Wet grindability of an industrial ore and its breakage parameters estimation using population balances

The grindability of a diasporic ore was studied by wet grinding in a laboratory ball mill and its breakage parameters were determined based on the population balance model (PBM). Four different feeds with unnatural size distributions were designed to save grinding and sieving work. It was found that three size-intervals fitted the first-order breakage, but the coarsest interval did not. The non-first order breakage was most probably caused by the heterogeneity of the material. The heterogeneity was then confirmed by experiments. The breakage rate and the breakage distribution parameters were back calculated by treating the non-first order breakage as two linear segments according to the grinding time. The back-calculated breakage rates were in good agreement with the values calculated directly from the experimental data, and non-normalizable breakage distribution was observed. The model with the obtained parameters simulated the experimental product size distributions with good accuracy. These findings are valuable to the simulation and optimization of the industrial grinding processes of diasporic ores.     

我国江河工程凌汛计算研究进展综述

冬季,我国北纬30°以北和青藏高原的江河上都存在不同程度冰情,有些江河还会发生较严重凌汛。在这些地区兴建水利水电工程及跨河建筑物,因改变了部分河道热力、动力及边界条件,不仅影响到河道防凌安全,而且往往对工程本身安全构成威胁。50年来,我国的工程凌汛研究工作,在吸取了国外凌汛研究经验基础上,结合工程设计、施工和管理实践,进行了大量资料测验、科学试验及分析研究。通过总结以上研究成果,对工程影响下的3类冰凌洪水形成条件及主要特征量提出了较完整、科学且实用的分析计算方法,以期为兴建同类工程时的凌汛计算提供有益借鉴。     

中国河流流域化学风化和全球碳循环

通过研究中国境内九大水系中大河流域的河水、大气降水、沉积物和岩体中的化学成分并结合水文信息,对流域中的化学风化作用及其消耗大气CO<,2>的能力与机制进行了粗略的调查,探讨了不同气候、岩性、地形、植被等条件下化学风化的变化趋势,分析了控制风化反应的因素,为在我国境内进行CO<,2>捕获与封存的场地、矿物类型选择提供了参...     

Impacts of human activities on the hydrology of Baiyangdian Lake,China

Baiyangdian Lake is the biggest natural freshwater wetland in North China Plain. It provides important ecosystem services such as water regulation and supply, reed production and biodiversity protection. Baiyangdian Lake, however, was threatened by lack of freshwater in recent decades. In this paper, the hydrological changes of the lake were quantified using historical data of water level and groundwater table, and satellite images. In addition, the relationship between water level and socioeconomic development of the basin was investigated. The result revealed a significant decreasing trend of water level in the lake. Water level and groundwater table of Baiyangdian Lake decreased rapidly, caused by the great increase of water withdrawal and consumption due to socioeconomic development in the basin. In particular, population growth and the expansion of irrigated agriculture were two major contributors to the decline of water level and groundwater table. While precipitation was positively correlated with water level, it has less impact on water level and groundwater table than human activities. The diversion of water to the lake raised the water level temporarily and had significant benefits on the wetland ecosystem. The best way to solve ecological problems of Baiyangdian Lake, however, is to control the growth of population, adjust the industrial structure, control land use conversion and improve water use efficiency at the basin scale.     

试论吉拉沟的构造成因

从吉拉沟的形态、第四纪沉积物特征、人工地震剖面、电磁场特征及探槽揭露等认为：吉拉沟在深部对应于一基底隆起，该隆起被海西期断裂所限制。这些断裂在印支早期便停止了活动。在区域南北向应力场及差异压实作用下，基底隆起形成潜山型内核。其上覆中－新生界盖层形成披覆型背斜，在背斜顶部产生一系列平行于轴向的纵张裂隙。在内外营力的共同作用下，这些纵张裂隙不断发展贯通，并演变成规模巨大、近东西走向的吉拉沟。     

论东河塘组的时代

东河塘组在塔里木盆地分布广泛，长期以来被视为早石炭世早期的沉积。近年来，开展了对巴楚小海子露头剖面和塔里木盆地沙漠覆盖区钻井剖面的深入研究，积累了大量资料。根据露头和井下东河塘组及其上覆、下伏地层层序的辨别和所含古生物化石的鉴定，认为东河塘组的地质时代应属于晚泥盆世，大致可与塔西南的奇自拉夫组进行对比。     

用剪切波速判别砂土液化的新方法

本文目的是建立剪切波速评价场地砂土液化的定量方法,以西特简化法的思路为基础,提出了用剪切波速估算地震应力和抗液化应力的计算公式,并编制了相应的程序,计算了液化与非液化实例,计算结果与实际情况颇为一致。     

沙地柠条(Caragana)灌丛微生境节肢动物群落特征

以宁夏荒漠草原柠条（Caragana）灌丛林地为研究对象,于2011年春、夏、秋季,利用陷阱诱捕法,调查了灌丛微生境节肢动物群落分布特征。结果表明：（1）调查共获得节肢动物9目31科32个类群,分属于4种功能群（植食性、捕食性、腐食性和杂食性）。其中,优势类群为蚁科（Formicidae）和拟步甲科（Tenebrionidae）,个体数占总个体数的71.97%;常见类群有7科8个类群,个体数占总个体数的19.72%;其余22个类群为稀有类群,个体数仅占总个体数的8.30%。（2）随着季节变化,灌丛内外节肢动物类群组成和个体数分布均发生改变。春季灌丛内外均包括优势类群、常见类群和稀有类群;夏季灌丛内外均包括优势类群,而灌丛下仅有常见类群,无稀有类群,灌丛外既没有常见类群也没有稀有类群;秋季灌丛内外均有优势类群和常见类群,但灌丛内外均无稀有类群。（3）夏季灌丛内外共有类群数最少,相似性指数最低,秋季次之,而春季灌丛内外共有类群数最多,相似性指数也最高。（4）春季和秋季,灌丛内外微生境中节肢动物个体数、丰富度和Shannon指数均无显著差异（P>0.05）。夏季,节肢动物个体数灌丛内外无显著差异性（P>0.05）,但丰富度和Shannon指数均表现为灌丛内显著高于灌丛外（P<0.05）。（5）春季灌丛内外捕食性、植食性和杂食性节肢动物的个体数和丰富度均无显著差异性（P>0.05）;但是,腐食性动物个体数和丰富度均表现为灌丛内显著高于灌丛外（P<0.05）。夏季,仅有捕食性动物丰富度呈现出灌丛内显著高于灌丛外（P<0.05）,而其他指标灌丛内外均无显著差异性（P>0.05）。秋季,每种功能群动物的个体数和丰富度灌丛内外均无显著差异性（P>0.05）。沙地灌丛内外生境中节肢动物的空间分布,既与灌丛本身生理生态学特性相关,也与季节性降雨和温度等气象条件的改变密切相关。     

城市计算视角下的空间粗糙关联规则方法研究

同位模式表示不同类型的实体在空间邻域内共同频繁出现的规律,是城市实体空间关联的主要表达形式,但不能挖掘出指定实体的空间关联,需要寻找新的计算方法。在城市计算的视角下,通过引入粗糙集研究城市空间关联问题发现：1）该方法能把复杂的地理空间关联问题转换成信息决策问题,在信息决策表中计算城市实体之间的空间关联等拓扑关系,计算过程和结果可以挖掘城市行业之间的空间集聚和关联问题。2）通过属性约简得到属性核可以把高维空间数据降维,找到影响空间关联的重要因子。3）该方法拓宽了城市计算的理论方法体系和粗糙集方法的行业应用。最后,通过Python爬取南宁市城市服务业数据,进行方法的验证,计算结果与成熟的Apriori算法结果,以及南宁市服务业空间关联实际情况基本一致,证明了粗糙空间关联方法的可行性和正确性。