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专一选择性反应策略合成2′-O-甲基腺嘌呤核苷
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作者 薛莲 杜杨 +1 位作者 张宇 罗军 《合成化学》 CAS 2024年第5期424-436,443,共14页
2′-O-烷基核糖核苷由于其在赋予寡核苷酸高度的目标特异性、代谢稳定性以及优良的药代动力学和药效动力学特征上所展现的重要作用,成为了反义药物研究领域的热点,尤其是2′-O-甲基腺嘌呤核苷,作为第二代反义寡核苷酸的关键原料药,其的... 2′-O-烷基核糖核苷由于其在赋予寡核苷酸高度的目标特异性、代谢稳定性以及优良的药代动力学和药效动力学特征上所展现的重要作用,成为了反义药物研究领域的热点,尤其是2′-O-甲基腺嘌呤核苷,作为第二代反义寡核苷酸的关键原料药,其的高效合成研究具有重要意义。现有合成方法存在的成本高和选择性不足等问题,本文基于专一选择性反应思路设计了一条新的合成路线,即以腺嘌呤核苷为起始物,经过缩醛化实现2′-和3′-位羟基选择性地保护、环状缩醛保护基可控区域选择性还原开环、2′-位羟基选择性甲基化及氢化脱苄反应,成功实现了2′-O-甲基腺嘌呤核苷的高效合成,单程总产率为36.7%。此策略不仅每一步反应表现出高选择性以及温和的反应条件,而且使用的试剂更加廉价易得,合成步骤也相对简短,为核苷类化合物核糖骨架上羟基的区域选择性功能化提供了新的思路。 展开更多
关键词 反义寡核苷酸 腺嘌呤核苷 2′-o-甲基腺嘌呤核苷 缩醛化 还原开环 烷基化 氢化脱苄
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Finding a Practical IT Solution-Open Source Accounting Software 被引量:1
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作者 Manar Abu Talib Adel Khelifi +4 位作者 Osama El-Temtamy Fatima Ismaeel Mahra Rashed Najah Hasan Summaya Khaled 《通讯和计算机(中英文版)》 2012年第4期406-413,共8页
关键词 会计软件 开放源码 IT 小型企业 开源软件 阿联酋 研究论文 挑战性
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How to Open Bank Account in China?
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《China's Foreign Trade》 2019年第2期54-54,共1页
Tips①There is often a bank near areas that may have high concentrations of foreigners. This includes, near a university or in a central business district, these branches are also more likely to provide services in En... Tips①There is often a bank near areas that may have high concentrations of foreigners. This includes, near a university or in a central business district, these branches are also more likely to provide services in English.②You’d better not to go too far to find a branch, because there are some services you have to return to the branch in which you opened your account. This includes services such as resetting your account password. So it will be more convenient for you to open a bank account at a branch nearby. 展开更多
关键词 open BANK account China
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Capital Account Openness,Exchange Rate Volatility and Economic Growth:International Experiences and Implications
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作者 李丽玲 王曦 《China Economist》 2017年第6期69-85,共17页
Based on the Barro classical growth model, this paper introduces capital account openness and exchange rate volatility to conduct an empirical analysis using the panel data of 182 countries(regions) during 1970-2013 t... Based on the Barro classical growth model, this paper introduces capital account openness and exchange rate volatility to conduct an empirical analysis using the panel data of 182 countries(regions) during 1970-2013 to examine the combined effects of capital account openness and exchange rate risks on economic growth. Our findings are as follows:(1) Without considering exchange rate volatility, capital account openness is subject to a threshold effect, i.e. capital account openness significantly promotes the economic growth of middle-and high-income countries but exerts the opposite effect on low-income countries; and(2) after exchange rate volatility is taken into account, the growth effect of capital account openness is reduced and the greater the exchange rate volatility is, the smaller the marginal effect of capital account openness will be; sample-specific results also proved the existence of the threshold effect. This paper offers the following implications:(1) The effect of capital account openness can be better examined based on risk factors;(2) moderately controlling exchange rate volatility is conducive to acquiring greater benefits from capital account openness; and(3) the threshold effect of capital account openness cannot be overlooked. 展开更多
关键词 汇率风险 经济增长 账户 资本 波动 国际经验 增长模型 实证分析
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NEW REGULATION BY THE PEOPLE'S BANK OF CHINA-TRADING B STOCKS ABROAD,OPENING ACCOUNTS IN CHINA
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作者 Ma Zhou 《大经贸》 北大核心 1997年第12期90-90,共1页
The People’s Bank of China promulgated andput in force days ago Regulation on Foreign Ex-change Accounts in China, according to which for-eign individuals or legal persons can open foreignexchange accounts to keep fo... The People’s Bank of China promulgated andput in force days ago Regulation on Foreign Ex-change Accounts in China, according to which for-eign individuals or legal persons can open foreignexchange accounts to keep foreign exchange fortrading B stock in China.As stipulated by the regulation, as to foreigncurrency stock accounts opened bydomestic insti-tutions with the income from issuing stocks, theirreceipt shall be income from issuing stocks anddisbursement shall be used for the purposes pro-vided for in the prospectus approved by securitiessupervising organs; as to foreign exchange ac-counts opened by foreign individuals or legal per-sons for trading B stocks in China.their receipt shallbe the income of trading stocks and foreign ex-change remitted or brought in from abroad, andtheir disbursement shall be used for buying andselling stocks.As provided in the regulation, for the purposeof opening B stock account to trade B stocks 展开更多
关键词 NEW REGULATIoN BY THE PEoPLE’S BANK oF CHINA-TRADING B SToCKS ABRoAD openING accountS IN CHINA
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Public Communication in the Processes of Transparency and Accountability in the Era of Open Data
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作者 Gea Ducci 《Journal of Sociology Study》 2015年第2期83-90,共8页
关键词 透明度 传播 通信技术 公用系统 行政部门 公共产品 管理部门 ICT
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NPV risk simulation of an open pit gold mine project under the O'Hara cost model by using Gas 被引量:1
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作者 Franco-Sepulveda Giovanni Campuzano Carlos Pineda Cindy 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2017年第3期557-565,共9页
This paper analyzes an open pit gold mine project based on the O'Hara cost model. Hypothetical data is proposed based on different authors that have studied open pit gold projects, and variations are proposed acco... This paper analyzes an open pit gold mine project based on the O'Hara cost model. Hypothetical data is proposed based on different authors that have studied open pit gold projects, and variations are proposed according to the probability distributions associated to key variables affecting the NPV, like production level, ore grade, price of ore, and others, so as to see what if, in a gold open pit mine project of 3000 metric tons per day of ore. Two case scenarios were analyzed to simulate the NPV, one where there is low certainty data available, and the other where the information available is of high certainty. Results based on genetic algorithm metaheuristic simulations, which combine basically Montecarlo simulations provided by the Palisade Risk software, the O'Hara cost model, net smelter return and financial analysis tools offered by Excel are reported, in order to determine to which variables of the project is more sensitive the NPV. 展开更多
关键词 Genetic algorithms(GAs) o’Hara cost model Montecarlo simulation open pit gold mine NPV risk analysis
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Account Based Ticketing: The Benefits and Drivers for Transit Operators
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作者 Khaled Zohdi Zamer 《Journal of Transportation Technologies》 2018年第4期331-342,共12页
This paper aims to explore the importance and efficiency of using open payment cards in transit applications as an alternative to current propitiatory cards. This data can be beneficial to transit planners, from regul... This paper aims to explore the importance and efficiency of using open payment cards in transit applications as an alternative to current propitiatory cards. This data can be beneficial to transit planners, from regular operation of the transit system down to the long-term strategic planning of the network. This paper covers several aspects of open payment cards in the transit planning context. First, the methods of payments are presented: cash, debit/credit cards, proprietary cards, and mobile payments. Then the several cases where open payments on transit are beneficial. Also reported are open card payment research conducted around the globe. Finally, the most promising online survey is performed to measure the perspective of the rider on using account-based ticketing versus the traditionally closed loop scheme. Mobility and payments are foundations pillars for developing communities and advancing economy [1]. 展开更多
关键词 TRANSIT Payments open Payments Integrated Payments ECoSYSTEM account BASED TICKETING
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Effect of Oxygen Therapy by Venturi Mask versus Non Invasive Ventillation on the Outcome of Patients Who Devolope Hypoxia after Open Heart Surgery
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作者 Yousry El-Saied Rizk Tarek Samy Essawy +2 位作者 Ahmed Hamdy Abd Elrahman Ali Mohamed Ahmed El-Gazzar Abdelkhalek Fouad Mahmoud 《Open Journal of Anesthesiology》 2018年第9期241-254,共14页
Background: Cardiothoracic surgery is a common cause of acute respiratory failure and is associated with increased morbidity and mortality. We aimed to compare the outcomes of open heart surgery patients treated using... Background: Cardiothoracic surgery is a common cause of acute respiratory failure and is associated with increased morbidity and mortality. We aimed to compare the outcomes of open heart surgery patients treated using oxygen delivery devices with patients who receive NIV as a first-line therapy for hypoxemic respiratory failure. Materials and Methods: 40 patients who developed acute hypoxemic respiratory failure after open heart surgery and admitted to cardiothoracic ICU 20 patients received NIV and 20 patient received oxygen by venture mask. For all patients the following measurements were performed before and after CPAP AND Venture use: CBC, blood urea, serum creatinine body temperature, chest X-ray, Arterial blood gases (arterial pH, sodium bicarbonate, pcO2, SpO2 and PaO2-to-FiO2 ratio). Results: Mean PO2 and SO2 have increased after using of both venture and Cpap, increase in both PCO2 and HCO3 levels after using Venturi mask, CPAP mask was superior to venturi mask in avoiding the need of intubation, decreasing The ICU stay median length and also median length of hospitalization, all were lower in CPAP group than venture group. Also the mortality rate was lower in CPAP group than the venturi group. Conclusion: Using CPAP mask in severe AHRF following open heart surgery can avoid intubation, decreases the levels of tachypnea and arterial hypoxemia, decreases ICU stay, the length of hospitalization and also decreases the mortality rate compared with patients receiving high-concentration oxygen therapy with venture mask. 展开更多
关键词 open Heart Surgery VENTURE MASK CPAP MASK Non INVASIVE Ventilation o2 Therapy
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Control-Relevant Identification Test Design for Open-Loop Experiment
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作者 张立群 邵惠鹤 《Journal of Shanghai Jiaotong university(Science)》 EI 2004年第1期6-9,共4页
An optimal experiment design (DED) with respect to the use of designing model-base controller was studied. The mean squared error at the setpoint is chosen as the performance criterion. Simple design formulas are deri... An optimal experiment design (DED) with respect to the use of designing model-base controller was studied. The mean squared error at the setpoint is chosen as the performance criterion. Simple design formulas are derived based on the asymptotic theory. The signal is used for the open loop experiment. The design constraint is the power of the process signal or the process input signal. The results give guideline for identification application. 展开更多
关键词 开环实验 实验优化设计 信号谱 相关控制识别测试 自动化技术
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An Analysis of the Causes and Countermeasures of China's Pension "Empty Account"
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作者 YAO Yiran 《International English Education Research》 2018年第2期68-70,共3页
关键词 养老金 中国 原因 反措 经济发展 背景分析 消费 保险
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扩大金融领域制度型开放的运行机理、现实风险和实施路径 被引量:2
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作者 刘凌 黄建忠 汪建新 《国际贸易》 北大核心 2024年第1期77-86,共10页
扩大金融领域制度型开放是开放型经济发展的必然要求,是实现国民经济高质量发展和中国式现代化的重要保证。以习近平新时代中国特色社会主义思想为指导,结合数字科技产业发展与中国积极加入CPTPP、DEPA的趋势要求,以国际高标准规则和中... 扩大金融领域制度型开放是开放型经济发展的必然要求,是实现国民经济高质量发展和中国式现代化的重要保证。以习近平新时代中国特色社会主义思想为指导,结合数字科技产业发展与中国积极加入CPTPP、DEPA的趋势要求,以国际高标准规则和中国金融开放的问题为导向,厘清金融领域制度型开放的瓶颈和基于RTA规则的差距,从金融服务业务、金融市场和资本账户等领域分析扩大金融领域制度型开放的运行机理和现实风险,并在此基础上提出金融领域制度型开放有序扩大的长中短期目标、实施路径、战略规划和方案设计。文章的研究为中国克服金融开放瓶颈,推进“金融深化”,建设金融强国,建立和完善中国特色的自主性开放型金融理论知识体系提供有益贡献。 展开更多
关键词 制度型开放 金融开放 高水平对外开放 资本账户开放
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SYNTHESIS AND CATIONIC RING-OPENING POLYMERIZATION OF 1, 4-ANHYDRO-2, 3-DI-O-(P-AZIDOBENZYL)-α-D-RIBOPYRANOSE
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作者 Toshiyuki Uryu 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1999年第2期123-128,共6页
New highly stereoregular 2, 3 -di- O-(p-azidobenzyl )-(1 →5 ) - α-D -ribofuranan was synthesized byselective ring-opening polymerization of 1, 4-anhydro-2, 3 - di-O -(p-azidobenzyl )-α-D -ribopyranose(ADABR) using ... New highly stereoregular 2, 3 -di- O-(p-azidobenzyl )-(1 →5 ) - α-D -ribofuranan was synthesized byselective ring-opening polymerization of 1, 4-anhydro-2, 3 - di-O -(p-azidobenzyl )-α-D -ribopyranose(ADABR) using phosphorus pentafluoride or tin tetrachloride as catalyst at low temperature indichloromethane. The monomer was obtained by the reaction of p - bromomethyl -phenyleneazide with 1, 4 -anhydro-α-D-ribose in DMF. The structure of poly(ADANR) was identified by specific rotation and ^(13)C-NMR spectroscopy. Acid chloride-AgCl_4 complex catalyst such as CH_2=C(CH_3)C^+OClO_4^- used in thepolymerization resulted in polymers with mixed structures, i.e. (1→5)-α-D-ribofuranosidic and (1→4)-β-D-ribopyranosidic units. However, with C_6H_5C^+OClO_4^- as catalyst, pure (1→5)-α-D-ribofuranan was obtained.The effects of catalyst, polymerization temperature and time on polymer stereoregularity were examined, andthe mechanism of the ring-opening polymerization was discussed. 展开更多
关键词 Cationic ring-opening polymerization Azido-containing polysaccharide Lewis acid catalysts 1 4-anhydro-2 3-di-o-(p-azidobenzyl)-α-D-ribopyranose STEREoREGULARITY
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全球O-RAN专利态势和布局分析
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作者 李立 闫坤 王潇 《长江信息通信》 2023年第9期215-217,共3页
文章分析了O-RAN的全球发展现状和技术创新方向,从专利申请趋势、法律状态、地域分布、重要申请人等多个维度分析了O-RAN全球专利发展态势和布局,从知识产权视角为我国的创新主体布局和O-RAN技术研发提供参考。
关键词 开放式无线接入网 o-RAN 专利
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董事高管责任保险与会计信息质量——基于党组织参与治理的替代或互补效应
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作者 谢海娟 王江烜 +1 位作者 王成龙 栗念坤 《南京审计大学学报》 北大核心 2024年第3期76-87,共12页
以国务院在2020年10月出台的《关于进一步提高上市公司质量的意见》政策为研究契机,选取我国2010—2021年A股上市公司为样本,采用双向固定效应模型,在研究董事高管责任保险对会计信息质量治理作用的基础上,研究党组织参与公司治理是替... 以国务院在2020年10月出台的《关于进一步提高上市公司质量的意见》政策为研究契机,选取我国2010—2021年A股上市公司为样本,采用双向固定效应模型,在研究董事高管责任保险对会计信息质量治理作用的基础上,研究党组织参与公司治理是替代还是互补董事高管责任保险发挥这一治理效应,以及剖析其传导效应和企业异质性效应。研究结果表明:董事高管责任保险对企业会计信息质量有治理效应,且“双向进入”式党组织参与治理会提升董事高管责任保险对会计信息质量的治理效应,即存在互补效应;而“交叉任职”式党组织参与治理抑制董事高管责任保险对会计信息质量的治理效应,即替代效应。进一步分析研究表明:董事高管责任保险会通过促进企业创新和提高内部控制质量对会计信息质量发挥治理效应,并在媒体关注度或盈利能力越高的企业中这种治理效应更好。上述研究结果不仅从新视角拓展会计信息质量影响因素的研究,而且丰富董事高管责任保险和党组织参与公司治理的单独及联合治理效果,并为政府、企业等相关利益者在实践中发掘董事高管责任保险的积极作用和提高会计信息质量提供了有益的实践启示。 展开更多
关键词 董事高管责任保险 会计信息质量 党组织参与治理 双向进入 交叉任职 企业创新 内部控制
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一个水稻开颖不育突变体ohs1(t)的遗传分析及基因定位 被引量:10
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作者 刘晓玲 毛毕刚 +3 位作者 刘华清 陈建民 田大刚 王锋 《分子植物育种》 CAS CSCD 2009年第2期413-419,共7页
我们在明恢86的转基因后代中发现了一个水稻花器官发育突变体,暂命名为开颖不育(open hull sterile1,ohs1(t))突变体。ohs1(t)突变体表现颖花开裂,内外稃片变细,内稃微弯向外稃,有雌雄蕊分化,但雌雄蕊较野生型株的小,大多数花药没有花粉... 我们在明恢86的转基因后代中发现了一个水稻花器官发育突变体,暂命名为开颖不育(open hull sterile1,ohs1(t))突变体。ohs1(t)突变体表现颖花开裂,内外稃片变细,内稃微弯向外稃,有雌雄蕊分化,但雌雄蕊较野生型株的小,大多数花药没有花粉,少数花药中含有不育花粉,雌雄配子均不育。突变体ohs1(t)分别与明恢86、R527、93-11和中花16号杂交后代遗传分析表明,ohs1(t)是一个隐性基因控制的突变体。以ohs1(t)和93-11杂交F2群体中突变个体作为初步定位群体,采用已报道的SSR标记将OHS1(t)初步定位在1号染色体的长臂端RM493和RM5638两个标记间。随后利用已公布的水稻基因组序列(http://rgp.dna.affrc.go.jp/E/index.html)及93-11和日本晴间SSR标记数据库(http://www.gramene.org/),新开发和筛选了SSR和In-Del标记,并以ohs1(t)和中花16号杂交F2群体中突变个体作为新定位群体,将OHS1(t)基因进一步定位在NSSR0115和InDel0102之间,遗传距离分别为0.2cM和0.3cM,物理距离约66kb。 展开更多
关键词 水稻 开颖不育突变体 遗传分析 基因定位
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开放教育全网办学成本核算——理论模型构建与经济学规律
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作者 岳江秀 李莹 +2 位作者 李柘桦 齐阳 张旭红 《山西开放大学学报》 2024年第1期35-42,共8页
研究使用国家开放大学实验学院财务数据,构建了开放教育“全网办学”模式下的成本测算模型。通过成本-效益分析,考察了以双向交互为特征的我国第三代远程教育所呈现的经济学规律。研究结果发现,在我国第三代远程教育双向交互特征日益增... 研究使用国家开放大学实验学院财务数据,构建了开放教育“全网办学”模式下的成本测算模型。通过成本-效益分析,考察了以双向交互为特征的我国第三代远程教育所呈现的经济学规律。研究结果发现,在我国第三代远程教育双向交互特征日益增强背景下,开放教育仍然享有明显的规模经济优势;由于成本结构中变动成本占比逐步提高,因分摊固定成本而表现出的规模经济效益逐渐减弱,开放教育呈现由资本密集型经济向劳动密集型经济回归的经济学规律。研究进一步丰富了开放教育成本核算研究文献,尤其是发展中国家案例;同时也为我国开放教育在转型升级发展的新阶段进一步合理确定学费收取标准提供了实证依据。 展开更多
关键词 开放教育 远程教育 开放大学 成本核算 成本-效益
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WTO与中国会计市场的发展取向 被引量:4
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作者 邓川 《财经论丛(浙江财经学院学报)》 北大核心 2002年第2期62-65,共4页
中国已经入世 ,会计市场面临进一步的开放。国内会计师事务所将受到竞争加剧、人才流失等冲击 ,如何应对将是一严峻问题。本文从入世前我国会计市场开放情况、WTO相关规则及我国承诺、进一步开放会受到的冲击以及相应对策四个方面加以... 中国已经入世 ,会计市场面临进一步的开放。国内会计师事务所将受到竞争加剧、人才流失等冲击 ,如何应对将是一严峻问题。本文从入世前我国会计市场开放情况、WTO相关规则及我国承诺、进一步开放会受到的冲击以及相应对策四个方面加以阐述。提出扩大规模 ,拓展服务领域 ,专门化策略 ,建立人才培养引进机制以及提高管理水平将是可行之举。 展开更多
关键词 中国 会计市场 对外开放 会计师事务所 审计 WTo
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MOOC环境下高校图书馆读者培训研究 被引量:7
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作者 王芙蓉 王琛 《大学图书情报学刊》 2016年第2期74-79,共6页
MOOC以其直观、鲜明、生动的授课方式给传统的课堂教学带来了新的活力,不仅改变了传统的高等教育模式,也引起了图书馆界关注。将MOOC引入图书馆读者教育,借鉴MOOC的优势及独特的应用价值可以弥补读者培训中存在的不足,是图书馆提高培训... MOOC以其直观、鲜明、生动的授课方式给传统的课堂教学带来了新的活力,不仅改变了传统的高等教育模式,也引起了图书馆界关注。将MOOC引入图书馆读者教育,借鉴MOOC的优势及独特的应用价值可以弥补读者培训中存在的不足,是图书馆提高培训师资水平、改进培训方式、提升读者信息素养的有效途径。 展开更多
关键词 M00C 网络教育 高校图书馆 读者培训 信息素养教育
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O-氰乙基壳聚糖修饰的开管毛细管电色谱柱的制备与表征 被引量:1
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作者 吕海霞 李青音 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2013年第3期147-149,共3页
制备了O-氰乙基壳聚糖修饰的开管毛细管电色谱柱。O-氰乙基壳聚糖的最佳浓度为7.5 mg/mL,通过电渗流表征了柱的稳定性和重现性较好,相对标准偏差(RSD)日内小于0.2%(n=3)、日间小于0.6%(n=3)、柱与柱之间小于1.0%(n=3)、批次与批次之间小... 制备了O-氰乙基壳聚糖修饰的开管毛细管电色谱柱。O-氰乙基壳聚糖的最佳浓度为7.5 mg/mL,通过电渗流表征了柱的稳定性和重现性较好,相对标准偏差(RSD)日内小于0.2%(n=3)、日间小于0.6%(n=3)、柱与柱之间小于1.0%(n=3)、批次与批次之间小于3.4%(n=3)。用红外光谱和扫描电镜进行了结构及形貌表征。4种核苷酸在修饰后的毛细管电色谱柱上得到了较好的分离,柱效达到37,000 plate/m-140,000 plate/m。结果表明,所建立的开管柱制备方法简单有效、稳定性好。 展开更多
关键词 毛细管电色谱 开管柱 o-氰乙基壳聚糖
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