基于HEC-HMS的水打沟泥石流汇流过程

以四川省都江堰市龙池镇水打沟泥石流流域为研究区,利用遥感影像与GIS技术提取流域信息,基于HEC-HMS分布式水文模型,模拟了"2010-08-13"泥石流的暴雨汇流过程,并综合考虑泥石流的特征参数,从最大流量角度初步研究水打沟泥石流的汇流过程;探讨了研究区土地利用情况、模拟降雨时间及暴雨频率对泥石流汇流过程的影响,从而揭示三者与汇流过程之间的内在联系。研究结果表明:泥石流20 a一遇峰值流量为53.49 m3/s,灌木林将峰值流量降低24%,而休耕地的峰值流量提高70%。100 a一遇的暴雨,泥石流峰值流量增加到70.62 m3/s,同比增长32%,50 a一遇的增长23%,10 a、5 a一遇的降雨分别同比降低4%、16%。降雨总量一定的情况下,仅增加泥石流暴发前后的降雨模拟时间对汇流的影响不大,且泥石流发生之前的降雨对汇流的影响大于之后的降雨。

水打沟岸坡堆积体滑坡转化为泥石流的前期降雨条件分析

2010年8.13水打沟滑坡型泥石流危害严重,为此有必要分析研究滑坡起动条件及滑坡转化为泥石流的前期降雨条件,以便为预测滑坡型泥石流奠定基础。针对水打沟处地形地貌条件、地层岩性、地质构造条件和2010年8月13日的暴雨条件,从静力学和动力学角度分析了滑坡堆积体在强降雨条件下的起动条件及斜坡松散堆积体其失稳条件时的地表径流水深,得到了水打沟8.13泥石流形成前滑坡转化为泥石流时的前期降雨量、降雨强度及泥石流爆发时间等,可为经历过2008年汶川5.12大地震后的同类冲沟滑坡及泥石流预测、预防提供参考。

黑龙江省讷河市采取综合技术措施有效治理水打沟

水打沟是在一定地形、地质、气候条件下形成的,出现在土质疏松、缺少植被和暴雨较多地区的斜坡和塬畔。遇有骤雨或积雪急剧消融时产生急流,急流沿着凹形汇水斜坡向下倾泻,具有较大流量、流速,冲刷能力很强。在流动过程中发生显著线状冲刷,形成水打沟,并把冲刷下来的碎屑物质夹带到山麓平原或沟谷堆积下来形成冲积层。

公路水打沟的治理与防治措施

水打沟的形成、危害和治理方法,以及水打沟的防治措施。着重强调了生态平衡、绿化的重要性。

《醒世姻缘传》方言词补释

本文补充解释了“除的家”、“打立水”、“黑面”三则向来解释欠确或未曾解释过的词语。

Research on hydraulic slotting technology controlling coal-gas outbursts

Measured to control serious coal-gas outburst in coal seam were analyzed by theory and experimented in test site.A new technique to distress the coal-bed and drain methane,called hydraulic slotting,was described in detail,and the mechanism of hydrau- lic slotting was put forward and analyzed.The characteristic parameter of hydraulic slotting was given in Jiaozuo mining area and the characteristic of validity,adaptability and secu- rity was evaluated.The results show that the stress surrounding the strata and the gas in coal seam is released efficiently and thoroughly while new techniques are taken,as slot- ting at heading face by high pressure large diameter jet.The resistance to coal and gas outbursts is increased dramatically once the area of slotting is increased to a certain size. In the process of driving 2 000 m tunnel by hydraulic slotting excavation,coal and gas outburst never occurre.The technique could be used to prevent and control potential coal-gas outburst in the proceeding of tunnel driving,and the speed tunneling could be as high as more than 2 times.

构式“铁打的X,流水的Y”探析

本文首先对"铁打的X,流水的Y"构成成分中的常项和变项进行分析,接着抽象出其构式义和表达作用,最后就该构式的传播原因和发展机制进行解释。认为构式"铁打的X,流水的Y"在语用层面的表达及其传播与以下几个方面有关:一是与独特的信息传递功能和形象经济性有关;二是社会热点事件的焦点性关注和年轻网民群体的大力推广有关;三是该构式有着语言内部和外部相互作用的发展因素。

Sintering properties of in situ Ti-TiB microlattices created by 3D extrusion printing of TiH_(2)+TiB_(2) inks

A direct 3D extrusion printing technique was used to produce Ti-TiB filaments and microlattices.The sintering properties of 3D ink extrusion and sintering of in situ Ti-TiB composite structures made from TiH_(2)+TiB_(2) ink were investigated.The sintering kinetics of TiH2+TiB2 inks was studied during densification by pressureless sintering at 1050−1200℃ for 4−24 h in Ar.The linear shrinkage,grain size,microhardness,X-ray diffraction(XRD)patterns,and microstructural evolution of the Ti-TiB composite were studied.The sintering temperature had a more pronounced influence than the sintering time on the density of the Ti-TiB composite.There were two kinds of pores,irregular and spherical,caused by the Kirkendall effect and indiffusable gases.The TiB formed by in situ synthesis existed as either separated TiB whiskers(needle-like shapes)or clusters of TiB whiskers.The results of this work could be useful for controlling microporosity through incomplete sintering within filaments,especially for the production of in situ Ti-TiB with high volume fractions of TiB or other composites.

Basic formation mechanisms of Lake Doroninskoye soda water, East Siberia, Russia

The primary scientific goal of studying salt lakes is to better understand the formation of small continental- type hydrogeochemical systems. Many scientists have attributed the metamorphism of the chemical composition of salt lakes to the evaporative concentration of water. How- ever, the formation of soda water is inconsistent with this hypothesis. Thus, analyzing intrabasinal biochemical pro- cesses and water--rocks interactions during the evaporative concentration of water allows us to understand the major mechanisms of the formation and evolution of water com- positions. Therefore, the aim of this paper is to identify the key processes involved in the formation of the chemical composition of the water in Lake Doroninskoye. An analysis of the distribution of major components shows that Na＋, HCO3-, CO32-, and C1- are dominant in this water. High concentrations of these elements are the result of evaporative water concentration. Calcium, magnesium, and potassium are not accumulated because the water is saturated in min- erals containing these elements. The main barrier to the growth of the sulfate content of water is sulfate reduction. This process also contributes to the additional reproduction of carbon dioxide, which reacts with the products of the hydrolysis of aluminosilicates OH- to form HCO3- and CO32-, thus further contributing to the natural processes of soda formation.

Genre Effect on L2 Syntactic Complexity and Holistic Rating for Writing Quality of Intermediate EFL Learners

This exploratory study examines whether genre has an impact on syntactic complexity and holistic rating in EFL writing. Over 300 sample texts produced by intermediate learners were collected from a test and some regular after-class assignments for English writing courses. Each participant completed two writing tasks, one argumentative and the other narrative. Results show that genre type has a significant impact on L2 syntactic complexity. Genre effect is found stronger with timed writing tasks. L2 holistic ratings show correlation with syntactic complexity on the different measure(s) depending on genre type and planning conditions. Regression analyses reveal that for timed writing tasks, clausal density(clauses per sentence) is a reliable predictor for holistic assessment on intermediate EFL learners’ writing quality. It is found to account for 6% of the score variance for timed writing and 10% for timed argumentative writing. Genre is evidenced to be related to EFL writing holistic ratings. Closer examination indicates that while syntactic complexity is predictive of holistic writing scores for argumentative writing, it does not correlate with holistic scores for narrative writing. Other linguistic features rather than syntactic complexity may be accountable. Overall, the study lends support to genre effect in the relationship between syntactic complexity and L2 writing quality holistic rating.

Influence of feature size of micro-scale channel on ink flow characteristics

Under the micro-scale condition,feature size of the channel is one of the main factors influencing the fluid flow characteristics. In printing process,ink thickness in the extrusion zone formed by two ink rollers may reach micron scale. Compared with macroscopic fluid,the velocity field and the pressure field of fluid may change when the feature size of fluid channel reaches micron scale. In order to control printing quality,it is necessary to research the influence of feature size on ink flow characteristics in micro scale. This paper analyzes it in theory,and then numerical simulation of an ink flow model with different feature sizes is carried out in no slip condition. The influence of the feature size on the ink flow characteristics and the wall shear force are obtained. Besides,the ink flow model with different feature sizes is simulated numerically in slip condition,and the influence of feature size on ink flow characteristics is obtained. Finally,by comparing and analyzing the above results,it can be concluded that both the ink velocity and pressure at the inlet of the extrusion zone are inversely proportional to the feature sizes whether in slip condition or not. And the ink velocity in slip condition is larger than that without slip,the pressure at the inlet of the extrusion zone is less than that in no slip condition. Within the micro-scale range,the ink velocity difference between the two conditions cannot be ignored. Therefore,it is necessary to consider slip when analyzing the influence of feature size of micro-scale channel on ink flow characteristics.

RESEARCH ON DEEP COAL SEAM MINING FLOOR STARTA WATER BURSTING INFLUENCED FACTORS BASED ON ANALYTIC HIERACHY PROCESS

Deep coal seam mining floor strata water bursting is a complicate nonlinear system, whose factors are coupling and influencing themselves. It built the analytic structure model for deep coal seam mining floor strata water bursting, the judgment matrix was found by the expert scoring method, the contribution weights of the influenced factors were given out by the equation analytic process. The thirteen controlling factors and five main controlling factors were put award by analyzing weights, so the result was basically conform to the field practice. The expert scoring method and analytic process can convert the objective fact to the subjective cognition, so it is a method that can turn the qualitative into the quantitative. This can be relative objectively and precisely to study the question of many factors and grey box.

Impact of Mechanization on Lowland Rice Production in Nigeria

The study examined the impact of using power tiller as a means of mechanizing lowland rice production in Nigeria. The study was carried out in Bida area, Niger State, where the sawah rice production was disseminated by Watershed Initiative in Nigeria （WIN）. And in Ajase Ipo of Kwara State, some of the parameters assessed during the study included average speed of operation, average wheel slip/travel reduction, average draught of implement, and fuel consumption. The cost of operation and yield over five years of usage at Niger State and two years in Kwara State was determined and it was therefore concluded that the power tiller is the most appropriate field machinery for tillage operations such as puddling, leveling on lowland rice production in Nigeria.

三峡春夏节气气象谚语与农业气候适应关系的探讨

一、气象(候)、节气和节气气象谚语1.气象(候)气象:大气中的冷、热、干、湿、风、云、雷、电、雨、雪、霜、雾等各种物理状态和物理现象的统称。天气:指一定区域和一定时间内各种气象变化,如阴、暗、冷、暖、干、湿等。气候:一定地区的天气特征。天气与气候既有区别有又联系。

ASSESSMENT AND FUZZY COMPREHENSIVE GRADING OF STUDENTS' ENGLISH COMPETENCE

In light of the traditional teaching method used in English classes in China and many other places, this article states the importance of linking instruction and assessment in the English teaching process and presents different approaches to linking instruction and assessment in classroom teaching which are proven effective in solidifying students' knowledge of English and improving students' comprehensive English competence. Then, based on the results from the assessments, a Fuzzy Comprehensive Grading Approach is adopted in calculating students' final grade. The Approach is based on the fuzzy set theory of fuzzy mathematics, and it considers diverse factors and assigns proper weight to different factors in grading, using fuzzy matrix operation in calculating students' grades; therefore, it is comprehensive and reliable, and can avoid the influence of odd scores and give a truer and more balanced measurement of students' English ability.

State-of-the-art of 3D printing technology of cementitious material—An emerging technique for construction

In recent few years, significant improvement has been made in developing largescale 3 D printer to accommodate the need of industrial-scale 3 D printing. Cementitious materials that are compatible with 3 D printing promote rapid application of this innovative technique in the construction field with advantages of cost effective, high efficiency, design flexibility and environmental friendly. This paper firstly reviews existing 3 D printing techniques that are currently being used in commercial3 D printers. It then summarizes three latest development of largescale 3 D printing systems and identifies their relationships and limiting factors. Thereafter, critical factors that are used to evaluate the workability and printable performance of cementitious materials are specified. Easy-extrusive, easy-flowing, well-buildable, and proper setting time are significant for cementitious material to meet the critical requirements of a freeform construction process. Finally, main advantages, potential applications and the prospects of future research of 3 D printing in construction technology are suggested. The objective of this work is to review current design methodologies and operational constraints of largescale 3 D printing system and provide references for optimizing the performance of cementitious material and promote its responsible use with largescale 3 D printing technology.

Coaxial 3D bioprinting of organ prototyps from nutrients delivery to vascularization

Vascular networks inside organs provide the means for metabolic exchange and adequate nutrition.Similarly,vascular or nutrient networks are needed when building tissue constructs>500μm in vitro due to the hydrogel compact pore size of bioinks.As the hydrogel used in bioinks is rather soft,it is a great challenge to reconstruct effective vascular networks.Recently,coaxial 3 D bioprinting was developed to print tissue constructs directly using hollow hydrogel fibers,which can be treated as built-in microchannels for nutrient delivery.Furthermore,vascular networks could be printed directly through coaxial 3 D bioprinting.This review summarizes recent advances in coaxial bioprinting for the fabrication of complex vascularized tissue constructs including methods,the effectiveness of varying strategies,and the use of sacrificial bioink.The limitations and challenges of coaxial 3 D bioprinting are also summarized.

Regenerated hydrogel electrolyte towards an all-gel supercapacitor

Electrolyte regeneration is an important goal for environmental protection and sustainable development efforts.Herein,we report a facile strategy inspired by the transformation of edible dough from flour to regenerate hydrogel electrolytes from their dehydrated copolymer granules(CGs)via direct addition of water or salt solution.With the aid of heating,this procedure is efficient,relatively quick,and easily implemented.The dehydrated CGs are lightweight,reusable and stable under long-term storage.Even after 5 cycles of dehydration and regeneration,the regeneration efficiency of the hydrogel electrolytes,as evaluated based on retention of mechanical strength,is over 60%.The regenerated electrolytes possess considerable ionic conductivity,reprocessability,and 3D-printability.Furthermore,an all-gel supercapacitor assembled from the regenerated hydrogel electrolyte and activated carbon electrode with CGs as binder demonstrates excellent interfacial compatibility.The assembled all-gel supercapacitor can maintain 98.7% of its original specific capacitance after 100 bending tests,and can operate in a wide temperature range spanning from-15 to 60°C.This work may provide a new access to the development of renewable materials for various applications in the fields of intelligent devices,wearable electronics and soft robotics.