小湾水电站开挖有用料规划设计

小湾水电站工程开挖量及混凝土量巨大,工程利用从开挖料中分选出的有用料加工成混凝土骨料,既解决了工程弃渣难、石料场开采任务重的问题,又为工程节约了大量的资金。

基于地质三维模型巴塘水电站有用料鉴别与挑选

由于巴塘水电站坝址区岩体风化卸荷和倾倒变形强烈、结构面发育且围岩破碎,导致有用料鉴别挑选及开挖困难。针对该问题,基于巴塘水电站前期勘察资料及引水发电系统现场地质编录资料建立地质三维模型,利用地质三维模型的可视化窗口,直观展示开挖边坡各结构面发育情况,进行有用料鉴别与挑选,通过控制边坡爆破顺序即可迅速开展有用料开挖工作。本次研究所取得的成果可大大加快现场施工速度、节省人力物力,具有重要的应用价值。

白鹤滩水电站料场补充开采规划优选设计

为解决白鹤滩水电站料场有用料储量不足的问题,依据储量复核结果,重点考虑现场地质条件、开挖面貌、扩挖时机、施工条件、经济性等因素,对补充开采规划方案进行了优选设计,并提出了3个补充开采规划方案。依据有用料储量、扩挖时机、施工条件、经济性4项评价指标,运用线性加权和法对3个方案进行了对比分析。结果表明,方案3为最优的规划方案,其扩挖后能增加有用料380万m3,可确保大坝混凝土工程骨料的供应,保障白鹤滩水电站的顺利建设。

普西桥水电站料场开采规划优化分析

普西桥水电站在大坝填筑伊始就面临料场地质条件发生变化、建筑物开挖可利用料偏低的状况,结合已开采地形和征地红线,对料场有用料储量进行复核,对料场开采规划方案进行优化,需增加备用料场以满足规范要求。实施过程中,通过采取加强料物管理、减少各项损耗等施工措施,有效提高了有用料的利用率,在满足质量的前提下既保证了大坝填筑供料强度,又降低了料场因高开口带来的施工难度和支护成本,并且最终未启用备用料场,投资、进度、环保等综合效益显著。

三维设计在两河口水电站石料场开采中的应用

两河口水电站为坝高295 m的砾石土心墙堆石坝,大坝所需堆石总量大。电站地处砂、板岩地区,砂、板岩为互层状分布,且各自强度差异大,同时板岩具有明显的各向异性。由于两河口石料场砂、板岩有上述的特点,施工期分区开采利用、现场管理难度均较大。为解决该石料场开采中存在的一系列问题,需要进行全新的三维设计。本文即通过GeoSmart软件进行了石料场的三维建模,模型中融合了料场的原始勘探信息、施工期分区开采填筑信息、有用料鉴定信息,并在开采期间实现了部分信息的动态更新,直观准确地反映了剥离料和有用料的储量关系、开采和填筑的关系、石料优化利用信息。

Direct extrusion of thin Mg wires for biomedical applications

Biodegradable wires,able to provide load-bearing support for various biomedical applications,are the novel trends in current biomaterial research.A thin 99.92%Mg wire with a diameter of 250μm was prepared via direct extrusion with an extreme reduction ratio of 1:576.The total imposed strain in a single processing step was 6.36.Extrusion was carried out at elevated temperatures in the range from 230 to 310℃and with various ram speeds ranging from^0.2 to^0.5 mm/s.The resulting wires show very good mechanical properties which vary with extrusion parameters.Maximum true tensile stress at room temperature reaches^228 MPa and ductility reaches^13%.The proposed single-step direct extrusion can be an effective method for the production of Mg wires in sufficient quantities for bioapplications.The fractographic analysis revealed that failure of the wires may be closely connected with inclusions(e.g.,Mg O particles).The results are essential for determining the optimal processing conditions of hot extrusion for thin Mg wire.The smaller grain size,as the outcome of the lower extrusion temperature,is identified as the main parameter affecting the tensile properties of the wires.

Design of relief-cavity in closed-precision forging of gears

To reduce the difficulty of material filling into the top region of tooth in hot precision forging of gears using the alternative die designs, relief-cavity designs in different sizes were performed on the top of die tooth. The influences of the conventional process and relief-cavity designs on corner filling, workpiece stress, die stress, forming load and material utilization were examined. Finite element simulation for tooth forming, die stress and forming load using the four designs was performed. The material utilization was further considered, and the optimal design was determined. The tooth form and forming load in forging trials ensured the validity of FE simulation. Tooth accuracy was inspected by video measuring machine(VMM), which shows the hot forged accuracy achieves the level of rough machining of gear teeth. The effects of friction on mode of metal flow and strain distribution were also discussed.

Effective Utilization of Concrete Sludge as Soil Improvement Materials

The amount of muddy soil generated from various kinds of construction sites is always problematic. It is very difficult to treat muddy soil because of its low strength and high water content. But, the reuse of muddy soil is necessary to reduce the total amount of industrial wastes. Surplus concrete is also in a similar situation. Coarse and fine aggregates are removed from surplus concrete as an intermediate treatment, however, concrete sludge still remains. The authors propose a reuse method that involves the muddy soil being mixed with concrete sludge as an improvement material. The possibility of the utilization of concrete sludge was investigated through laboratory experiments. As a result, it was found that the unconfined compressive strength of the improved soil mixed with concrete sludge increased as the curing proceeded.

Application Effect of Bio-organic Fertilizer on Chuanzhu 16

Through the application of bio-organic fertilizer on Chuanzhuo 16, the re- sults showed that the yield could reach 185.23 kg in treatment with bio-organic fer- tilizer, 40.22 kg more than the conventional fertilization, and the yield increase rate reached up to 27.7%.

Effective Utilization of Coal Fly Ash in Building Material Production

This paper is aimed at verifying utilization possibilities of alkaline modified coal fly ash as cement replacement in the concrete. The influence of alkaline activated coal fly ash originating from Slovakian power plant in Novsky （Si/Al = 3,1） as a partial cement replacement in concrete on compressive strength of hardened composites after 28 and 90 days was investigated. Alkaline activation of coal fly ash was realized in an autoclave at 130 ℃ and pressure of 160 kPa during 5 hours and in a reactor under normal conditions （equal temperature during 36 hours） at solid/liquid ratio of 0.5. Coal fly ash/cement mixtures were prepared with 25 % cement replacement by starting and modified coal fly ash and given in forms. Compressive strengths of composites after 28 and 90 days of hardening were compared to referential composite without coal fly ash and evaluated according to the standard of STN EN 450 by the value of relative strength KR （compressive strength of coal fly ash/cement composite to compressive strength of comparative concrete）. The final compressive strengths of hardened composites based on alkaline activated coal fly ash reached values in the range of 6 up to 50 MPa. In the set of experimental composites based on alkaline activated coal fly ashes, the highest value of relative strength after 28- and 90- days of hardening reached composite with cement replacement by coal fly ash zeolitized in autoclave （105% of compressive strength of referential sample）, what is connected with formation of zeolitic phases on surface of coal fly ash particles. The achieved results confirm that alkaline activation of coal fly ash in an autoclave under observed conditions can be successfully used as a partial cement replacement in concrete of C20/25 and C25/30 in accordance with requirements of standards （STN EN 450 and STN EN 206）.

Corn Leaf Water Retention as Affected by OrganicFertilizations and Effective Microbes Applications

Effects of organic fertilizers and effective microbes on leaf water retention of sweet corn (Zea mays L. cv.Honey-Bantam) were studied. Sweet corns were grown with organic or chemical fertilizers with or without effective microbes (EM). A water retention curve was obtained by drying the excised leaves under a light of 500 μmol (m2·s)-1. The curve shows two distinct phases. The initial steep slope indicates the water loss speed by stomatal transpiration (Est) and the gentle slope of the second phase indicates water loss speed by cuticular transpiration (Ecu). Both Est and Ecu were lower for leaves of plants grown with organic materials than for those with chemical fertilizers. Addition of EM to both organic and chemical fertilizers decreased Est but showed no effect on Ecu. The water retention ability of the excised leaves was proportional to photosynthetic maintenance ability under soil water deficit conditions as well as the solute concentration in leaves. The results suggested that organic fertilization and EM application increased water stress resistance both under in situ conditions and in excised leaves of sweet corn plants.

De-polymerization of Waste Polymers to Produce Hydrocarbon Fuel Utilizing Thermal Degradation

Waste plastics are one of the biggest environmental concerns the world faces today. Waste plastics exposure to the environment is very hazardous. Over time waste plastics photo-degrade and become very tiny dust particles. These dust particles contain very harmful compounds including benzene, sulfur, carbon and many others. According to studies, waste plastic pollutions are one of the biggest reasons for the depletion of the ozone layer and contributor of global warming. Many scientists have been trying to figure out how to utilize these waste plastics and convert them into useful energy sources. It is possible to convert waste plastics into energy because they are made from petroleum. Scientists have succeeded in developing many methods including pyrolysis, catalytic cracking, thermal degrading and others. The purpose of this experiment is to convert these environmentally harmful waste materials into useful energy source using simple and viable methods. A particular thermal degradation process was successful in extracting fuel from waste plastics at 370-420 ~C. In this paper we will discuss our performed experiment and provide detailed analysis of the produced fuel. Thorough instrumental analysis of the produced fuel showed very considerable results including high energy contents, low levels of harmful emissions and compatibility with various types of existing appliances.

Effects of AsN 1980 phytase on growth and phosphorus utilization of broilers

The experiment was conducted with 180 one-day-old AA broilers that were randomly divided into one control group and one trial group to study the effects of AsN1980 phytase on broilers growth performance and P utilization in low available phosphorus diets. Results showed that phytase supplement decreased F/W by 12.4%-13.4%and increased phosphorus availability by 7.63%-8.27%, both of which were significantly superior to the control group (P< 0.05).

Preparation, Properties and Application of Polymeric Organic-Inorganic Nanocomposites

Six preparation methods for polymeric organic-inorganic nanocomposites and their respective mechanisms and features are reviewed. The extraordinary properties of polymeric organic-inorganic nanocomposites are discussed,and their potential applications are evaluated.

Effective Use of Cement for Modification of Base Course Material

Cement improves properties of soil materials, such as durability, stiffness, strength and moisture susceptibility. Each of them needs different cement contents that might not be suitable for other properties. Typically, high cement content is desirable for durability, but not for shrinkage and cracking issues on the surface. Thus, improving durability with low cement content while complying with other requirements is an ideal aim, which may be achieved by pozzolanic supplementary products. Pozzolans contribute in hydration reactions and optimise cement consumptions in favour of durable and low shrinkage products. In this paper, the mixes of nano-silica and fly ash are considered to investigate their effect on strength, durability and shrinkage of modified CRB （crushed rock base） material. In the end, the benefits and features of nano-silica as a pozzolanic material will be focused and discussed more for effective cement consumption in soils.

Suppression of Fusarium Wilt of Banana with Application of Bio-Organic Fertilizers

Fusarium wilt is one of the most serious diseases of banana plants caused by soil-borne pathogen Fusarium oxysporum f.sp. cubense(FOC). In this study a pot experiment was conducted to evaluate the effects of different bio-organic fertilizers(BIOs) on Fusarium wilt of banana, including the investigations of disease incidence, chitinase and β-1,3-glucanase activities of banana plants, and FOC populations as well as soil rhizosphere microbial community. Five fertilization treatments were considered, including chemical fertilizer containing the same N, P and K concentrations as the BIO(control), and matured compost mixed with antagonists Paenibacillus polymyxa SQR-21 and Trichoderma harzianum T37(BIO1), Bacillus amyloliquefaciens N6(BIO2), Bacillus subtilis N11(BIO3), and the combination of N6 and N11(BIO4). The results indicated that the application of BIOs significantly decreased the incidence rate of Fusarium wilt by up to 80% compared with the control. BIOs also significantly promoted plant growth, and increased chitinase andβ-1,3-glucanase activities by 55%–65% and 17.3%–120.1%, respectively, in the banana roots. The population of FOC in the rhizosphere soil was decreased significantly to about 104 colony forming units g-1with treatment of BIOs. Serial dilution plating and denaturing gradient gel electrophoresis analysis revealed that the application of BIOs increased the densities of bacteria and actinomycetes but decreased the number of fungi in the rhizosphere soil. In general, the application of BIOs revealed a great potential for the control of Fusarium wilt disease of banana plants.

Enzyme Activity in Water-Stable Soil Aggregates as Affected by Long-Term Application of Organic Manure and Chemical Fertiliser

The activities of invertase, protease, urease, acid phosphomonoesterase, dehydrogenase, and catalase in different fractions of waterstable aggregates (WSA) were examined in long-term (26 years) fertilised soils. The long-term application of organic manure (OM) with chemical fertiliser (CF) significantly increased macroaggregate and decreased microaggregate percentages, enhanced the mean weight diameter, and significantly increased soil total carbon (TC) and total nitrogen (TN) contents of WSA in different size fractions. Combined fertilisation with OM and CF also increased invertase, protease, urease, acid phosphomonoesterase, dehydrogenase, and catalase activities of WSA in different size fractions. Enzyme activities were higher in macroaggregates than in microaggregates. The distribution of enzyme activities generally followed the distribution of TC and TN in WSA. The geometric mean of the enzyme activities in different WSA of OM-treated soils was significantly higher than that in soils treated with 100% CF or no fertiliser. The results indicated that the long-term combined application of OM with CF increased the aggregate stability and enzyme activity of different WSA sizes, and consequently, improved soil physical structure and increased soil microbial activity.

Recent progress on intramolecular charge-transfer compounds as photoelectric active materials

This article summarized the recent advance on the structural design and synthetic strategies of intramolec- ular charge-transfer compounds as well as their potential ap- plications in two-photon absorption chromophores, organic photovoltaics and organic light-emitting diodes.

Purely organic optoelectronic materials with ultralong-lived excited states under ambient conditions

The exponential growth of utilizing synthetic organic molecules in optoelectronic applications poses strong demands for rational control over the excited states of the materials. The manipulation of excited states through molecular design has led to the development of high-performance optoelectronic devices with tunable emission colors, high quantum efficiencies and efficient energy/charge transfer processes. Recently, a significant breakthrough in lifetime tuning of excited states has been made;the purely organic molecules were found to have ultralonglived excited state under ambient conditions with luminescence lifetimes up to 1.35 s, which are several orders of magnitude longer than those of conventional organic fluorophores. Given the conceptual advance in understanding the fundamental behavior of excited state tuning in organic luminescent materials, the investigations of organic ultralong room-temperature phosphorescence(OURTP) should provide new directions for researches and have profound impacts on many different disciplines. Here, we summarized the recent understandings on the excited state tuning, the reported OURTP molecules and their design considerations,the spectacular photophysical performance, and the amazing optoelectronic applications of the newly emerged organic optoelectronic materials that free of heavy metals.

Two-dimensional organic-inorganic hybrid perovskite: from material properties to device applications

The two-dimensional（2D） perovskite（including pure-2D and quasi-2D） is formed by introducing large-group ammonium halides into conventional bulk perovskite. In the past twenty years, 2D perovskite materials were widely developed with the enriched species and advanced physicalknowledge in material characteristics as well as optoelectronic device applications. To review achievments in 2D perovskite,the fundamental mechanism and properties of 2D perovskite are introduced to offer insight into device performance.Moreover, the preparation methods of 2D perovskite films are summarized and compared. The latest successful applications of the 2D perovskite in the solar cells and light-emitting diodes fields, especially the advanced stability of 2D perovskite solar cells（PeSCs） and the efficient 2D perovskite lightemitting diodes（PeLEDs）, are also achieved. Furthermore, the challenges and outlook of 2D perovskite materials are proposed.