污水聚丙烯酰胺溶液高温稳定性研究

用污水（油田产出水）配制聚合物溶液,是扩大河南油田聚合物驱油技术应用规模的基本要求,研究污水配制聚丙烯酰胺（HPAM）溶液的稳定性非常重要。采用含有Na     

调剖用延缓交联剂MLH—1的研制

对于大庆油田处理注水井近井地带所用的HPAM/Cr3+冻胶调剖剂,要求调剖剂溶液在井温条件下(45℃)成胶时间在10-30 h范围内可调,形成的冻胶强度高(以表观粘度表示,为5×104-1.5×105 mPa·s),因此需要使用性能符合要求的延缓型交联剂.实验考察了3种氧化还原型铬交联剂交联1%HPAM水溶液的能力.重铬酸钠/木质素磺酸钠氧化还原体系使溶液成胶的配比范围很窄且成胶速率过高,成胶时间太短.重铬酸钠/硫脲氧化还原体系只有在重铬酸钠用量很高时(≥1.5%)才能使溶液延缓成胶,这在经济上是难以接受的.适当配比的重铬酸钠/木质素磺酸钠/硫脲氧化还原体系(延缓型铬交联剂MLH-1),可使HPAM溶液的成胶时间在5-30 h范围内调节,形成的冻胶表现粘度一般大于1.5×105 mPa·     

一种新的添加剂(Re-1)在硫脲浸金中的应用

报道了一种用于硫脲法浸金过程的新的Re－1型溶金添加剂,实验证实该添加剂可以改善硫脲浸金液状态,降低浸液硫脲浓度,提高金出率。可使含砷硫化原生矿的一次金浸出率达到89％以上。同时,测定了工艺的最佳条件并讨论了Re－1添加剂对浸金机理的影响。     

延缓型有机/无机复合交联剂LD-1的研制

LD 1是以铬盐 硫脲及铬盐 硫代硫酸钠两种氧化还原体系复合而成的一种延缓型交联剂。实验结果表明 ,单独使用铬盐 硫脲体系或铬盐 硫代硫酸钠体系作为聚丙烯酰胺溶液的交联剂配制堵水调剖剂时 ,均有交联时间难以控制或 48h不交联的问题。由这两种体系复合而成的LD 1用作交联剂时 ,堵水调剖剂成胶时间可调 (10— 30h) ,凝胶强度较高 [(5— 15 )× 10 4 mPa·s],具有明显的延缓交联效果 ,能满足现场施工要求。对LD 1的作用机理进行了探讨 ,认为诱导作用是LD 1起延缓交联作用的关键     

A quantitative measure of nitrifying bacterial growth

Nitrifying bacteria convert ammonia (NH3) to nitrate (NO3-) in a nitrification reaction. Methods to quantitatively separate the growth rate of these important bacterial populations from that of the dominant heterotrophic bacteria are important to our understanding of the nitrification process. The changing concentration of ammonia is often used as an indirect measure of nitrification but ammonification processes generate ammonia and confound this approach while heterotrophs remove nitrate via denitrification. Molecular probe methods can tell us what proportion of the microbial community is nitrifying bacteria but not their growth rate. The technique proposed here was able to quantify the growth rate of the nitrifying bacterial populations amidst complex ecological processes. The method incubates [methyl-3H] thymidine with water samples in the presence and absence of an inhibitor of nitrification-thiourea. The radioactively labeled DNA in the growing bacteria was extracted. The rate of incorporation of the label into the dividing bacterial DNA was used to determine bacterial growth rate. Total bacterial community growth rates in full-scale and pilot-scale fixed-film nitrifying reactors and an activated sludge reactor were 2.1 x 10(8), 4.1 x 10(8) and 0.4 x 10(8)cell ml(-1)d(-1), respectively; the growth rate of autotrophic-nitrifying bacteria was 0.7 x 10(8), 2.6 x 10(8) and 0.01 x 10(8)cell ml(-1)d(-1), respectively. Autotrophic-nitrifying bacteria contributed 30% and 60% of the total bacterial community growth rate in the nitrifying reactors whereas only 2% was observed in the activated sludge reactor that was not designed to nitrify. The rates of ammonia loss from the nitrifying reactors corresponded to the rate of growth of the nitrifying bacteria. This method has the potential to more often identify factors that enhance or limit nitrifying processes in both engineered and natural aquatic environments.     

在磷酸中缓蚀剂KA-01和硫脲对A3钢的缓蚀性能

缓蚀剂 Ｋ Ａ０１ 是室内合成的一种有机缓蚀剂。通过静态腐蚀检测和电化学测量对缓蚀剂 Ｋ Ａ０１ 和硫脲及其复配物在１５ ％ 和２８ ％ 磷酸中对 Ａ３ 钢的缓蚀性能进行了评价,评价结果表明 Ｋ Ａ０１ 和硫脲在３０ ℃和９０ ℃的１５ ％ 和２８ ％ 磷酸中单独使用时具有较好的缓蚀作用,而二者复配使用时缓蚀效果明显增加;在９０ ℃的１５ ％ 和２８ ％ 磷酸中加入１ ．８ ％ Ｋ Ａ０１ 和０ ．２ ％ 硫脲时 Ａ３ 钢的腐蚀速度低于１ ｇ／ ｍ２·ｈ ,缓蚀率高达９９ ．８ ％ 以上;电化学测量结果表明 Ｋ Ａ０１ 和硫脲是以阴极控制为主的缓蚀剂,而二者的复配物则表现出阴阳极混合控制的特征。     

Facile preparation and photocatalytic hydrogen production of WS2 and its composites

Two-dimensional transition metal dichalcogenides, MoS₂ and WS₂ have been widely considered as promising materials for photocatalytic hydrogen production. However, compared with the widely investigated MoS₂, researches on WS₂ are much less. Besides, for the synthesis of WS₂, methods suitable for large-scale preparation are still rare. Then in this paper, a facile method for the preparation of WS₂ was developed based on the liquid-phase precipitation-calcination method reported previously. In specific, thiourea was introduced in the calcination process to realize the in-situ conversion of impurity WO₃ to WS₂. As a result, WS₂ was successfully prepared. More interestingly, a series of photocatalysts with different compositions and performances were easily obtained only through changing the thiourea amount. When no thiourea was used, a WS₂/WO₃ heterostructure was constructed, while when excessive thiourea was introduced, an efficient WS₂/g-C₃N₄ heterostructure (g-C₃N₄ = graphitic carbon nitride) was fabricated. Moreover, their hydrogen production performances were investigated with Erythrosine B (ErB) and triethanolamine (TEOA) as photosensitizer and sacrificial agent, respectively. The results showed that the as-obtained WS₂ has a comparable H₂-evolving activity (1686.3 μmol h^?1 g^?1) to the WS₂/WO₃ (1637.8 μmol h^?1 g^?1), and the WS₂/g-C₃N₄ owns the highest performance (2428.7 μmol h^?1 g^?1). This work provides a facile and feasible route for the preparation of efficient WS₂-based photocatalysts.     

Investigation on the crystal growth and characterisation of an organometallic non linear optical crystal – Tetrathiourea mercury tetrathiocyanato manganate

An organometallic complex tetrathiourea mercury tetrathiocyanato manganate (TMTM) was synthesised by two step chemical route. The influence of pH on the solubility, stability of the growth solution and growth of TMTM single crystal was studied. The bulk crystal of dimension 2.7 cm × 0.5 cm × 0.4 cm was grown at an optimized pH value of 3.0 by solvent evaporation method using water as a solvent. The structure and the crystallinity of the grown crystal were confirmed from single crystal XRD and powder XRD studies. The presence of thiourea and thiocyanate ligand and their coordination with the metal ions are confirmed from the IR studies. The grown single crystal of TMTM shows 69% transparency over the entire range of visible region with a cut-off wavelength of 362 nm. The SHG efficiency of TMTM was found to be 0.08 time that of MMTC. The complex exhibits good thermal stability up to 205 °C and it is non-hygroscopic in nature. The surface analysis was carried out by etching studies which shows a layer growth pattern revealing the 2D nucleation growth mechanism. From the Vickers hardness studies, the work hardening coefficient and the elastic stiffness constant were calculated.     

载H2NCSNH2明胶微球的制备及其对Ag+吸附性能的研究

以明胶和硫脲(H2NCSNH2)为原料,戊二醛为交联剂,采用反相乳液聚合法制备了明胶负载硫脲微球(H2NCSNH2-GM).考察了pH值和乳化剂用量对GM表面形态、硫脲包埋率及其对Ag+的吸附特性的影响.结果表明,当pH=6,0、m(span-80)∶m(液体石蜡)=5％时,所得H2NCSNH2-GM表面形态较好且包埋率最高;随着pH值的减小和乳化剂span-80用量增加,H2NCSNH2-GM对Ag+的吸附能力增加.     

Reaction of 6-amino-5-nitrosouracil with thiourea: Structure of the hydrolysis product

The interaction of 6-amino-5-nitrosouracil with thiourea in aqueous acidic solution results in the 6-amino-5-formamidinosulfenimino-2,3,4,5-tetrahydropyrimidine-2,4-dione di-p-toluenesulfonate that is subjected to hydrolysis with the formation of 5-formamidinosulfeniminobarbituric acid p-toluenesulfonate monohydrate.