碱性环境对植物纤维水泥砂浆性能的影响

为了探究植物纤维在砂浆中的降解机理和分析碱性环境对水泥砂浆基本性能的影响,改变其降解碱液浓度,对纸纤维进行降解分析。随后将纸纤维加入到砂浆中去,改变其碱性环境,测试并分析了砂浆体积密度,吸水率和抗压强度随养护时间的变化,并对吸水率和抗压强度进行线性拟合。结果表明,随着降解碱液的浓度升高,纸纤维降解程度加剧。同时纸纤维的加入使得水泥砂浆的体积密度和抗压强度明显降低,吸水率明显升高。而且随着碱性环境的增强,纸纤维在砂浆内部的降解程度增大,在一定程度上也减小了砂浆的体积密度和抗压强度,增大了吸水率。通过纸纤维和砂浆试块的SEM微观照片,得出纸纤维在砂浆内部增大了砂浆内部的孔隙,发生了降解。对其吸水率和抗压强度进行线性拟合结果表明吸水率和抗压强度呈现负相关关系。

Research on the Marine Antifouling Ability and Mechanism of Acrylate Copolymers and Marine Coatings Based on a Synergistic Effect

Marine biofouling is an urgent global problem in the process of ocean exploitation and utilization.In our work,a series of zinc-based acrylate copolymers(ACZn-x)were designed and synthesized using benzoic acid,zinc oxide(ZnO)and a random quaternion copolymer consisting of ethyl acrylate(EA),butyl acrylate(BA),acrylic acid(AA)and methacrylic acid(MAA)by free radical polymerization and dehydration condensation.The ACZn-x with a zinc benzoate side chain is able to hydrolyze in natural seawater under static conditions,resulting in the formation of a smooth surface.We investigated and confirmed the antifouling(AF)behavior of ACZn-x in the laboratory and revealed that they have better antibacterial(86%for S.aureus and 72%for E.coli)and anti-algal(≥60.1%for N.closterium and≥67.5%for P.subcordiformis)activities.We also assessed the marine AF properties of ACZn-x and corresponding coatings in Qingdao,China;the ACZn-x exhibited ideal AF properties with little silt and biological mucosa adhered to the ACZn-x surface after 6 months,and corresponding coatings exhibited little biofouling after 16 months in the ocean.Importantly,possible AF mechanisms were further proposed at the cellular level.These results could be helpful for the development and application of effective AF coatings.

Synthesis and Excellent Antibacterial Activity of Ag_(2)O-Loaded Carboxymethyl Starch Nanocomposites

Carboxymethyl starch/silver oxide nanocomposites(CMS-Ag_(2)O NCs)were successfully fabricated by modifying carboxymethyl starch(CMS)with Ag_(2)O obtained from an aqueous AgNO_(3)solution as silver source.Ag_(2)O nanoparticles(NPs)formed on the surface of CMS by ion exchange.Based on SEM images,the diameters of Ag_(2)O NPs were determined to be between 50 and 100 nm.From the XRD spectra of CMS-Ag_(2)O NCs,the new diffraction peaks appeared at 33.88°and 38.08°,which were attributed to the Ag_(2)O NPs.According to the XPS analysis,Ag 3d_(5/2)and Ag 3d_(3/2)peaks in CMS-Ag_(2)O NCs were fitted into two main peaks centered at 367.6 eV and 373.6 eV,which were attributed to Ag^(+).The antibacterial efficiencies of CMS-Ag_(2)O NCs against Escherichia coli,Staphylococcus aureus,Pseudoalteromonas tetraodonis,Micrococcus luteus,and Shewanella putrefaciens were determined to be 99.6%,99.7%,99.4%,99.5%,and 99.6%,respectively.The antibacterial efficiencies of CMS-Ag_(2)O NCs against the bacterial species were all greater than 99%.Therefore,these results indicated that CMS-Ag_(2)O NCs was highly effective as a bactericidal agent against multiple bacterial species.CMS-Ag_(2)O NCs can be further applied to antifouling coating.

侧链悬挂辣素衍生结构丙烯酸树脂的合成及抗菌性能研究

以实验室自主合成的辣素类化合物——N-(4-羟基-2-甲基-5-甲硫基苄基)丙烯酰胺(HMMBA)为功能单体,通过与丙烯酸酯类单体的自由基聚合反应,合成出侧链悬挂辣素衍生结构的丙烯酸树脂,采用红外光谱(IR)和核磁氢谱(1 H NMR)对其结构进行了表征。考察了引发剂用量、聚合温度、聚合时间对树脂合成的影响,并确定了树脂的最佳合成条件为,引发剂用量为单体质量的1.5%,聚合温度为100℃,聚合时间为8h。以自然界常见细菌大肠杆菌作为受试菌对所合成的树脂进行了抗菌性能测试,实验结果表明,随着HMMBA含量的增加,树脂的抗菌率也相应增大。

基于杨木木屑改性的隧道工程透水砂浆性能研究

为研制出一种既能适用于初期支护基面找平又具有一定透水能力的砂浆,将杨木木屑加入砂浆试块中对其进行改性。通过对杨木木屑的降解特性进行分析,并将不同掺量的杨木木屑加入砂浆试块中,改变其养护方式,对其体积密度、孔隙率、吸水率、抗压强度等基本性能指标及微观结构进行测试和分析。由试验结果可知:(1)加入杨木木屑后普通砂浆试块的孔隙率和吸水率均提升了2~3倍,但同时也会使砂浆试块的体积密度和抗压强度降低;(2)内掺碱并加碱溶液养护方式的孔隙率和吸水率最高,体积密度和抗压强度最低。对砂浆试块吸水率和抗压强度进行线性拟合后发现其吸水率和抗压强度呈负相关关系。研究结果表明,通过杨木木屑提升砂浆透水性能是可行的,但是杨木木屑掺量和养护方式对砂浆其他性能的影响还有待进一步研究。

十二烷基苯磺酸掺杂聚吡咯在阳极-阴极交替极化下的防污性能

采用化学氧化聚合法合成了一系列十二烷基苯磺酸掺杂的聚吡咯(PPy-DBSA),并研究了其电化学防污性能.循环伏安(CV)曲线表明,PPy-DBSA在天然海水中具有良好的电化学活性和稳定性.采用循环伏安扫描方法实现阳极极化和阴极极化交替进行,并对极化后的PPy-DBSA电极进行了抑菌性能研究,发现PPy-DBSA在循环伏安阳极-阴极交替(-1. 0~2. 0 V vs. SCE)极化下,可成功抑制微生物(大肠杆菌)的附着,其中在-0. 6~0. 8 V范围内循环伏安阳极-阴极交替极化20 min时防污效果最佳,抑菌率可达99. 8%,明显优于恒电位阳极极化和恒电位阴极极化的结果.

含辣素衍生结构单体及其聚合物的合成、抑菌与抑藻性能

以取代芳烃和N-羟甲基丙烯酰胺为原料,采用傅克烷基化反应合成了四种含辣素衍生结构单体:4-羟基-2-甲基-5-甲硫基苄基丙烯酰胺(A)、2-羟基-4-丙烯酰胺甲基-5-甲硫基-6-甲基苄基丙烯酰胺(B)、3-丙烯酰胺甲基-2-羟基苯甲酰胺(C)和1-丙烯酰胺甲基-2-萘酚(D),并通过红外光谱(IR)和核磁氢谱(1 H NMR)对其结构进行了表征。抑菌实验结果表明化合物D对两种受试菌(金黄色葡萄球菌和大肠杆菌)的抑制活性最高,最小抑菌浓度均可达到0.187 5mg/mL,且D对两种受试藻(三角褐指藻和新月菱形藻)的抑制活性也最高。以四种化合物为功能单体合成出树脂,树脂对受试藻均具有较高的抑制活性,含化合物D的树脂的抑制活性最高,72h后抑制率均可达到50%以上。

新型无锡自抛光海洋防污涂料的研究进展

无锡自抛光防污涂料是继有机锡自抛光防污涂料之后应用最多的海洋防污涂料,是目前新型防污涂料研发的热点.鉴于此,对自抛光防污涂料的防污机理及其防污特点进行了概述,列举了无锡自抛光防污涂料应用现状,详细介绍了几种新型无锡自抛光防污涂料及其研究进展,并提出了无锡自抛光防污涂料的发展前景及可能的发展方向.

水溶性丙烯酰胺共聚物的缓蚀性能

采用失重法、电化学方法以及表面分析手段研究了水溶性良好的丙烯酰胺(AM)和2-丙烯酰胺-2-甲基丙磺酸(AMPS)的共聚物(PAA)对Q235钢在1mol/L盐酸溶液中的缓蚀性能。结果表明:PAA对碳钢的腐蚀具有良好的抑制作用,缓蚀率随着PAA加入量的增加而增大,当PAA加入量为500mg/L时,缓蚀率能达到91%。PAA是一种混合抑制型缓蚀剂,同时具有非常优良的后效性。缓蚀剂分子可以吸附在金属表面,形成一层疏水性的保护膜,从而起到减缓腐蚀的作用,吸附行为符合Langmuir吸附等温式。

Anticorrosion Coatings from Poly(Aniline-co-2-Ethylaniline) Micro/Nanostructures

PANI copolymer micro/nanostructures with different surface wettability were obtained from the chemical oxidation copolymerization of aniline(Ani)with 2-ethyl aniline(EA)at diverse[EA]/[Ani+EA]molar ratios,by employing ammonium persulfate as an oxidant.The results revealed that the poly(aniline-co-2-ethyl aniline)(PANI-EA)copolymer micro/nanostructures exhibited satisfactory anticorrosion performance for carbon steel,and the corrosion protection efficiency increased with the increase of water repellent property.Poly(2-ethyl aniline)(PEA)showed the largest contact angle(CA=145°)and show the best corrosion protection for the carbon steel(h=87.29%).It is found that the superior anticorrosion property of PEA is attributed to its high hydrophobicity,low conductivity and low porosity.

Extraction of Protease Produced by Sea Mud Bacteria and Evaluation of Antifouling Performance

Enzyme-based antifouling coatings are potential alternative to traditional tributyltin-based coatings in the marine biofouling control depended on its environmental friendliness.Proteases are usually the key antifouling active components in enzyme based antifouling coatings.In this work,based on biological antagonism effect,a marine proteolytic bacterial strain of Bacillus velezensis was isolated from the sea mud,and denoted as SM-1.The scanning electron microscope(SEM)revealed that the bacteria are rod-shaped with length 1-1.3μm.The protease-producing conditions of SM-1 were investigated,and it was found that the culture solution displays higher proteolytic activity under the culture conditions of 35℃,10‰-20‰salinity,pH 6-9 and more than 7 d culture time.Moreover,the 25 kDa protein was confirmed to be the main active component in the crude protease,which was revealed via the experiment of SDS-PAGE.The antifouling assay indicated that the protease SM-1 has remarkable effect on the decomposition of barnacle cement and diatom secretion,and also can effectively inhibit the attachment of barnacle cyprids,diatom and mussel byssus.Therefore,this protease potentially can be used as environmental-friendly antifoulant of enzyme-based marine antifouling coatings,and this work also provides a new approach to obtain antifouling protease via isolating proteolytic bacteria from the sea mud surrounding representative fouling organisms.

Adsorption Mechanism of Water Molecule on Goethite(010) Surface

Goethite widely exists among ocean sediments; it plays an important role in fixing heavy metals and adsorbing organic contaminants. So the understanding of the adsorbing process of water molecule on its surface will be very helpful to further reveal such environmental friendly processes. The configuration, electronic properties and interaction energy of water molecules adsorbed on pnma goethite(010) surface were investigated in detail by using density functional theory on 6-31G(d,p) basis set and projector-augment wave(PAW) method. The mechanism of the interaction between goethite surface and H_2 O was proposed. Despite the differences in total energy, there are four possible types of water molecule adsorption configurations on goethite(010) surface(Aa, Ab, Ba, Bb), forming coordination bond with surface Fe atom. Results of theoretical modeling indicate that the dissociation process of adsorbed water is an endothermic reaction with high activation energy. The dissociation of adsorbed water molecule is a proton transportation process between water's O atoms and surface. PDOS results indicate that the bonding between H_2 O and(010) surface is due to the overlapping of water's 2p orbitals and Fe's 3d orbitals. These results clarify the mechanism on how adsorbed water is dissociated on the surface of goethite and potentially provide useful information of the surface chemistry of goethite.

DFT and 3D-QSAR Studies of Anti-Cancer Agents m-(4-Morpholinoquinazolin-2-yl) Benzamide Derivatives for Novel Compounds Design

As a group of diversified frameworks, quinazolin derivatives displayed a broad field of biological functions, especially as anticancer. To investigate the quantitative structure-activity relationship, 3D-QSAR models were generated with 24 quinazolin scaffold molecules. The experimental and predicted pIC50 values for both training and test set compounds showed good correlation, which proved the robustness and reliability of the generated QSAR models. The most effective CoMFA and CoMSIA were obtained with correlation coefficient n_(cvr)~2 of 1.00(both) and leave-one-out coefficient q^2 of 0.61 and 0.59, respectively. The predictive abilities of CoMFA and CoMSIA were quite good with the predictive correlation coefficients(r_(pred)~2) of 0.97 and 0.91. In addition, the statistic results of CoMFA and CoMSIA were used to design new quinazolin molecules.

Antimicrobial Degradation Performance of Novel Polyacrylamide Derivatives by Microbial Consortia for Enhanced Oil Recovery

The pursuit of high oil recovery rate has been a persistent objective for oil industry. Pseudomonas sp. LP-7 and Bacillus sp. PAH-2 were isolated from oil-contaminated surface soil samples of an oilfield. The antimicrobial degradation rates(ADRs) of polymers achieved by LP-7 and PAH-2 were evaluated at a temperature of 35 °C in the mineral salt media during the shaken flask trial. The ADRs of copolymer synthesized by using a surfactant with a concentration of 5% could reach 8.4% for PAH-2 and 15.3% for LP-7. The ADRs of copolymer could reach 10.4% for PAH-2 and 21.3% for LP-7,when the polymer concentration was 2 g/L. All results confirmed that the ADRs of copolymers increased with an increasing content of HDDE(capsaicin derivative monomer) in the polymer. The copolymers also manifested excellent antimicrobial degradation performance in the presence of Cu^(2+), Zn^(2+), and Pb^(2+) ions, respectively, which had great potential for applications in enhanced oil recovery.

厂界无组织排放监测气象条件判定及布点问题对策研究

通过对现有技术要求的分析,指出大气污染物无组织排放监测主要技术依据中气象条件判定和监控布点存在监测时段选择不合理、条件设置不具代表性和不具可操作性等问题和难点。对此提出了相应对策,指出可通过滑动计算相关数值的方式将气象和监控布点设置条件扩展至监测全过程,使用气象条件和点位判定系统来解决上述问题和难点。对技术依据中未规定的多点和区域无组织排放源的有效监控区域确定提出了解决思路,探讨了监测全过程监控点位有效性的评价方式。通过实施示例对提出的对策进行了说明。

国有社会化检测机构在诚信建设中的引领作用

本文以近几年发展迅速的生态环境监测领域为例,分析行业引领者——环境监测国企在行业诚信建设过程中发挥的引领作用。作为生态环境监测行业中坚力量的环境监测国企,无论是在责任担当、行业影响还是在助力行业规范发展等方面,都应该承担起环境监测行业诚信建设引领者角色,这是由其政治属性、市场地位以及发展优势等特点所决定的。

前置渗氧对TC4钛合金低温等离子复合渗层微观结构和耐磨损性能的影响

针对钛合金硬度低、耐磨性差的缺点,提出了一种由渗氧和氧氮共渗两个过程组成的低温等离子复合渗工艺,并着重研究了前置渗氧对钛合金表面微观结构、物相组成及耐磨性能的影响。利用SEM、TEM、XRD等手段对复合渗层的微观结构和相组成进行了分析,结果表明,等离子复合渗处理的钛合金样品渗层主要由化合物层和扩散层组成,物相为金红石型TiO_(2)和氮化物TiN_(0.26)。采用显微硬度计、纳米压痕仪和往复式摩擦试验机对渗层的显微硬度和摩擦磨损性能进行了表征,结果表明,与传统等离子渗氮相比,等离子复合渗处理可增加渗层的厚度,显著提高钛合金的硬度和弹性模量,大幅改善钛合金的耐磨损性能。

接触溶蚀条件下玻璃粉对混凝土抗钙溶蚀能力的影响

混凝土钙离子的析出是造成隧道排水系统结晶的主要原因之一。为研究玻璃粉对混凝土在接触溶蚀条件下的抗钙溶蚀能力的影响,采用玻璃粉等质量替代0%、10%、15%和20%水泥的方式,制备一批混凝土试块和水泥砂浆试块,开展去离子水浸泡试验,进行钙离子浓度检测,并使用X射线衍射仪、扫描电子显微镜分析研究试块的水化产物的种类、含量、微观形貌及元素组成。结果显示:玻璃粉能减少水泥砂浆水化产物中氢氧化钙(CH)的含量及钙离子的析出,玻璃粉掺量为10%时效果最好;溶蚀28 d时,相较于纯水泥砂浆,掺有玻璃粉的水泥砂浆的微观结构得到了改善,但是玻璃粉的火山灰活性仍然还没有完全发挥。

接触溶蚀条件下混凝土游离钙离子固化效果研究

为研究将硅灰和硅酸钠作为掺合料内掺后的喷射混凝土在接触溶蚀条件下析出钙离子的规律,在不同掺量下制备了单掺和复掺混凝土试块,开展30 d去离子水浸泡试验,测试溶液中的钙离子浓度、溶液pH值的变化情况,并结合SEM等微观检测对接触溶蚀过程进行研究。结果显示:单掺硅灰试块在不换水条件下的钙离子溶出量大大低于空白组,换水条件下30 d内3%、5%、7%掺量组较空白组平均溶出钙离子总重依次减少73.29%、69.65%、69.26%;单掺硅酸钠后,不换水条件下3%掺量的试块钙离子溶出量也能得到明显的降低,换水条件下30 d内1%、3%、5%掺量组较空白组平均溶出钙离子总重依次减少9.22%、20.53%、29.96%;将单掺组中固化效果良好的3%掺量硅灰和5%掺量硅酸钠复掺入混凝土后,不换水条件下浸泡溶液初始钙离子浓度仅为20~30 mg/L,从第18天左右溶液游离钙离子清零,换水条件下复掺试块较空白组平均溶出钙离子总重减少约85%。

基于纸纤维改性的隧道工程透水砂浆性能研究

为提出一种适用于隧道初期支护基面找平并且具有一定透水性能的砂浆,将纸纤维加入砂浆试块中对其性能进行改性。通过分析纸纤维的降解原理,并将不同掺量的纸纤维加入砂浆试块中,对其体积密度、吸水率、抗压强度等基本性能指标及微观结构进行测试和分析。由试验结果可知:在碱性环境中,纸纤维具有可降解的性能特点;纸纤维可以使普通砂浆试块的吸水率提升2~3倍,同时也会造成砂浆试块的体积密度和抗压强度降低;对砂浆试块吸水率和抗压强度进行线性拟合后发现其吸水率和抗压强度呈现负相关关系。研究结果表明,通过纸纤维对砂浆进行透水性能的提升是可行的,但是纸纤维掺量对砂浆其他性能的影响还有待进一步研究。