调特点是：全浊入归阳平,次浊入归去声,清入归阴平)；4、儿化韵、轻声和声母的某些特点。

关键词：方音特点韵语谐声材料格律入声字