二副工作拾遗

二副工作除了航行值班和装卸货值班外,还有一些较为繁杂的本职工作要做,这些工作归纳起来也就是航海仪器的日常维护和使用的管理及航海图书资料的管理两个方面.要做好这两个方面的工作,要求二副平时要养成认真仔细、一丝不苟、勤快的工作态度和良好的工作作风,更要有“求实”的精神.下面就一些在实际工作中比较容易疏忽的地方写出来,供大家参照和指正.

大型履带起重机塔式副臂工况决定起重性能的因素分析

以大型履带起重机的塔式副臂工况为研究对象,针对目前吊装时难以选择合适的臂架组合方式,通过实际工程项目进行分析计算,得到最优臂架组合方式,并总结其组合规律,应用于现场吊装,便于今后的应用。

黄泛平原风沙区生态建设的途径——以刘屯村为例

黄泛平原风沙区,是世界高度沙漠化威胁区之一。如何治理风沙、建设生态环境、发展商品经济,山东省冠县刘屯村的从生态经济建设入手,治穷致富的经验,为风沙区的建设提供了有益的思路。

Synthesis and Characterization of Condensed Polynuclear Aromatic Resin Derived from Ethylene Tar

As a kind of low-cost and readily available industrial byproduct, ethylene tar （ET） was for the first time utilized for the preparation of heat-resistant condensed polynuclear aromatic resin （COPNAR）. The basic properties of ET and the resulted COPNAR were characterized by FT-IR, IH-NMR, TGA and elemental analysis. The test results showed that ET with high aromatic content （〉50%） was suitable for the synthesis of COPNAR with superior heat resistance. The average molecular structure of ET was obtained by means of the improved Brown-Ladner method, and the reaction mechanism was considered as an acid-catalyzed positive ion-typed polymerization. Our findings have provided a new route to develop ET into technology-added heat-resistant resins.

Structure Determination of By-product in Grignard Reaction for Preparing Mifepristone Derivatives

Aim To determine the structure of the by-product produced in Grignard reaction for preparing mifepristone derivatives, and elucidate the reaction mechanism.Methods The structure of the by-product was determined with elemental analysis, one- and two-dimension spectra NMR (DEPT, 1H-1Hcosy, HMQC, HMBC) and compared with those of mifepristone.Results The main by-product was 11,17-di-addition product of Grignard reagent of N, N-dimethylamino phenyl bromide.Conclusion This is the first complete assignment of 1H NMR and 13C NMR of compound (3).

Chemical Composition and Nutritive Value of Ramie Plant [Boehmeria nivea （L.） Gaud] and Its By-Products from the Textile Industry as Feed for Ruminants

In order to verify the possible use of ramie as feed for ruminants, a study was undertaken on the chemical and nutritional evaluation of different parts of this plant. Four stocks of samples picked up in two different periods （summer and autumn） were analyzed. The standard chemical composition was determined on the whole plant and on its parts, the study was particularly focused on leaves and tops, not used in fibre production and available as livestock feed. Organic matter enzymic digestibility （OMD） was determined on all the samples by a double step method based on cellnlolytic andproteolytic enzymes. The chemical analysis showed good crude proteins content in leaves, tops and whole plant： 17.00 ~ 1.52%, 15.25 ~ 0.77% and 11.79 ~ 3.32% on dry matter （DM） basis respectively and good acid （ADF） and neutral （NDF） detergent fibre fractions. Lignin and ash resulted high in all plant parts and organic matter （OM） was consequently low, ash analysis showed high calcium concentration, especially in leaves, with values exceeding 4% of din, whereas the other micro （except the lead） and macroelements were in a normal range. OMD and energy values resulted poor in leaves, tops and in the whole plant and lower than the other forages commonly used as feed for runninants, thus the utilisation of ramie plant and its by-products requests further investigations.

Can Industrial By-products Be Used as Tools in Sustainable Agriculture？

The goal of our study is to present results about the effects of selected industrial wastes-sewage sludge, lime sludge, compost-on the physiological parameters of plants. Maize seedlings （Zea mays L cvs. Norma SC） were used in soil plant （rhizobox） and nutrient solution plant system. The filtrates of the examined materials were used in the nutrient solution and the raw materials in the soil. Dry matter accumulation of shoots and roots, relative chlorophyll contents and the contents of some elements were measured in the plants grown on the nutrient solution. The examined materials contain some useful elements for plants e.g. Cu, Fe, K, and Mg and plenty of toxic metals e.g. AI, Cr. Root growth in the rhizoboxes was monitored, as well as that of roots in the experiment using soil. This type of growth was more intensive with the use of lime sludge than with of sewage sludge. On the other hand, the results were better at the sewage sludge than the lime sludge on the nutrient solution.

Lightweight Concrete Using Local Industrial By-product

Construction is one of the largest users of energy, material resources and water and it is a formidable polluter. One of the major materials used in construction is concrete and ordinary concrete contains about 12% cement which is a major producer of greenhouse gas in the world. The use of waste materials as partial replacement of cement in concrete reduces greenhouse gases, frees up land fill space, and reduces raw materials consumption. This contributes towards sustainable development, as in a sustainable society, nature is not subject to systematically increasing concentrations of substances extracted from the earth＇s crust. This research work explores the possibility of replacing some percentage of cement in concrete with marble sludge powder to produce lightweight concrete. This was achieved by determining the compressive strength and some hardened properties of concrete like sorptivity and carbonation with marble sludge. The results so far have been able to prove that lightweight concrete can be produced when some percentage of cement is replaced with this waste.

Potential of Industrial Byproducts in Ameliorating Acidity and Aluminum Toxicity of Soils Under Tea Plantation

It is imperative to choose some low cost, available and effective ameliorants to correct soil acidity in southern China for sustainable agriculture. The present investigation dealt with the possible role of industrial byproducts, i.e., coal fly ash （CFA）, alkaline slag （AS）, red mud （RM） and phosphogypsum （PG） in correcting acidity and aluminum （Al） toxicity of soils under tea plantation using an indoor incubation experiment. Results indicated that CFA, AS and RM increased soil pH, while PG decreased the pHs of an Ultisol and an Alfisol. The increment of soil pH followed the order of RM 〉 AS 〉 CFA. All the industrial byproducts invariably decreased exchangeable Al and hence increased exchangeable Ca, Mg, K and Na and effective cation exchange capacity. RM, AS and lime decreased total soluble Al, exchangeable Al and organically bound Al. Formation and retention of hydroxyl-Al polymers were the principal mechanism through which Al phytotoxicity was alleviated by application of these amendments. In addition, the heavy metal contents in the four industrial byproducts constituted a limited environmental hazard in a short time at the rates normally used in agriculture. Therefore, the short-term use of the byproducts, especially AS and RM, as amendments for soil acidity and AI toxicity in acid soils may be a potential alternative to the traditional use of mined gypsum and lime.

Ten years of microalgal biofuels in environmental applications

Over the past ten years,microalgae have been investigated as promising sources of renewable energy to replace the diminishing supply of fossil fuels and mitigate the environmental pollution caused by use of fossil fuels.In addition to providing oil-based biofuels,the use of microalgae can potentially reduce environmental pollution because algae can use industrial byproducts(CO_2,NOx,wastewater,and others)as nutrition sources.However,our previous study showed that the unacceptably high cost of biofuels production,especially culturing microalgae,remains the biggest obstacle hindering the large-scale implementation of microalgae biofuels.Therefore,future efforts will likely emphasize biotechnological approaches to improve the economic feasibility of algal biofuel production.This review summarizes the progress made over the last decade in environmental applications of microalgae,combined with data on CO_2 capture,NOx biotransformation,wastewater treatment,and synergistic applications,and discusses future prospects.