用硫铁尾矿生产水泥的研究

用X射线荧光分析(XRF)。扫描电镜(SEM)、能谱分析(EDAX)、差热分析(DTA)、X射线分析(XRD)和红外光谱(IR)等测试工具,对尾矿、煅烧尾矿、尾矿水泥及其水化物等进行了研究。同时还研究了水泥强度、论证了尾矿水泥的稳定性。     

海南特有野生花卉资源及其利用

通过对海南特有野生植物资源的实地考察和文献查阅,初步统计了海南特有野生花卉约320种,隶属于69科182属,主要为茜草科(32种)、樟科(27种)、竹亚科(16种)、桃金娘科(13种)、兰科(13种)、莎草科(11种)、蝶形花科(11种)和萝藦科(9种)等所含种类.对海南特有野生植物资源的种类、重要类群与观赏特性等进行了综述,最后就其资源保护与利用提出了建议.     

铝酸盐水泥对硫氧镁水泥强度和耐水性的影响EI北大核心CSCD

为改善硫氧镁水泥(MOS)耐水性差的问题,引入了铝凝胶相(AH_(3)),研究了铝酸盐水泥(CAC)掺量对MOS凝结时间、抗压强度以及水化产物相组成的影响.结果表明:CAC可明显缩短MOS的凝结时间,并提升其抗压强度和耐水性;掺加CAC后,MOS水化产物中出现了新的水化相CAH10、镁钙矾石相(3CaO·Al_(2)O_(3)·3Mg(OH)_(2)·(30~32)H_(2)O)、AH_(3)和C_(3)AH_(6);掺加5%~15%CAC时,MOS中水化产物5·1·7相的含量增加,MgO、Mg(OH)_(2)含量减少;掺加10%CAC时,空气养护28 d后MOS的抗压强度提升了25.11%,5·1·7相的含量提升了36.85%;浸水养护28 d后,5·1·7相的含量提升了51.86%,耐水性最好,强度保留系数达到0.99;掺加CAC使体系中生成了3CaO·Al_(2)O·33Mg(OH)·(230~32)H_(2)O和AH_(3),促进了MgO的后期水化并消耗了体系中的Mg(OH)2,但是CAC掺量超过20%时会出现水榴石反应,大量CAH10转化为C_(3)AH_(6),导致强度严重倒缩.     

丁基磺酸纤维素醚减水剂的合成及应用

纤维素棉桨粕经酸水解得到具有确定聚合度的微晶纤维素(MCC)后,以其为原料,在氢氧化钠活化下,与1,4-丁烷磺内酯(BS)反应.得到了具有良好水溶性的丁基磺酸纤维素醚(SBC)减水剂.采用红外光谱(FTIR)、核磁共振谱、扫描电镜(SEM)、X-衍射(XPD)等分析手段对产品结构进行了表征,考察了MCC聚合度、原料配合...     

加强研发(技术)中心建设提升企业核心竞争力

本文针对水泥公司研发(技术)中心建设的情况,概述了企业研发(技术)中心建设的必要性、研发(技术)中心建设的性质、作用与任务;论述了如何建立和管理企业研发(技术)中心;提出了下一步研发(技术)中心建设工作的思路.分析了水泥公司当前研发(技术)中心存在的主要问题,并就如何进一步提高企业研发(技术)中心的运行效率,真正发挥企业研发(技术)中心在企业技术创新活动中的基地作用提出了相应的对策与建议.     

加强研发(技术)中心建设提升企业核心竞争力

本文针对水泥公司研发(技术)中心建设的情况,概述了企业研发(技术)中心建设的必要性、研发(技术)中心建设的性质、作用与任务;论述了如何建立和管理企业研发(技术)中心;提出了下一步研发(技术)中心建设工作的思路。分析了水泥公司当前研发(技术)中心存在的主要问题,并就如何进一步提高企业研发(技术)中心的运行效率,真正发挥企业研发(技术)中心在企业技术创新活动中的基地作用提出了相应的对策与建议。     

微波消解-电感耦合等离子体质谱(ICP-MS)法测定板栗中的矿物元素及稀土元素

为了准确测定板栗中矿物元素和稀土元素的含量水平,采用冷冻干燥方式预处理样品,选用硝酸和过氧化氢体系微波消解样品,结合电感耦合等离子体质谱技术,建立了板栗中钠(Na)、钾(K)、镁(Mg)、锰(Mn)、铁(Fe)、钒(V)、钴(Co)等19种矿物元素及镧(La)、铈(Ce)、镨(Pr)、钕(Nd)、钐(Sm)、铕(Eu)、钆(Gd)、铽(Tb)、镝(Dy)、钬(Ho)、铒(Er)、铥(Tm)、镱(Yb)、镥(Lu)、钇(Y)等15种稀土元素的同时分析测定方法。方法检出限为0.002 7～0.78μg/L,相对标准偏差为1.4%～6.3%。通过国家标准物质GBW10019苹果的准确度实验验证,测定结果均在标准证书值范围内。实验结果表明,方法适用于板栗中矿物元素及稀土元素的同时测定。     

园林绿化工程成本控制分析

园林绿化工程成本控制是合理投资、低碳循环、增强建设效率的必然要求。以某城市园林绿化工程为例,以挣值法为核心,研究了园林绿化工程成本的计划值(PV)、实际值(AC)、挣值(EV),以及进度偏差(SV)、进度绩效指数(SPI)、成本偏差(CV)、费用绩效指数(CPI)等参数,从材料费、人工费、机械费等角度,提出了施工成本控制策略。     

(WLD)T式“微作文”的实践与反思

<正>近几年来,笔者所接触的学生写作素养总体偏低。对此,笔者提出了(WLD)T式"微作文"训练。所谓(WLD)T式,就是指所见(watch)、所闻(listen)、所做(do)、所感(thought)。具体来说,在写作时,要求学生写了所见之后就写所感,写了所闻之后就写所感,写了所做之后就写所感。这样,一段话就由所见(watch)所感(thought)(WT)、所闻(listen)所感(thought)(LT)、所做(do)所感(thought)(DT)三部分组成,合起来就是WTLTDT,简称(WLD)T。这里的所感     

中国风景园林学学科简史

回顾了《中国风景园林学学科史》写作的缘起,总结了学科史的特征、结构和内容,划分了世界和中国风景园林学学科的发展阶段。世界风景园林学学科的发展可划分为5个阶段:造园阶段(1828年以前)、孕育和创立阶段(1828—1900年)、现代主义运动阶段(1900年—1960s)、生态运动阶段(1960s—1980s)、多元发展阶段(1980s—)。与此相对,中国风景园林学学科的发展也可分为5个阶段:中国风景园林知行传统(1912年以前)、孕育和萌芽(1912—1949年)、创立和艰辛曲折发展(1949—1978年)、蓬勃发展(1978—2011年)、全面规范发展(2011年以后)。重点阐述了中国风景园林学学科不同发展阶段的外部条件和内生动力,总结归纳了各阶段的主要特征和内容。     

Spatio-temporal change of water chemical elements in Lake Dianchi, China

Lake Dianchi is a large lake, which is listed in the 'Three Important Lakes Restoration Act in China'. The water quality has deteriorated from class II in the 1970s to class V today, with an attendant increase in the frequency and intensity of the formation of blue algae blooms. From 2003 to 2006, a water quality monitoring programme was implemented for eight regional zones in Lake Dianchi. It monitored the following substances: carbon (C), nitrogen (N), phosphorus (P), sulphur (S), calcium (Ca), magnesium (Mg), iron (Fe), potassium (K), sodium (Na), zinc (Zn), copper (Cu), manganese (Mn) and chlorine (Cl), together with water temperature, pH, total hardness and total salt content. Data were analysed using regression models to determine the impacts of these substances and conditions for the formation of blue algae bloom, and to assess their relationship with chlorophyll a . The results showed a significant relationship between chlorophyll a and C, P, N, Cl, Fe, Mg, water temperature, pH, total hardness and total salt. There was no significant relationship between chlorophyll a and total manganese (TMn), Mn, sulphate (SO₄²⁻), soluble total manganese STMn, Ca, Zn, K, Na and Cu. The study showed that the concentration of chlorophyll a in different regions of the lake was different, indicating that the mix of chemicals in a region has a different impact on pollution levels throughout Lake Dianchi.     

O3/BAC工艺应用于城市污水深度处理

为使再生水适合不同用途,对经过混凝沉淀和砂滤处理的再生水进行了臭氧-生物活性炭的深度处理.在臭氧消耗量和反应时间分别为5 mg/L和10 min,BAC空床停留时间(EBCT)为10 min的条件下,臭氧-生物活性炭工艺对CODMn、DOC、UV254和色度平均去除率为32.4%、29.2%、48.6%和80.1%,出水CODMn、DOC、UV254和色度的平均值分别为3.3 mg/L、4.0mg/L、0.05 cm-1和2.0倍;臭氧生物活性炭工艺出水SDI《4,从而满足了反渗透系统的进水要求.     

Removal of copper,nickel, cobalt and manganese from aqueous solution by kaolinite

The removal of some heavy metals such as Mn(II), Co(II), Ni(II), and Cu(II) from aqueous solution is studied using a raw kaolinite. The sorption of these metals on kaolinite conformed to linear form of Langmuir adsorption equation. Langmuir C(m) constants for each metal were found as 0.446 mg/g (Mn), 0.919 mg/g (Co), 1.669 mg/g (Ni), 10787 mg/g (Cu) at 25 degrees C, respectively. Also, kinetic and thermodynamic parameters such as enthalpy (deltaH), free energy (deltaG) and entropy (deltaS) were calculated and these values show that adsorption of heavy metal on kaolinite was an endothermic process and the process of adsorption was favoured at high temperatures.     

Phenol oxidation kinetics in water solution using iron(3)-oxide-based nano-catalysts

The influence of inorganic ions (HCO(3), PO(4)/HPO(4)/H(2)PO(4), Cl, SO(4), Ca, Na and Mg) on the advanced chemical oxidation process of organic compounds dissolved in water is reported here. The catalytic behavior of iron(3)-oxide-based nano-particles was investigated together with inorganic ions and hydrogen peroxide concentrations, and pH level. Phenol was chosen as a typical organic contaminant for this study as a simulating pollutant. The limiting concentrations of radical scavengers making the oxidation process inefficient were identified. The strong effect of concentration of radical scavengers HCO(3), PO(4)/HPO(4)/H(2)PO(4), the nano-catalyst and hydrogen peroxide concentrations, and pH on the phenol oxidation rate and lag time period before reaction starts was determined. It was shown that Cl, SO(4), Ca, Na and Mg ions had no significant effect on the kinetics of phenol oxidation.     

DNA damage and lipid peroxidation vs. protection responses in the gill of Dicentrarchus labrax L. from a contaminated coastal lagoon (Ria de Aveiro, Portugal)

The present research work aimed to investigate the damage vs. protection responses in gill of European sea bass (Dicentrarchus labrax) captured at a polluted coastal lagoon, Ria de Aveiro (Portugal), as a tool to evaluate the human impacts on environmental health. Damage was assessed as DNA strand breakage and lipid peroxidation (LPO) whereas protection was evaluated by measuring catalase (CAT), glutathione peroxidase (GPX), glutathione reductase (GR), glutathione S-transferase (GST), total glutathione (GSHt), thiols and metallothioneins (MT). Fish were caught at five locations: Gafanha (GAF), Rio Novo do Príncipe (RIO), Laranjo (LAR) and Vagos (VAG) presenting each a different recognized source of contamination, and Torreira (TOR), assumed as reference site. Among the surveyed sites, gill damage was observed only at GAF, as measured by DNA integrity loss and LPO increase. An overall induction in enzymatic antioxidant protection was perceptible in fish from GAF and VAG, expressed as higher GPX, GR and GST activities. In addition, LAR fish showed elevated GST and CAT activities. Thiols content was higher in all study sites irrespective to the pollution spectrum, whereas GSHt increase was only observed at GAF and VAG. The highest MT level was detected in fish from VAG and the lowest level from RIO suggesting a low contamination degree on this particular site. Globally, the results expressed site-specific response patterns, signalling two critical areas - GAF and VAG. Additionally, a joint analysis (damage vs. protection) allowed the following ordering of surveyed sites according to the contamination degree and risk to fish health; GAF>VAG>LAR>RIO>TOR. D. labrax gill responses demonstrated their efficacy as early warning signals of the contaminants presence. Moreover, the adopted approach, considering simultaneously protection responses and damaging effects, also revealed its usefulness on the pollution extent assessment.     

The mineralisation of methamidophos using ionised AN air water treatment pilot system and ultraviolet irradiation

The degradation of methamidophos in pure bi-distilled water (with initial concentration 5 mg L(-1), pH = 7 at the beginning) was studied. For the first time, 2 ionised air water treatment pilot systems (IAPS-1, -2, no additives) were set up (Figs. 1 and 2). The degradation of methamidophos was carried out with only the IAPS-2 and with two different ultraviolet (UV) lamps: high- and low-pressure mercury lamps (HP and LP, with or without H202). The kinetics of these oxidative processes was investigated. The highest rate constant was reached by the LP, 0.2% H2O2 (k = 0.7524min(-1), t 1/2 = 0.9min), followed closely by both treatments with the HP, 0.2% H202 (k = 0.6328min(-1), t 1/2 = 1.1 min) and LP, 0% H202 (k = 0.4749min(-1), t 1/2 = 1.5 min). The lowest rate constants were achieved from the HP, 0% H202 process (k = 0.0303min(-1), t 1/2 = 22.9min) and from the IAPS-2 (k = 0.0117 min(-1), t 1/2 = 59.2min). The mineralisation of methamidophos was confirmed by the determination of the anions produced including NO3-, PO4(3-) and SO4(2-) during and at the end of each experiment. The toxicity of water samples before, during and after the experiments was tested with Daphnia test.     

Sources and elemental composition of ambient PM(2.5) in three European cities

Source apportionment of urban fine particle mass (PM(2.5)) was performed from data collected during 1998-1999 in Amsterdam (The Netherlands), Erfurt (Germany) and Helsinki (Finland), using principal component analysis (PCA) and multiple linear regression. Six source categories of PM(2.5) were identified in Amsterdam. They were traffic-related particles (30% of the average PM(2.5)), secondary particles (34%), crustal material (7%), oil combustion (11%), industrial and incineration processes (9%), and sea salt (2%). The unidentified PM(2.5) fraction was 7% on the average. In Erfurt, four source categories were extracted with some difficulties in interpretation of source profiles. They were combustion emissions related to traffic (32%), secondary PM (32%), crustal material (21%) and industrial processes (8%). In Erfurt, 3% of PM(2.5) remained unidentified. Air pollution data and source apportionment results from the two Central European cities were compared to previously published results from Helsinki, where about 80% of average PM(2.5) was attributed to transboundary air pollution and particles from traffic and other regional combustion sources. Our results indicate that secondary particles and local combustion processes (mainly traffic) were the most important source categories in all cities; their impact on the average PM(2.5) was almost equal in Amsterdam and Erfurt whereas, in Helsinki, secondary particles made up for as much as half of the total average PM(2.5).     

Synthesis of dawsonite: a method to treat the etching waste streams of the aluminium anodising industry

Synthesis of dawsonite was studied as a way to deal with the etching waste streams of the aluminium anodising industry in order to reduce the emissions to the environment and also to recover useful and marketable mineral resource materials. The process of synthesis was carried out using two different waste streams arising from the etching section of an anodising process when a cascade rinsing system is employed, the spent etching bath solution (132 g/l of Al and 151 g/l of Na), and the first stage effluent from the cascade rinsing system (67 g/l of Al and 71 g/l of Na). The synthesis of dawsonite was studied as a function of NaHCO3/Al molar ratio (1-10), crystallization temperature (30-150 degrees C), and reaction time (2-48 h) using supersaturated NaHCO3 solutions. A NaHCO3/Al molar ratio of 3 was optimal to obtain dawsonite as a single phase, and a reaction time of 24 h and high crystallization temperature (150 degrees C) to improve its crystallinity. The mineral characterisation was performed using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and differential thermal analysis (DTA), all of which indicated characteristics typical of the desired compound. Almost 100% of the aluminium initially present in the etching waste streams was recovered in the form of dawsonite when the appropriate conditions for its synthesis were used.     

Identifying model pollutants to investigate biodegradation of hazardous XOCs in WWTPs

Xenobiotic organic compounds (XOCs) in wastewater treatment plant (WWTP) effluents might cause toxic effects in ecosystems. Several investigations have emphasized biodegradation as an important removal mechanism to reduce pollution with XOCs from WWTP effluents. The aim of the study was to design a screening tool to identify and select hazardous model pollutants for the further investigation of biodegradation in WWTPs. The screening tool consists of three criteria: The XOC is present in WWTP effluents, the XOC constitutes an intolerable risk in drinking water or the environment, and the XOC is expected to be biodegradable in WWTPs. The screening tool was tested on bisphenol A (BPA), carbamazepine (CBZ), di(2ethylhexyl)-phthalate (DEHP), 17beta-estradiol (E2), estrone (E1), 17alpha-ethinyloetradiol (EE2), ibuprofen, naproxen, nonylphenol (NP), and octylphenol (OP). BPA, DEHP, E2, E1, EE2, and NP passed all criteria in the screening tool and were selected as model pollutants. OP did not pass the filter and was rejected as model pollutant. CBZ, ibuprofen, and naproxen were not finally evaluated due to insufficient data.     

基于絮体结构指标的丝状菌膨胀污泥SVI预测

为了建立更加准确的膨胀活性污泥沉降性表征方法,筛选出5个反映污泥微观絮体结构的特征指标:絮体大小(SZ)、伸长性(ST)、密实性(CP)、规则性(RG)和丝状菌(FL),分析众多特征参数降维的可能性,建立丝状菌膨胀污泥絮体结构特征指标体系,以偏最小二乘回归法(PLS)探索膨胀污泥絮体结构特征指标与污泥容积指数(SVI)的关系,建立丝状菌膨胀污泥的SVI预测函数。结果表明,污泥絮体特征参数之间具有较好的相关性,可采用主成分分析法(PCA)进行降维。污泥絮体结构特征指标与丝状菌膨胀活性污泥的SVI之间有较强的线性相关性(R2=0.779),据此建立了SVI预测模型,丝状菌膨胀污泥的SVI实测值与预测值呈现较强的线性相关性(R2=0.801),模型能较好地预测丝状菌污泥膨胀。