木材表面的功能性改良

论述了木材表面功能性改良的目的，介绍了木材染色，表面强化，无电解电渡处理，化学表面修饰，等离子体聚合和表面活性化的功能性改良方法，概述了改良木材的性能和用途。     

Effects of genetic strain and holding facility on the characteristics of alkaline phosphatase and brush border enzymes in silver perch (Bidyanus bidyanus)

The activity of the enzymes located in the digestive tract (pyloric caeca and intestine) in two strains and F₁ crosses of the Australian freshwater fish silver perch [Murray River (M) and Cataract Dam (C)] was evaluated. The effect of the fish holding system (cages or ponds) on the activity of alkaline phosphatase (AP) and the brush border enzymes: maltase, leucine amino peptidase (LAP) and γ‐glutamyl transferase (γ‐GT) was examined. The enzymatic activity was tested in three intestinal sections: the pyloric caeca, upper and lower intestine. All the tested enzyme activities were influenced by an interaction between the intestinal section and the strain or cross of silver perch. For fish maintained in ponds, there were two distinct enzymatic activity patterns, one for the pure strains (C × C and M × M) and one for the crosses (C × M and M × C). Significantly higher (P<0.05) enzymatic activities of the crosses compared with the pure strains were particularly noticeable in the pyloric caeca. In fish held in cages, there was a significantly higher (P<0.05) enzymatic activity in the pyloric caeca of the C × C strain. The total enzymatic activities in the fish reared in the ponds were significantly higher (P<0.05) than those in the fish held in cages. The results of the present investigation confirm that the different genetic background of the silver perch in the Murray River and in the Cataract Dam influences the activity of the brush border digestive enzymes. This activity also varies between maintenance systems.     

Effect of the molecular form of dietary nitrogen supply in sea bass larvae: Response of pancreatic enzymes and intestinal peptidases

Sea bass (Dicentrarchus labrax) larvae were weaned at day 25 with microparticulated diets in which 10% of the nitrogen supply had different molecular forms: amino acid mixture (SLAA), casein hydrolysate (SLH) or fish meal (SLP). The control group (LP) was fed live prey. No difference was observed in larval growth between the weaned groups, but the survival was significantly higher in the SLH group. Trypsin secretion was stimulated in the SLAA group, whereas the SLH diet reduced the secretion from the exocrine pancreas. The activity of the leucine-alanine peptidase, located in the cytosol of enterocytes, remained high in all weaned groups. However, the activity of the peptidases of the brush border membrane increased during the development phase in the control group. These results suggest that weaning with a classic compound diet delays enterocyte differentiation by maintaining the larval features of digestion. A compound diet containing protein hydrolysate can attenuate the delay of intestinal maturation.     

Effects of graded levels of standard soybean meal on intestinal structure, mucosal enzyme activities, and pancreatic response in Atlantic salmon (Salmo salar L.)

Duplicate tanks of c.280 g Atlantic salmon (Salmo salar L.) were fed for 60 days on diets in which fishmeal was substituted with graded levels of extracted soybean meal (SBM) comprising 0%, 10%, 15%, 20%, 25% or 35% of total protein. The effects on feed intake, growth, feed conversion, apparent digestibility and utilization of macronutrients and energy, pathohistological response of the distal intestine (DI), activities of digestive enzymes in the mid and distal intestinal mucosa, and faecal trypsin and plasma insulin concentrations were studied. A negative, dose‐dependent effect of SBM was observed on nearly all performance parameters with a notable exception of feed intake. The lowest SBM inclusion level of 10% resulted in moderate pathohistological changes in the DI. Each subsequent increase in SBM level increased the number of fish displaying severe changes. In contrast to the mid‐intestine (MI), all enzyme activities in the distal intestinal mucosa decreased dose‐dependently with increasing SBM inclusion. Faecal trypsin increased up to an SBM inclusion level of 20% and then levelled off. Plasma insulin increased from 0% to 15% SBM inclusion and then decreased. The results suggest that caution should be exercised in the use of even low levels of extracted SBM in salmon feeds.     

Application of VVVF to the Automatic Control of Aeration Brush

As VVVF (Variable Voltage Variable Frequency) used in the automatic control of aeration brush can realize the best matching of oxygen demand and oxygen supply through changing the revolving velocity of aeration brush in an oxidation ditch, as a result, the energy consuming is reduced in the greatest extent with guaranteed effluent water quality. At the same time, the feasibility and necessity of VVVF in the automatic control of aeration brush is proved. In this paper all ways of the control of aeration brush are introduced in the factual use. The energy saving can be achieved through the control of changing frequency in the automatic control ways of computer system.     

Investigation of the Negombo estuary (Sri Lanka) brush park fishery, with an emphasis on community-based management

The Negombo estuary brush park fishery in Sri Lanka was investigated from June 1998 to March 1999. The mean fish yield (all species) in the fishery was 12.46 t ha⁻¹ yr⁻¹. Fin fish species formed about 91% of the yield and the rest was formed by penaeid shrimps and crabs. Fish yield and the twig density in the brush park exhibited a second order polynomial relationship indicating a minimum yield at an intermediate value of twig density in the brush parks. The relationship between fish yield and duration of implantation of brush parks showed an optimal period of 30–40 days for high fish yields. Income levels of fishermen, availability of construction material and suitable sites for implantation of brush parks are some of the factors determining size and number of brush parks per fisherman and duration of installation. Indigenous knowledge within the fishing community about the effect of salinity variations, twig density and mangrove species used on the harvests greatly contribute to effective operation of this fishing practice. Cultivation of mangroves to obtain twigs and branches is a unique feature in this estuary. Indigenous knowledge on mangroves has led to the adoption of sound silvicultural practices. Although cultivating mono-specific mangrove stands may not increase diversity of mangrove forests, it reduces denudation of naturally occurring mangrove forests because of brush park construction, and retains habitats for other organisms. Mangrove management plans in the Negombo estuary should therefore be viewed and treated in an integrated manner that takes into account both resource and social components.     

抚育施肥措施对毛竹林笋产量的影响及效益分析

在毛竹林5个区组内分别采取劈杂(X2)、劈杂+施肥(X3)、劈杂+深翻+施肥(X4)和对照(X1)4种处理措施,翌年测定各处理小区春笋产量并进行经济效益分析。结果表明,竹笋产量在各处理间有极显著差异,在各区组间差异不显著。4种处理措施中,X4、X3与X1、X2之间竹笋产量差异极显著,X4与X3之间差异显著、X1与X2之间差异不显著,表明劈杂对竹笋产量影响有限,施肥和深翻均能显著促进竹笋增产。经济收益以X4为最大,每公顷可增加收益3475.5元,明显高于X3和X2,说明抚育施肥可以取得显著的经济效益。     

木材化学镀镍的镍活化工艺对镀层均匀度的影响因素分析

为了确定镍活化工艺在木材化学镀镍活化过程中的可行性,本文分析了活化液的镍盐浓度、还原剂浓度、酸和碱的浓度以及活化时间等对活化后木材表面镀镍层均匀度的影响,从而得出木材化学镀镍比较理想的活化液组成和活化工艺,这对于在木材化学镀镍领域开展非贵金属活化新工艺的进一步研究有重要的意义。     

逸人·逸笔·逸气——论倪瓒诗画创作风格的互通

倪瓒身处元末，散尽家财，隐迹山水，交游甚广，以写诗、作画以自娱。倪瓒之画，不求形似，简笔率略而成，自得天真逸趣，形成简远空疏之境。倪瓒之诗，不事雕琢，遇事感兴，得乎性情之正，有冲淡萧散之风。作为画家兼诗人，倪瓒打破了画与诗两种不同艺术形式之间的壁垒，实现了其诗画艺术风格的互通。     

响应面法优化兔尾草漂白工艺研究

蓬松度是兔尾草干花市场价格的关键影响因素，传统兔尾草漂白工艺中毛笔尖形貌概率接近80%，且总漂白工艺流程约72 h，漂白时间为8～12 h。本文采用响应面法对传统兔尾草漂白工艺进行研究，对比了亚氯酸钠和过氧化氢的漂白效果，优化了体系的pH值、温度、漂白时间、溶液浓度等因子。结果表明，用pH=2.3的亚氯酸钠溶液于53℃恒温条件下漂白兔尾草3.5 h，并以过氧化氢溶液漂白2 h，再以鼓风机干燥可获得最优效果，成品毛笔尖形貌概率低于10%，工艺流程时间压缩到8 h。本研究可改善兔尾草干花蓬松度、优化漂白效果、缩短工艺时间，有利于提高兔尾草干花品相、降低生产成本和提高经济附加值。