河北坝上退耕还林草区新农村建设面临的问题与对策

以河北省康保县为例,在实地调查和资料分析基础上,探讨了退耕还林还草区新农村建设面临的主要生态和社会经济问题,并针对性提出了相应对策。     

Pb(Ⅱ)、Zn(Ⅱ)对孔石莼吸收总氨氮的影响

在实验室条件下研究了大型海藻孔石莼Ulva pertusa在Pb（Ⅱ）、Zn（Ⅱ）胁迫下对不同浓度总氨氮的吸收过程。总氨氮的设计水平为0、0．25、0．5、1．0、1．5、2．0mg／L,Pb（Ⅱ）、Zn（Ⅱ）的质量浓度为0．5、1．0mg／L,持续时间为12h。结果表明：对照组在0～1h内,孔石莼对总氨氮的吸收速率显著高于之后的时间段,有明显的快吸收过程;在Pb（Ⅱ）、Zn（Ⅱ）的胁迫下,这种初期快速吸收的现象减弱;两种重金属都能对孔石莼吸收总氨氮产生抑制作用,其中Pb（Ⅱ）、Zn（Ⅱ）对孔石莼吸收总氨氮初期阶段（0～1h）的胁迫作用显著,抑制率达40％～70％;高浓度（1mg／L）的Pb（Ⅱ）、Zn（Ⅱ）对孔石莼吸收总氨氮的胁迫作用大于低浓度（0．5mg／L）;Zn（Ⅱ）对孔石莼吸收总氨氮的抑制作用强于Pb（Ⅱ）。     

Detection of arboviruses in Culicoides(Diptera: Ceratopogonidae) collected from animal farms in the border areas of Yunnan Province,China

Biting midges of the genus Culicoides(order Diptera, family Ceratopogonidae) are potential biological vectors for the transmission of certain arboviruses among humans, livestock, and wild animals. This study collected a total of 405 Culicoides individuals from seven animal farms located in five counties in the border areas of Yunnan Province, China, and examined the Culicoides species composition and the major arboviruses carried by the Culicoides species. The collected Culicoides were classified into seven species with variable abundances: Culicoides arakawae(5.43%, 22/405), Culicoides homotomus(1.23%, 5/405), Culicoides obsoletus(19.75%, 80/405), Culicoides orientalis(17.28%, 70/405), Culicoides oxystoma(29.38%, 119/405), Culicoides peregrinus(5.68%, 23/405), and Culicoides nipponensis(21.23%, 86/405). Among the seven species, C. oxystoma and C. nipponensis were distributed in all the five counties with abundances of 13.33–44.87% and 10.00–46.83%, respectively, suggesting that these were the dominant species of Culicoides widespread on animal farms in the border areas. PCR was used to detect major arboviruses in the collected Culicoides specimens, including bluetongue virus(BTV), Japanese encephalitis virus, Dengue virus, Zika virus, African swine fever virus, and African horse sickness virus. Among the tested viruses, only BTV serotype 1 was tested positive in C. oxystoma specimens collected from a buffalo farm. Culicoides oxystoma was the dominant species on animal farms in the sampled areas, but it has not previously been documented as positive for BTV in China. The current results thus suggest that C. oxystoma could be an important vector for BTV transmission in these border areas, which, however, needs to be confirmed by further comprehensive experiments. Overall, the present study provides the first profile of Culicoides species on animal farms in the China, Vietnam, and Myanmar border areas, establishes the prevalence of arboviruses carried by these Culicoides species, and suggests the vector potential of C. oxystoma species for the transmission of BTV.     

74.7%农民乐防除休闲耕地杂草试验研究

采用农民乐防除休闲地杂草,结果表明,74.7%农民乐对苣荬菜的防除适宜剂量为1 500g.hm-2;对野胡萝卜为750—1 050g.hm-2;赖草、硬枝早熟禾为2 250g.hm-2;对西伯利亚蓼、三脉紫菀、茵陈蒿为3 000g.hm-2。     

羟丙基二淀粉磷酸酯对虾糜凝胶特性及其蛋白结构的影响

为考察羟丙基二淀粉磷酸酯(HPDSP)对中华管鞭虾虾糜凝胶性能的改善效果,在虾糜中分别添加1％、3％、5％、7％和9％的HPDSP,以凝胶强度、质地剖面分析、持水性、凝胶微观结构等为指标,并提取虾糜溶胶、凝胶化虾糜、虾糜凝胶中的肌原纤维蛋白,通过圆二色光谱分析蛋白分子二级结构,探究HPDSP对虾糜凝胶性能的影响及其机理...     

汞对克氏原螯虾血清部分生化指标的影响

用0、0.1、0.5、1.0 mg/L浓度的HgC l2对克氏原螯虾染毒后,进行血清生化指标检测。结果表明:总蛋白、球蛋白、白蛋白在较高浓度Hg2 作用下上升,而在低浓度Hg2 作用下总蛋白、球蛋白含量下降;甘油三酯和胆固醇含量随Hg2 的升高呈不同程度的下降趋势。谷草转氨酶(GOT)、谷丙转氨酶(GPT)、乳酸脱氢酶(LDH)、肌酸激酶(CTK)活性在高浓度Hg2 作用下呈应急性上升。     

青海省绿色食品发展的思考(二)

青海省具有发展绿色食品的自然资源优势和市场基础优势。本文论述了青海发展绿色食品的重要意义,发展现状及存在的问题,提出了发展绿色食品的思路与对策。     

花绒寄甲研究进展

花绒寄甲是大型天牛类林木蛀干害虫最为有效的天敌昆虫。文章综述了花绒寄甲生活史、生物学特性、人工繁育、释放防治天牛等方面的研究进展,以促进对花绒寄甲的更深入研究。     

四川省菊科艾纳香属一新记录种

通过野外调查及标本鉴定研究,报道了菊科旋覆花族六耳铃在中国四川省的新分布记录。本文提供了它们详细形态描述、新纪录标本及其在中国的地理分布。这一发现进一步丰富了四川省植物多样性和中药材资源种类。     

成都市土地利用时空结构变化研究

随着经济的高速发展,城市化对土地利用结构变化的影响较大,土地利用时空结构变化研究对土地规划及可持续发展具有重要意义.本文对成都市2000—2020年的土地利用数据进行处理,计算土地利用年变化率(R)、土地利用程度综合指数和土地利用变化量(S),得出以下结论:(1)耕地和建设用地变化幅度较大,总体呈增大的趋势;林地和其他...