石匣小流域坡地水土流失监测系统的建立及应用

以石匣小流域为坡地水土流失监测试点,以遥感及地理信息系统技术为手段,以坡地径流小区定位观测为依据,建立石匣小流域坡地水土流失监测系统,定位、定性、定量监测各种坡地类型的水土流失量、污染物流失量,为水土流失监测预报提供数据,为全市山区水土流失监测预报工作提供经验及方法,为制定水土流失防治方针政策及水土流失生态环境建设提供依据.     

非法DHCP服务器攻击解决方案

DHCP服务是一种常见的网络服务,该服务简化了网络管理员大量的配置工作。然而有些网络内会产生非法DHCP服务器的攻击行为。文中介绍了三种应对DHCP攻击的方法,采用交换机的DHCP Snooping绑定表和利用"域"的方式减少冲突,采用查询非法DHCP主机的方法找到源头加以处理。采用三种应对方法可以解决网络中存在的DHCP冲突问题。     

透明香皂的研制

介绍了生产透明香皂的新配方和新工艺 ,提出了透明香皂的企业标准。新工艺用丙二醇取代传统工艺所用的乙醇做溶剂 ,生产周期大为缩短。采用速冻隧道设备 ,可方便地实现不同品种的切换 ,操作方便 ,设备投资少 ,产品综合成本低 ,具有较大的工业应用价值     

Preparation,characterization and salt-resistance of a coal based super absorbent composite

Potassium humate was extracted from brown coal.A novel super absorbent composite,poly (acrylic acid-co-acrylamide)/potassium humate (PAA-AM/KHA),was prepared by graft polymerization of acrylic acid,acrylamide and coal based potassium humate using N,N'-methylenebisacrylamide as a crosslinker and potassium peroxydisulfate as an initiator.The effects of reaction temperature,degree of neutralization of the poly (acrylic acid) and the amounts of crosslinker,initiator and potassium humate were investigated.Salt resistance tests were also carried out.The composite prepared under optimal conditions had a potassium humate content of 10% and exhibited a water absorption of 770 g/g in distilled water,and 349,286 and 41 g/g in 0.5 mol/L KC1,MgCl2 and AlCl3 solutions respectively.The results indicate that the salt resistance of PAA-AM/KHA was superior to that of poly (acrylic acid-co-acrylamide) because of the collaborative effect of functional groups of the coal based potassium humate.The PAA-AM/KHA micro powder was characterized by IR spectroscopy and the micrographic surface was characterized by scanning electron microscopy.Introduction of potassium humate into the poly (acrylic acid-co-acrylamide) structure creates a composite more suitable for use as a water-managing material in the renewal of arid and desert environments.The salt resisting property of the composite is improved,production costs are reduced and the growth stimulant effect is still present.     

Formation and thermal stability of amorphous Ni-Mo-P alloys

The experimental researches on the chemical deposition of Ni-Mo-P amorphous alloys were carried out by adding Na2 MoO4 into acidic solutions. The optimum technology conditions were obtained by orthogonal design experiments. The structures and the relationship between compositions and their thermal stability were studied by energy spectrum (EC), scanning electron micrograph and X-ray diffraction spectrum. Compared with Ni-P amorphous alloys, the Ni-Mo-P amorphous alloys have high crystallization temperature and thermal stability, and the hardness reaches its peak when the annealing temperature is 500 ℃. With the increase of the heat treatment temperature, the surface morphology of the alloys changes.     

盘式自动折叠纸盒结构设计中的数学模型

盘式自动折叠纸盒因其方便性得到了广泛的应用.本文讨论了盘式自动折叠纸盒的折叠角及体板高度等数学问题,为该类包装纸盒CAD开发建立了有效的数学模型.     

Synthesis of MoS2 and MoO2 for their applications in H2 generation and lithium ion batteries: a review

Abstract

Scientists increasingly witness the applications of MoS₂ and MoO₂ in the field of energy conversion and energy storage. On the one hand, MoS₂ and MoO₂ have been widely utilized as promising catalysts for electrocatalytic or photocatalytic hydrogen evolution in aqueous solution. On the other hand, MoS₂ and MoO₂ have also been verified as efficient electrode material for lithium ion batteries. In this review, the synthesis, structure and properties of MoS₂ and MoO₂ are briefly summarized according to their applications for H₂ generation and lithium ion batteries. Firstly, we overview the recent advancements in the morphology control of MoS₂ and MoO₂ and their applications as electrocatalysts for hydrogen evolution reactions. Secondly, we focus on the photo-induced water splitting for H₂ generation, in which MoS₂ acts as an important co-catalyst when combined with other semiconductor catalysts. The newly reported research results of the significant functions of MoS₂ nanocomposites in photo-induced water splitting are presented. Thirdly, we introduce the advantages of MoS₂ and MoO₂ for their enhanced cyclic performance and high capacity as electrode materials of lithium ion batteries. Recent key achievements in MoS₂- and MoO₂-based lithium ion batteries are highlighted. Finally, we discuss the future scope and the important challenges emerging from these fascinating materials.     

Application of material strength reserve method to the stability analysis of earth dam of feilaixia multipurpose project

The material strength reserve method is practical in the study of the stability and failure mechanism of earth dam by analysing the development of failure zone of different shear strength parameters of the earth mass of the dam. The stability in the concrete dam and ensemble architecture has got general application while analysing. In combination with Feilaixia Multipurpose Project, application of this method to earth dam stability analysis was studied by plane Finite Element Method（FEM） for the first time. Through plane FEM, we can get the failure mechanism of earth dam and appraise to the security, for operating and managing put forward some reference suggestions.     

天然气置换后铸铁管承插接口漏气对策

分析了天然气置换人工煤气后铸铁管道承插接口漏气原理,介绍了4种解决方案:管道更换、PE管内衬、接口修补及燃气加湿,对其进行了技术经济比较。     

SVD based scale transform invariant observable degree for LTI system

Dear editor, The basic concept of observability is used to express the possibility to recover the state from measurements in modern control theory [1-3].It is a...