川北某黑色页岩型铼矿工艺矿物学研究

通过矿相显微镜、扫描电镜、电子探针、X射线能谱元素面分析等多种手段综合研究了川北某黑色页岩型铼矿中铼的赋存状态。样品为黑色页岩,有机碳含量较高。粘土矿物总量为14.6%,黄铁矿含量16.2%,石英含量37.7%。样品具典型的粘土结构,矿物粒度微细。铼有两种赋存状态,一种呈类质同象形式赋存于黄铁矿内,另一种则以分散形式存在。典型黄铁矿测点Re平均含量为0.024%。黄铁矿是Re的重要载体矿物。建议通过浮选分离黄铁矿,从而实现Re的富集。      

中国低空大气波导出现概率和波导特征量的统计分析

本文简要说明了我们对大气波导的统计方法，并对统计结果作了讨论和分析。文中详细讨论了中国低空大气波导在不同地区的出现情况，说明了它们在各地出现概率随季节月份的变化情况及日变化情况，还说明了悬空波导和贴地波导基本分布状况；对于波导顶高、强度、厚度、高度等特征量，主要给出了它们的平均值和波导在不同数值上的分布。结果表明，我国低空大气波导出现的高概率区是南部沿海、东南沿海、东部沿海和西北地区中部；我国的四大高原、天山以北和东北平原是无波导区；我国低空大气波导的顶高一般在地面上２０００ｍ以内，强度在０～２０Ｍ单位之间，厚度一般是１００～５００ｍ，高度是西北地区绝大部分为０米，沿海地区大多数超过３００ｍ。同时文中也讨论了我国低空大气波导的分布和我国各地的具体地理位置、气候条件的相关情况。     

出现网的t型s切和t切

首先引入出现网的t切的转移的概念,利用t切的转移集τ,可以得到t切p[τ]。其次引入s切的伴随集E(u)和t型s切的概念。证明了出现网的t型s切和t切有对应的关系以及这种对应关系保持t型s切的转移和t切的转移。给出了在s切有向图中查找t切的算法,证明了出现网的t切都是t型s切的伴随集。     

鲁南碳酸盐岩丘陵贫水区典型地下水赋存模式分析——以沂南、费县为例

根据山东省沂南、费县两县的抗旱找水打井工作,利用物探定井、成井以及水文地质试验过程,对松林、西柳沟、响井、颜河庄4个村的水文地质条件进行了深入分析,总结了鲁南碳酸盐岩分布区两种典型的地下水蓄水模式,即断层蓄水构造模式和裂隙-岩溶蓄水构造模式。断层蓄水构造主要分布于该区中下寒武统地层,分布并不均匀和普遍,出水效果主要取决于断层的分布、张扭性质以及地下水径流方向的补给源,与地形情况关系不大;裂隙-岩溶蓄水构造在该区主要分布于奥陶系及上寒武统地层,裂隙岩溶发育,富水性好,发育较为广泛和普遍,打井出水成功概率高。对于两种典型地下水赋存模式的深入分析,可以为今后碳酸盐岩丘陵贫水区的地下水勘查工作提供思路。     

Petri网展开图法的分析和应用

Petri网的展开图是一种特殊的并发系统状态空间搜索方法，它不需要重复考虑并发事件的所有可能的交集，从而大大缩减状态空间爆炸给验证分析带来的空间复杂度和时间复杂度。使用展开图分析Petri网的行为属性与传统的Petri网分析方法相比，具有自己的特点。该文首先介绍了Petri网展开图的构造算法，在此基础上使用展开图分析方法对一个典型Petri网的活性，有界性和可逆性等行为属性进行了分析，并与传统的Petri网分析方法作比较。     

Influences of sodium species with different occurrence modes on the thermal behaviors and gas evolution during pyrolysis of a sodium-rich Zhundong subbituminous coal

The Zhundong coal (ZDC) with a huge proven reserve is featured by high abundance of sodium species which behaves actively in the thermal conversion of it. In this work, to better understand the multiple roles of sodium species in coal pyrolysis, influences of sodium species with different occurrence modes on the thermal behaviors and gas evolution during pyrolysis of a sodium-rich ZDC were investigated. Raw coal was initially demineralized by dilute hydrochloric acid. Subsequently, sodium species was reloaded into the demineralized sample by ion-exchanged or immersed method. For quantitative analyses, a thermo-gravimetric analyzer coupled with a mass spectrometer was used to record the weight loss of different samples and the ever-changing amount of gaseous products in pyrolysis. The results show that the structural change induced by demineralized and ion-exchanged treatment is mainly reflected in the band intensity of carboxyl groups. In pyrolysis of ZDC, total volatile matters yield has a close relation with the occurrence modes of sodium species. It is proved that water-soluble sodium species has catalytic effects on the thermal-cracking reactions, whereas exchangeable sodium species tends to facilitate char-formed reactions. Compared with exchangeable ones, water-soluble sodium species can be also volatilized more easily in pyrolysis. As for gas evolution, exchangeable sodium species can obviously affect formation of CO through char gasification and it is also favorable to formation of hydrogen radicals. Moreover, due to the low sulfur content in ZDC, the intensity of H₂S released from all samples is extremely weak, which suggests that ZDC is a suitable feedstock for clean coal utilization.     

四川某粘土型钒矿工艺矿物学研究

通过矿相显微镜、扫描电子显微镜、电子探针、X射线能谱元素面分析等多种手段综合研究四川某地黏土型钒矿中钒的赋存状态。样品为铝质黏土岩，V2O5含量为0.93%。黏土矿物总量为61.7%，石英含量13.4%，黄铁矿含量17.1%。样品具典型的黏土结构，矿物粒度微细。钒有两种赋存状态，一种呈钒云母的独立矿物形式存在，另一种则呈类质同相的形式存在于绢云母和伊利石中。典型测点平均含钒量为0.873%，fm-5测点钒含量2.143%，为钒云母；fm-6测点钒含量0.138%，为含钒伊利石；fm-7测点钒含量0.333%，为含钒绢云母。与钒云母、伊利石、绢云母三者结构相似，且粒度极其微细，无法分离，故应作为一个整体单元来回收利用钒。建议通过浮选脱除黄铁矿，然后通过擦洗—脱泥的方式对石英和黏土矿物进行分离，从而实现钒的富集。     

不同的配比对LiCoO_2和NaHSO_4·H_2O混合物在酸性焙烧产物中元素赋存状态的研究

了解废旧锂离子电池回收利用的现状和存在的问题对回收金属元素具有非常重要的意义。将LiCoO_2与NaHSO_4·H_2O按照摩尔比1∶1、1∶2、1∶3、1∶4进行混合,混合均匀后进行酸性焙烧,采用TG-DSC-MS、XRD和SEM研究了焙烧产物中元素的存在形式和赋存状态,研究结果表明:Na元素是以LiNa(SO_4)和Na_2Co(SO_4)_2的形式存在,Li元素的赋存形式是LiNa(SO_4),Co元素的赋存形式是Co_3O_4和Na_2Co(SO_4)_2,焙烧产物致密,形状不规则。     

会泽铅锌矿深部矿体稀贵金属的赋存状态

对会泽铅锌矿深部矿体稀贵金属的赋存状态进行了研究。结果表明,矿石中铅锌品位比较高,伴生元素锗、镉和银也已达到综合利用指标要求。锗和镉主要以类质同象存在于闪锌矿中,银主要以独立矿物形式存在于方铅矿中。在选别时,锗和镉进入锌精矿,而银进入铅精矿,锗、镉和银的回收率随铅锌回收率的增加而增加。因此,矿石中锗、镉和银亦可综合回收,该矿床具有良好的经济价值。     

Occurrence and factors associated with the presence of aflatoxin M1 in breast milk samples of nursing mothers in central Mexico

Aflatoxin M₁ (AFM₁) is the main mycotoxin frequently found in milk and dairy products. Exposure of infants to AFM₁ is of great health public concern because of its toxic and carcinogenic properties. The aim of this study was to determine the occurrence, levels and factors associated with the presence of aflatoxin M₁ in breast milk samples of nursing mothers in central Mexico. A total of 112 samples were collected and analyzed by a competitive-ELISA assay during January–August 2014. A Semi-Quantitative Food Frequency Questionnaire was used to determine weekly intake of food groups. Results showed that 89% of breast milk samples contained AFM₁ in a range of 3.01–34.24 ng/L. AFM₁ mean level was significantly higher (P < 0.05) in winter (12.78 ng/L) and spring (12.09 ng/L) than summer (7.91 ng/L). It was also detected that 7% of samples exceeded the European Community regulation (25 ng/L) for milk infant formula. The presence of aflatoxin M₁ was significantly associated (P < 0.05) to consumption of egg, cola drink and sunflower oil. The high occurrence and noticeable levels of AFM₁ detected, as well as the mean AFM₁ estimated daily intake (2.35 ng/kg b.w./day) suggested, for the first time, that breast-fed infants in the central region of Mexico, may be exposed to significant levels of this toxin through mother's breast milk.