Catalytic activity of various iron sulphides in coal liquefaction

Iron sulphides with various S-Fe atomic ratios, such as pyrite, iron(III) sulphide, pyrrhotite and troilite, were used as catalysts for coal liquefaction. Catalytic activities were compared on the basis of the temperature of the exothermic peak due to coal hydrogenolysis. Effects of hydrogen sulphide on catalytic activity of iron sulphides were also investigated. It is concluded that:

• 1.1. The catalytic activity of iron sulphides increases with increasing S-Fe ratio;
• 2.2. pyrite, with the highest catalytic activity, is converted to pyrrhotite before the onset of exothermic reactions from coal hydrogenolysis, this evidently being the reason for the high catalytic activity;
• 3.3. the catalytic activity of iron sulphides depends on the coal type;
• 4.4. the high catalytic activity of pyrite may be due to the creation of fresh pyrite surface during the reaction rather than to the presence of high concentrations of hydrogen sulphide.

     

Biological additives for improved mechanical dewatering of fuel-grade peat

Several different biological compounds were found to be effective pretreatment agents for the removal of water from highly humified peat by mechanical pressing. The peat was pressed for 2.5 min at 1.96 MPa. The agents added were polymers or surfactants. Two compounds were particularly effective. The cationic polysaccharide, chitosan, increased the amount of water removed by 60% compared with the control. The surfactant from Bacillus subtilis increased the amount of water removed by 〉 50%. The mechanism of dewatering by the chitosan is shown to be coagulation of the colloidal particles of peat suspended in water. This allows efficient phase separation by pressing. It is suggested that the surfactant improves dewatering by increasing the spreading coefficient between the trapped interstitial water and the peat waxes.     

基于WinPcap的网络分析的研究与实现

主要讨论利用WinPcap开发包实现Windows下网络数据包的捕获技术,分析了IP、TCP等协议的解析过程,利用MS-Sql数据库来存储网络数据,建立了系统硬件运行环境。通过测试,实现了对局域网的监控功能。     

A multi-agent model system for land-use change simulation

This paper presents a multi-agent model system to characterize land-use change dynamics. The replicable parameterization process should be useful to the development of simulation frameworks, important to environmental policy makers to analyze different scenarios during decision making process. The methodological two-fold approach intends to form a solid backbone based on: (i) the systematic and structured empirical characterization of the model; and (ii) the conceptual structure definition according to the agent-based model documentation protocol – Overview, Design concepts and Details. A multi-agent system for land-use change simulation was developed to validate the model, which is illustrated with a case study of the Brazilian Cerrado using LANDSAT ETM images. The simulation results prove the model importance with a figure of merit greater than 50%, what means the amount of correctly predicted change is larger than the sum of any type of error. The results are very good compared with nine popular peer-reviewed land change models.     

PUseqClust:一种RNA-seq数据聚类分析方法

基因的聚类分析是基因表达数据分析研究的重要技术,它按照表达谱相近原则将基因表达数据归类,探究未知的基因功能.近年来,RNA-seq技术广泛应用于测量基因表达水平,产生了大量的读段数据,为基因表达聚类分析提供了充分条件.由于读段非均匀分布的特性,对读段计数一般采用负二项分布进行建模.现有的负二项分布算法和传统的聚类算法对于聚类分析都是直接对读段计数进行建模,没有充分考虑实验本身存在的各种噪声,以及基因表达水平测量的不确定性,或者对聚类中心的不确定性考虑不够.基于PGSeq模型,模拟读段的随机产生过程,采用拉普拉斯方法考虑多条件多重复基因表达水平之间的相关性,获得了基因表达水平的不确定性,联合混合t分布聚类模型,提出PUseqClust （propagating uncertainty into RNA-seq clustering）框架进行RNA-seq读段数据的聚类分析.实验结果表明,该方法相比其他方法获得了更具生物意义的聚类结果.     

一种新颖的智能码盘的研究

在此介绍了一种由极少硬件构成的简易智能码盘,该系统主要由单片机和拨码开关组成,采用拨码开关设置输入数据量的位码和数码,通过外部中断数据采集按键控制该位数据量的输入,并由显示器监视,内部E-PROM保存,同时通过串行口向用户系统发送设置数据。故使用该码盘用户系统仅占用一个串行口或虚拟串行口就可实现16位BCD码设置或64位二进制码输入,16住BCD码可根据用户需要分割为几组,每组数据的位数也可任意定义,以满足各种控制系统控制参数设置的需要。     

2D MoN1.2-rGO Stacked Heterostructures Enabled Water State Modification for Highly Efficient Interfacial Solar Evaporation

Improving interfacial solar evaporation performance is crucial for the practical application of this technology in solar-driven seawater desalination. Lowering evaporation enthalpy is one of the most promising and effective strategies to significantly improve solar evaporation rate. In this study, a new pathway to lower vaporization enthalpy by introducing heterogeneous interactions between hydrophilic hybrid materials and water molecules is developed. 2D MoN_1.2 nanosheets are synthesized and integrated with rGO nanosheets to form stacked MoN_1.2-rGO heterostructures with massive junction interfaces for interfacial solar evaporation. Molecular dynamics simulation confirms that atomic thick 2D MoN_1.2 and rGO in the MoN_1.2-rGO heterostructures simultaneously interact with water molecules, while the interactions are remarkably different. These heterogeneous interactions cause an imbalanced water state, which easily breaks the hydrogen bonds between water molecules, leading to dramatically lowered vaporization enthalpy and improved solar evaporation rate (2.6 kg m⁻² h⁻¹). This study provides a promising strategy for designing 2D-2D heterostructures to regulate evaporation enthalpy to improve solar evaporate rate for clean water production.