植被混凝土在采石场生态恢复中的应用

针对目前我国众多采石场面临的生态问题,以广州岑村东升采石场的生态治理为例,通过具体工程项目的实施,详细介绍了植被混凝土在采石场生态恢复治理中的施工工艺流程及应用前景,并提出了在我国南方等亚热带地区进行采石场生态恢复、岩质边坡绿化工程施工的治理思路和植物应用搭配的基本原则,从而为同类型采石场的生态恢复、混凝土或岩质边坡绿...     

振冲碎石桩在川西河谷地带地基加固工程中的应用

介绍了振冲碎石桩在四川省黑水县某建设用地地基加固工程中的应用情况，根据工程实际，对地基处理方案进行了比较和优化设计。结果表明，振冲碎石桩对地基的加固效果最好，该工法可在地基加固工程中广泛应用。     

论园林景石设计

本文以中国传统赏石情节为起缘,概括总结了景石在园林设计中的设计手法,探讨了景石的品格及景石的意境,并对景石的传统设计手法在现代园林中的运用进行举例论证。     

松针粉-麦饭石复合添加剂对肉鸡法氏囊生长发育的影响

试验取144只1日龄健康AA肉仔鸡,随机分为2组,每组72只,组内设2个重复,每个重复36只。对照组饲喂基础日粮,试验组饲喂添加1%松针粉、1%麦饭石的基础日粮,饲养期42d。分别于7、14、21、28、35、42日龄随机取鸡12只,每组6只,各重复3只。颈静脉放血致死,解剖取法氏囊称重,取材制作石蜡切片,光镜观察,显微摄影。结果表明:试验组与对照组鸡法氏囊指数在7、35日龄差异极显著(P<0.01),14、42日龄差异显著(P<0.05);法氏囊小结皮质均显著厚于对照组。本试验从组织学角度证明,在基础日粮中添加松针粉和麦饭石可显著促进肉鸡法氏囊的早期发育,延缓退化的时间。     

Genetic diversity and molecular epidemiology of the T strain of Plum pox virus

Very limited information is available on the origin, diversity and evolution of Plum pox virus (PPV) ‘Turkey’ (T) strain. Phylogenetic analyses based on partial sequences of 421 isolates and complete genome sequences of 57 isolates, representing the geographical distribution of PPV-T in Turkey, revealed the existence of several monophyletic and, in some cases, geographically limited groups within the PPV-T strain (Ankara-Konya1-Kayseri, Ankara-Balkan, Istanbul, Konya2 and Balkan). PPV-T diversity (0.018%) was found to be greater than that of PPV strains D and Rec but lower than that of the M strain when including the newly described and divergent M-Istanbul isolates, suggesting a long evolutionary history for PPV-T. The European part of Turkey in the Balkans, close to Bulgaria where PPV was identified for the first time, appears as a likely centre of origin for PPV-T isolates. The colonization of various parts of Turkey by diverse isolates from that region, followed by secondary local spread, is the most likely scenario for the diffusion of PPV-T in Turkey.     

Study on Seepage Model of Rock Mass in Baodingshan Grotto Area of Dazu County

Based on the analysis of hydrogeological condition, and hydraulic characteristics and hydraulic relation in rock mass,the seepage of rock mass in carved stone area has been generalized and its mathematics models established. By numerical simulating,correctness of Seepage models of rock mass have been proved.     

枣不同品种果核性状研究

枣核是鉴定品种的重要特征,对冬枣、榆次团枣、婆婆枣、紫圆枣等37个枣品种和1个毛叶枣品种台湾青枣的果核和种仁的外部形态指标进行了详细地描述和测量,以研究枣不同品种果核、种仁各数量指标间的相关性,得出核纵径和核喙长的线性方程Y=-0.064 1+0.184X。     

Soil and water conservation in Tigray (Northern Ethiopia): the traditional dagat technique and its integration with introduced techniques

Between the cultivated fields in the highlands of Tigray, one finds, besides the recently introduced stone bunds, many lynchets, with a height ranging from 0·3–3 m. Grasses occupy the riser and a more or less large strip on the shoulder. Traditionally, farmers established an untilled strip of about 2 m wide at the lower plot limit. This grass strip reduced runoff velocity, allowed for water to infiltrate and trapped sediment. Year after year, these lynchets, locally called dagat, continued to grow. In this study, the dagat technique is characterized and its evolution and reasons for partial destruction are outlined. Stereoscopic aerial photo analysis shows for the study area near Hagere Selam (13 °39′N, 39 °10′E, 2650 m a.s.l.) that 20·7 per cent of the major dagats (more than 1 metre high) have disappeared between 1974 and 1994. These lynchets, however, remain an important linear element in the landscape (22·7 m ha⁻¹, i.e. their density on cultivated fields is much higher). Of the smaller lynchets, a great proportion has been levelled in order to increase plot surfaces and spread fertile soil over the field. Famines and impoverishment caused the farmers to increase short‐term agricultural production in this way. Since the 1980s, the farmers built stone bunds on most of the cultivated land. Their average length equals 56·1 m ha⁻¹ in the study area. The establishment of stone bunds results in the development of small terraces. Especially during recent years, there is a tendency to integrate the traditional knowledge of dagat with the building of stone bunds. A quantitative assessment of the effectiveness of both techniques must be made. Copyright © 2000 John Wiley & Sons, Ltd.     

Species differences and effects of soft coral extracts from <Emphasis Type="Italic">Sinnularia maximus</Emphasis> on the expression of cytochrome P4501A and 2N in butterflyfishes (<Emphasis Type="Italic">Chaetodon</Emphasis> spp.)

Cytochrome P450 (CYP) has been shown to confer resistance in numerous terrestrial insects that consume potentially toxic secondary metabolites in plants, but fewer studies have examined the role of critical biotransformation enzymes in allowing marine organisms to consume chemically defended foods. This study examined the expression of CYP1A and CYP2N mRNAs in several butterflyfish species, which can feed on numerous chemically defended soft and hard corals. In addition, the effect of an extract from a soft coral (Sinnularia maxima) on expression of hepatic CYP1A and CYP2 mRNAs was also examined. Fish were fed extracts on days 1, 3 and 5, and expression was examined on day 5. Phylogenetic analyses of the CYP1A cDNA from 12 species of butterflyfish (DNA, amino acid) indicate well-separated groupings according to their feeding strategies. The non-coralline feeding Chaetodon xanthurus exhibited a 7-fold higher basal expression of CYP2N8 relative to the other species studied. Although induction of CYP2N7 expression was observed in C. punctatofasciatus, CYP1A and CYP2N was largely unaffected or diminished by extract treatment in the other species of butterflyfish. These results indicated groupings of feeding strategy with CYP1A phylogeny in Chaetodon, but generally unaltered expression of CYP1A and CYP2N following dietary treatment with an extract from a chemically defended soft coral suggesting an inconclusive role of these isoforms in the detoxification of chemicals in these extracts.