脱硫溶液中Na2S203含量的快速准确测定

由于脱硫溶液中含有S^2-等还原性离子干扰Na2S2O3的测定，故在测定中需要寻找一种合适的方法来消除S^2-等还原性离子的干扰。对通常的3种测定Na2S2O3，含量的方法进行了试验取舍，并在此基础上摸索出了一种操作简便、快速，准确度高的测定脱硫溶液中Na2S2O3，含量的方法。     

矿渣中负二价硫离子对硅酸盐水泥物理性能的影响

结合工程实际中遇到的问题,通过理论分析和试验研究,探讨了矿渣中负二价硫离子(S2-)对硅酸盐水泥物理性能的影响。通过加入硫化钠(Na2S)的形式掺加S2-的研究表明:Na2S在设定掺量范围内(0～1.5%),对水泥的凝结时间基本不造成影响;加入Na2S后,水泥的3d抗压强度与纯水泥基本相同,7d和28d抗压强度略低,但并没有随所加Na2S的量变化而变化的趋势。碱金属硫化物是易溶于水的,其它硫化物其溶出速度慢,对水泥性能的影响应该更小。试验中采用的硫化物量要远高于实际水泥或矿渣中的量,所以在水泥中S2-含量极低的情况下,通常不会对水泥物理性能产生明显的影响,也不会由于掺加矿渣而引发耐久性不良等混凝土工程质量问题。     

脱硫副反应及副盐回收技术研究

通过例举生成Na2S2O3、Na2SO4、NaCNS的副反应,阐述了碱性水溶液脱除H2S多过程中发生的脱硫副反应,分析了温度、pH值和运转时间与生成物Na2S3O3的关系;简述了副产物对脱硫的影响;论述了回收Na2S3O3、NaCNS、(NH4)2S2O3、NH4CNS以及采用硫酸法和盐酸法精制NaCNS的基本原理和工艺流程;介绍了Na2S2O3等副盐的产品质量标准.     

控制硫酸铜加入量实现脱硫废水回用的初步研究

以Na2CO3-NaHCO3缓冲溶液为吸收液的湿法氧化脱硫技术所形成的脱硫废液,含有大量的Na2SO4、Na2S2O3、NaSCN,导致脱硫效率降低且严重超出污水排放标准,成为生产和环保的难题。提出在脱硫废液中加入适量硫酸铜,当硫酸铜的加入量为废液中NaSCN含量的50%左右时,可形成物相纯净的CuSCN沉淀,同时水体中S2O32-转化为SO42-,而且未检测出溶液中有残余的铜离子。经过该法处理过的水体中SCN-、S2O32-浓度显著降低,SO42-浓度增加接近饱和浓度值,再采用低温结晶法析出部分Na2SO4后可作为脱硫液补水回用。     

脱硫溶液中Na2S2O3含量分析的探讨

脱硫溶液中的Na2S2O3是脱硫过程中的副产物，其含量的高低既是溶液脱硫能力的一种体现，也是操作工对脱硫溶液进行加料操作时的一个重要参考数据，所以，脱硫溶液中Na2S2O3含量分析很重要。由于脱硫溶液中含有S^2-等还原性离子干扰Na2S2O3的测定，故在测定中需要寻找一种合适的方法来消除S^2-等还原性离子的干扰。     

不同底物下硫氧化菌的硫氧化特性及其对砂浆性能的影响

研究了不同底物下硫氧化菌的硫氧化特性及其对砂浆试样的力学性能和微观结构的影响.结果 表明:硫氧化菌生长浓度在不同底物环境中表现不同,其生长浓度由高到低所对应的底物分别是Na2S2O3、Na2SO3、Na2S;不同底物下硫氧化菌转化SO42-的方式均存在自然氧化和生物氧化两种形式.硫氧化菌代谢途径中发现了一种先将S2O3...     

加勒比松Na_2S预处理硫酸盐─AQ蒸煮机理及脱木素反应活化能

对加勒比松Na2S预处理硫酸盐─AQ法蒸煮过程纤维细胞各部位木素与Na2S的反应和溶出规律进行了研究．在本试验条件下，Na2S预处理段及硫酸盐─AQ蒸煮段脱木素反应活化能分别为41．1kJ／mol及94．2kJ／mol，其相对反应速率常数分别用下列方程式计算：KR1=e12.28－4952/T;KR2=e26020-11349/T.     

Na_2S药剂添加方法的研究和工艺改进

主要针对磷酸脱砷药剂Na2S添加方法进行研究和工艺改进,利用Na2S水解过程可逆的原理,通过在Na2S药剂加入前添加抑制剂石灰乳来抑制H2S气体的生成,从而达到改善工作环境,杜绝人员中毒的目的;同时能够减少Na2S药剂添加量,降低生产成本,在实际运用过程中取得了较好的环保效果和经济效益。     

活化过硫酸钠处理地下水中氯苯的研究

以Na2S2O8为氧化剂,Fe SO4溶液为活化剂,对模拟氯苯污染地下水进行处理,研究了初始p H值、Na2S2O8/Fe2+摩尔比、Na2S2O8浓度、Cl-等对氯苯降解的影响。结果显示,在p H值为7时,氯苯去除率最高,达到了93.2%;随着Na2S2O8/Fe2+摩尔比值的降低,氯苯的去除率呈现先升高后下降的趋势;当Na2S2O8浓度超过12mmol/L时,Na2S2O8浓度的增加并不能明显提高氯苯的去除率;Cl-的存在对氯苯的降解存在较大的影响。实验过程中,水样迅速呈现出稳定的酸性和氧化环境。     

高分子絮凝剂结构剖析

用红外光谱、核磁共振波谱、X射线能谱等手段剖析了国外某公司2种高分子絮凝剂的引发体系、相对分子质量等。结果显示:一种为聚丙烯酰胺,相对分子质量约为3.50×106,引发体系可能为Na2S2O8或Na2S2O8-Na2S2O4;另一种为丙烯酰胺-丙烯酸共聚物,共聚链节摩尔比约为1:1,引发剂与前者相同。     

γ-C2S和 β-C2S的碳化与水化活性研究

在常温常压下,γ-C2 S的水化活性很低,β-C2 S的水化活性相对较高;但在一定湿度和二氧化碳浓度下,γ-C2 S与β-C2 S都能快速地发生碳化反应.作者在实验室条件下制备了纯的γ-C2 S和β-C2 S,在比表面积相近的条件下,通过XRD、SEM、TG-DSC、游离氧化钙含量和烧失量的测试与分析,对γ-C2 S与β-C2 S在不同温度下的水化活性和常温常压下的碳化反应进行了研究.结果表明:γ-C2 S和β-C2 S的碳化产物主要是方解石和少量的球霰石,γ-C2 S碳化后还有少量的文石生成,并且γ-C2 S的碳化活性略高;在140℃时,γ-C2 S的水化活性较β-C2 S低很多,当温度升高到200℃时,γ-C2 S的水化活性大幅提升,β-C2 S的水化活性也有一定提升,两者的水化活性差距显著缩小.     

NiO-Ag2S复合纳米结构的合成及光催化性能研究

利用水热合成方法制备了一种由Ag2S纳米颗粒均匀填充在片层状NiO空隙内的NiO-Ag2S复合纳米结构,该复合结构中NiO与Ag2S均匀地融合在一起。通过SEM、二维EDX及XRD对该复合纳米结构的形貌、均一性、晶体特性进行了分析。以500 W氙灯为光源,考察了NiO2-Ag2S复合纳米结构光催化降解甲基橙能力。结果表明,NiO2-Ag2S复合纳米结构具有良好的光催化活性,不仅比单独的NiO2和Ag2S降解能力强,而且在光照180 min后的降解效率比NiO2和Ag2S的物理混合物(质量比为1:1)高30%。分析认为NiO-Ag2S复合纳米结构中形成的p-n结是其高效催化性能的重要因素。     

BaSO_4对C_2S结构及性能的影响

通过XRD ,EDM /EDAM及化学分析等手段测定了Ba2 + 和S6 + 2种离子对C2 S结构的影响 ,得出Ba2 + 、S6 + 在C2 S中的固溶形式和极限固溶量 ,以及固溶引起的结构变化 .并对固溶 2种离子的C2 S水化活性进行了研究 .结果表明 :固溶Ba2 + ,S6 + 离子的C2 S水化活性大大提高 .     

The intermolecular interaction studies in the complexes of isothiocyanic acid (HNCS) and its derivatives with H2S: a computational study

The computational investigations are carried out on the complexes of isothiocyanic acid (HNCS) and its derivatives with H₂S through MP2/aug-cc-PVTZ//MP2/aug-cc-PVDZ level. Five, four, three and four structures are located on the potential energy surface of the HNCS?H₂S, HSCN? H₂S, HCNS? H₂S and HSNC?H₂S heterodimers, respectively. The calculated results reveal that the most stable heterodimers among all heterodimers obtained for the HNCS?H₂S, HSCN?H₂S, HCNS?H₂S and HSNC?H₂S systems belong to HSCN?H₂S system. Therefore, HSCN?H₂S system has a key role in the atmosphere.     

BaSO4对C2S结构及性能的影响

通过XRD，EDM/EDAM及化学分析等手段测定了Ba^2 和S^6 2种离子对C2S结构的影响，得出Ba^2 、S^6 在C2S中的固溶形式和极限固溶量，以及固溶引起的结构变化，并对固溶2种离子的C2S水化活性进行了研究，结果表明：固溶Ba^2 ，S^6 离子的C2S水化活性大大提高。     

龙眼核中的神经酰胺和脑苷脂的分离和鉴定

研究龙眼(Dimocarpus longan Lour.)果核的化学成分,采用硅胶柱色谱对龙眼果核石油醚提取物和体积分数95%乙醇提取物进行分离,并利用理化性质和光谱数据鉴定化合物的结构。从龙眼果核的提取物中分离得到一组混合神经酰胺(化合物1、2)和一组混合脑苷脂(化合物3～6),结构鉴定为Rel-(3S,4S,5S)-3-[(2'R)-2'-羟基二十二酰胺]-4-羟基-5-[(4″Z)-十四烷-4″-烯]-2,3,4,5-四氢呋喃(1)、Rel-(3S,4S,5S)-3-[(2'R)-2'-羟基二十四酰胺]-4-羟基-5-[(4″Z)-十四烷-4″-烯]-2,3,4,5-四氢呋喃(2)、1-O-(β-D-吡喃葡萄糖基)-(2S,3S,4R,8E)-2-(2'-羟基二十四酰胺)-8-十八烯-1,3,4-三醇(3)、1-O-(β-D-吡喃葡萄糖基)-(2S,3S,4R,8Z)-2-(2'-羟基二十四酰胺)-8-十八烯-1,3,4-三醇(4)、1-O-(β-D-吡喃葡萄糖基)-(2S,3S,4R,8E)-2-(2'-羟基二十二酰胺)-8-十八烯-1,3,4-三醇(5)、1-O-(β-D-吡喃葡萄糖基)-(2S,3S,4R,8Z)-2-(2'-羟基二十二酰胺)-8-十八烯-1,3,4-三醇(6)。     

Field and electroantennogram responses to sex pheromone optical isomers by monophagous jack pine sawflies (Hymenoptera: Diprionidae)

Several species of monophagous jack pine sawflies (Hymenoptera: Diprionidae) were tested in the field and by electroantennograms (EAG) for activity toward the optical isomers of a pine sawfly sex pheromone, the acetate and propionate esters of 3,7-dimethylpentadecan-2-ol.Neodiprion rugifrons andNeodiprion dubiosus were attracted to a mixture of the propionate esters of the 2S,3R,7R and 2S,3R,7S isomers, whereasNeodiprion swainei was attracted to the 2S,3S,7S propionate isomer. Samples containing the 2S,3R,7S propionate isomer elicited the strongest EAG responses in these three species andNeodiprion nigroscutum. The 2S,3S,7S propionate isomer was equally active (EAG) in the case ofN. swainei.     

不同硫化氢流率与浓度对硫化氢固体氧化物燃料电池性能影响

A solid state H2S/air electrochemical cell having the configuration of H2S, (MoS2 NiS Ag)/YSZ/Pt,air has been examined with different H2S flow rates and concentrations at atmospheric pressure and 750-850 ℃.Performance of the fuel cell was dependent on anode compartment H2S flow rate and concentration. The cell open-circuit voltage increased with increasing H2S flow rate. It was found that increasing both H2S flow rate and H2S concentration improved current-voltage and power density performance. This is resulted from improved gas diffusion in anode and increased concentration of anodic electroactive species. Operation at elevated H2S concentration improved the cell performance at a given gas flow rate. However, as low as 5% H2S in gas mixture can also be utilized as fuel feed to cells. Highest current and power densities, 1750mA.cm-2 and 200mW.cm-2,are obtained with pure H2S flow rate of 50ml.min-1 and air flow rate of 100ml.min-1 at 850℃.     

The Synthesis and Absolute Configuration of Enantiomeric Pure (R)- and (S)-3-(piperidin-3-yl)-1H-Indole Derivatives

This article describes the synthesis of new chiral 3-(piperidin-3-yl)-1H-indole derivatives (R)-10a-c and (S)-11a-c from the corresponding diastereomers: (3R, 2R) and (3S, 2R)-2-[3-(1H-indol-3-yl)-1-piperidyl]-2-phenyl-acetamides (3R, 2R)-4a, (3R, 2R)-6b, (3R, 2R)-8c and (3S, 2R)-5a, (3S, 2R)-7b, (3S, 2R)-9c. Diastereomers were obtained by N-alkylation of derivatives of racemic 3-(piperidin-3-yl)-1H-indoles 1a-c using (S)-2-(4-toluenesulfonyloxy)-phenylacetic amide (S)–II. The same method was applied to obtain (3R, 2S)-methyl-2-[3-(1H-indole-3-yl)-1-piperidyl]-2-phenylacetate (3R, 2S)-2a and (3S, 2S)-methyl-2-[3-(1H-indole-3-yl)-1-piperidyl]-2-phenylacetate (3S, 2S)-3a diastereomers by treating amine 1a with (R)-2-(4-toluenesulfonyloxy)-phenylacetic acid methylester (R)-I. Systematic studies via single crystal X-ray crystallography were used to determine the molecular structure of the racemates 1a-c and the absolute configuration of the enantiomers. The solid racemates 1b and 1c were “true racemates” crystallizing in a centrosymmetric space group, while 1a formed a racemic conglomerate of homoenantiomeric crystals. The absolute configuration was determined for the enantiomeric pairs (R)-10a/(S)-11a, (R)-10b/(S)-11b, and (R)-12c/(S)-13c, as well as for (3S,2S)-3a. Spectra of ¹H, ¹³CNMR, HPLC, and HRMS for diastereomers and enantiomers were consistent with the determined structures.     

Human Milk Antibodies against S1 and S2 Subunits from SARS-CoV-2, HCoV-OC43, and HCoV-229E in Mothers with a Confirmed COVID-19 PCR,Viral SYMPTOMS,and Unexposed Mothers

Background: Preexisting immunity to SARS-CoV-2 could be related to cross-reactive antibodies to common human-coronaviruses (HCoVs). This study aimed to evaluate whether human milk antibodies against to S1 and S2 subunits SARS-CoV-2 are cross-reactive to S1 and S2 subunits HCoV-OC43 and HCoV-229E in mothers with a confirmed COVID-19 PCR test, in mothers with previous viral symptoms during COVID-19 pandemic, and in unexposed mothers; Methods: The levels of secretory IgA (SIgA)/IgA, secretory IgM (SIgM)/IgM, and IgG specific to S1 and S2 SARS-CoV-2, and reactive to S1 + S2 HCoV-OC43, and HCoV-229E were measured in milk from 7 mothers with a confirmed COVID-19 PCR test, 20 mothers with viral symptoms, and unexposed mothers (6 Ctl1-2018 and 16 Ctl2-2018) using ELISA; Results: The S2 SARS-CoV-2 IgG levels were higher in the COVID-19 PCR (p = 0.014) and viral symptom (p = 0.040) groups than in the Ctl1-2018 group. We detected a higher number of positive correlations between the antigens and secretory antibodies in the COVID-19 PCR group than in the viral symptom and Ctl-2018 groups. S1 + S2 HCoV-OC43-reactive IgG was higher in the COVID-19 group than in the control group (p = 0.002) but did not differ for the other antibodies; Conclusions: Mothers with a confirmed COVID-19 PCR and mothers with previous viral symptoms had preexisting human milk antibodies against S2 subunit SARS-CoV-2. Human milk IgG were more specific to S2 subunit SARS-CoV-2 than other antibodies, whereas SIgA and SIgM were polyreactive and cross-reactive to S1 or S2 subunit SARS-CoV-2.