H_(2)O_(2)-sensitive nanoscale coordination polymers for photoacoustic tumors imaging via in vivo chromogenic assay

Photoacoustic(PA)imaging with much deeper tissue penetration and better spatial resolution had been widely employed for the prevention and diagnosis of many diseases.In this study,a new type of hydrogen peroxide(H_(2)O_(2)T-activated photoacoustic nanoprobe[Mn-AH nanoscale coordination polymer nanodots(NCPs)]was successfully synthesized by a simple one-step method in water phase containing 2,20-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS),horse radish peroxidase(HRP),and manganese ion(Mn^(2+).After modification by polyethylene glycol(PEG),Mn-AH NCPs exhibited excellent stability and biocompatibility for in vivo H_(2)O_(2)-responsive chromogenic assay with great speci¯city and sensitivity.In the presence of H_(2)O_(2),colorless ABTS would be converted by HRP into the oxidized form with strong near-infrared(NIR)absorbance,enabling photoacoustic detection of endogenous H_(2)O_(2).Using H_(2)O_(2)-activated Mn-AH NCPs,we have successfully performed PA imaging and H_(2)O_(2)detection of subcutaneous murine colon CT26 tumor and deep-seated orthotopic bladder tumor.Due to the inherent Mn element existence inside the Mn-AH,this nanoprobe also serves as a good T1-weighted magnetic resonance imaging(MRI)contrast agent simultaneously.Lastly,after accomplishing its imaging functions,the Mn-AH NCPs could be cleared out from the body without any long-term toxicity,providing a new opportunity for cancer diagnosis and treatment.

Significant role of nanoscale Bi-rich phase in optimizing thermoelectric performance of Mg3Sb2

Mg3Sb1.5Bi0.5-based alloys have received much attention,and current reports on this system mainly focus on the modulation of doping.However,there lacks the explanation for the choice of Mg3Sb1.5Bi0.5 as matrix.Here in this work,the thermoelectric properties of Mg3Sb2-xBix(0.4≤x≤0.55)compounds are systematically investigated by using the first principles calculation combined with experiment.The calculated results show that the band gap decreases after Bi has been substituted for Sb site,which makes the thermal activation easier.The maximum figure of merit(ZT)is 0.27 at 773 K,which is attributed to the ultra-low thermal conductivity 0.53 W·m-1·K-1 for x=0.5.The large mass difference between Bi and Sb atoms,the lattice distortion induced by substituting Bi for Sb,and the nanoscale Bi-rich particles distributed on the matrix are responsible for the reduction of thermal conductivity.The introduction of Bi into Mg3Sb2-based materials plays a vital role in regulating the transport performance of thermoelectric materials.

Degradation of nitrobenzene-containing wastewater by sequential nanoscale zero valent iron-persulfate process

As nitrobenzene(NB)is structurally stable and difficult to degrade due to the presence of an electron withdrawing group(nitro group).The sequential nanoscale zero valent iron-persulfate(NZVI-Na_(2)S_(2)O_(8))process was proposed in this study for the degradation NB-containing wastewater.The results showed that the NB degradation efficiency and the total organic carbon removal efficiency in the sequential NZVINa_(2)S_(2)O_(8)process were 100%and 49.25%,respectively,at a NB concentration of 200 mg L^(-1),a NZVI concentration of 0.75 g L^(-1),a Na_(2)S_(2)O_(8)concentration of 26.8 mmol L^(-1),an initial pH of 5,and a reaction time of 30 min,which were higher than those(88.53%and 35.24%,respectively)obtained in the NZVI/Na_(2)S_(2)O_(8)process.Sulfate radicals(SO_(4)·-)and hydroxyl radicals(·OH)generated in the reaction were identified directly by electron paramagnetic resonance spectroscopy and indirectly by radical capture experiments,and it was shown that both SO_(4)^(·-)and·OH played a major role in the sequential NZVI-Na_(2)S_(2)O_(8)process.The possible pathways involved in the reduction of NB to aniline(AN)and the further oxidative degradation of AN were determined by gas chromatography-mass spectrometry.

Nanoscale Pore Characteristics of the Upper Permian Mudrocks from a Transitional Environment in and around Eastern Sichuan Basin, China

Nanoscale pore characteristics of the Upper Permian Longtan transitional mudrocks and their equivalent strata Wujiaping Formation marine mudrocks in and around the eastern Sichuan Basin was investigated using field emission scanning electron microscopy(FE-SEM)and low-pressure N2 adsorption experiments.The results indicate that the Upper Permian mudrock is at a mature stage with total organic carbon(TOC)values ranging between 0.47%and 12.3%.The Longtan mudrocks mainly contain vitrinite,and their mineral composition is primarily clay.In contrast,the Wujiaping mudrocks are dominated by sapropelinite and solid bitumen,and their mineral compositions are mainly quartz and a notably high amount of pyrite.The FE-SEM reveals that clay mineral pores and microcracks are the common pore types in the Longtan mudrocks.The specific surface area and pore volume depend on the clay content but are negatively correlated with the TOC.The generation of nanometer pores in the Longtan mudrocks is caused by high clay mineral contents.Meanwhile,the Wujiaping mudrock mainly contains OM pores,and the pore parameters are positively correlated with the TOC.The OM pore development exhibits remarkable differences in the Longtan and Wujiaping mudrocks,which might be related to their sedimentary facies and maceral fractions.Vitrinite and inertinite appear as discrete particles in these mudrocks and cannot generate pores during thermal maturation.Sapropelinite often contains many secondary pores,and solid bitumen with large particles,usually with several pores,is not the major contributor to the pore system of the investigated mudrock.

纳米SiO_(2)包覆Na_(2)Ca_(2.93)Si_(6)O_(16):7% Eu^(3+)荧光粉的制备及性能研究

采用传统高温固相法在1050℃烧结下制备了Na_(2)Ca_(3-x)Si_(6)O_(16)∶xEu^(3+)红色荧光粉,其中Na_(2)Ca_(2.93)Si_(6)O_(16)∶7%Eu^(3+)荧光粉的发光性能最好。采用溶胶-凝胶法制备出纳米SiO_(2)并包覆在Na_(2)Ca_(2.93)Si_(6)O_(16)∶7%Eu^(3+)荧光粉表面,包覆量为2%~10%(wt,质量分数,下同)。通过X射线衍射仪、激发-发射光谱分别对荧光粉物相结构和发光性能进行表征,采用CIE色度坐标分析软件对样品的色度图进行绘制。结果表明纳米SiO_(2)包覆量不同的荧光粉其基质结构未发生改变,纳米SiO_(2)包覆膜是无定型的,样品的发射峰位置没有变化,但发射强度不同;当纳米SiO_(2)包覆量为8%时,荧光粉发射强度最高,比Na_(2)Ca_(2.93)Si_(6)O_(16)∶7%Eu^(3+)荧光粉的发光强度明显提高,且此时色纯度更高,更接近正红色,CIE色度坐标为(0.5282,0.3210)。

纳米TiO_2光催化氧化乙醇反应机理的研究

以纳米TiO2 为催化剂 ,主波长为 36 4nm的汞灯为光源 ,通过气相色谱测定反应物和生成物的浓度变化 ,分别研究了体积量浓度为 0 1mol·L- 1 的CH3CH2 OH、CH3CHO和CH3COOH水溶液进行光催化氧化反应的速率。经Langmuir Hinshelwood方程进行核算 ,证明该组反应均为零级反应。TEM、XRD、SSA和FT IR PAS对催化剂进行了表征。根据FT IR PAS的检测结果提出了CH3CH2 OH光催化氧化反应的机理 :CH3CH2 OH [O] CH3CHO[O] CH3COOH [O] 碳 碳键断开[O] … [O] CO2 +H2

纳米TiO_2光催化氧化正丙醇和异丙醇反应的研究

分别研究了纳米TiO2 在主波长为 364nm的汞灯光照下催化氧化 0 .1mol·L- 1 的n C3H7OH及i C3H7OH水溶液反应的速率 ,证明了该组反应均为零级反应 .用XRD、TEM、SSA和FT IR PAS对催化剂进行了表征 .根据FT IR PAS的检测结果提出了光催化氧化反应的机理i C3H7OH [O] CH3COCH3[O] CH3COOH [O] … [O] CO2 +H2 On C3H7OH [O] CH3CH2 CHO [O] CH3CH2 COOH [O] … [O] CO2 +H2

Sol-gel法制备纳米TiO2锐钛矿相的晶化动力学

采用Sol gel技术制备了纳米级锐钛矿TiO2 ,并在 30 0～ 4 5 0℃之间发生了非晶向纳米晶的转变 ,运用非等温结晶过程的计算原理经过数学变换 ,计算了Avrami指数n、晶化激活能E、晶粒长大维数m和晶粒长大激活能Q等动力学参数。结果表明 ,在非晶向纳米晶的转变过程中 ,纳米晶体的特殊结构m对应着独特的动力学性质。

纳米TiO_2的制备与表征

通过金属醇盐水解制备了纳米TiO2 颗粒 ,用XRD、TEM、ICP等方法进行了分析与表征 ,给出了相关的工艺参数。实验结果表明 ,通过控制溶液的pH值和水解用水量 。

纳米Fe_3O_4对红壤微生物数量、酶活性及2,4-D降解的影响

【目的】从磁致效应的角度考察纳米四氧化三铁(Fe3O4)对红壤微生物数量和酶活性的影响,研究纳米Fe3O4处理对红壤中2,4-D的降解效果,为纳米磁处理技术用于污染土壤修复提供依据。【方法】采用不同剂量的纳米Fe3O4处理红壤,用稀释平板法和化学比色法测定处理前后微生物数量和酶活性的变化;利用高效液相色谱(HPLC)测定土壤中2,4-D浓度的变化。【结果】纳米Fe3O4对细菌和放线菌有激活效应,但对真菌存在抑制作用,且当纳米Fe3O4投加量为80 g.kg-1时磁致效应最显著;同样,纳米Fe3O4对淀粉酶、脲酶、中性磷酸酶和过氧化氢酶也具有激活效应,但对不同酶活性的影响程度存在差异;经纳米Fe3O4处理后红壤中2,4-D的降解率明显高于未处理组,7 d内2,4-D的降解率可达84%。【结论】纳米Fe3O4处理后红壤中的微生物数量和酶活性显著增加,且红壤对2,4-D的降解能力明显增强。

纳米晶金红石TiO_2结晶形态

ＴｉＣｌ３氧化烧结制备了纳米晶金红石ＴｉＯ２。通过Ｘ射线衍射（ＸＲＤ）分析其物相，采用透射电镜（ＴＥＭ）详细观察和分析了不同温度烧结的金红石ＴｉＯ２纳米晶的形态结构。研究表明，纳米晶金红石与常规金红石有很大的区别，前者为｛１１０｝面组成的单形。

Sol-Gel法制备Al_2O_3-SiO_2-TiO_2-ZrO_2复合陶瓷膜的研究

将Sol-Gel法应用于无机膜的制备,成功的研制出一种新型的膜面平整、膜厚均匀且无宏观缺陷的Al2O3-SiO2-TiO2-ZrO2复合陶瓷膜,复合膜含有γ-Al2O3、SiO2、TiO2、ZrO2和Al2SiO5等晶相,改变体系组成含量,晶相组成和含量随之变化,从而引起膜的显微结构的变化。利用XRD、SEM、AFM、EPMA等测试手段重点研究了膜的表面形貌和显微结构,并分析了添加剂、热处理方式等对膜的表面形貌和显微结构影响。

冬凌草负载纳米零价铁吸附废水中的Pb^(2+)

针对冶金行业产生的含铅废水导致的环境污染问题,以太行山脉盛产的野生冬凌草为载体,采用液相化学还原法制备了冬凌草负载纳米零价铁(RR-nZVI),并用于去除水中的Pb^(2+),详细考察了酸度、温度、RR-nZVI投加量、Pb^(2+)初始浓度和反应时间对Pb^(2+)去除率的影响。通过FTIR、XRD、SEM等手段对RR-nZVI去除Pb^(2+)的机理进行分析。结果表明,RR-nZVI投加量0.6 g/L、pH=5.0、Pb^(2+)初始浓度200 mg/L、室温下反应60 min时,Pb^(2+)的去除率达到了99.9%,吸附量达到394.7 mg/g。动力学试验表明,RR-nZVI对溶液中Pb^(2+)的吸附符合Lagergren准二级动力学模型,吸附过程主要受化学吸附控制。Langmuir模型能较好地描述RR-nZVI对Pb^(2+)的吸附过程,吸附以单层吸附为主。当Pb^(2+)的初始浓度小于10 mg/L时,滤液中的Fe浓度低于国家《铅、锌工业污染物排放标准(GB 25466—2010)》中规定的限量要求,不会对环境造成二次污染,为含Pb^(2+)废水的处理提供了一种有效的可供选择的材料。

TiO_2光催化氧化降解聚乙二醇研究

以纳米TiO2为光催化剂,分别选择不同的实验条件,对聚乙二醇水溶液进行光催化降解实验。根据实验结果,证明该反应的可行性并得到了优化的实验条件。用气相色谱法测定了在纳米TiO2粉末上进行光催化反应的宏观动力学数据,从反应物浓度及生成CO2的量与反应时间的关系测定了该组反应的级数和速率常数。

AFM研究Sol-Gel法制备的TiO_2和Al_2O_3-TiO_2-SiO_2涂膜表面形貌

载玻片在金属醇化物的溶胶中浸涂、热处理，获得厚度为５０～９０ｎｍ的ＴｉＯ２和ＸＡｌ２Ｏ３－ＹＴｉＯ２－ＺＳｉＯ２涂膜（Ｘ＝０～３０，Ｙ＝０．２５～０．６０，Ｚ＝０．２０～０．６５，摩尔分数）。使用原子力显微镜（ＡＦＭ）研究涂膜表面纳米范围的形貌。研讨了化学组成，热处理温度与时间，以及热处理前或后的贮存史对表面形貌，ｒｍｓ－均方根粗糙度和锐钛矿结晶的影响。

CeO2-β-CD改性阳极微生物燃料电池处理抗生素废水的性能研究

为了提高微生物燃料电池的性能,提出采用纳米级氧化铈(CeO_(2))和β-环糊精(β-CD)进行阳极改性的方法。采用溶液浸泡法制备CeO_(2)-β-CD改性碳毡阳极,以制药废水为阳极液,以驯化污泥为微生物菌种,对比分析3种不同阳极对双室微生物燃料电池性能的影响。结果表明,采用CeO_(2)-β-CD改性阳极的微生物燃料电池的稳态电流密度、最大功率密度、150 h的发电能量及对制药废水的化学需氧量(COD)去除率分别约为0.22 A·m^(-2)、0.073 W·m^(-2)、86.26 J和68%,较采用未改性碳毡阳极的微生物燃料电池分别提高了266.7%、114%、522.4%和94%。CeO_(2)-β-CD改性阳极显著提高了微生物燃料电池的产电能力和废水处理效果。

Y型分子筛嵌载纳米零价铁对水中Pb^(2+)的去除机理研究

为克服纳米零价铁(nZVI)易团聚、易钝化的缺点,本文以具备阳离子交换性能的Y型分子筛为载体,制得Y型分子筛嵌载纳米零价铁复合材料,对比研究了nZVI、Y型分子筛及所制复合材料对水中Pb^(2+)的去除能力,并利用SEM、TEM、XRD和XPS等手段,对去除Pb^(2+)前后复合材料的微观形貌、物相组成及元素价态等进行表征,分析了Y型分子筛嵌载nZVI复合材料对水中Pb^(2+)的去除机理。结果表明,Y型分子筛嵌载nZVI复合材料对水中Pb^(2+)有较好的去除效果,反应60 min时对Pb^(2+)的吸附量可达425.8 mg/g,相较于纳米零价铁和Y型分子筛,复合材料对水中Pb^(2+)的吸附量分别增大了37.6%和46.9%。所制复合材料对水中Pb^(2+)的去除机理主要为:Y型分子筛的阳离子交换作用,纳米零价铁的还原作用,纳米零价铁被氧化生成的羟基氧化铁及Y型分子筛中的硅、铝氧化物对Pb^(2+)的表面配合作用。

树脂D001负载纳米Pd/Fe双金属脱溴2,2＇,4,4＇-四溴联苯醚(BDE-47)的研究

采用大孔树脂D001交换吸附Pd2+、Fe2+并在厌氧条件下以硼氢化钠溶液还原吸附的钯铁离子制备成负载纳米Pd/Fe双金属树脂。利用该树脂对2,2',4,4'-四溴联苯醚(BDE-47)进行脱溴反应,探讨了该法的可行性和特性。结果表明:当大孔树脂D001、氯化钯、硫酸亚铁用量分别为0.75 g、2μg和0.2 g时所制备的双金属树脂脱溴水-乙醇溶液中的BDE-47效果最佳,反应遵循准一级动力学,速率常数k约为0.161 d-1,半减期为1.21 d。负载Pd/Fe的D001连续3次脱溴反应都有较好的效果,水-乙醇溶液中超过90%以上的BDE-47在反应6 d后被降解。负载Pd/Fe双金属的树脂可以重复活化再生,但再生2次后其脱溴效率变差,反应6 d只有47.3%的BDE-47被降解。用气相色谱-质谱联用仪和离子色谱仪跟踪Pd/Fe双金属树脂脱溴BDE-47反应,可知产物包括溴离子、三溴联苯醚、二溴联苯醚、一溴联苯醚和联苯醚。

纳米板钛矿基TiO_2的晶粒尺寸效应

借助精确的 X射线衍射测量 ,结合独立衍射峰对不同晶粒度纳米板钛矿基 Ti O2 样品中板钛矿和金红石相的微结构参量进行了较细致的研究 ,给出了标征物相、晶面指数 (hk1)和晶面间距 dhkl值 ,详细分析结果的系列 XRD谱 ,并得到晶面间距、晶格常数、轴比、晶胞体积等参数数值及其相对常规粗晶的变化情况 ,从而初步揭示出其晶粒微结构的尺寸效应 .作者首次发现 ,纳米板钛矿基 Ti O2 样品中板钛矿和金红石相晶粒均存在着非单调的各向异性晶格畸变 .

纳米钯/铁双金属对2,4-二氯酚的还原脱氯研究

应用改进液相还原法合成纳米Pd/Fe双金属颗粒并对2,4-二氯酚进行还原脱氯,探讨双金属颗粒的钯负载率和初始pH值对脱氯效率的影响.结果表明,合成的纳米钯/铁颗粒分散均匀,平均粒径为50 nm.纳米Pd/Fe双金属颗粒对2,4-二氯酚的脱氯反应符合拟一级反应动力学方程.量子化学计算与还原脱氯实验均表明,分子中氯原子的化学环境对还原脱氯过程具有明显影响.