Periodic oscillation and fine structure of wedge-induced oblique detonation waves

An oblique detonation wave for a Mach 7 inlet flow over a long enough wedge of 30 turning angle is simulated numerically using Euler equation and one-step rection model.The fifth-order WENO scheme is adopted to capture the shock wave.The numerical results show that with the compression of the wedge wall the detonation wave front structure is divided into three sections：the ZND model-like strcuture,single-sided triple point structure and dual-headed triple point strucuture.The first structure is the smooth straight,and the second has the characteristic of the triple points propagating dowanstream only with the same velocity,while the dual-headed triple point structure is very complicated.The detonation waves facing upstream and downstream propagate with different velocities,in which the periodic collisions of the triple points cause the oscillation of the detonation wave front.This oscillation process has temporal and spatial periodicity.In addition,the triple point trace are recorded to obtain different cell structures in three sections.

Studies on Wool-Eating Ailment in Guizhou Semi-Fine Wool Sheep

The clinical symptoms of a disorder which is known locally as ＂wool-eating ailment＂ in Guizhou semi-fine wool sheep in the Weining County of Guizhou Province, China, are poor weight gain, lost appetite, pica, emaciation, and wool-eating. The mineral composition of forage, and samples of blood, liver and wool from Guizhou semi-fine wool sheep in affected ranches were compared with those from the unaffected areas. The mean concentration of iron in forage from affected pasture was significantly higher than that from the unaffected pasture. The mean concentration of sulfur in forage from the affected and unaffected pasture was similar and within normal ranges. The mean concentration of sulfur in blood, liver and wool from the affected Guizhou semi-fine wool sheep was significantly lower than that from the unaffected sheep while the content of iron in blood, liver and wool from the affected sheep was significantly higher than that from the unaffected sheep. Oral administration of calcium sulfate prevented and cured the disease. We concluded that the disease of Guizhou semi-fine wool sheep in the Weining County is due to S deficiency caused by the high Fe in forages.

Possible radio precursors/signatures of the CMEs onset:radio type Ⅲ bursts and fine structures in the centimeter-metric wavelength region

Seventy-one occurrences of coronal mass ejections （CMEs） associated with radio bursts, seemingly associated with type III bursts/fine structures （FSs）, in the centimeter-metric frequency range during 2003-2005, were obtained with the spectrometers at the National Astronomical Observatories, Chinese Academy of Sciences （NAOC） and the Culgoora radio spectrometer and are presented. The statistical results of 68 out of 71 events associated with the radio type III bursts or FSs during the initiation or early stages of the CMEs indicate that most CMEs contain the emissions of radio type III bursts/FSs near the time of the CME＇s onset, in spite of their fast or slow speeds. Therefore, we propose that type III bursts and FSs are possible precursors of the onset of CMEs. We stress that the radio type III bursts/FSs in the centimetermetric wavelength region and the CME transients possibly occurred in conjunction with the origin of the coronal precursor structures. Thus, the statistical results support the suggestions that type III bursts/FSs are indicators of extra energy input into the corona at the CMEs＇ onset, and that the type III bursts/FSs are produced primarily due to a coronal instability which eventually triggers the CME process. This may signify that the centimeter-metric radio bursts corresponding to or near the CME＇s onset are caused by the disturbed corona （possibly including minor magnetic reconnections）.

Molecular Engineering Design for High-Performance Aqueous Zinc-Organic Battery

Novel small sulfur heterocyclic quinones(6a,16adihydrobenzo[b]naphtho[2′,3′:5,6][1,4]dithiino[2,3-i]thianthrene-5,7,9,14,16,18-hexaone(4S6Q)and benzo[b]naphtho[2′,3′:5,6][1,4]dithiino[2,3-i]thianthrene-5,9,14,18-tetraone(4S4Q))are developed by molecule structural design method and as cathode for aqueous zincorganic batteries.The conjugated thioether(–S–)bonds as connected units not only improve the conductivity of compounds but also inhibit their dissolution by both extendedπ-conjugated plane and constructed flexible molecular skeleton.Hence,the Zn//4S6Q and Zn//4S4Q batteries exhibit satisfactory electrochemical performance based on 3.5 mol L-1(M)Zn(ClO4)2electrolyte.For instance,the Zn//4S6Q battery obtains 240 and 208.6 mAh g^(-1)of discharge capacity at 150 mA g^(-1)and 30 A g^(-1),respectively.The excellent rate capability is ascribed to the fast reaction kinetics.This system displays a superlong life of 20,000 cycles with no capacity fading at 3 A g^(-1).Additionally,the H+-storage mechanism of the 4S6Q compound is demonstrated by ex situ analyses and density functional theory calculations.Impressively,the battery can normally work at-60℃benefiting from the anti-freezing electrolyte and maintain a high discharge capacity of 201.7 mAh g^(-1),which is 86.2%of discharge capacity at 25℃.The cutting-edge electrochemical performances of these novel compounds make them alternative electrode materials for Zn-organic batteries.

Application of Rare Earth Spin Finishes Chloride on PET/PA Composite Super-fine Denier Fiber

The primariy application of rare - earth spin finishes on PET/PA composite super - fine denier fiber has been studied in this paper. It results in the improvement of fi-ber’s properties, such as increased whiteness, brightness and brilliance, effective and uniform spliting of compos-ite fiber into super - fine denier fiber and enhanced dye-ing effect.

Propene and CO oxidation on Pt/Ce-Zr-SO_4^(2-) diesel oxidation catalysts:Effect of sulfate on activity and stability

Platinum/cerium-zirconium-sulfate（Pt/Ce-Zr-SO_4^（2-）） catalysts were prepared by wetness impregnation.Catalytic activities were evaluated from the combustion of propene and CO.Sulfate（SO_4^（2-））addition improved the catalytic activity significantly.When using Pt/Ce-Zr-SO_4^（2-） with 10 wt%SO_4^（2-）,the temperature for 90%conversion of propene and CO decreased by 75℃ compared with Pt/Ce-Zr.The conversion exceeded 95%at 240℃ even after 0.02%sulfur dioxide poisoning for 20 h.Temperature-programmed desorption of CO and X-ray photoelectron spectroscopy analyses revealed an improvement in Pt dispersion onto the Ce-Zr-SO_4^（2-） support,and the increased number of Pt particles built up more Pt^（-）-（SO_4^（2-））^（-） couples,which resulted in excellent activity.The increased total acidity and new Bronsted acid sites on the surface provided the Pt/Ce-Zr-SO_4^（2-） with good sulfur resistance.

EH-2中温耐硫水解催化剂与单醇精脱硫工艺

介绍了EH-2中温耐硫水解催化剂的实验室试验项目和实验数据,分析了EH-2的工厂侧流试验结果,论述了由EH-2催化剂与常温精脱硫新工艺组成的精脱硫组合技术在单醇生产中的工业应用效果。结果表明,甲醇催化剂寿命超过3年,每立方米催化剂的甲醇生产强度达到14 000 t。

云南某贫细硫化铜矿石选矿工艺优化研究

云南某低品位细粒嵌布的铜矿石铜、硫品位分别为0.161%和9.704%,有价铜矿物嵌布粒度细,铜硫分离富集难度较大。为实现该硫化铜矿石资源的高效开发利用,在选厂原选矿流程及原矿工艺矿物学研究基础上,进行了系统的磨浮试验。结果表明:矿石采用磨矿—1粗2扫铜硫混合浮选—混浮粗精矿再磨—1粗3精2扫铜硫分离浮选闭路流程处理,可获得铜品位14.69%、铜回收率63.15%的铜精矿,硫品位29.16%、硫回收率75.10%的硫精矿,试验铜精矿品位较现场提高近3个百分点,铜回收率提高15个百分点以上,显著优于现场生产指标,达到了理想的综合回收铜硫效果。研究结果可作为工艺流程优化的依据。

煤炭高梯度磁选-浮选脱硫降灰试验

通过分析煤样性质,说明原煤中无机硫主要以硫化铁硫为主,有机硫较高,仅依靠物理方法很难达到理想脱除效果。通过煤粉高梯度磁选试验研究了磁介质、磁通密度、脉冲对煤炭磁选效果的影响。结果表明:聚磁介质选用不加铜套细网介质,当磁通密度为1.295 T,脉冲为25次/min时,煤粉湿法高梯度磁选脱硫效果最好,此时硫分为1.59%,精煤产率为85.44%,脱硫率为31.87%,脱灰率为38.17%,黄铁矿硫脱除率为45.02%。通过正交试验确定了最佳高梯度磁选条件为:煤粉粒度0.075 mm,磁通密度1.295 T,脉冲25次/min,可得到硫分1.35%,灰分10.37%的磁选精煤产品。最后对磁选精煤进行再浮选试验,得到最佳浮选条件为:石灰500 g/t,捕收剂1360 g/t,起泡剂90 g/t,可获得产率76.29%,硫分1.28%,灰分8.14%的精煤,产品脱硫率为57.73%,脱灰率为58.52%,黄铁矿硫脱除率为84.56%。采用磁选-浮选综合流程,煤粉基本达到理想的脱硫降灰效果,可作为煤种脱硫降灰技术方案的参考。

安钢高炉煤气精脱硫技术工业实践

结合当前环保形势和政策背景,分析了高炉煤气的典型特点和主流工艺路线,提出预处理水解和兰炭吸附的工艺组合,阐述了该工艺的技术原理和工业实践情况,该技术的应用和推广将带来广泛的环境效益和经济社会效益。

EAC-2、EAC-3型活性炭精脱硫剂的工业应用

报道EAC-2、EAC-3型活性炭精脱硫剂在焦炉气脱硫、保护甲醇及氨合成催化剂、食品CO_2生产中的工业应用。

EAC-6型硫醇精脱硫剂的开发及其工业应用

介绍了对华烁科技股份有限公司研制的EAC-6型硫醇精脱硫剂的实验评价。结果表明,EAC-6精脱硫剂对硫醇有优异脱除性能。实验考察了水汽和温度对硫醇硫容的影响。在进口φ(CH3SH)为0.5%的干气中,空速1000h-1,30℃～90℃时,出口φ(CH3SH)≤0.03×10-6,工作硫容可达7%～10%。工业应用表明,EAC-6型硫醇精脱硫剂出口各种形态硫醇的体积分数均≤0.03×10-6,很好地保护了下游的甲醇合成等的高效催化剂。

钢铁行业高炉煤气精脱硫技术应用现状和未来趋势研究

高炉炼铁处于长流程钢铁冶炼生产工艺中的关键环节,高炉煤气是炼铁过程副产的重要二次能源,通常在高炉热风炉、轧钢加热炉和自备电厂煤气发电等生产工序进行燃烧利用。高炉煤气精脱硫技术的工程应用作为钢铁行业进行源头减排的典型实施方案具有非常重要的意义,国家与地方相关部门对于高炉煤气脱硫技术的应用也明确提出了最新要求。结合高炉煤气组分复杂、工况波动的特征和硫组分形态不同、有机硫为主的含硫特点以及不同脱硫技术的主要特点,重点分析了针对煤气中硫化氢的脱除方法、羰基硫的脱除方法以及硫化氢和羰基硫的一体化脱除方法,并通过对近年来钢铁行业高炉煤气精脱硫技术的工程应用现状调研,进一步对高炉煤气精脱硫技术后续的研发方向和工程应用等方面提出了几点建议。

高炉煤气精脱硫技术干扰因素及应用现状

在超低排放政策的引领下,高炉煤气精脱硫技术的开发和应用已日趋成熟。结合钢铁企业高炉煤气精脱硫技术工程案例的调查和研究,总结出高炉煤气精脱硫过程中存在的干扰因素,并对主流工艺的应用现状进行概括和分析,旨在为钢铁企业精准选择合适的工艺路线提供参考。

某多金属选矿厂选锡工艺优化

某矿山锌、铜、锡、铁、硫多金属选矿厂开展锡石选别工艺优化,在优先回收70%的铜金属,90%的锌金属,在除铁硫后,原矿含锡品位为0.21%,铜、锌、铁、硫中锡已经带走20%的前提下,锡指标提升5个百分点,经济效益显著。

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.

Utility of endoscopic ultrasound, cytology and fluid carcinoembryonic antigen and CA 19-9 levels in pancreatic cystic lesions

AIM: To assess the diagnostic accuracy of endoscopic ultrasound (EUS), fluid tumor markers and cytology in distinguishing benign from (pre)malignant pancreatic cystic lesions. METHODS: 46 consecutive patients, referred to a gastroenterologist and surgeon for a symptomatic or incidental pancreatic cyst, were reviewed. EUS, cytology, and carcinoembryonic antigen (CEA) and carbohydrate antigen (CA 19-9) levels were compared with the final diagnosis, based on surgical pathology and/or imaging follow-up of at least 12 mo. Cysts were classified as benign (pseudocyst, serous cystadenoma) or malignant/ pre-malignant (mucinous cystic neoplasm). Receiver- operator characteristics (ROC) curve analysis was performed. RESULTS: The mean age was 56 years; 29% were male and median cyst diameter was 3 cm. Final outcome was obtained in 41 (89%) patients. Twenty-three (56%) of these 41 had surgical pathology. Twenty-three (56%) had benign lesions and 18 (44%) had malignant/pre- malignant lesions. Sensitivity, specificity and positive and negative predictive value of EUS alone to distinguish benign from malignant/premalignant pancreatic cystic lesions were 50%, 56%, 36% and 54% and for cytology were 71%, 96%, 92% and 85%, respectively. The corresponding values for the ROC-derived ideal cutoffswere 75%, 90%, 75%, 90% for CA 19-9 (> 37 U/mL) and 70%, 85%, 79% and 78% for CEA (> 3.1 ng/mL). Subgroup analysis of those with surgical pathology yielded almost identical performance and cutoffs. CONCLUSION: Cytology and cyst fluid tumor marker analysis is a very useful tool in distinguishing benign from (pre)malignant pancreatic cystic lesions.

Atmospheric Sulfur Deposition for a Red Soil Broadleaf Forest in Southern China

A two-year study in a typical red soil region of Southern China was conductedto determine 1) the dry deposition velocity (V_d) for SO_2 and particulate SO_4^(2-) above abroadleaf forest, and 2) atmospheric sulfur fluxes so as to estimate the contribution of variousfractions in the total. Using a resistance model based on continuous hourly meteorological data,atmospheric dry sulfur deposition in a forest was estimated according to V_d and concentrations ofboth atmospheric SO_2 and particulate SO_4^(2-). Meanwhile, wet S deposition was estimated based onrainfall and sulfate concentrations in the rainwater. Results showed that about 99% of the drysulfur deposition flux in the forest resulted from SO_2 dry deposition. In addition, the observeddry S deposition was greater in 2002 than in 2000 because of a higher average concentration of SO_2in 2002 than in 2000 and not because of the average dry deposition velocity which was lower for SO_2in 2002. Also, dry SO_2 deposition was the dominant fraction of deposited atmospheric sulfur inforests, contributing over 69% of the total annual sulfur deposition. Thus, dry SO_2 depositionshould be considered when estimating sulfur balance in forest ecological systems.

CNJ-5P超精脱硫剂在工业装置上的应用

介绍了CNJ-5P超精脱硫剂在焦炉气甲烷化制合成天然气工业装置上的运行情况,包括脱硫剂的装填、升温还原、工业运行数据等,充分说明该脱硫剂具有脱硫精度高、使用寿命长、脱硫性能稳定、副产物少等优点,是一种工业化较为成功的超精脱硫剂。

四川盆地普光高含硫气田长周期高产稳产关键技术

普光气田是我国探明储量最大的高含硫气田,储层以礁滩相为主,具有非均质性强、边水能量强、高含硫等特点,面临礁滩储层地震预测精度低、气藏边水推进快、产能快速递减、硫沉积逐步析出、气井产能和气藏储量动用效果差等一系列技术难点和挑战。为此,针对普光气田开发面临的难点和挑战,全面、系统总结了自“十三五”以来,为实现气田长周期高产稳产而开展的技术攻关与矿场实践。研究结果表明:①建立了台内滩储层预测岩石物理量版,提出了有效动用对策,研发了“自转向清洁酸+降阻滑溜水+缝内暂堵”造复杂缝酸压工艺,实现了超深礁滩相低品位台内滩储层有效动用;②建立了礁滩相储层气水前缘运动方程,研发了新型抗硫三元复合泡排剂、高抗硫超高膨胀率比桥塞,设计了过油管注塞堵水工艺,实现了高含硫气井全生命周期控水稳气;③揭示了高含硫天然气单质硫析出机理,建立了高含硫气藏硫沉积分布模型,研发了快速分散型溶硫剂,配套射流冲洗工艺,形成了井筒硫沉积治理技术。结论认为,普光气田目前边水突进导致剩余气分布复杂、硫沉积逐渐从井筒扩展到地层、井口压力接近外输压力,下一步需要开展剩余气精细描述与挖潜、精准堵水、储层硫沉积治理、集输系统增压开采等技术攻关,以期进一步改善气田开发效果进而提高采收率。