丙稀酸甲酯在天然胶乳硫化胶膜表面的接枝共聚

采用氩等离子体激发及紫外辐射引发技术可以使丙稀酸甲酯接枝共聚到天然橡胶硫化胶膜表面。接枝处理硫化胶膜表面接触角测定结果表明,随着接枝反应的进行,较多的聚丙烯酸甲酯接枝到硫化胶膜表面,使硫化胶膜表面接触角显著下降。采用等离子体激发 2 min,紫外光照射 16 min 的处理条件,可使硫化胶膜表面与水的接触角由 105°下降至约 60°。接枝处理硫化胶膜表面形态分析结果表明,接枝后的聚丙烯酸甲酯分子链在硫化胶膜表面互相叠加,使胶膜表面变得粗糙,从而使天然橡胶硫化胶膜表面亲水性能得到改善。     

转Bt基因棉花对棉田天敌的影响

就转Bt基因棉花对棉田害虫寄生性天敌、捕食性天敌的个体发育和种群的影响进行了综述,并且分析了影响机理。     

自然风景质量评价法在绵阳市旅游资源分等定级中的应用

采取自然风景质量评价法,以绵阳市8个旅游风景区作为基本单位,选取地形、植物、水体、色彩、近景观的影响、稀有性与人为改变7个风景质量因子作为风景资源质量评价项目,对这8个旅游风景区进行评价,依据美国土地管理局的风景资源管理系统,用特尔菲法评分,算出8个旅游风景区的风景质量等级,绘出绵阳市旅游资源等级图,得出绵阳市旅游资源优劣状况,提出景区的发展方向和相关问题的解决措施,为绵阳市旅游资源的开发提供有用的依据。     

黔中喀斯特植被自然演替过程中物种组成及多样性研究———以贵州省普定县为例

根据植物群落的特征,将黔中喀斯特地区石漠化后植被自然演替过程分成草丛阶段、草灌阶段、藤刺灌丛阶段、次生乔林阶段和常绿阔叶林阶段,应用物种丰富度指数、Simpson指数、Shannon-Wiener指数和Pielou均匀度指数分别研究各演替阶段草本层、灌木层、乔木层和群落总体的物种多样性.结果表明:在植被演替过程中,物种多样性从草丛阶段开始增加,草本层到藤刺灌丛阶段达到峰值,随后下降;灌木层、乔木层和群落总体则增长到次生乔林阶段达到峰值.草丛阶段和草灌阶段物种多样性为草本层＞灌木层;藤刺灌丛阶段乔木层物种多样性最低,草本层与灌木层物种多样性大小对比因测度方法不同而有差异;次生乔林阶段和常绿阔叶林阶段物种多样性为灌木层＞草本层＞乔木层.黔中喀斯特地区石漠化后在人为干扰较小的情况下,植物群落由草本植物占优势逐渐向灌木和乔木树种占优势转移,并最终形成喀斯特森林.     

Seaweeds and Their Natural Products for Preventing Cardiovascular Associated Dysfunction

Cardiovascular disease (CVD), which involves the onset and exacerbation of various conditions including dyslipidemia, activation of the renin–angiotensin system, vascular endothelial cell damage, and oxidative stress, is a leading cause of high mortality rates and accounts for one-third of deaths worldwide. Accordingly, as dietary changes in daily life are thought to greatly reduce the prevalence of CVD, numerous studies have been conducted to examine the potential use of foods and their bioactive components for preventing and treating CVD. In particular, seaweeds contain unique bioactive metabolites that are not found in terrestrial plants because of the harsh environment in which they survive, leading to in vitro and in vivo studies of their prevention and treatment effects. This review summarizes studies that focused on the beneficial effects of seaweeds and their natural products targeting markers involved in a cascade of mechanisms related to CVD pathogenesis. The purpose of this review is to describe the potential of seaweeds and their natural products for preventing and treating CVD based on in vivo and in vitro studies. This review provides a basis for future research in the field of marine drugs.     

A meta-analytic review of monoterpene for fish anaesthesia

The use of anaesthetic agents has been increasing to address the welfare needs of different fish species in scientific and aquaculture practices. MS-222 is the most used synthetic anaesthetic but some limitations and side effects have been reported. Natural substances have been used as potential substitutes with clove oil playing an important role due to its eugenol content. Yet, other monoterpenes have shown anaesthetic properties in different fish species. As such, a quantitative assessment has been conducted to explicitly relate and summarise the use of monoterpenes with described anaesthetic properties in fish. A combined PubMed, Web of Science, Scopus, PubMed Central and Europe PMC electronic database search was performed, from January 2002 to August 2022, following the PRISMA guidelines. Out of 1555 articles retrieved from the literature search, 30 English reports met the criteria for inclusion in the meta-analysis through a generic inverse-variance method (random-effects model) and according to the fish age. The findings show a total of 10 different monoterpenes with high homogeneity and effectiveness in inducing anaesthesia and recovery according to the fish anaesthetic criteria. Further subgroup analysis showed these effects were independent of fish age. Meta-regression of the included studies revealed an inverse linear association between anaesthesia induction and recovery time and water bath temperature while no further correlation was found with other confounding factors (body weight, water pH and dissolved oxygen levels). Although further studies will be required, this meta-analysis provides robust evidence that different monoterpenes serve as an attractive and effective alternative for fish anaesthesia although water bath temperature also played an important role in anaesthesia outcome.     

勐腊分公司速生、高抗、高效二代胶园建设技术

勐腊橡胶分公司在植胶资源极为有限的条件下,为将二代胶园建设成速生、高抗、高效,集社会效益和经济效益为一体的生态环保型橡胶园。充分利用现有更新胶园的土地资源进行科学规划,采用宽行密株种植形式,合理密植、规范开垦,使土地资源利用率比更新前提高50.53%。并根据植胶小区环境,结合品种特性对口配置具有相应抗性的速生、高抗、高产优良品种,充分发挥地力和品种的潜力。积极推广应用高吸水树脂春季抗旱、节水、保肥、速生栽培技术,促进胶苗速生,可比新植胶园提前一年投产开割,增加经济效益480.73万元/年。     

天然橡胶介质三维粘弹性问题边界元分析(Ⅰ)--理论分析和基本方程建立

应用边界元理论对天然橡胶介质三维粘弹性问题进行理论分析,建立空间边界(Г)上基本方程、空间区域(Ω)内基本方程、对区域(Ω)内存在的强奇异积分做有效处理,得出能够通过高斯积分求解的基本方程,为下一步进行基本方程的数值化、计算机数值计算提供理论依据。     

信阳茶区自然生态环境条件分析

通过对信阳7县2区茶叶生产状况的调查,利用9个气象台站1971～2000年气候整编资料及局地农业小气候观测资料,在对信阳绿茶产区自然地理和生态环境进行考察的基础上,按照茶树栽培环境和茶园地理特征将其细分为淮南丘陵茶区、豫南山地茶区两种类型,并对茶区光、热、水等农业气候资源进行了分析评价.结果表明信阳茶区茶树生长季节的热量条件适宜,降水量适中且分布均匀,年平均相对湿度为75%,日光散射辐射的比例高,云雾天数最长可达160 d,光、热、水气象要素同期协调递增,其优越的自然生态环境和独特的过渡气候条件,是造就“信阳毛尖”名品绿茶质量的真正原因.并提出了＂信阳毛尖＂走可持续发展道路的策略.     

株洲市城郊植物多样性调查研究

植物多样性是生物多样性的重要层面,园林绿化是人工群落组成部分。保护生物多样性,模拟地带性人工植被,才能实现园林绿化低成本、高效益、高生产力、高生物量的总体目标。因此,对城郊天然林调查有其必要性。调查结果表明：株洲城郊有种子植物约500种（不含栽培植物）,隶属73科,187属,其中木本植物193种,草本植物300余种。过渡特征明显,特有成分丰富,观赏植物资源众多,外来种是株洲城郊生物多样性重要成分。其结果为人工模拟天然植被与保护生物多样性提供科学依据。