检索结果-南通市图书馆

Changes of Air–sea Coupling in the North Atlantic over the 20th Century

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

Advances in Atmospheric Sciences 2015年第4期32卷 445-456页

作者： YANG yun WU Lixin Physical Oceanography Laboratory Ocean University of China

Changes of air–sea coupling in the North Atlantic Ocean over the 20 th century are investigated using reanalysis data,climate model simulations, and observational data. It is found that the ocean-to-atmosphere feedback over the North Atlantic is significantly intensified in the second half of the 20 th century. This coupled feedback is characterized by the association between the summer North Atlantic Horseshoe（nah） SST anomalies and the following winter North Atlantic Oscillation（NAO）. The intensification is likely associated with the enhancement of the North Atlantic storm tracks as well as the nah SST anomalies. Our study also reveals that most IPCC AR4 climate models fail to capture the observed NAO/nah coupled feedback.

关键词： air–sea coupling climate change North Atlantic Ocean 20th Century

同方期刊数据库

Modified pretreatment method for total microbial DNA extraction from contaminated river sediment

在线全文

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2015年第3期9卷 444-452页

作者： yun FANG Meiying XU Xingjuan CHEN Guoping SUN Jun GUO Weimin WU Xueduan LIU Guangdong Institute of Microbiology Guangzhou 510070 China School of Minerals Processing and Bioengineering Central South University Changsha 410083 China Key Laboratory of Biometallurgy of Minislry of Education Changsha 410083 China State Key Laboratory of Applied Microbiology (Ministry-Guangdong Province Jointly Breeding Base) Guangzhou 510070 China Department of Civil & Environmental Engineering Center for Sustainable Development & Global Competitiveness Stanford University Stanford CA94305 USA

Extraction of high-quality microbial DNA from contaminated environmental samples is an essential step in microbial ecological study. Based on previously published methods for soil and sediment samples, a modified pretreatrnent method was developed for extracting microbial DNA from heavily contaminated river sediment samples via selection of optimal pretreatment parameters （i.e., reagent solution, reaction duration, and temperature）. The pretreatment procedure involves wash ing the river sediment sample for three times with a solution containing 0.1 mol.L-1 ethylene diamine tetra- acetic acid （EDTA）, 0.1 mol- L-1 Tris （pH 8.0）, 1.5 mol. L1 NaC1, 0.1 mol. L-1 nah2PO4, and Na2HPO4 at 65~C with ***-1 for 15min to remove humic materials and heavy metals prior to the employment of standard DNA extraction procedures. We compared the results of standard procedure DNA extraction following pretreatrnent, without pretreatment, and with using a commercial PowerSoilTM DNA Isolation Kit. The results indicated that the pretreatment significantly improved the DNA quality based on DNA yield, DNA fragment length, and determination of prokaryotic diversity. Prokaryotic diversity exhibited in the DNA with the pretreatment was also considerably higher than that extracted with the Power- SoilTM DNA Isolation Kit only. The pretreatment method worked well even with a small amount of sediment sample （0.25 g or even lower）. The method provides a novel, simple, cost-effective tool for DNA extraction for microbial community analysis in environmental monitoring and remediation processes.

关键词： river sediment DNA extraction contaminant,pretreatment microbial community

Synthesis of Organic-Inorganic Hybrid Aluminum Hypophosphite Microspheres Flame Retardant and Its Flame Retardant Research on Thermoplastic Polyurethane

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2024年第1期39卷 221-233页

作者：刘生鹏 XU Zhi ZHANG Xinyuan WEI Huan XIONG yun DING Yigang HUANG Wenbo 许莉莉 Engineering Research Center of Phosphorus Resources Development and Utilization of Ministry of Education Key Laboratory for Green Chemical Process of Ministry of EducationSchool of Chemical Engineering and PharmacyWuhan Institute of TechnologyWuhan 430205China Hubei Three Gorges Laboratory Yichang 443007China School of Technology Materials Science and Engineering Wuhan Institute of TechnologyWuhan 430205China

Aluminum hypophosphite microspheres(AHP) were synthesized by hydrothermal method using nah2PO2·H2O and AlCl3·6H2O as raw materials, and then the AHP microspheres were polymerized by surface polymerization of micro-nanospheres with cyclic cross-linked poly(cyclotriphosphazene-co-4,4'-sulfonyldiphenol)(PZS). A new organic-inorganic poly(phosphonitrile)-modified aluminum hypophosphite microspheres(PZS-AHP) were synthesized by encapsulation and applied to flame retardant thermoplastic polyurethane(TPU). The microstructure and chemical composition of the PZS-AHP microsphere were characterized by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy and X-ray spectroscopy. The thermal stability of PZS-AHP microsphere was explored with thermogravimetric analysis. Thermogravimetric data indicate that the PZS-AHP microspheres have excellent thermal stability. The thermal and flame-retarding properties of the TPU composites were evaluated by thermogravimetric(TG), limited oxygen index tests(LOI), and cone calorimeter test(CCT). The TPU composite achieved vertical burning(UL-94) V-0 grade and LOI value reached 29.2% when 10 wt% PZS-AHP was incorporated. Compared with those of pure TPU, the peak heat release rate(pHRR) and total heat release(THR) of TPU/10%PZS-AHP decreased by 82.2% and 42.5%, respectively. The results of CCT indicated that PZS-AHP microsphere could improve the flame retardancy of TPU composites.

关键词： polyphosphazene thermoplastic polyurethane flame retardancy aluminum hypophosphite surface polymerization

Partial Order-Disorder Transformation of Interpenetrated Porous Coordination Polymers

在线全文

学校读者我要写书评

暂无评论

CCS Chemistry 2022年第5期4卷 1587-1596页

作者： yun Li Xin-Yi Cao Kai Zheng Xue-Wen Zhang Dong-Dong Zhou Wei-Xiong Zhang Xiao-Ming Chen Jie-Peng Zhang MOE Key Laboratory of Bioinorganic and Synthetic Chemistry School of ChemistrySun Yat-sen UniversityGuangzhou 510275 Key Laboratory of Coal to Ethylene Glycol and Its Related Technology Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhouFujian 350002

Controlling interpenetration and flexibility behaviors is intriguing and fundamental for porous coordination *** report exceptional interpenetration behaviors involving controllable partial order–disorder structural transformations.A new bis-benzotriazolate ligand(nah2sbbta)with a twisted and anionic backbone was designed and *** solvothermal reaction of ZnCl_(2) and nah_(2)sbbta yielded(Et_(2)NH_(2))_(3)[Zn_(5)Cl_(4)(sbbta)_(3)]·6DEF(2)possessing two-fold interpenetrated anionic pcu networks with symmetry,shape,and charge different from the known *** interestingly,powder and single-crystal X-ray diffractions showed that 2 can undergo solvent-induced structural transformation to form a noninterpenetrated anionic pcu network with larger pores(1).Consequently,1/2 can selectively adsorb/exchange cationic dyes fromneutral and anionic dyes with tunable size ***,since the transformations are reversible without obvious change of crystal sizes,the network that disappeared in X-ray crystallography should be mainly disordered rather than ***,the structural transformations can be suppressed by thermal decomposition/removal of Et_(2)NH_(2)^(+)/Et_(2)*** simulations indicate that the ordered and disordered structures are stabilized by relatively large and small solvent molecules,respectively.

关键词： order disorder interpenetration crystalto-crystal structural transformation dye adsorption and separation

碘-碱性艳蓝BO体系分光光度法测定痕量银的研究

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

光谱学与光谱分析 2005年第5期25卷 765-767页

作者：施文健徐斐俞芸上海理工大学城建学院上海200093

研究了萘基二苯甲烷染料和染料与[AgI2]-缔合物光谱和分析性能。提出了一种基于在H3PO4～nah2PO4缓冲溶液中碱性艳蓝BO与[AgI2]-反应生成蓝色缔合物,采用分光光度法测定痕量银。其最大吸收波长为574nm,表观摩尔吸光系数7.25×104L·mol-... 详细信息

研究了萘基二苯甲烷染料和染料与[AgI2]-缔合物光谱和分析性能。提出了一种基于在H3PO4～nah2PO4缓冲溶液中碱性艳蓝BO与[AgI2]-反应生成蓝色缔合物,采用分光光度法测定痕量银。其最大吸收波长为574nm,表观摩尔吸光系数7.25×104L·mol-1·cm-1,线性范围4～250μg·L-1,回收率97.0%～98.3%,相对标准偏差2.7%。此方法可应用于水体中痕量银的测定。

关键词：萘基二苯甲烷染料银分光光度法

光谱和电化学方法研究自组装纳米簇模拟过氧化物酶

在线全文

学校读者我要写书评

暂无评论

分析化学 2012年第10期40卷 1543-1548页

作者：王玮洪军黄琨肖保林杨卫云赵莹雪高云飞河南大学生命科学学院

利用细胞色素c与Nafion,通过自组装方式,构建了纳米簇模拟过氧化物酶;利用电子透射显微镜、圆二色谱仪、紫外可见光分光光度仪及电化学工作站等设备测量模拟酶结构变化、酶促动力学参数以及电化学特性;在50 mmol/L Na2HPO4-nah2PO4缓冲... 详细信息

利用细胞色素c与Nafion,通过自组装方式,构建了纳米簇模拟过氧化物酶;利用电子透射显微镜、圆二色谱仪、紫外可见光分光光度仪及电化学工作站等设备测量模拟酶结构变化、酶促动力学参数以及电化学特性;在50 mmol/L Na2HPO4-nah2PO4缓冲溶液(pH 10.0)中,测得模拟酶米氏常数Km、催化速率及催化效率分别为2.5μmol/L、0.069 s"1、0.028±0.005(μmol/L)"1s"1,其催化效率为天然辣根过氧化物酶的39%±5%,该模拟酶具有很好的稳定性和活性,能够替代辣根过氧化物酶。该模拟酶可以固定在功能化多壁纳米管与纳米金复合材料修饰玻碳电极上,在50 mmol/L Na2HPO4-nah2PO4缓冲溶液(pH 7.0)中测得模拟酶与电极之间电子迁移速度常数ks为0.65 s"1。利用循环伏安法测量模拟酶催化浓度为0.02～10 nmol/L的H2O2,其阴极峰电流随H2O2浓度增加而增大,并且得出模拟酶催化H2O2检出限为0.05 nmol/L,电化学表观米氏常数Kmapp为2.3×10"10mol/L。

关键词：自组装纳米簇模拟酶光谱学电化学

来源：博看期刊

在线全文

学校读者我要写书评

暂无评论

磺胺-氨基萘磺酸光度法测定食品中亚硝酸盐

食品与生物技术学报 2009年第2期28卷 206-209页

作者：钟晓永施文健陈肖云俞芸宋伟上海理工大学城市建设与环境工程学院上海200093

筛选了重氮组分和偶合组分。研究了重氮反应和偶合显色反应的条件和方法，提出了磺胺-8-氨基-1-萘磺酸分光光度法测定食品中亚硝酸盐。常温，溴化钾共存下，亚硝酸盐在pH3的磷酸-磷酸二氢钠缓冲溶液中与磺胺发生重氮化反应，重氮盐与8-... 详细信息

筛选了重氮组分和偶合组分。研究了重氮反应和偶合显色反应的条件和方法，提出了磺胺-8-氨基-1-萘磺酸分光光度法测定食品中亚硝酸盐。常温，溴化钾共存下，亚硝酸盐在pH3的磷酸-磷酸二氢钠缓冲溶液中与磺胺发生重氮化反应，重氮盐与8-氨基-1-萘磺酸偶合生成红色偶氮化合物，最大吸收峰在518nm波长处。磺胺-8-氨基-1-萘磺酸偶氮化合物的表观摩尔吸光系数3．9×10^4L·mol^-1·cm^-1，线性范围0．02～1．4mg／L，相对标准偏差2．22％，回收率98.0%～102％。该方法可用于食品中痕量亚硝酸盐的测定。

关键词：亚硝酸盐磺胺 8-氨基-1-萘磺酸分光光度法

在线全文

学校读者我要写书评

暂无评论

多晶硅表面酸腐蚀制备绒面研究

光子学报 2011年第2期40卷 222-226页

作者：张发云叶建雄新余学院太阳能科学与工程系江西新余338004 南昌工程学院机械与动力工程系南昌330099

采用各向同性腐蚀法制备多晶硅绒面,腐蚀液为HF和HNO3的混合溶液,缓和剂为nah2PO4.2 H2O溶液.利用SEM、AFM和紫外分光光度计对硅片绒面进行检测和分析,初步探讨了酸腐蚀机理.结果表明：采用nah2PO4.2 H2O溶液作为缓和剂,腐蚀后的硅片表... 详细信息

采用各向同性腐蚀法制备多晶硅绒面,腐蚀液为HF和HNO3的混合溶液,缓和剂为nah2PO4.2 H2O溶液.利用SEM、AFM和紫外分光光度计对硅片绒面进行检测和分析,初步探讨了酸腐蚀机理.结果表明：采用nah2PO4.2 H2O溶液作为缓和剂,腐蚀后的硅片表面具有均匀的腐蚀坑,表面陷光效果较好,通过优化各种参量,反应速度可以控制在2μm/min左右,适合工业生产的要求.在富HF时,硅片表面易形成尖锐边缘的腐蚀坑,出现或多或少的小孔,反射率最低可达16.5%-17.5%;在富HNO3时,硅片表面易形成腐蚀坑较浅、尺寸偏大的气泡状绒面或光面,反射率较高.

关键词：多晶硅酸腐蚀绒面反射率形貌

在线全文

学校读者我要写书评

暂无评论

平面螺旋声阵列近场旋转扫描全息成像研究

振动与冲击 2015年第5期34卷 122-127,140页

作者：陈林松曹跃云郭文勇海军工程大学动力工程学院武汉430033 海军工程大学电子工程学院武汉430033

针对一平面螺旋阵列在噪声源成像应用,分析了波束形成方法在低频段噪声成像能力的局限性,采用等效源法实现了对低频噪声的全息成像。为提高近程声全息成像性能,提出并采用不规则平面阵进行旋转扫描测量,重点研究了无参考传感器条件下对... 详细信息

针对一平面螺旋阵列在噪声源成像应用,分析了波束形成方法在低频段噪声成像能力的局限性,采用等效源法实现了对低频噪声的全息成像。为提高近程声全息成像性能,提出并采用不规则平面阵进行旋转扫描测量,重点研究了无参考传感器条件下对扫描数据的相位处理方法,实现了不同时刻测量数据的相位同步,利用仿真研究验证了该方法的有效性和优越性,并通过实际实验进行验证,对450Hz以下频率噪声的成像能力有显著提高。该方法测试条件要求低,测试结果可靠,相关结论具有参考价值。

关键词：波束形成声全息等效源法旋转扫描