There are rich resources of wild ornamental plant in Xihuangshan of Mayang in Hunan Province.In this paper, the type of wild ornamental plants,the composition of families and genera and the diversity are analyzed on the basis of preliminary investigation. It is found that 422 species of wild plants have ornamental value,many species are rare and have extremely high ornamental value. And some propose on the exploitation and utilization of wild ornamental plants resources is put forward.

从种子的收集处理、过冬贮藏、播种床准备、播种方法、苗期管理及大苗培育等方面介绍了榉树的播种育苗技术,以期为榉树的推广应用提供技术参考。

The synchrocontrol of a new chaotic system was studied. Based on Lyapunov stability theory, ada- pting control method and activated control method were used to realize the synchrocontrol when parameters were unknown. The smmm＇y, reasoning and simulation experiments further prove the correctness of this conclusion. Finally, adaptive methods of chaotic synchronization were used to experimentalize secret commu- nication. The findings show that using chaotic masking can effectively restore the information signal.

180 strains of bacteria were isolated from the intestinal tract of Ctenopharyngodon idellus and Carassius auratus gibelio.The ability to produce four extracellular enzymes(protease,lipase,amylase and cellulase)of all strains was measured.The results indicated that the dominant group of the digestive enzymes-producing isolates in all parts of intestine were strains Aeromonas.45.71% of all strains Aer.can produce digestive enzyme.There were 33 strains could produce four extracellular enzymes,which account for 36.67% of the total bacterial populations in the gut of C.idellus.From the gut of C.auratus gibelio,43 digestive enzymes-producing strains were isolated,which accounted for 47.78% of the total bacterial populations.Extracellular enzymes active isolates comprised 20%,66.67% and 23.33% of all bacteria in foregut,midgut and hindgut of C.idellus,respectively.The largest number of four extracellular enzymes active strains was detected in the midgut of C.idellus.But in the gut of C.auratus gibelio,the difference of the number of digestive enzymes-producing strains between midgut and hindgut was not significant,while the strains in the foregut was lower compared to the midgut and hindgut isolates.There were no cellulase-producing strains in the gut of C.auratus gibelio.So that the intestinal bacteria of fish produce extracellular enzymes have a beneficial effect in the digestive processes of fish.

红螯螯虾(Cherax quadricarinatus)自从80年代末被开发利用以来,国内外许多学者对其生物学、增养殖技术等进行了研究,但至今尚未见有关光照对红螯螯虾影响的报道.本文研究了光周期对红螯螯虾抱卵、胚胎发育及虾苗生长的影响,以期为提高和完善红螯螯虾的人工繁殖及育苗技术提供科学依据.