世界自然遗产地区域旅游合作研究——以荔波县与独山县为例

通过对旅游资源、区位、交通、政策和其他发展条件等的分析,对比荔波县和独山县区域旅游合作现状,并从合作意识、政府主导、旅游设施、旅游市场,旅游品牌、旅游人才、环境保护等方面提出荔波县和独山县区域旅游合作,实现旅游可持续发展的对策。     

番麻蛋白酶活性中心基团的初步研究

在不引起酶变性的条件下,用半胱氨酸(Cys)专一性化学修饰试剂碘乙酸、对氯汞苯甲酸(?)(CMB),5,5′-二硫双硝基苯甲酸(DTNB)对酶分子进行化学修饰后,酶活性显著下降。发现酶的失活程度与修饰剂浓度间存在着化学计量关系,同时底物(酪蛋白)对酶活性有明显的保护作用。说明被修饰的部位(Cya残基)是酶的活性中心基团。Cys对酶有明显的激活作用;同时,(?)CMB、DTNB、碘乙酸对酶活性有明显的抑制作用(?)CMB抑制或O_2氧化而失活的酶溶液,又可被Cys重新激活,而恢复其活力,进一步证明其活性中心存在着Cys残基。以上事实均与典型的植物巯基蛋白酶——木瓜蛋白酶一致,说明番麻蛋白酶是一种巯基蛋白醇,其活性中心存在着Cys。     

Phylogenetic and epidemiological characteristics of H9N2 avian influenza viruses in Shandong Province,China from 2019 to 2021

H9N2 avian influenza virus(AIV) has widely circulated in poultry worldwide and sporadic infections in humans and mammals. During our surveillance of chicken from 2019 to 2021 in Shandong Province, China, we isolated 11 H9N2AIVs. Phylogenetic analyses showed that the eight gene segments of the 11 isolates were closely related to several sublineages of Eurasian lineage: BJ/94-like clades(HA and NA genes), G1-like clades(PB2 and M genes), and SH/F/98-like clades(PB1, PA, NP and NS genes). The isola...     

棉花功能叶不同位点SPAD值与氮素养分相关性

通过水培试验,设N0(0,不供氮)、N1.5(1.5mmol/L,适量供氮)、N15(15mmol/L,过量供氮)3个供氮处理,分4次测定棉花功能叶1～17个不同位点SPAD值和含氮量,分析棉花功能叶片不同位点SPAD值与植株氮素养分的相关关系。结果表明,随施氮量增加,棉花生长量也显著增加,N0、N1.5、N15处理的施氮量与棉花生长量、氮吸收量及叶片氮含量的相关性达到显著水平,相关系数分别为0.669 0、0.769 1和0.742 0,而棉花叶片平均SPAD值与施氮量、氮素吸收量相关性不显著,相关系数仅为0.241 8。可见,棉花地上部生物量随施氮量增加而显著增加,地上部的植株氮素水平与功能叶平均SPAD值相关性低,另外,选择适宜的观测位点十分必要,棉花功能叶中远离叶柄而靠近叶缘的位点适宜作为SPAD仪的测定区域。     

塞罕坝植物区系新分类群与河北新分布Ⅱ

本文发表了塞罕坝植物区系２１个河北新记录种，涉及６科１０属。考证了有关文献；并对每种的分布区域及适生条件进行了记述。     

苏州新区高新国际商务广场设计构思

通过对苏州新区高新国际商务广场设计的背景、理念和规划手法的总结与分析,探讨了在追求人、活动、功能协调统一的人性场所前提下,如何创造室内外空间一体、景观连续完整的广场空间。     

南京地区油菜田杂草群落特点及分布规律的研究

利用７ 级目测法调查了南京地区油菜田３１ 个样点的杂草优势度级,并以其重要值为指标,对３１ 个样点的杂草群落进行计算机模拟聚类分析。结果表明,受耕作措施、除草剂的施用等因素的影响,南京地区油菜田杂草群落类型多样化。３１ 个样点主要聚为四种类型,其中旱（ 大豆、玉米等） 茬油菜田样点聚为一类,主要以猪殃殃、波斯婆婆纳、野老鹳草等旱生杂草为优势种,稻茬油菜田样点聚为三类,分别以日本看麦娘、牛繁缕、硬草为优势种。旱生杂草猪殃殃、大巢菜等在稻茬油菜田发生量加大。多年使用盖草能、绿麦隆的田块,耐药性杂草野老鹳草、稻搓菜、硬草数量上升。     

Temporal and spatial patterns of denitrification enzyme activity and nitrous oxide fluxes in three adjacent vegetated riparian buffer zones

The aim of this study was to investigate temporal and spatial patterns of denitrification enzyme activity (DEA) and nitrous oxide (N₂O) fluxes in three adjacent riparian sites (mixed vegetation, forest and grass). The highest DEA was found in the surface (0–30 cm) soil and varied between 0.7±0.1 mg N kg^–1 day^–1 at 5°C and 5.9±0.4 mg N kg^–1 day^–1 at 15°C. There was no significant difference (P >0.05) between the DEA in the uppermost (0–30 cm and 60–90 cm) soil depths under different vegetation covers. In the two deepest (120–150 cm and 180–210 cm) soil depths the DEA varied between 0.0±0.0 mg N kg^–1 day^–1 at 5°C and 4.4±0.9 mg N kg^–1 day^–1 at 15°C and was clearly associated with the accumulation of buried organic carbon (OC). Two threshold values of OC were observed before DEA started to increase significantly, namely 5 and 25 g OC kg^–1 soil at 10–15°C and 5°C, respectively. In the three riparian sites N₂O fluxes varied between a net N₂O uptake of –0.6±0.4 mg N₂O-N m^–2 day^–1 and a net N₂O emission of 2.5±0.3 mg N₂O-N m^–2 day^–1. The observed N₂O emission did not lead to an important pollution swapping (from water pollution to greenhouse gas emission). Especially in the mixed vegetation and forest riparian site highest N₂O fluxes were observed upslope of the riparian site. The N₂O fluxes showed no clear temporal trend.     

Bat activity affected by sewage effluent in Irish rivers

Bat activity and benthic macroinvertebrates were sampled at nine paired sites, upstream and downstream from sewage effluent discharges into Irish rivers. Bat activity was measured using broadband acoustic detectors and macroinvertebrates by three 30-s standard benthic kick samples per site. Biological indices of water quality were significantly lower downstream from sewage outfalls, relative to upstream. The soprano pipistrelle (Pipistrellus pygmaeus) was significantly more active (as measured by bat passes per unit time) at downstream sites, while Daubenton’s bat (Myotis daubentonii) was less active. These results contrast with those of a similar study in England, where P. pygmaeus were less active, and Myotis spp. were more active downstream from sewage outfalls. We suggest that P. pygmaeus were more active downstream in our study because of a preference for preying on small orthocladiinid Chironomidae (non-biting midges), which were significantly more abundant downstream. M. daubentonii may prefer Trichoptera (caddis fly), which were significantly more abundant upstream. Organic pollution may then affect bats, but its effect appears to be more complex than previously implied. Implications of changing nutrient levels in freshwaters for populations of M. daubentonii and P. pygmaeus may be different from what is currently suggested in the literature.