氮中硫化氢标准物质制备及不确定度分析

以高纯硫化氢和高纯氮气为原料,采用称量法制备20～100μmol/mol的氮中硫化氢气体标准物质,进一步考察其均匀性、稳定性以及进行不确定度分析。结果表明,氮中硫化氢气体标准物质均匀性、稳定性良好,相对扩展不确定度与国家标准物质相当,可进一步用于硫化氢报警器等仪器的校准、检测。

轮胎蒸气充氮硫化在国内应用的探讨

论述了轮胎蒸气充氮硫化在国内应用的现实性,对各种氮气制备方法及氮气供应方式的特点、可靠性和经济性进行分析比较。认为国内轮胎厂或轮胎生产线有可能选择碳分子筛变压吸附装置供氮系统、膜分离装置供氮系统或液氮气化供氮系统。轮胎厂应用蒸汽充氮硫化将会获得技术上的优势和显著的经济效益。

蒸汽充氮硫化装置开发

介绍了蒸汽充氮硫化装置的研制目的，主要技术特征，工艺流程的组成及确定因素，轮胎硫化的工作原理及工艺流程，在生产使用中取得的经济效益及装置的优点，应用注意事项。该装置已通过技术鉴定，可推广使用。

充氮硫化工艺在轻载斜交轮胎生产中的应用

通过轻载斜交轮胎硫化过程的热平衡分析,在7.50-1616PR轻载斜交轮胎上试用了充氮硫化工艺,产品试制和室内试验结果表明,充氮硫化工艺与过热水硫化工艺相比轮胎性能相当;产品批量生产并投放市场后,实际使用效果良好,证明在轻载斜交轮胎生产中可以使用充氮硫化工艺。

轮胎充氮硫化工艺的应用研究

针对轮胎充氮硫化工艺的温差等问题,建立模型分析原因。结果表明,进行工艺优化,可以有效降低轮胎硫化温度,降低轮胎硫化能耗,提升轮胎动态性能。

氮掺杂二硫化钨纳米线阵列的制备及其高效碱性电催化析氢研究

WS2是一种有前景的非贵金属析氢电催化剂,实验和理论计算表明其在酸性条件下具有较好的析氢催化活性。但在碱性条件下其析氢性能较差,过高的水解离能垒是限制其碱性析氢活性的一个关键因素。掺杂是一种常用的调节催化剂水解离能垒的有效方法,考虑到N原子具有较小的原子半径和更强的电负性,在WS2中掺杂非金属N可能是一种相对容易实现的方案。X射线衍射、扫描电镜、X射线光电子能谱等分析测试表明,合成了N掺杂的WS2纳米线阵列(N-WS2)。变温反应速率及电化学阻抗谱测试表明,相比于WS2纳米线阵列,N-WS2纳米线阵列具有明显降低的水解离能垒,其碱性析氢活性大大增强。在1mol/L KOH溶液中,电流密度为10mA/cm2时,其过电位仅为115mV、塔菲斜率为73mV/dec,明显优于WS2纳米线阵列的292mV、137mV/dec。通过掺杂调节碱性电催化剂水解离能垒的设计理念为碱性析氢电催化剂的合理设计提供了一条可能的有效途径。

充氮硫化工艺应用与研究

针对充氮硫化工艺的温差等问题,建立模型进行原因分析及工艺优化,并对充氮硫化工艺独特的优越性进行论证,既节约了硫化能耗,又提升了轮胎动态性能。

氮杂石墨烯/硫化铋近红外光催化降解氨氮

采用水热法一步合成氮杂石墨烯/硫化铋(NG/Bi2S3)复合材料,以X射线粉末衍射、拉曼光谱、扫描电子显微镜、紫外可见近红外漫反射光谱等对催化剂进行了表征。以此复合材料为催化剂,在近红外光辐射下研究了氨氮催化降解。结果表明,当氨氮初始浓度为100.0 mg·L^-1、溶液的pH值为9.0、催化剂量为0.050 g、NG负载量为3 wt%、近红外光照射10 h时,氨氮的降解率达到91.4%。相同条件下,Bi2S3对氨氮的降解率只有65.5%。动力学研究表明,氨氮降解遵循一级反应动力学规律,其表观速率常数为0.1240 h^-1。7次循环氨氮的降解率仍然大于85.5%,显示出NG/Bi2S3复合催化剂非常稳定。

全钢载重子午线轮胎充氮硫化工艺

通过试验建立蒸汽和氮气硫化轮胎过程中的温度场模型。对测温结果进行分析后,对B型硫化机中心机构蒸汽和氮气入口进行改进,改进后的硫化机采用氮气硫化可提高成品轮胎动平衡性能20%~30%,并节约轮胎生产过程中蒸汽、过热水、电能和维修费用,降低轮胎生产成本。

Self-assembled S-scheme In_(2.77)S_(4)/K^(+)-doped g-C_(3)N_(4)photocatalyst with selective O_(2) reduction pathway for efficient H_(2)O_(2) production using water and air

The development of an efficient artificial H_(2)O_(2) photosynthesis system is a challenging work using H_(2)O and O_(2) as starting materials.Herein,3D In_(2.77)S_(4) nanoflower precursor was in-situ deposited on K^(+)-doped g-C_(3)N_(4)(KCN)nanosheets using a solvothermal method,then In_(2.77)S_(4)/KCN(IS/KCN)het-erojunction with an intimate interface was obtained after a calcination process.The investigation shows that the photocatalytic H_(2)O_(2) production rate of 50IS/KCN can reach up to 1.36 mmol g^(-1)h^(-1)without any sacrificial reagents under visible light irradiation,which is 9.2 times and 4.1 times higher than that of KCN and In_(2.77)S_(4)/respectively.The enhanced activity of the above composite can be mainly attributed to the S-scheme charge transfer route between KCN and In_(2.77)S_(4) according to density functional theory calculations,electron paramagnetic resonance and free radical capture tests,leading to an expanded light response range and rapid charge separation at their interface,as well as preserving the active electrons and holes for H_(2)O_(2) production.Besides,the unique 3D nanostructure and surface hydrophobicity of IS/KCN facilitate the diffusion and transportation of O_(2) around the active centers,the energy barriers of O_(2) protonation and H_(2)O_(2) desorption steps are ef-fectively reduced over the composite.In addition,this system also exhibits excellent light harvesting ability and stability.This work provides a potential strategy to explore a sustainable H_(2)O_(2) photo-synthesis pathway through the design of heterojunctions with intimate interfaces and desired reac-tion thermodynamics and kinetics.

Preparation and application of g-C_3N_4-ZnS-DNA nanocomposite with enhanced electrocatalytic activity

We successfully designed and prepared a g-C3N4-ZnS-DNA nanocomposite by a simple method and systematically investigated its morphology,microstructure,and electrocatalytic properties.The as-prepared g-C3N4-ZnS-DNA nanocomposite possessed the electrocatalytic activity of g-C3N4-ZnS and the conductivity of DNA.The presence of DNA was found to enhance the electrocatalytic response of the nanocomposite towards environmental hormones,e.g.pentachlorophenol and nonylphenol,owing to the interaction between g-C3N4-ZnS and DNA,indicating that a stable nanocomposite was formed.The three components showed synergistic effects during electrocatalysis.Electrochemical impedance spectra indicated that the g-C3N4-ZnS-DNA nanocomposite dramatically facilitated the electron transfer of a modified electrode.The co-doping of g-C3N4 film with ZnS and DNA doubled the electrochemical response of the modified electrode in comparison with that of unmodified g-C3N4 film.The detection limits（3 S/N） of pentachlorophenol and nonylphenol were3.3×10^-9 mol L^-1.Meanwhile,we propose a possible Z-scheme mechanism for electron transfer in the g-C3N4-ZnS-DNA nanocomposite and the possible pentachlorophenol and nonylphenol electrocatalytic oxidation mechanism.The g-C3N4-ZnS-DNA nanocomposite-modified electrode was demonstrated to be effective for electrochemical sensing of trace environmental hormones in water samples.

缅甸瑞宝盆地非烃气成因及其地质意义

非烃气成因类型的研究与烃类气的生成、运移、聚集成藏有密切联系。瑞宝盆地天然气具有有机成因烃类气与无机成因烃类气、非烃气混源特征;烃类气以甲烷为主;非烃气为N_2、H_2、CO_2、CO及H_2S;利用单因子(δ^(13)C_1或δ^(13)C_(co2))方法判别天然气成因存在一定偏差,δ^(13)C_(co2)-δ^(13)C_1、δ^(13)C_1-R_0等二元关系图版并考虑沉积背景综合判别效果好;有机成因烃类气主要来源于煤系烃源岩,有机成因非烃气主要来源于煤和干酪根的热解;无机成因烃类气、非烃气主要来源于碳酸盐岩的高温还原作用和火山活动。控盆深大断裂及火山岩的空间分布规律是控制非烃气富集的主要因素。非烃气的赋存对烃源岩的演化、油气运移聚集、储层质量以及成藏组合都有积极的地质指向意义。

Removal of SO_2 and NO_x by Pulsed Corona Combined with in situ Ca(OH)2 Absorption

Removal of SO2 and NOx by pulsed corona combined with in situ alkali absorption was experimentally investigated.In the reactor,a plate-wire-plate combination is devised for generating pulsed corona and then alkaline absorbent slurries were introduced into the reactor by a continuous band conveying system to capture the gaseous reaction products.It was found that both SO2 and NO could be removed by corona combined with in situ alkali absorption.The removal of SO2 increased to 75%with the corona discharge,compared with 60%removal only with Ca(OH)2 absorption.About 40%removal of NO was reached by pulsed corona combined with in situ Ca(OH)2 absorption.It was found that SO2 and NO in the gas stream are oxidized to SO3 and NO2 by pulsed corona respectively,and then absorbed by the alkali in the reactor.The removals of SO2 as well as NO were higher with Ca(OH)2 as the absorbent,compared with using CaCO3 or ZnO.

Influence of sulfation on CeO_2-ZrO_2 catalysts for NO reduction with NH_3

CeO2‐ZrO2 (CeZr) and sulfated CeO2‐ZrO2 (S‐CeZr) catalysts were prepared for the selective catalytic reduction of NO with NH3. The CeZr catalysts exhibited higher activity at low temperatures (< 200°C) and lower activity at high temperatures (> 200 °C) than the S‐CeZr catalysts. The sulfation ofCeZr was studied in terms of surface acidity, redox properties and NO adsorption‐desorption bytemperature‐dependent experiments and in situ infrared spectroscopy. S‐CeZr displayed high concentrationsof acidic sites and increased surface acidities, but poor reducibility compared with CeZr.The high acidity of S‐CeZr was attributed to the presence of Br?nsted acid sites, arising mainly fromthe surface sulfates. Because the surface was covered with sulfate species, S‐CeZr showed lower NOadsorption and weaker oxidation ability than CeZr. The adsorption of NH3 on the Br?nsted acid sites restricted the reaction with NO at low temperatures, but the selective catalytic reduction cycle occurred easily at relatively low temperatures (150 °C), and the weakly bound nitrite was partially activated on the S‐CeZr catalyst at relatively high temperatures (300 °C). The catalytic mechanisms for the CeZr and S‐CeZr catalysts at 150 and 300 °C were also studied.

Effects of precipitation variation on severe acid rain in southern China

Acid rain has been recognized as a serious environmental problem in China since the 1980s, but little is known about the effects of the climatic change in regional precipitation on the temporal and spatial variability of severe acid rain. We present the effects of the regional precipitation trend change on the area and intensity of severe acid rain in southern China, and the spatio-temporal distribution characteristics of SO2 and NO2 concentrations are analyzed on the basis of SO2 and NO2 column concentration data. The results are as follows. （1） The emission levels of SO2 and NO2 have reached or passed the precipitation scavenging capacity in parts of southern China owing to the emission totals of SOz and NO2 increasing from 1993 to 2004. （2） Notable changes in the proportion of cities subject to severe acid rain occurred mainly in the south of the middle-lower reaches of the Yangtze River during 1993-2004. With an abrupt change in 1999, the severe acid rain regions were mainly located in central and western China during 1993-1999 and moved obviously eastward to the south of the lower-middle reaches of the Yangtze River with the proportion of cities subject to severe acid rain increasing significantly from 2000 to 2004. （3） The spatial distribution and variation in the seasonal precipitation change rate of more than 10 mm/10a are similar to those of severe acid rain in southern China. An abrupt change in 1999 is seen for winter and summer precipitation, the same as for the proportion of cities subject to severe acid rain in southern China. The significant increase in summer storm precipitation from 1991 to 1999 mitigated the annual precipitation acidity in the south of the Yangtze River and reduced the area of severe acid rainfall. On the other hand, the decrease in storm rainfall in summer expanded the area of severe acid rainfall in the south of the Yangtze River in 2000-2006. Therefore, the change in seasonal precipitation is an important factor in the severe acid rain regions moving eastward and expanding in southern China.

Enhanced photocatalytic H_2 production over dual-cocatalyst-modified g-C_3N_4 heterojunctions

Ag nanoparticles (NPs) were deposited on the surface of g-C3N4 (CN) by an in situ calcination method. NiS was successfully loaded onto the composites by a hydrothermal method. The results showed that the 10 wt%-NiS/1.0 wt%-Ag/CN composite exhibits excellent photocatalytic H2 generation performance under solar-light irradiation. An H2 production rate of 9.728 mmol·g^-1·h^-1 was achieved, which is 10.82-, 3.45-, and 2.77-times higher than those of pure g-C3N4, 10 wt%-NiS/CN, and 1.0 wt%-Ag/CN composites, respectively. This enhanced photocatalytic H2 generation can be ascribed to the co-decoration of Ag and NiS on the surface of g-C3N4, which efficiently improves light harvesting capacity, photogenerated charge carrier separation, and photocatalytic H2 production kinetics. Thus, this study demonstrates an effective strategy for constructing excellent g-C3N4-related composite photocatalysts for H2 production by using different co-catalysts.

Tentative Study on a New Way of Simultaneous Desulfurization and Denitrification

Thiobacillus denitrificans, a kind of autotrophic facultative bacteria, can oxidize sulfide into elemental sulfur or sulfate when nitrate was adopted as its electron accepter and carbon dioxide as its carbon resource under anoxic or anaerobic environment. In this way, nitrate is converted into nitrogen. In addition, ThiobaciWus denitrificans can accumulate sulfur extracellularly. In this study, in a process of simultaneous desulfurization and denitrification, a strain of Thiobacillus denitriificans is employed as sulfur-producer in the treatment of wastewater containing sulfide and nitrate. The key factors affecting this process are investigated through batch tests. The experimental results indicate that the sulfide concentration and the ratio of sulfide to nitrate (S2-/NO3-) in the influent are the key factors, and their suitable values are suggested to be 5/3 and no more than 300mg·L-1, respectively, in order to achieve high conversion of sulfur.

Bio-derived N-doped porous carbon as sulfur hosts for high performance lithium sulfur batteries

Shuttle effect,poor conductivity and large volume expansion are the main factors that hinder the practical application of sulfur cathodes.Currently,rational structure designing of carbon-based sulfur hosts is the most effective strategy to address the above issues.However,the preparation process of carbon-based sulfur hosts is usually complex and costly.Therefore,it is necessary to develop an efficient and cost-effective method to fabricate carbon hosts for high-performance sulfur cathodes.Herein,we reported the fabrication of a bio-derived nitrogen doped porous carbon materials(BNPC)via a molten-salt method for high performance sulfur cathodes.The long-range-ordered honeycomb structure of BNPC is favorable for the trapping of polysulfide(PS)species and accommodates the volumetric variation of sulfur during cycling,while the high graphitization degree of BNPC favors the redox kinetics of sulfur cathodes.Moreover,the nitrogen doping content not only enhances the electrical conductivity of BNPC,but also provides ample anchoring sites for the immobilization of PS,which plays a key role in suppressing the shuttle effect.As a result,the S@BNPC cathode exhibits a high initial specific capacity of 1189.4 mA·h/g at 0.2C.After 300 cycles,S@BNPC still maintains a capacity of 703.2 mA·h/g which corresponds to a fading rate of 0.13%per cycle after the second cycle.This work offers vast opportunities for the large-scale application of high performance carbon-based sulfur hosts.

Effect of carrier and axial ligand on the photocatalytic activity of cobalt thioporphyrazine

The photocatalytic activity of cobalt octakis（butylthio） porphyrazine（CoPz（BuS）8） was assessed through photodegradation of the dye rhodamine B（RhB） in water under irradiation with a Xe lamp and aerated conditions.The photocatalytic activity of CoPz（BuS）8 loaded on Al2O3 or SiO2@Fe3O4nanoparticles or coordinated with an axial azide ligand was also investigated.The results demonstrated that the photocatalytic activity of CoPz（BuS）8 loaded on Al2O3 was higher than that loaded on SiO2@Fe3O4.The kinetic curves of RhB degradation in aqueous solutions at different pH indicated the pseudo first-order kinetics of the reaction.The highest degradation rate for CoPz（BuS）8 loaded Al2O3 at pH = 4 after 160 min was 84.6%.However,the advantages of easier separation and recycling as well as the ability to terminate the reaction at any time for the CoPz（BuS）8 loaded SiO2@Fe3O4 cannot be ignored.When electron-rich NaN3 was coordinated with CoPz（BuS）8 as an axial ligand and loaded on Al2O3,the resulting catalyst produced more active oxygen species such as O2^- and HO· to promote the quicker degradation of RhB than that by the other catalysts.For the N3-coordinated CoPz（BuS）8 loaded on Al2O3,the reactions at pH = 4 and 7 distinctly deviated from first-order kinetics,and the degradation rate reached 77.6%after 80 min at pH = 4.

Highly dispersed few-layer MoS_2 nanosheets on S, N co-doped carbon for electrocatalytic H_2 production

Ultrathin small MoS2nanosheets exhibit a higher electrocatalytic activity for the hydrogen evolution reaction.However,strong interactions between MoS2layers may result in aggregation;together with the low conductivity of MoS2,this may lower its electrocatalytic activity.In this paper we present a method that we developed to directly produce solid S,N co‐doped carbon(SNC)with a graphite structure and multiple surface groups through a hydrothermal route.When Na2MoO4was added to the reaction,polymolybdate could be anchored into the carbon materials via a chemical interaction that helps polymolybdate disperse uniformly into the SNC.After a high temperature treatment,polymolybdate transformed into MoS2at800°C for6h in a N2atmosphere at a heating rate of5°C/min,owing to S2?being released from the SNC during the treatment(denoted as MoS2/SNC‐800‐6h).The SNC effectively prevents MoS2from aggregating into large particles,and we successfully prepared highly dispersed MoS2in the SNC matrix.Electrochemical characterizations indicate that MoS2/SNC‐900‐12h exhibits a low onset potential of115mV and a low overpotential of237mV at a current density of10mA/cm2.Furthermore,MoS2/SNC‐900‐12h also had an excellent stability with only^2.6%decay at a current density of10mA/cm2after5000test cycles.