《中国钼业》来稿须知

1刊登范围和要求 本刊主要刊登钼及其共（伴）生金属（钨、铼、金、银、铂、镍、钯、铱、铜、铁、、锌、钙、铅、铀、锡等）的地质、采矿、选矿、冶炼、合金、加工、化工、有价金属回收与利用、设备、分析检测等领域内的”四新”（新产品、新工艺、新技术、新材料）科技与成果,还报道钼市场动态、行业信息、专利技术等。     

《中国钼业》来稿须知

1刊登范围和要求 本刊主要刊登钼及其共（伴）生金属（钨、铼、金、银、铂、镍、钯、铱、铜、铁、、锌、钙、铅、铀、锡等）的地质、采矿、选矿、冶炼、合金、加工、化工、有价金属回收与利用、设备、分析检测等领域内的”四新”（新产品、新工艺、新技术、新材料）科技与成果,还报道钼市场动态、行业信息、专利技术等。     

电感耦合等离子体原子发射光谱法测定高碳除尘灰中11种元素

实验重点探讨了高含量碳对除尘灰样品中镁、铝、钾、钙、铬、锰、铜、钡、铅、镉、锌等元素测定的影响,并解决了除碳的问题。样品使用马弗炉高温除碳,采用盐酸-硝酸-氢氟酸-高氯酸消解样品灰分,选择了镁、铝、钾、钙、铬、锰、铜、钡、铅、镉、锌等元素的分析谱线和扣背景模式,建立了使用电感耦合等离子体原子发射光谱法(ICP-AES)测定高碳除尘灰中镁、铝、钾、钙、铬、锰、铜、钡、铅、镉、锌等元素的方法。在仪器最佳工作条件下,各元素校准曲线线性相关系数r均大于0.999 5,方法检出限在1.08～26.01 mg/kg之间。方法应用于除尘灰实际样品中镁、铝、钾、钙、铬、锰、铜、钡、铅、镉、锌的测定,结果的相对标准偏差(RSD,n=11)为0.90%～7.1%,目标元素的加标回收率为90%～117%;按照实验方法测定除尘灰中镁、铝、钾、钙、锌,结果与火焰原子吸收光谱法(FAAS)的测定结果相吻合。     

《鞍钢技术》投稿须知

正(1)来稿应为针对鞍钢及国内外矿山、焦化、烧结、炼铁、炼钢、轧钢、金属材料、节能环保、耐火材料、能源动力、自动化及仪表、理化检验、综合利用、机电技术等钢铁领域上下游产业链相关的新技术、新装备和新工艺等方面撰写的论文,应做到选题新颖、工艺技术先进、试验研究成果借鉴性强。     

沁阳市沁龙化学防腐有限公司

河南省沁阳市沁龙化学防腐有限公司是从事研制生产多功能新型螺旋溜槽、摇床、旋流分级机、磁选机、浮选机、搅拌槽、打砂机、玻璃钢冷却塔、风机、管道、防腐贮罐等多种产品的专业公司,已有近三十年的生产历史,通过了lS09001:2000质量体系认证,主导产品为多功能新型螺旋溜槽、摇床,是选别有色金属、黑色金属、非金属、贵重金属的理想选矿设备,如金矿、银矿、沙金矿、锅矿、钛铁矿、硫铁矿、赤铁矿、褐铁矿、铬铁矿、钨矿、钽泥矿、煤矿、独居石、蓝宝石、重晶石、金红石、锆英石、硅砂等。现有8000多台设备在全国各地矿山使     

辉光放电光谱法测定因瓦合金中14种元素

采用11种与因瓦合金成分含量相接近的镍基合金标准样品绘制校准曲线,建立了基本不需要样品处理即可对因瓦合金中14种元素(C、Si、Mn、P、S、Ni、Cr、Mo、Cu、Al、Nb、Ti、Co、Fe)同时测定的辉光放电光谱法。确定辉光光谱仪检测因瓦合金的最佳条件:模块电压和相电压分别为8.22 V和3.82 V;功率为70 W;冲洗时间为80 s;积分时间为60 s。以各元素质量分数为横坐标,其对应的光谱强度为纵坐标绘制校准曲线,各元素校准曲线的相关系数均在0.99以上。采用实验方法对因瓦合金实际样品进行分析,结果显示:Cr、Ni、Mo、Ti、Fe的质量分数均大于0.3%,各元素测定值的相对标准偏差(RSD,n=11)均不大于1%;C、Si、Mn、P、S、Cu、Al、Nb、Co的质量分数均小于0.3%,各元素测定值的RSD(n=11)均小于5%。将实验方法应用于对因瓦合金样品中14种元素的测定,测得结果与滴定法测定Ni和Fe、高频燃烧红外吸收法测定C和S、电感耦合等离子体原子发射光谱法测定Si、Mn、P、Cr、Mo、Cu、Al、Nb、Ti和Co元素的结果基本一致。     

《中国钼业》来稿须知

1刊登范围和要求本刊主要刊登钼及其共(伴)生金属(钨、铼、金、银、铂、镍、钯、铱、铜、铁、锌、钙、铅、铀、锡等)的地质、采矿、选矿、冶炼、合金、加工、化工、有价金属回收与利用、设备、分析检测等领域内的"四新"(新产品、新工艺、新技术、新材料)科技与成果,还报道钼市场动态、行业信息、专利技术等。     

《中国钼业》来稿须知

1刊登范围和要求本刊为中国科技核心期刊。主要刊登钼及其共(伴)生金属(钨、铼、金、银、铂、镍、钯、铱、铜、铁、锌、钙、铅、铀、锡等)的地质、采矿、选矿、冶炼、合金、加工、化工、有价金属回收与利用、设备、分析检测等领域内的     

国家拟出台严厉措施淘汰落后产能

国家拟出台进一步加强淘汰落后产能工作的通知,协调发改委、工信部、环保部、国土部、商务部、海关总署、财政部、央行、银监会、质检总局、安监总局、工商总局、电监会、能源局等,以严厉措施,重点完成电力、煤炭、钢铁、水泥、有色、焦炭、造纸、皮革、     

《太钢科技》投稿指南

《太钢科技》是太原钢铁（集团）有限公司根据党和国家的政策、法令创办的,经山西省新闻出版局批准备案的科学技术刊物。主要刊登太钢矿山、耐火、焦化、炼铁、炼钢、连铸、轧钢、锻造、理化检验、能源、机械、土建、计控、自动化、环保、安全等专业以及科研、工艺质量攻关、产品开发、技术开发和技术管理等方面的试验研究、科技成果、技术总结、综合评述和经验介绍等。     

Systemic mastocytosis presenting as profound cardiovascular collapse during anaesthesia

BACKGROUND: To assess the efficacy of a single measurement of amniotic fluid optical density deviation at 450 nanometers in predicting fetal anemia in Rhesus-alloimmunization before 27 weeks gestation. METHODS: In this cross-sectional study, fetal blood and amniotic fluid samples from 43 Rhesus-alloimmunized pregnancies at 18 to 26 weeks gestation were obtained under ultrasound guidance. Amniotic fluid samples were scanned by spectrophotometry for optic density at various wavelengths. Deviation at 450 nanometers was calculated between 550 and 365 nanometers. The fetuses were divided into three groups based on their hematocrit levels and the predictive efficacy of optic density zones for anemia was evaluated. RESULTS: A high number of false positive and false negative results were observed when the delta-amniotic fluid optical density of fetuses at risk for anemia was plotted to the zones recently proposed to manage Rhesus-alloimmunized pregnancies. CONCLUSIONS: These data confirm previous results that the diagnosis of fetal anemia in Rhesus-alloimmunized pregnancies before 27 weeks' gestation cannot be accurately made by a single measurement of amniotic fluid optical density at 450 nanometers.     

Relative Buoyancy Dominates Thermal-Like Flow Interaction along an Incline

This paper describes laboratory investigations of the motion between two fixed volumes of dense fluid (surge-type gravity currents) with different salt concentrations that interact above an incline in the presence of ambient stratification. The experiments include both large and small density contrasts between the interacting surges. Initially, the propagation of each fluid mass assumes a thermal-like nature, but then the lower density surge is quickly caught up by the denser fluid flow because of its higher velocity. There are two key process regarding the surge interaction. With a large density contrasting the fluid volumes, the denser flow moves to the front of the current as an intrusion with no mixing. With a small density difference, pronounced mixing occurs between the surges with the development of a homogeneous underflow. A simple energy parameterization is developed to evaluate the source conditions under which the different flow dynamics develop.     

Management of Fluid Mud in Estuaries, Bays, and Lakes. II: Measurement, Modeling, and Management

Techniques for measurement, modeling, and management of fluid mud are available, but research is needed to improve them. Fluid mud can be difficult to detect, measure, or sample, which has led to new instruments and new ways of using existing instruments. Multifrequency acoustic fathometers sense neither density nor viscosity and are, therefore, unreliable in measuring fluid mud. Nuclear density probes, towed sleds, seismic, and drop probes equipped with density meters offer the potential for accurate measurements. Numerical modeling of fluid mud requires solving governing equations for flow velocity, density, pressure, salinity, water surface, plus sediment submodels. A number of such models exist in one-, two-, and three-dimensional form, but they rely on empirical relationships that require substantial site-specific validation to observations. Management of fluid mud techniques can be classified as those that accomplish: Source control, formation control, and removal. Nautical depth, a fourth category, defines the channel bottom as a specific fluid mud density or alternative parameter as safe for navigation. Source control includes watershed management measures to keep fine sediment out of waterways and in-water measures such as structures and traps. Formation control methods include streamlined channels and structures plus other measures to reduce flocculation and structures that train currents. Removal methods include the traditional dredging and transport of dredged material plus agitation that contributes to formation control and/or nautical depth. Conditioning of fluid mud by dredging and aerating offers the possibility of improved navigability. Two examples—the Atchafalaya Bar Channel and Savannah Harbor—illustrate the use of measurements and management of fluid mud.     

Second-trimester echogenic bowel and intraamniotic bleeding: association between fetal bowel echogenicity and amniotic fluid spectrophotometry at 410 nm

OBJECTIVE: Our purpose was to determine whether the presence of heme pigments in amniotic fluid is associated with the ultrasonographic findings of increased fetal bowel echogenicity in the second trimester. STUDY DESIGN: Spectrophotometric analysis of amniotic fluid for optical density at 410 nm was prospectively performed to study the presence of heme pigments in (1) 104 pregnancies undergoing second-trimester amniocentesis for routine cytogenetic indications and (2) in 14 pregnancies undergoing amniocentesis for prenatal karyotyping because of fetal strongly echogenic bowel. In the routine amniocentesis group the fetal small bowel echogenicity was assessed immediately before amniocentesis and classified as nonechogenic (n = 64), mildly echogenic (n = 36), or hyperechogenic (n = 4) with the fetal iliac wing and liver used as references. Only amniotic fluid specimens that were obtained at the first attempt and that were not blood-stained were included in this study, with the first milliliter being discarded in all samples. RESULTS: In the routine amniocentesis group abnormal amniotic fluid optical density readings were significantly more frequent in fetuses with increased bowel echogenicity compared with those with nonechogenic bowel (8/40 [20%] vs 3/64 [5%], respectively; p < 0.001). In the hyperchogenic bowel group abnormal amniotic fluid optical density readings were found in four samples (29%). Overall, 12 of 54 fetuses (22%) with increased bowel echogenicity had a detectable peak at 410 nm. Three of the 12 (25%) fetuses with echogenic bowel and positive readings for hemoglobin were chromosomally abnormal. CONCLUSIONS: Fetal small bowel echogenicity is associated with the presence of heme pigments in amniotic fluid as determined by amniotic fluid optical density at 410 nm. Swallowing of amniotic fluid after intraamniotic bleeding seems implicated in the etiology of second-trimester echogenic bowel in both euploid and aneuploid fetuses.     

Particle Image Velocimetry Measurements and Numerical Modeling of a Saline Density Current

Particle image velocimetry scalar measurements were carried out on the body of a stably stratified density current with an inlet Reynolds number of 2,300 and bulk Richardson number of 0.1. These measurements allowed the mass and momentum transport between the current and the less dense ambient fluid to be investigated. Reynolds stress, Reynolds flux, and shear production of turbulent kinetic-energy profiles revealed local maxima at the bed, as well as at the interface with the ambient fluid. Profiles of excess density variance and buoyancy production of turbulent kinetic energy revealed only local maxima at the interface with the ambient. These maxima decreased downstream as the stable density gradient reduced the turbulent intensities, until turbulence collapsed. A two-dimensional, unsteady, Reynolds-averaged Navier-Stokes (2DV-URANS) simulation was also performed on this density current. Good agreement was found between the modeled and measured normalized mean flow profiles. A comparison was also made between the measured and modeled outer flow scales of the density current.     

Pulmonary fluid extraction and osmotic conductance, sigmaK, measured in vivo

The change in aortic blood density in an in vivo rabbit preparation was measured to assess fluid movement at the pulmonary capillaries caused by infusion of hypertonic solution (NaCl, urea, glucose, sucrose, or raffinose in isotonic saline) into the vena cava over 20 s. The hypertonic disturbance increased the plasma osmotic pressure by 相似文献   

Large vestibular aqueduct syndrome with high CT density and high MR signal intensity

We report a case of large vestibular aqueduct syndrome with a markedly dilated endolymphatic sac bilaterally. The density and signal intensity of the extraosseous portion of the sac were higher than those of cerebrospinal fluid on CT and MR studies. The findings may represent protein-rich and hyperosmolar fluid within the endolymphatic sac.     

垂直自由降膜流表面波的非线性演化

环状两相流和液体薄膜流具有小流量、小温差下高热流密度和高换热系数等独特优点 ,同时液体薄膜流存在着表面波 ,这种表面波对其稳定性有着不容忽视的影响。冶金企业普遍使用的热管换热器管内传热强化是其应用的一个方面。借助自行研制并经改进的多点电导传感器和微机化实时在线测量系统 ,对垂直管外自由降膜流表面波的演化进行实时在线测量。结果表明 ,自然产生的垂直自由降膜流表面波呈现明显的非线性特性 ,其演化形态不仅取决于纵向距离和时间 ,而且还和液膜雷诺数有极大关系。     

Lung density for assessment of hydration status in hemodialysis patients using the computed tomographic densitometry technique

The density of the lung reflects the total mass of fluid, air, and dry lung tissue per unit volume of the lung. Lung density can be measured by evaluation of attenuation of an electron beam with computed tomography (CT). This technique has been shown to be sufficiently reliable and sensitive to distinguish normal from abnormal lung water. The aim of this study was to find out whether lung density properly reflects the hydration status in hemodialysis patients in comparison with other standard methods. Fourteen hemodialysis patients, with an ultrafiltration ranging from 0.3 to 4.5 liters per session, underwent CT measurements of lung density, ultrasonographic measurements of the diameter of the inferior vena cava after quiet expiration (IVCe) and quiet inspiration (IVCi), and measurements of the hematocrit and plasma levels of the biochemical hydration markers cyclic guanosine monophosphate (cGMP) and atrial natriuretic peptide (ANP). These measurements were performed before and 3.5 to 4 hours after termination of dialysis. Quantitative estimates of lung density were obtained within pixels with CT numbers ranging between -1000 and -100 Hounsfield Units (HU), and compared with normal data from 18 normal controls. In normal controls, the lung density ranged from -800 to -730 HU. In hemodialysis patients, lung density was significantly higher than normal before dialysis (-678 +/- 96 HU, P < 0.01) and significantly decreased after dialysis (-706 +/- 92 HU, P < 0.05), indicating a decrease in fluid content of the lung. The density was normalized in 5 patients. A significant correlation was found between lung density and IVCe both before and after dialysis (r = 0.8, P < 0.01 for both). Change in density was significantly correlated to amount of ultrafiltration (r = 0.67, P < 0.01) and percent change in blood volume (r = 0.63, P < 0.05), indicating that lung density is greatly affected by changes in the extracellular fluid volume, mainly the intravascular volume. In conclusion, lung water reflects the hydration status in hemodialysis patients and can be monitored by measuring the lung density by CT. Accordingly, normalization of lung density can help to achieve a proper dry weight in these patients.     

Fluid flow from a low to a higher density liquid

The penetration of liquid from a low density brine solution into a higher density solution below it has been measured as a function of vertical flow velocity and the density difference of the two solutions. The flow velocity was produced by a horizontal disc rotating in the low density liquid. The results show the penetration distance and penetration rate are dependent on flow velocity and in particular are very sensitive to small changes in the density difference between the two liquids. The observations are considered in relation to liquid penetration into dendritic arrays, and fluid flow in the pool of ingots and continuously cast steel billets, during solidification.