高压水枪湿土法和瓶旋转播种法加速温室批量拟南芥的栽培进程

[目的]为了寻找适用于温室批量拟南芥栽培过程中快速且经济实用的盆栽土浇湿方法和播种方法。[方法]结合温室批量拟南芥栽培中土壤要求特点和播种特点,摸索出实用、简易且快速的批量盆装土浇湿方法和播种方法——高压水枪湿土法和瓶旋转播种法。高压水枪湿土法采用简单的覆水、穿透、浇湿和浇平四步,能快速备好用于播种或移栽等盆装湿土;瓶旋转播种法利用自制播种瓶,采用简易的旋转、挤压和倾倒等操作,能快速播种。[结果]使用高压水枪湿土法浇湿50托盘1 000盆土只需约35 min,浇好的盆装土具有土壤湿润、通气性好、基质分布均匀和表面平整等优点,利于种子播撒、萌发和移栽幼苗成活与正常生长;使用瓶旋转播种法播种50托盘1 000盆土仅需15 min,播种后种子疏密一致、分布较均匀。[结论]利用这两种方法,加上后期日常管理,可快速培养出大量生长健壮、表型稳定和符合实验要求的拟南芥,加快了实验室科研项目推进的速度。高压水枪湿土法对其他温室栽培植物如花卉、蔬菜和果树幼苗等移栽前的盆装土浇湿适用,瓶旋转播种法对其他微小种子的播撒也有重要参考价值。

干线公路网化工程改造中的问题与对策

公路改造中常遇到路肩、边坡、集镇段整治等诸多问题。论述其原因,提出在干线公路网化改造工作中应重视路基备土的土源质量,合理划分标段严格验收,重视征地、拆迁工作;对集镇段的整治统一规划、统一管辖,公路的绿化工作统一安排。

油松容器育苗造林试验初报

太行山系的中低山区,气候干燥,雨量稀少,土层薄,历年油松造林成活率都很低。1987—1988年,我们在博爱县山区寨豁乡采用容器育油松苗25万袋 (株),成苗17万袋 (株),移栽造林420亩。阳坡、阴坡造林成活率分别达到80.6％和93.8％。一、试验地概况及材料试验地设在寨豁乡大底、汉高城。

Evaluation of Land Reclamation and Implications of Ecological Restoration for Agro-pastoral Ecotone: Case Study of Horqin Left Back Banner in China

The agro-pastoral ecotone has been recognized as the main distribution area of reserved land resource for cultivation. Accordingly, clarifying this assumption, as well as concerting land reclamation and ecological restoration, is important to ensure food security and environmental improvement in the agro-pastoral ecotone. We selected Horqin Left Back Banner(HLBB) as the subject of our case study. The landscape ecological security pattern of this area was determined using the minimum cumulative resistance model. Over-cultivation, quantity of reserved land resource for cultivation, and changes in landscape indexes before and after land use adjustment were then analyzed. Over-cultivation is a serious problem in the agro-pastoral ecotone. Reserved land resource for cultivation is less than that considered previously, and the area of reserved land resource for cultivation in HLBB only accounts for 11.50% of total uncultivated land. With regard to changes in landscape indexes, the adjusted land use pattern is effective for anti-desertification. The compensation standard for abandoned cultivated land should be improved and the comprehensive results of ‘Grain for Green' should be evaluated to further implement ecological restoration in the agro-pastoral ecotone.

Preparation and properties of geopolymer-lightweight aggregate refractory concrete

Geopolymer-lightweight aggregate refractory concrete (GLARC) was prepared with geopolymer and lightweight aggregate. The mechanical property and heat-resistance (950 ℃) of GLARC were investigated. The effects of size of aggregate and mass ratio of geopolymer to aggregate on mechanical and thermal properties were also studied. The results show that the highest compressive strength of the heated refractory concrete is 43.3 MPa,and the strength loss is only 42%. The mechanical property and heat-resistance are influenced by the thickness of geopolymer covered with aggregate,which can be expressed as the quantity of geopolymer on per surface area of aggregate. In order to show the relationship between the thickness of geopolymer covered with aggregate and the thermal property of concrete,equal thickness model is presented,which provides a reference for the mix design of GLARC. For the haydite sand with size of 1.18-4.75 mm,the best amount of geopolymer per surface area of aggregate should be in the range of 0.300-0.500 mg/mm2.

Heterogeneous photo-assisted Fenton catalytic removal of tetracycline using Fe-Ce pillared bentonite

In the present work, a novel heterogeneous photo-Fenton catalyst was prepared by iron and cerium pillared bentonite. The catalyst Fe-Ce/bentonite was characterized by X-ray diffraction （XRD）, X-ray fluorescence （XRF）, Brunauer-Emmett-Teller （BET） and scanning electron microscopy （SEM） methods. It is found that Fe and Ce intercalate into the silicate layers of bentonite successfully. Tetracycline was removed by heterogeneous photo-Fenton reaction using the catalyst in this work. The effects of different reaction systems, hydrogen peroxide concentration, initial pH, catalyst dosage, UV power and introduction of different anions on degradation were investigated in details. The stability of catalyst was investigated through recycling experiment. The results show that removal rate of tetracycline is 98.13% under the conditions of 15 mmol/L H202, 0.50 g/L catalyst dosage, initial pH 3.0, 11 W UV lamp power and 60 min reaction time. However, the removal rate decreases after adding some anions. The hydroxyl radical plays an important role in heterogeneous photo-assisted Fenton degradation of tetracycline. The catalyst is very stable and can be recycled many times.

Effect of Percolation Pattern on Yields and Accumulation of Copper and Cadmium in the Rice Plants with Soil Dressing Models

A greenhouse experiment was conducted using stratified paddy field models, which were prepared by polluted soil with 12.5 cm soil dressing. The paddy models were assembled with open and closed percolation system to focus the effect of percolation pattern on accumulation of cupper （Cu） and cadmium （Cd） in rice plants in contaminated paddy filed with soil dressing models. Percolation pattern has significant effect on soil environment, especially redox potential that may influence mobilization of Cd, Cu and other elements. In open system percolation models, the plowsole and subsoil were in oxidative condition （600 mV）, whereas reduction condition （-200 mV） was measured in closed system percolation models. Accumulations of Cu and Cd in all parts of rice plants （roots, grains, stems and leaves） were found higher in an open system percolation with the paddy field model comparatively than in a closed system percolation. The soil redox （Eh） condition influenced by the percolation pattern might be one of the main factors for uptake and accumulation of Cu and Cd in rice plants. The plant height and stem number were found lower in open system percolation comparatively to closed system percolation. In the yields section, the average panicle length, number of panicle and rice grain/hill and weight of grain/hill were lower in open system percolation than the closed system percolation.

Preparation of SO_4^(2-)/TiO_2-La_2O_3 solid superacid and its catalytic activities in acetalation and ketalation

SO4^2- / TiO2-La2O3, a novel solid superacid, was prepared and its catalytic activities at different synthetic conditions are discussed with esterification of n-butanoic acid and n-butyl alcohol as probing reaction. The optimum conditions have also been found, mole ratio of n（La^3＋）：n（Ti^4＋） is 1：34, the soaked consistency of H2SO4 is 0.8 tool/L, the soaked time of HESO4 is 24 h, the calcining temperature is 480 ℃, the calcining time is 3 h. Then it was applied in the catalytic synthesis often important ketals and acetals as catalyst and revealed high catalytic activity. Under these conditions on which the molar ratio of aldehyde/ketone to glycol is l： 1.5, the mass ratio of the catalyst used in the reactants is 0.5%, and the reaction time is 1.0 h, the yields of ketals and acetals can reach 41.4%-95.8%.

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.

Thermodynamic analysis on the direct preparation of metallic vanadium from NaVO_3 by molten salt electrolysis

A novel and environmentally friendly route to directly prepare metallic vanadium from NaV03 by molten salt electrolysis is proposed. The feasibility about the direct electro-reduction of NaV03 to metallic vanadi- um is analyzed based on the thermodynamic calculations and experimental verifications. The theoretical decomposition voltage of NaV03 to metallic vanadium is only 0.47 V at 800 ℃ and much lower than that of the alkali and alkali earth metal chloride salts. The value is slightly higher than that of low-valence vanadium oxides such as V203, V305 and VO. However, the low-valence vanadium oxides can he further electro-reduced to metallic vanadium thermodynamically. The thermodynamic analysis is verified by the experimental results. The direct preparation of metallic vanadium from NaV03 by molten salt electrolysis is feasible.

Preparation and properties of composite polymer electrolyte modified with nano-size rare earth oxide

Poly（vinylidene fluoride-co-hexafluoropropylene） （PVDF-HFP） based composite polymer electrolyte （CPE） modified with CeO2, La2O3 and Y2O3 nano-rare earth oxides was prepared by phase inversion technique. Physical and chemical properties of the modified CPEs were studied by SEM, TG-DSC and electrochemical methods. The results show that the CPE modified with 10% La2O3 （mass fraction） has the best practical applicability, which indicates that the thermal and electrochemical stability can reach over 400 ℃ and 4.5 V, respectively, and temperature dependence of ionic conductivity follows Vogel-Tamman-Fulcher （VTF） relationship and ionic conductivity at room temperature is up to 3.3 mS/cm. The interfacial resistance Ri reaches a stable value about 557 Ω after 6 d storage.

Flame Retardancy Evaluation of Nanocomposites Prepared from Sawdust and Montmorillonite Clay

Composites of montmorillonite clay and sawdust were prepared with the desired result being having new materials which burn longer than unmodified sawdust. The three forms of clay used for preparation of composites were unmodified montmorillonite, mono-ionic montmorillonite and organically modified montmorillonite. Montmorillonite clay was converted to mono-ionic clay by ion exchange with sodium using a sodium chloride solution. The mono-ionic clay was organically modified with an organic surfactant, methyl triphenyl phosphonium bromide. Nanocomposites were then prepared by combining the modified and raw forms of the clay with sawdust. The solution blending method was used to make the nanocomposites. The samples were analysed using thermogravimetric analysis and cone calorimetry. The studies showed that the nanocomposite which was made from sawdust and 1% organically modified clay had the most improved results in terms of burning time and thermal stability, as well as giving a calorific value closest to unmodified sawdust and the least amount of residue.

Instruments of Urban Planning in Algerian City： Reality and Challenges

The year 1990 marks a line of rupture in the history of Algeria in general by the fundamental changes that have occurred, especially in the fields of urbanism and the land use planning, which has an important impact on space of the city and its environment. However, the absence of directives based on the reality of upstream territories and sometimes the conflict and the weakness of the instruments created at different levels： national, regional and local, have accelerated the galloping development of urbanization （the irrational consumption of land reserves inside and around the city）, often at the expense of the agricultural land. On the other hand, the involvement of new actors in the production of the framework built in the Algerian town was made without compliance with the rules of architecture and urbanism contained in the build permit and in the MPU （Master Plan of Land Use and Urbanism） and the SOP （Soil Occupation Plan） approved. The analyses conducted in the cities such as the capital Algiers and Setif illustrate this situation well. This article presents these situations of paradox, identifies their causes and suggests the recommendations to implement in the framework of studies and actions to take, to correct and regulate their mutations.

Preparation of Rapid Hardening Mortars Using Ultrafine Portland Cement

During the hydration process, the Ultra-fine Cements present specific physical and chemical characteristics; they are, very short setting time and high heat release. For special applications, such as rapid hardening and early high strength mortars or concretes, these characteristics can be considered advantageous. Some commercial products used for concrete reinforcement and repairs are the Rapid Hardening Mortars, these mortars must develop a time of setting up to 3 h and an initial compressive strength of about 3.5 MPa once the hardening of the paste is reached. The objective of the present research work is to use Ultra-fine Cement for the preparation of a series of different Rapid Hardening Mortars （with different percentages of Ultra-fine Cement）, these mortars required the addition of a polycarboxylate-base specification F Superplasticizer. It was observed that the optimum water/cement （W/C） ratio for the hydration of the Ultra-fine Cements is W/C = 0.385. The Ultra-fine Cements were obtained by the High Energy Ball-milling technique at laboratory scale, 90% of the Particle Size Distribution is below 11 μm and the Blaine Specific Surface Area is over 9000 cm^2/g.

Anion Content in Surface and Subsurface Water Flows in Grassland

Grassland devoted about 90% of agricultural Irish land. Anion retention capacity of most agriculture soils is less than cation retention capacity, therefore chemical analyzed for anion （NO3 （nitrate）, CI- （chloride）, SO42 （sulphate） and HPO4 （biphosphate）） in different water flow types （overland flow, interflow and vertical flow or drainage） samples. In this work, simple equipment was used to operationally distinguish between overland flow and interflow while vertical flow collected in different depths using soil water sampler equipments. Episodes of overland flow and interflow occurred even though the site is located in the lowest rainfall in Ireland and on well-drained soil. Samples of different origin showed marked differences in their anion contents, while HPO4 concentrations were almost equal to zero in all water flow types, nitrate where relatively high in overland and interflow samples and was very high in drainage samples. No sampling was carried out below the root zone but it must be assumed that the high concentrations measured in drainage samples would constitute a threat to groundwater resources. When overland flow and interflow did occur, NO3 concentrations were usually close to or in excess of the maximum admissible concentrations for drinking water and it will be constituted a threat to inland surface water bodies.

Black Pine Afforestations in Abruzzo （Central Italy）： Perspectives and Management

In Italy, the hydro-geological protection of the Apennine territories is a well-known issue. For this reason, at the end of the 19th century, a new reforestation technique was proposed by the Inspector of Forest Service, Pietro Montanari to cope with difficult soil conditions of the mountain areas. This new approach was the first application of the so-called ＂gradoni＂ （small terraces） method of soil preparation. Each ＂gradone＂ was 100-120 cm wide and made with a slight counter slope （ca 10-15 degrees） to promote the accumulation of water and organic matter. Along each ＂gradone＂, bare root black pine seedlings （Pinus nigra Am.） were planted at a distance of 1 m from each other with a density of more than 3,000/ha. Nowadays, 19,158 hectares of black pine forests are growing in the Apennine of the Abruzzi region, largely resulting from those reforestation projects realized since the beginning of the 20th century. A case study of Monte Plaia （42°00′ 12″ N 13°53′39″ E）, that illustrates the situation after 70-110 years in consequence of lacking of silvicultural treatment and the application of aforest restoration method is presented.

Physical Status of Soils Developed from Loesslike Loams in the Southwest of the Central Russian Plain （the Belogor＇e Reserve）

Soils developed from the Quaternary loesslike loams have been studied in the south of the forest-steppe zone on the Central Russian Upland. A polygenetic nature of the soil profile on the loesslike loams is shown. The modem pedogenetic processes in this soil ensure its eluvial-illuvial differentiation with the development of multilayered coatings in the illuvial horizon. The middle horizons in the studied soil profiles are referred to as textural （clay-illuvial） horizons. Differences in physical soil properties （bulk density, airconductivity, texture, water content, and temperature dynamics） were studied in the soil on the loesslike loam.

Impact of Prevailing Wages on the Cost among the Various Construction Trades

In 1997, the Ohio Senate passed Senate Bill 102 which established the Ohio School Facilities Commission as a separate agency to oversee the rebuilding projects of the public schools in Ohio. The bill also exempted the construction contractors from paying prevailing wages on these projects on the hypothesis that this exemption would lower the construction cost. The purpose of this study is to investigate this hypothesis through the statistical analysis of 8,093 bids received from the years 2000 through 2007 for the schools＇ construction. Union contractors who paid their workers union wages and non-union contractors who did not pay prevailing wages bid these projects. The hypothesis, that prevailing wage laws increased the construction cost, was tested by comparing the bids/SF （square foot） from both groups （union and nonunion） for the different construction trades. The study indicated that there was statistical significant difference between the bids/square foot for union contractors and the bids/square foot for non-union contractors for only the following trades： earthwork, existing conditions, plumbing, electrical and HVAC （heating, ventilation and air conditioning）. The averages of bids/SF from the union contractors were higher than those from the non-union contractors for earthwork, existing conditions and plumbing works, and the opposite for electrical and HVAC works. There was no statistical significant difference in the bids from the communications, concrete, conveying equipment, electronic safety and security, equipment, finishes, fire suppression, furnishings, masonry, openings, structural steel, thermal and moisture protection, plastics and composites and wood works.

Preparation of High Purity Neodymium Oxide from Brazilian Monazite by Ion Exchange

A simple and economical chemical process for obtaining high purity neodymium oxide is discussed. The raw material in the form of RE （rare earth） carbonates is produced industrially in Brazil from monazite. Using this concentrate as the feed material, ion exchange with a strong cationic resin, commonly used for water treatment, and without the use of retention ions was used for the fractionating of the REE （rare earth elements）. The eluent was ammonium salt of EDTA （ethylenediaminetetraacetic acid） at pH 4.0. The complex of EDTA-neodymium was transformed into neodymium oxides via oxalate precipitation. We produced 99.9% pure Nd203 in yields greater than or equal to 80%. Molecular absorption spectrophotometry was used to monitor the neodymium content during the process and sector field inductively coupled plasma mass spectrometry was used to certify the purity of the neodymium oxides. The typical neodymium oxides obtained contained the followings contaminants in micrograms per gram： Sc （4.09）; Y （0.39）; La （0.78）; Ce （5.62）; Pr （4.56）; Sm （11.10）; Eu （1.10）; Gd （14.30）; Tb （29.3）; Dy （4.15）; Ho （8.39）; Er （13.80）; Tm （0.23）; Yb （2.29）; Lu （0.39）. High purity neodymium oxides obtained from this procedure replaced the imported product used in research and development work on rare earth at IPEN/CNEN-SP （Instituto de Pesquisas Energeticas e Nucleares/Comissfio Nacional de Eneergia Nuclear-Sao Paulo）.

Preparation and microstructure characterization of poly-sialate-disiloxo type of geopolymeric cement

In order to investigate the influence of three key molar ratios （n（SiO2）/n（Al2O3）, n（K2O）/n（Al2O3） and n（H2O）/n（K2O））, a total of nine potassium poly-sialate-disiloxo （K-PSDS） geopolymeric cement matrices were designed according to orthogonal design principle. Subsequently, XRD, ESEM-EDXA and MAS-NMR techniques were employed to further characterize the microstructure of the most fully reacted geopolymeric cement matrix. The experimental results show that n（K2O）/n（Al2O3） has the most significant effect on compressive strength amongst the three ratios. The highest compressive strength （20.1 MPa） can be achieved when n（SiO2）/n（Al2O3）=6.5, n（K2O）/n（Al2O3）=0.8 and n（HEO）/n（K2O）=10.0. The FTIR spectra of nine PSDS geopolymeric cement matrices also indicate that geopolymeric cement matrix with the highest strength is the most fully reacted one and possesses the largest amount of geopolymeric cement products. The microscopic analysis reveals that PSDS geopolymeric cement matrix possesses structural characteristics similar to gel substances in having a wide range of Si endowments, but predominantly the framework molecular chains of Si partially replaced by 4-coordinated Al tetrahedral.