CO2激光用于船体型线放样切割的研究及应用

用激光打标和激光切割方法,实现对船舶建造中船体型线样板箱制作材料的划线与下料的工艺步骤.介绍了由激光器、数控系统、机床构架和冷水机组、除尘与空气压缩机组等辅助设备组成的龙门式三维激光加工联合机床的设计配置与工作原理,并通过对机床的操作试验,选定对木制材料加工的主要工艺参数,并对影响加工质量的现象进行了分析.     

六种木材的微波处理实验研究*

微波处理可以破坏木材的微观结构,有效提高木材的流体渗透性。为探究微波处理木材流体渗透性改善机理,同时为人工林木材的功能化改性研究提供理论依据,文章对杉木、落叶松、樟子松、毛白杨、泡桐及尾巨桉六种木材进行微波处理实验。从扫描电镜图片中可以看出,微波处理后,微波处理材会产生射线薄壁细胞之间或与轴向组织的胞间层处产生破坏、闭塞纹孔的打开、纹孔膜破坏、细胞壁破坏及内含物重新分布等变化。微观结构的破坏导致处理材力学性能下降。其中,微波处理后樟子松、杉木、落叶松、尾巨桉、毛白杨及泡桐的抗弯弹性模量(MOE)较处理前分别下降了31.1%、35.4%、45.6%、5.5%、24.4%和23.2%;抗弯强度(MOR)分别下降了38.4%、29.4%、67.2%、9.1%、34.0%和29.1%。同时,不同树种木材中不同的微观结构破坏形式造成处理材不同的吸水性测试结果。而根据微波处理材的吸水性及力学性能测试结果,可以选择适合用于微波处理后进行功能化改性处理的树种。     

油基钻屑电磁加热脱附可行性及参数优化

油基钻屑含有大量的矿物油、乳化剂等化学药剂,成分复杂、处理困难,是页岩气等非常规油气开发的环保难题。为此,设计了一套油基钻屑电磁加热脱附处理设备,并进行了现场小试试验。通过检测电磁加热设备热脱附处理后的钻屑残渣含油率,分析试验过程中的温度变化规律,对设备处理油基钻屑的可行性进行了初步验证,并在此基础上优化了设备的主要运行参数:温度、负荷、时间。结果表明:1该电磁加热脱附处理设备对于油基钻屑具有良好的处理效果,处理后残渣含油率低于1%;2该设备适用范围广,可同时处理钻井过程中产生的编织袋、防渗塑料布等其他含油废物;3处理固控系统振动筛出渣(物料A)的最佳条件为温度375℃、进料负荷15 L/h、时间45 min;4处理固控系统离心机出渣(物料B)的最佳条件为温度350℃、进料负荷20 L/h、时间50 min;5电磁加热脱附炉内部温度的波动不受设定温度的影响,对不同负荷的物料也均能保证内部温度的稳定,具有稳定的控制温度能力和良好的保温效果。     

(Ti,V)_3AlC_2/Al_2O_3复合材料的制备及力学性能

为了提高Ti_3Al C_2陶瓷的力学性能,本研究以Ti C粉、Ti粉、Al粉和V2O5粉为起始反应原料,采用原位热压技术在1350°C下反应烧结合成出了(Ti,V)_3AlC_2/Al_2O_3复合材料。利用X-射线衍射和扫描电子显微技术对合成产物的物相和微观结构进行了表征,并分析了复合材料的合成机制。最后,对(Ti,V)_3AlC_2/Al_2O_3复合材料的力学性能进行了研究。测试结果表明:(Ti_(0.92),V_(0.08))_3Al C_2/10wt%Al_2O_3复合材料具有最佳的力学性能,其硬度、断裂韧性及抗弯强度分别为5.56 GPa、12.93 MPa·m~(1/2)和435 MPa,相比于单相Ti_3Al C_2材料分别提升了60%、108%和31%。     

星用固放的现状

介绍了星用固态放大器的现状及其主要技术，展望了星用固放的发展趋势。     

污染地层渗透率分布特征研究

关于悬浮物固相侵入造成的地层伤害,研究人员做了大量的工作,并在文献上发表了一些模型的建立方法。但是没有对地层中渗透率的具体情况作详细研究。文中介绍了一个以颗粒通过多孔介质的物质平衡为基础的数学模型,采用有限差分法求解,编制计算机软件,将渗透率在不同污染距离和时间的结果描绘出来,并作了一些详细研究。这对研究污染状况和后面要采取的酸化等解堵措施提供了更好的条件。     

固态13C-NMR法表征渣油沥青质的结构组成

以长庆常压渣油、胜利减压渣油和加拿大减压渣油为原料,研究了正庚烷沥青质的结构及组成,根据固态13C NMR分析结果,计算了沥青质分子的平均结构单元参数,并模拟出了沥青质的结构单元模型。结果表明,沥青质分子由4个左右的结构单元组成,每个结构单元包括5～7个缩合芳香环。沥青质中的饱和碳以环烷碳为主,并包含少量的短烷基侧链,沥青质的n(HS)/n(CS)在16左右。对于平均相对分子质量较大、具有较短烷基侧链和较少取代基的沥青质分子,由核磁共振氢谱计算其结构参数时,采用重油计算过程的假设--芳香环烷基侧链上α位及β位和β位以远的氢/碳比为2(x=y=2)是不合理的,可能会导致计算结果与沥青质的真实结构存在较大的误差。     

Effects of increased wood energy consumption on global warming potential,primary energy demand and particulate matter emissions on regional level based on the case study area Bavaria (Southeast Germany)

Wood energy use has strongly increased in Europe in the last decade entailing enhanced resource competition between the wood energy sector and the material-based wood sector. We applied the basket of benefit method for the forestry and wood cluster of the study area Bavaria to evaluate the impact of increased wood energy use and decreased material-based wood use on global warming potential, primary energy demand and particulate matter emissions. A baseline and a wood energy scenario were developed until 2035 and wood utilization in both scenarios was assessed via a Life Cycle Assessment of prevalent wood products, imported timber and conventional alternatives of use. The study reveals that, according to the modelled scenarios and the average substitution factors used, a demand shift towards more wood energy leads to a minor increase in global warming potential and to a reduction in primary energy demand. Increase in particulate matter emissions from wood energy use is strong, but definite conclusions cannot be drawn due to lack in data for material-based wood use. Moreover, the study results vary strongly depending on the products used for the comparative analysis. Through our approach, the ecological impact of increased wood energy use becomes visible for a whole region, taking into account the effect of a demand shift and of interdependent substitution effects.     

Sickle bush (Dichrostachys cinerea L.) field performance and physical–chemical property assessment for energy purposes

The sickle bush (Dichrostachys cinerea (L.) Wight & Arn.) comprises a woody legume shrub which is widely distributed throughout of the tropical areas of Africa, Asia and Oceania, being found as well in Cuba where it represents a difficult to control invasive plant. It holds great silvopasture and energy crop potentials. In southwestern Spain a two year field trial was conducted contemplating also another six hardwood taxa commonly used as energy crops. The sickle bush above ground dry biomass fraction was 60.4%; sickle bush displayed a high transpiration rate during hot days (3.02 kg m⁻² d⁻¹ to 6.82 kg m⁻² d⁻¹); cold winter temperatures (<−2 °C) together with hot and dry summer air (<20% relative humidity) committed survival and growth. The physical-chemical wood properties and the pellets thereof derived were analyzed and compared to those of the other energy crop taxa. The within other woody species normal chemical composition range coupled to a high wood density and energetic use properties (19.2 MJ kg⁻¹ higher heating value, 29 g kg⁻¹ ash content) all allow for an industrial use. Pellets evidenced also good physical and mechanical properties (690 kg m⁻³ bulk density, 42 g kg⁻¹ moisture content). However, the mechanical durability (93.9%) was slightly less than that required by the non-industrial use standards, therefore further improvements should be studied. All of the above could encourage scrubland cuts in Cuba as a mechanical control method, in addition to the expansion of plantations within of their tropical climate based natural habitats.     

Fabrication of Cu(In,Ga)Se2 thin films solar cell by selenization process with Se vapor

CIGS films were prepared on Mo-coated glass by sputtering and selenization processes. The metallic precursors were selenized under higher pressure in selenium vapor instead of H₂Se. In order to improve the performance of CIGS thin film solar cells, the morphologies of CIGS thin films were studied carefully by various temperature profiles. The relationship between temperature decrease rate and fill factor (FF) of solar cells was investigated thoroughly. On the other hand the value of open circuit voltage (V_oc) was improved by increasing the gallium content near the surface of CIGS thin film. A glass/Mo/CIGS/CdS/ZnO cell was fabricated and the conversion efficiency of 9.4% was obtained without antireflective film.