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海外白银流入、被迫通商与银铜平行本位有效性研究--来自1819-1919年清代宁波府的经验证据 预览
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作者 赵红军 《杭州师范大学学报:社会科学版》 CSSCI 2019年第3期105-121,共17页
以1819-1919年海外白银流入、宁波口岸被迫通商背景下的银铜平行本位的有效性问题为考察对象,发现宁波当地相对市场化的银铜比价平行本位体制具有较高的市场有效性,对海外白银流入与宁波被迫通商等都做出了灵敏反应,并且也对冲了相关外... 以1819-1919年海外白银流入、宁波口岸被迫通商背景下的银铜平行本位的有效性问题为考察对象,发现宁波当地相对市场化的银铜比价平行本位体制具有较高的市场有效性,对海外白银流入与宁波被迫通商等都做出了灵敏反应,并且也对冲了相关外部冲击对当地大米价格的负面影响,但这一机制在大米市场的有效性不应被高估。宁波通商口岸的开通,对宁波大米市场产生了正向冲击,其中相对市场化的宁波银铜平行本位制度却在一定程度上抑制了这种外来冲击,说明市场化基础上的和平贸易而不是强迫贸易才是世界贸易可持续发展的人间正道。 展开更多
关键词 白银 清代 宁波 银铜平行本位 银铜比价 米价 市场有效性
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含银废液中银的回收和利用 预览
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作者 许亚兰 宁梦洁 +2 位作者 陶鹏程 王梦巧 杨明 《武汉轻工大学学报》 2019年第2期91-93,108共4页
实验探究了高温石墨还原法、甲醛还原法和锌粉置换法回收银的效果,并对不同的实验方法进行了分析,高温石墨还原法、甲醛还原法和锌粉置换法回收银的回收率分别为99.3%,98.7%和90.5%。高温石墨还原法具有银的回收率较高,反应时间短,实验... 实验探究了高温石墨还原法、甲醛还原法和锌粉置换法回收银的效果,并对不同的实验方法进行了分析,高温石墨还原法、甲醛还原法和锌粉置换法回收银的回收率分别为99.3%,98.7%和90.5%。高温石墨还原法具有银的回收率较高,反应时间短,实验安全性高,无有害气体产生等特点,值得采用。同时,还对用回收银制备高锰酸银的工艺进行了探讨,并取得了满意的结果。 展开更多
关键词 回收 废液 高锰酸银
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焙烧-氰化浸出锰银矿中银的扩大试验 预览
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作者 王明 齐建云 +1 位作者 宁新霞 王祥 《贵金属》 CAS CSCD 北大核心 2019年第1期47-50,共4页
采用添加剂焙烧-氰化浸出中试处理锰银矿。回转窑连续运转80h,物料焙烧时间30±5min,所得焙砂产率85.54%,焙砂中银含量237.73g/t、锰含量24.68%,银回收率99.19%,锰回收率98.70%;焙砂经500L反应釜直接氰化浸出,浸出液固比2:1~2.2:1,... 采用添加剂焙烧-氰化浸出中试处理锰银矿。回转窑连续运转80h,物料焙烧时间30±5min,所得焙砂产率85.54%,焙砂中银含量237.73g/t、锰含量24.68%,银回收率99.19%,锰回收率98.70%;焙砂经500L反应釜直接氰化浸出,浸出液固比2:1~2.2:1,时间6~15h,氰化钠用量700g/t原矿,所得银浸出率86.5%,氰化尾渣满足冶金用锰矿石标准。 展开更多
关键词 有色金属冶金 焙烧-氰化 中试 锰银矿
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Ag/AgO/羧甲基壳聚糖抗菌水凝胶制备及其释药性能研究
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作者 官淑敏 曹渊 +1 位作者 徐彦芹 王烨 《化工新型材料》 CAS CSCD 北大核心 2019年第5期167-171,共5页
通过银(Ag)/氧化银(AgO)原位沉淀法制备具有pH敏感性的Ag/AgO/羧甲基壳聚糖(CMCS)抗菌水凝胶(Ag/AgO/CMCS)以及载药阿司匹林(ASA)的Ag/AgO/CMCS/ASA载药水凝胶,并对水凝胶的溶胀性能、降解性能、释药性能及抗菌性能的影响进行了研究。... 通过银(Ag)/氧化银(AgO)原位沉淀法制备具有pH敏感性的Ag/AgO/羧甲基壳聚糖(CMCS)抗菌水凝胶(Ag/AgO/CMCS)以及载药阿司匹林(ASA)的Ag/AgO/CMCS/ASA载药水凝胶,并对水凝胶的溶胀性能、降解性能、释药性能及抗菌性能的影响进行了研究。制得的Ag/AgO/CMCS/ASA载药凝胶的网络主要通过氢键和分子间作用力交联,交联点Ag主要以单质Ag和Ag2+态存在。在缓冲溶液pH=7.4条件下,制得的Ag/AgO/CMCS/ASA载药凝胶在12h内的累计释药量为75.20%,对革兰氏阴性大肠杆菌(Ec.oli)的抑制率最大达到92.32%,在医疗领域具有广阔的应用前景。 展开更多
关键词 氧化银 羧甲基壳聚糖 pH敏感性水凝胶 抗菌
Effects of silver nanoparticles with different dosing regimens and exposure media on artificial ecosystem
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作者 Jingwen Zeng Piao Xu +9 位作者 Guiqiu Chen Guangming Zeng Anwei Chen Liang Hu Zhenzhen Huang Kai He Zhi Guo Weiwei Liu Jing Wu Jiangbo Shi 《环境科学学报:英文版》 SCIE EI CAS CSCD 2019年第1期181-192,共12页
Due to the wide use of silver nanoparticles(AgNPs) in various fields, it is crucial to explore the potential negative impacts on the aquatic environment of AgNPs entering into the environment in different ways. In thi... Due to the wide use of silver nanoparticles(AgNPs) in various fields, it is crucial to explore the potential negative impacts on the aquatic environment of AgNPs entering into the environment in different ways. In this study, comparative experiments were conducted to investigate the toxicological impacts of polyvinylpyrrolidone-coated silver nanoparticles(PVP-AgNPs) with two kinds of dosing regimens, continuous and one-time pulsed dosing, in different exposure media(deionized water and XiangJiang River water). There were a number of quite different experimental results(including 100% mortality of zebrafish,decline in the activity of enzymes, and lowest number and length of adventitious roots) in the one-time pulsed dosing regimen at high PVP-AgNP concentration exposure(HOE)compared to the three other treatments. Meanwhile, we determined that the concentration of leached silver ions from PVP-AgNPs was too low to play a role in zebrafish death. Those results showed that HOE led to a range of dramatic ecosystem impacts which were more destructive than those of other treatments. Moreover, compared with the continuous dosing regimen, despite the fact that higher toxicity was observed for HOE, there was little difference in the removal of total silver from the aquatic environment for the different dosing regimens. No obvious differences in ecological impacts were observed between different water columns under low concentration exposure. Overall, this work highlighted the fact that the toxicity of Ag NPs was impacted by different dosing regimens in different exposure media, which may be helpful for assessments of ecological impacts on aquatic environments. 展开更多
关键词 SILVER nanoparticles TOXICITY DOSING REGIMEN SILVER ions ZEBRAFISH
Value-added anticancer reactivity of sub-5 nm Ag-drug nanoparticles derived from organosilver (Ⅰ) MOF
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作者 Chao-Yu Song Jia-Yuan Zhang +6 位作者 Yuan Qiu Hai-Ping Jin Hui-Ming Zhang Shuang Liu Hong Liu Hong-Bin Qiu Guang-Gang Gao 《中国科学:化学英文版》 SCIE EI CAS CSCD 2019年第3期347-354,共8页
A totally structure-determined organosilver(I) metal-oganic framework(MOF) of [{Ag18(CF3COO)18(H2O)2}{Ag4(erlotinib)4}]n·7nCH3OH·3nH2O(1) was first synthesized by the self-assembly of erlotinib drug ligand a... A totally structure-determined organosilver(I) metal-oganic framework(MOF) of [{Ag18(CF3COO)18(H2O)2}{Ag4(erlotinib)4}]n·7nCH3OH·3nH2O(1) was first synthesized by the self-assembly of erlotinib drug ligand and silver salts in the study. 1 formed a NbO-like 3D network, which was built from Ag(I)-erlotinib induced chains and 18-core silver(I) nanoclusters. When 1 was dispersed in methanol solution, it formed derivative nanoparticles(1-NPs) with the average size of 3.81 nm. Silver(Ⅰ) ion is an efficient reactive oxygen species(ROS) evocator, whereas the erlotinib ligand possesses the targeting activity towards tumor cells. Therefore, IC50 values of 1-NPs for A549 and MRC-5 cells were respectively 0.97 and 7.28 μM, which were lower than IC50 value of erlotinib. It should be noted that the 7.5-fold higher inhibition effect on A549 cells allows 1-NPs to be a potential targeting anticancer drug for curing lung cancer. The study opens a new avenue to design anticancer drugs based on organosilver(I)MOF derivatives that can realize the value-added reactivity by combining clinical drugs with ROS-inductive silver(Ⅰ) ion. 展开更多
关键词 ERLOTINIB silver NANOCLUSTER targeting A549 cell SUPRAMOLECULAR
含银介孔二氧化硅-壳聚糖复合材料的制备与性能研究 预览
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作者 夏德萌 王胥人 +3 位作者 王元辰 熊文韬 许硕贵 周潘宇 《中华损伤与修复杂志(电子版)》 CAS 2019年第4期256-262,共7页
目的探讨含银介孔二氧化硅-壳聚糖复合材料(Ag/MSN-Chi)的制备方法及其微观表征、细胞毒性、吸水性能、抗菌性能及止血性能。方法以正硅酸乙酯为前驱体,十六烷基三甲基溴化铵为致孔剂,采用离子交换法在介孔二氧化硅纳米粒子(MSN)中引入... 目的探讨含银介孔二氧化硅-壳聚糖复合材料(Ag/MSN-Chi)的制备方法及其微观表征、细胞毒性、吸水性能、抗菌性能及止血性能。方法以正硅酸乙酯为前驱体,十六烷基三甲基溴化铵为致孔剂,采用离子交换法在介孔二氧化硅纳米粒子(MSN)中引入银离子,制备出具有抗菌作用的新型有序的含银介孔二氧化硅纳米粒子(Ag/MSN)材料。再利用烷基化壳聚糖负载Ag/MSN,制备出Ag/MSN-Chi。根据所用材料不同将实验分为实验组和空白对照组,实验组又分为3个亚组:MSN组、Ag/MSN组、Ag/MSN-Chi组,空白组为不加任何材料的阳性对照。计算MSN和Ag/MSN的比表面积、孔容、孔径和Ag/MSN与Ag/MSN-Chi的电荷。并通过吸水实验、体外凝血实验、抗菌实验对MSN、Ag/MSN和Ag/MSN-Chi的细胞毒性、吸水性能、止血性能及抗菌性能进行评价,计算细胞相对存活率、吸水率、凝血酶原时间(PT)、凝血活酶时间(APTT)及抑菌率。取健康成年新西兰大白兔18只,随机分成3组:对照组(采用医用纱布处理)、Ag/MSN组(采用Ag/MSN处理)、Ag/MSN-Chi组(采用Ag/MSN-Chi处理),每组6只,建立肝创伤出血模型,计算止血时间。数据比较采用方差分析和t检验。结果 MSN的比表面积为(523.8±12.4) m~2/g、孔容为(1.2±0.4) m~3/g、孔径为(3.5±0.9) nm;Ag/MSN的比表面积为(521.6±11.7) m~2/g、孔容为(1.15±0.5) m~3/g、孔径为(3.6±0.7) nm,2种材料的比表面积、孔容、孔径比较差异均无统计学意义(t=0.224、0.135、0.015,P值均大于0.05)。经测量,Ag/MSN的Zeta电位为-19.7 mV,Ag/MSN-Chi的Zeta电位为10.27 mV,表明Ag/MSN表面电荷从负值变为正值。Ag/MSN-Chi组、Ag/MSN组和MSN组与小鼠成肌细胞共培养1、4、7 d的细胞相对存活率比较,差异均无统计学意义(F=2.61、4.72、3.52,P值均大于0.05)。Ag/MSN组吸水率分别与MSN组和Ag/MSN-Chi组比较,差异均无统计学意义(t=0.482、1.159,P值均大于0.05)。经检测,Ag/MSN-Chi组、A 展开更多
关键词 壳聚糖 止血 介孔二氧化硅 抗菌
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Nanosecond Pulse Generation with Silver Nanoparticle Saturable Absorber
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作者 R.Z.R.R.Rosdin M.T.Ahmad +3 位作者 A.R.Muhammad Z.Jusoh H.Arof S.W.Harun 《中国物理快报:英文版》 SCIE CAS CSCD 2019年第5期31-34,共4页
Nanosecond pulse generation in an erbium-doped fiber laser (EDFL) passively mode-locked by a silver nanoparticle(SNP)-based saturable absorber(SA) is experimentally demonstrated. The SA is fabricated by depositing a n... Nanosecond pulse generation in an erbium-doped fiber laser (EDFL) passively mode-locked by a silver nanoparticle(SNP)-based saturable absorber(SA) is experimentally demonstrated. The SA is fabricated by depositing a nanosized SNP layer onto the surface of polyvinyl alcohol film through the thermal evaporation process. By inserting the SA into an EDFL cavity, stable mode-locked operation is achieved at 1561.5 nm with the maximum pulse energy up to 52.3 nJ. The laser operates at a pulse repetition frequency of 1.0 MHz with a pulse width of 202 ns. These results suggest that SNPs could be developed as an effective SA for mode-locking pulse generation. 展开更多
关键词 SA Nanosecond PULSE Generation with SILVER NANOPARTICLE Saturable ABSORBER
Sensitive and Label-Free Detection of Protein Secondary Structure by Amide Ⅲ Spectral Signals using Surface-Enhanced Raman Spectroscopy 预览
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作者 Kang-zhen Tian Chang-chun Cao +2 位作者 Xin-ming Nie Wen Wang Cai-qin Han 《化学物理学报》 SCIE CAS CSCD 2019年第5期603-610,共8页
Proteins and peptides perform a vital role in living systems, however it remains a challenge for accurate description of proteins at the molecular level. Despite that surface-enhanced Raman spectroscopy (SERS) can pro... Proteins and peptides perform a vital role in living systems, however it remains a challenge for accurate description of proteins at the molecular level. Despite that surface-enhanced Raman spectroscopy (SERS) can provide the intrinsic fingerprint information of samples with ultrahigh sensitivity, it suffers from the poor reproducibility and reliability. Herein, we demonstrate that the silver nanorod array fabricated by an oblique angle deposition method is a powerful substrate for SERS to probe the protein secondary structures without exogenous labels. With this method, the SERS signals of two typical proteins (lysozyme and cytochrome c) are successfully obtained. Additionally, by analyzing the spectral signals of the amide Ⅲ of protein backbone, the influence of concentration on the folding status of proteins has been elucidated. With the concentration increasing, the components of α-helix and β-sheet structures of lysozyme increase while the secondary structures of cytochrome c almost keep constant. The SERS method in this work offers an effective optical marker to characterize the structures of proteins. 展开更多
关键词 Surface-enhanced RAMAN SPECTROSCOPY SILVER nanorod Protein SECONDARY structures
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Characterization and Biosorption Performance of Silver by Bacillus Licheniformis 预览
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作者 卞霄婧 柯志滨 +3 位作者 钟超 骆韵涵 刘明华 程扬健 《结构化学》 SCIE CAS CSCD 2019年第1期61-68,2共9页
The demand of silver is increasing rapidly in recent decades, because silver and its related products are widely used in modern industry and decoration. It is necessary to recover silver from waste water using an effi... The demand of silver is increasing rapidly in recent decades, because silver and its related products are widely used in modern industry and decoration. It is necessary to recover silver from waste water using an efficient and environmental friendly method due to its environmental and economic benefits. In this paper, we eliminated the interference of Cl-and light conditions, and then studied the characterization and biosorption performance of silver by Bacillus licheniformis. The max biosorption amount was 87.4 mg/g(dry weight) with the initial Ag+concentration of 100 mg/L at pH 6.0. XRD pattern showed that the product was an amorphous compound. SEM/EDS-mapping and FT-IR results implied that phosphate, amino and carboxyl groups located on the cell walls involved in the biosorption of Ag^+. The XPS spectra result showed that the value of EB of Ag 3d(5/2367.51 eV corresponded to the energy values for Ag(Ⅰ), and indicated Ag^+ adsorbed to the surface of cell still maintained mono-valence. The results confirm that B. licheniformis just adsorb Ag^+ but cannot covert soluble Ag^+ to silver nano-particles(AgNP). 展开更多
关键词 SILVER precious METAL BIOSORPTION BACILLUS LICHENIFORMIS
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基于功能化Fe3O4@Ag纳米粒子快速检测Hg^2+的SERS方法
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作者 左方涛 徐威 赵爱武 《化学学报》 SCIE CAS CSCD 北大核心 2019年第4期379-386,共8页
近年来,汞作为一种重要的污染物引起了人们的广泛关注.迄今为止,基于表面增强拉曼光谱(Surface-enhancedRaman scattering, SERS)的Hg^2+检测方法因其在不同的检测方法中具有高灵敏度而备受关注.基于“turn-off”机制,我们合成出一种磁... 近年来,汞作为一种重要的污染物引起了人们的广泛关注.迄今为止,基于表面增强拉曼光谱(Surface-enhancedRaman scattering, SERS)的Hg^2+检测方法因其在不同的检测方法中具有高灵敏度而备受关注.基于“turn-off”机制,我们合成出一种磁性Fe3O4@Ag (FA)纳米材料用于Hg^2+的SERS 检测.磁等离子体共振纳米颗粒结合了磁共振和等离子体共振特性,可用于高灵敏度和高选择性的汞离子的SERS 检测.通过修饰带正电的聚二烯丙基二甲基氯化铵(PDADMAC, PolyDADMAC, PDDA)层, Fe3O4@Ag表面吸附上带负电的甲基橙探针分子,在Hg2+存在的情况下,可以观察到SERS 信号显著降低.由于Hg^2+与Ag纳米颗粒会快速反应并在Ag 纳米颗粒表面形成一层汞齐,从而影响了Ag 纳米颗粒的表面等离子体共振(Surface Plasmon Resonance, SPR)性能,导致电磁场强度的减弱;同时,这样也会导致Ag 纳米颗粒的表面Zeta 电位的降低,并且影响拉曼探针分子在其表面的吸附,从而进一步导致SERS信号的降低.因此,在含有Hg^2+的情况下, SERS强度的降低主要归因于Hg^2+与AgNPs的相互作用.通过我们的实验可以证明,基于“turn-off”机制检测Hg2+的方法的检测限可以低至10^-10 mol/L.本实验设计的SERS纳米传感器可用于快速检测环境中Hg^2+,为构建重金属离子SERS纳米传感器提供了巨大的潜力. 展开更多
关键词 表面增强拉曼光谱 汞离子(Ⅱ) 磁性纳米材料 快速检测 银纳米粒子
Breaking 12% efficiency in flexible organic solar cells by using a composite electrode
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作者 Guang Zeng Jingwen Zhang +3 位作者 Xiaobin Chen Hongwei Gu Yaowen Li Yongfang Li 《中国科学:化学英文版》 SCIE EI CAS CSCD 2019年第7期851-858,共8页
The performance of flexible organic solar cells(OSCs)significantly relies on the quality of transparent flexible electrode.Here,we used silver nanowires(AgNWs)with various weight ratios to dope high-conductive poly(3,... The performance of flexible organic solar cells(OSCs)significantly relies on the quality of transparent flexible electrode.Here,we used silver nanowires(AgNWs)with various weight ratios to dope high-conductive poly(3,4-ethylenedioxythiophene):polystyrene sulfonate(PH1000)to optimize the optical and electronic properties of PH1000 film.A high-quality flexible composite electrode PET/Ag-mesh/PH1000:AgNWs-20 with smooth surface,a low sheet resistance of 6Ω/sq and a high transmittance of 86%at 550-nm wavelength was obtained by doping 20 wt%AgNWs to PH1000(PH1000:AgNWs-20).The flexible OSCs based on the PET/Ag-mesh/PH1000:AgNWs-20 electrode delivered a power conversion efficiency(PCE)of12.07%with an open circuit voltage(Voc)of 0.826 V,a short-circuit current density(Jsc)of 20.90 m A/cm2and a fill factor(FF)of69.87%,which is the highest reported PCE for the flexible indium-tin oxide(ITO)-free OSCs.This work demonstrated that the flexible composite electrodes of PET/Ag-mesh/PH1000:AgNWs are promising alternatives for the conventional PET/ITO electrode,and open a new avenue for developing high-performance flexible transparent electrode for optoelectronic devices. 展开更多
关键词 FLEXIBLE ELECTRODES FLEXIBLE organic solar cells silver NANOWIRE composite ELECTRODE power conversion EFFICIENCY
大面积银微纳光栅的制备及其表面等离子体共振传感特性研究 预览
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作者 陈志伟 郎咸忠 +3 位作者 唐斌 朱熠奇 吴钦 蒋美萍 《电镀与涂饰》 CAS CSCD 北大核心 2019年第7期311-316,共6页
提出了一种基于普通CD-R光盘聚碳酸酯层表面磁控溅射镀银的简便纳米制备技术,用以大面积制备一维银微纳光栅,该光栅可作为高灵敏、低成本的表面等离激元共振(SPR)传感器。通过实验测量和数值计算的方法研究了银层厚度对银微纳光栅SPR的... 提出了一种基于普通CD-R光盘聚碳酸酯层表面磁控溅射镀银的简便纳米制备技术,用以大面积制备一维银微纳光栅,该光栅可作为高灵敏、低成本的表面等离激元共振(SPR)传感器。通过实验测量和数值计算的方法研究了银层厚度对银微纳光栅SPR的影响。结果发现,银层厚度为108 nm的银微纳光栅具有最优的综合传感性能,其灵敏度和品质因数分别达到490 nm/RIU和22 RIU?1。该技术在化学生物传感器制备方面具有潜在的应用价值。 展开更多
关键词 聚碳酸酯 磁控溅射 光栅 表面等离子体共振 时域有限差分法 蔗糖 折射率传感
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不同金属改性对ZSM-5分子筛催化正戊烷和甲醇共芳构化反应性能的影响 预览
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作者 侯扬飞 于明煊 +2 位作者 张娇玉 祝晓琳 李春义 《石油炼制与化工》 CAS CSCD 北大核心 2019年第8期46-51,共6页
通过浸渍法对ZSM-5分子筛进行改性,得到不同金属、不同负载量改性的分子筛,采用XRD和Py-IR方法对催化剂进行表征。在固定床微型反应装置上,系统探究了不同金属改性对ZSM-5分子筛催化正戊烷和甲醇共芳构化反应性能的影响。结果表明:Zn,Ag... 通过浸渍法对ZSM-5分子筛进行改性,得到不同金属、不同负载量改性的分子筛,采用XRD和Py-IR方法对催化剂进行表征。在固定床微型反应装置上,系统探究了不同金属改性对ZSM-5分子筛催化正戊烷和甲醇共芳构化反应性能的影响。结果表明:Zn,Ag,Ni,Cu改性ZSM-5分子筛均能提高共芳构化反应的芳烃选择性,Ni、Ag改性ZSM-5分子筛表现出更优的芳构化效果,在最优金属负载量下,共芳构化反应中正戊烷和甲醇转化率保持在100%,芳烃选择性高达37.69%;Zn,Ag,Ni,Cu改性ZSM-5分子筛均有新的L酸位形成,B酸量减少,L酸量增加,促进了脱氢反应,反应过程中有更多的烯烃中间体转化为芳烃,提高了芳烃选择性;在不同金属改性ZSM-5分子筛作用下,产物芳烃组成中有不同组分含量的提高。 展开更多
关键词 ZSM-5分子筛 金属 正戊烷 甲醇 共芳构化
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一种银粉工业化生产的制备方法探讨 预览
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作者 于照阳 白继春 +1 位作者 唐光炜 马国 《甘肃冶金》 2019年第5期83-85,89共4页
通过对银粉生产工艺的可行性进行探讨,整理出一种银粉的工业化生产方法。通过对各工序的反应机理、反应原理、反应方程式、经济性、环保性等方面找出银粉生产工业化的一种思路。
关键词 结晶 喷雾热解法 银粉 氨分解炉 纯碱吸收塔 臭氧
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聚乳酸-聚吡咯/银多层复合抗菌薄膜的制备与性能表征 预览
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作者 毛龙 姚进 +1 位作者 刘跃军 白永康 《表面技术》 EI CAS CSCD 北大核心 2019年第1期154-160,共7页
目的提高聚乳酸(PLA)薄膜的抗菌性能。方法受到导电高分子材料可以通过静电作用方式起到抗菌作用的启发,利用Fe3+引发吡咯(Py)在PLA薄膜表面发生化学氧化反应,聚合形成抗菌涂层(PPy),成功制备出PLA-PPy多层复合抗菌薄膜。采用等物质的量... 目的提高聚乳酸(PLA)薄膜的抗菌性能。方法受到导电高分子材料可以通过静电作用方式起到抗菌作用的启发,利用Fe3+引发吡咯(Py)在PLA薄膜表面发生化学氧化反应,聚合形成抗菌涂层(PPy),成功制备出PLA-PPy多层复合抗菌薄膜。采用等物质的量Ag+替代Fe3+,引发Py在PLA薄膜表面聚合形成双重抗菌涂层(PPy/Ag),成功制备出PLA-PPy/Ag多层复合抗菌薄膜,并探讨了不同氧化剂和Py浓度对多层复合薄膜结构和性能的影响。结果当PLA薄膜表面积为72cm2,水溶液体积为40mL,FeCl3·6H2O的浓度为0.047mol/L,Py的浓度为0.223mol/L时,PLA-PPy多层复合薄膜的表面PPy层结构致密,拉伸强度(40.1MPa)和断裂伸长率(24.9%)分别降低了7.6%和12.6%,热稳定性得到较为明显的提高。此外,PLA-PPy/Ag与PLA-PPy多层复合薄膜表现出相似的力学性能和热稳定性。更为重要的是,相比于PLA-PPy多层复合薄膜,PLA-PPy/Ag多层复合薄膜表现出更为优异的抗菌特性,大肠杆菌的菌落总数降低至2.9×106CFU/cm2,相比于纯PLA薄膜(4.8×1010CFU/cm2),降低了超过4个数量级。结论相比于完全采用成本较高的纳米银离子负载抗菌方式来说,较低成本的双重抗菌涂层(PPy/Ag)将会在PLA活性包装领域具有一定的研究意义。 展开更多
关键词 聚乳酸 聚吡咯 抗菌 涂层
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精铅与电解铅的区分方法探讨 预览
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作者 项本申 姚秋实 +1 位作者 丁建中 茆黎明 《蓄电池》 2019年第2期65-68,74共5页
由于电解铅和精铅是铅酸蓄电池行业常用的两种铅,因此区分它们对生产经营具有重要意义。从光谱、金相、硬度和拉伸测试4个方面进行分析的结果显示,金相和硬度测试不能直接区分这两种铅。基于精铅和电解铅的生产工艺,采用光谱分析可以从B... 由于电解铅和精铅是铅酸蓄电池行业常用的两种铅,因此区分它们对生产经营具有重要意义。从光谱、金相、硬度和拉伸测试4个方面进行分析的结果显示,金相和硬度测试不能直接区分这两种铅。基于精铅和电解铅的生产工艺,采用光谱分析可以从Bi元素和Ag元素含量上进行区分。电解铅和精铅的力学性质有一定差异,因此拉伸强度测试也可以区分电解铅和精铅。 展开更多
关键词 精铅 电解铅 铅酸蓄电池 光谱 金相 拉伸强度 硬度
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沉淀分离-铅试金富集-氯化钠电位滴定法测定贵铋中银 预览
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作者 肖刘萍 《冶金分析》 CAS 北大核心 2019年第3期74-78,共5页
对贵铋中银采用铅试金法富集后再测定时,存在铋干扰银的富集从而使得银的测定结果偏低的问题。实验采取硝酸、氟化铵和高氯酸分解样品后,加入EDTA溶液以络合铋,加入氯化钠使银以氯化银沉淀的形式析出,而铋仍留在溶液中,过滤,实现了铋与... 对贵铋中银采用铅试金法富集后再测定时,存在铋干扰银的富集从而使得银的测定结果偏低的问题。实验采取硝酸、氟化铵和高氯酸分解样品后,加入EDTA溶液以络合铋,加入氯化钠使银以氯化银沉淀的形式析出,而铋仍留在溶液中,过滤,实现了铋与银的分离,从而消除了铋对银富集的干扰。分离铋后,用铅试金法使沉淀中银富集于合粒中,用硝酸溶解合粒,最后用氯化钠电位滴定法测定,据此建立了沉淀分离-铅试金富集-氯化钠电位滴定法测定贵铋中银的分析方法。探讨了贵铋样品中共存组分(铋、钙、铅、铁、锌、锡、锑、砷、铜和金)对银测定结果的影响,结果表明,样品中共存组分对银的测定无影响。按照实验方法对4个贵铋实际样品中银进行测定,测定结果的相对标准偏差(RSD,n=10)为0.26%~0.68%,加标回收率在99%~101%之间,所得结果与重量法的测定值相吻合。 展开更多
关键词 沉淀分离 铅试金 氯化钠电位滴定法 贵铋
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Interaction of silver nanoparticles with mediterranean agricultural soils: Lab-controlled adsorption and desorption studies
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作者 Laura Torrent Eva Margui +2 位作者 Ignasi Queralt Manuela Hidalgo Monica Iglesias 《环境科学学报:英文版》 SCIE EI CAS CSCD 2019年第9期205-216,共12页
The production of silver nanoparticles(AgNPs) has increased tremendously during recent years due to their antibacterial and physicochemical properties. As a consequence, these particles are released inevitably into th... The production of silver nanoparticles(AgNPs) has increased tremendously during recent years due to their antibacterial and physicochemical properties. As a consequence, these particles are released inevitably into the environment, with soil being the main sink of disposal. Soil interactions have an effect on AgNP mobility, transport and bioavailability. To understand AgNP adsorption processes, lab-controlled kinetic studies were performed.Batch tests performed with five different Mediterranean agricultural soils showed that cation exchange capacity and electrical conductivity are the main parameters controlling the adsorption processes. The adsorption kinetics of different sized(40, 75, 100 and 200 nm)and coated(citrate, polyvinylpyrrolidone and polyethyleneglycol(PEG)) AgNPs indicated that these nanoparticle properties have also an effect on the adsorption processes.To assess the mobility and bioavailability of AgNPs and to determine if their form is maintained during adsorption/desorption processes, loaded soils were submitted to leaching tests three weeks after batch adsorption studies. The DIN 38414-S4 extraction method indicated that AgNPs were strongly retained on soils, and single-particle inductively coupled plasma mass spectrometry confirmed that silver particles maintained their nanoform, except for 100 nm PEG-AgNPs and 40 nm citrate-coated AgNPs. The DTPA(diethylenetriaminepentaacetic acid) leaching test was more effective in extracting silver,but there was no presence of AgNPs in almost all of these leachates. 展开更多
关键词 Silver nanoparticles Agricultural soils SORPTION kinetics LEACHING tests SINGLE-PARTICLE inductively coupled plasma mass spectrometry
Comparison of ethanolic extracts of phytoestrogenic Dendrolobium lanceolatum and non-phytoestrogenic Raphanus sativus to mediate green syntheses of silver nanoparticles 预览
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作者 Kamchan Bamroongnok Arunrat Khmahaengpol Sineenat Siri 《化学报告(英文)》 2019年第1期43-50,共8页
Green synthesis of silver nanoparticles (AgNPs) mediated by plant extracts has drawn many research interests due to its simple, cost-effective, and eco-friendly approach. However, the extracts derived from phytoestrog... Green synthesis of silver nanoparticles (AgNPs) mediated by plant extracts has drawn many research interests due to its simple, cost-effective, and eco-friendly approach. However, the extracts derived from phytoestrogenic plants that produce high phenolic-based compounds exhibiting the estrogenic activity have not yet investigated. This work reported the comparison of ethanolic extracts derived from phytoestogenic Dendrolobium lanceolatum and non-phytoestrogenic Raphanus sativus to facilitate the green synthesis of AgNPs. The total phenolic content and the reducing activity of D. lanceolatum extract were significantly higher than those of R. sativus extract. In addition, the formation of AgNPs could detect in the reaction using D. lanceolatum extract, but not R. sativus extract, as determined by the characteristic surface plasmon resonance peak of AgNPs at 416 nm. The synthesized AgNPs were spherical with an average diameter of 74.6017.11 nm, which their face-centered cubic structure of silver was confirmed by X-ray diffraction analysis. Moreover, the synthesized AgNPs exhibited the antibacterial activity against both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. The results of this work, thus, suggested the potential uses of phytoestrogenic plants as a good source of reducing and stabilizing agents for the production of AgNPs and other metallic nanoparticles. 展开更多
关键词 ANTIBACTERIAL ACTIVITY PHENOLIC content plant extract reducing ACTIVITY silver nanoparticles
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