改善低毒脲醛树脂微观结构的方法

本研究通过理论研究和实验探索，采用适当降低缩聚段的ｐＨ值和引入缩醛化反应，从而改善了树脂的微观结构，得到不脱水低毒脲醛树脂胶，其性能达到ＧＢ／Ｔ１４７３２－９３要求，制得的刨花板满足ＧＢ／Ｔ４８９７－９２Ａ类板一等品要求，甲醛释放量达到欧洲Ｅ２级。     

生地黄与马兜铃配伍缓解马兜铃毒性的研究

试验旨在探究生地黄与马兜铃配伍对鸡肝脏和肾脏的影响，为中药配伍解毒提供现代理论依据。将80只雄性雏鸡随机分为10组，分别为对照组，马兜铃高、中、低剂量组，生地黄高、中、低剂量组，马兜铃与生地黄配伍高、中、低剂量组。各组中药经过煎煮、过滤、离心去除杂质，制成煎液。每日灌服给药，连续28 d。采用试剂盒检测谷草转氨酶（AST）、谷丙转氨酶（ALT）、肌酐（Cr）、尿素氮（BUN）肝脏和肾脏功能指标；利用试剂盒检测总抗氧化能力（T-AOC）、超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-Px）和丙二醛（MDA）。采集肝脏和肾脏并制备切片观察组织病理学变化。结果显示，与单用马兜铃组相比，马兜铃与生地黄配伍后机体的AST、ALT、Cr和BUN含量显著降低（P<0.05），马兜铃与生地黄配伍后能明显提高机体的T-AOC、SOD和GSH-Px含量；单用马兜铃能引起机体氧化损伤，导致MDA含量显著升高，生地黄与马兜铃配伍后能显著降低MDA含量（P<0.05），减缓马兜铃对机体的氧化损伤；病理结果表明，生地黄与马兜铃配伍后能显著降低马兜铃煎煮液对肝脏和肾脏造成的病理性损伤。综上，与单用马兜铃相比，马兜铃与生地黄配伍联用对鸡肝脏和肾脏造成的损伤有缓解作用，可提高马兜铃的用药安全。     

Novel chelant‐based washing method for soil contaminated with Pb and other metals: A pilot‐scale study

Remediation with chelants can restore metal‐contaminated soils for use as a natural resource. Calcareous soil from Meza Valley, Slovenia, and acidic soils from Arnoldstein, Austria, and Pribram, Czech Republic (with 1,028, 862, and 926 mg ∙Pb∙kg⁻¹, respectively), were washed with 60–100 mmol EDTA per kilogram of air‐dried soil in series of 30 batches (50 kg soil batch⁻¹). The approach involves a novel reaction that incorporates alkaline substitution, precipitation and adsorption of toxic metals on polysaccharides, and chelant acidic precipitation via 83% EDTA (on average) and complete process water recycling (no wastewater was generated). The pH gradient was imposed by Ca(OH)₂ and H₂SO₄, and excess reagent was removed with the remediated soil as CaSO₄, thereby preventing the salification of the recycled waters. Remediation removed 60%, 78%, and 71% of the Pb from the Meza, Arnoldstein, and Pribram soils, respectively, and reduced the Pb bioaccessibility levels in the simulated human gastrointestinal phase by 5.0, 7.7, and 8.1 times. Residual emissions (EDTA, toxic metals) were reduced with soil aging and remediated soil deposition on a reactive permeable barrier. The solid waste generated from the process totaled 10.8 kg tons⁻¹ of the air‐dried soil, and the material/energy costs of remediation reached 20.6 € tons⁻¹. These results demonstrate the robustness, efficiency, and safety of this novel approach.     

参与式林业规划过程中的利益相关群体分析

通过对参与式林业规划过程中相关利益群体的实地调查,揭示了不同利益群体的思想世界。结果分析证明发展干预的话语将被不同的利益相关群体逐级解构与塑型;利益相关群体在技术领域的参与容易实现,但关键是造林的有关权属安排;利益相关群体之间存在利益竞争与冲突。因此,发展干预的话语应该进行基层可操作化;在权属制度保证的基础上应实现技术操作灵活化;应实现从角色间的利益相关向角色内利益相关的转变。     

克鼠星1号对甘肃鼢鼠毒杀作用测定

据测定 ,克鼠星 1号成品灭鼠剂对甘肃鼢鼠的室内杀灭效果为 10 0 % ,最佳致死量为 4 4.6～4 9.5 g/ kg,平均致死时间为 10 6 .5 4h。甘肃鼢鼠 2 4～ 4 8h食毒量与龄级、体重呈负相关 ,且雌鼠大于雄鼠。致死时间与龄级、体重呈正相关 ,与食毒呈负相关。雌鼠中 3年耐药性最强 ,而雄鼠的最弱。最佳致死温度 ,日最低为 10 .6± 0 .4℃ ,最高为 13.2± 2 .5℃ ,平均为 11.7± 1.6℃。     

串珠镰刀菌素的理化性质、毒作用机理及中毒动物概况

串珠镰刀菌素是由多种镰刀菌产生的有毒次级代谢产物。其产毒菌种常侵染玉米、小麦和水稻等禾谷类作物,不仅造成农作物减产,更会危害动物和人类健康。串珠镰刀菌素的毒性主要会造成心脏损伤和免疫力下降,同时也会损伤肝、肾、胰等内脏器官以及骨组织和软骨组织。文章综合论述了串珠镰刀菌素的理化性质、毒作用机理以及中毒动物的病理学检查、组织学检查和临床症状。     

浅析《黑人奴隶弗雷德里克·道格拉斯的生平自述》中的语言偏离现象

弗雷德里克·道格拉斯在其自传体小说《黑人奴隶弗雷德里克.道格拉斯的生平自述》中,借助语法偏离和书写偏离等语言偏离手段,以艺术的形式为自己构建了一个自由的深度空间,在精神与灵魂的自由中突破了话语权力的藩篱,表现了自我与自主,彰显了主体和个性。     

学习目标下的大学英语教学实验研究

以学习目标为重点进行的大学英语教学实验,探讨学习目标在大学英语教学,特别是阅读技巧教学过程中的重要作用,旨在提高学生的英语语篇分析和阅读能力。实验结果表明:以学习目标为中心的大学英语教学可以提高学习者的读写能力,两者具有关联性。     

Production of UV-light-detectable faeces from house mice (Mus musculus domesticus) after consumption of encapsulated fluorescent pigment in monitoring bait

BACKGROUND: The authors investigated whether fluorescent pigment in thermoset melamine microcapsules incorporated into monitoring baits would be excreted in the faeces of wild house mice in a quantity and intensity that would be detectable by a human observer. RESULTS: Experimental mice produced 24–116 UV‐visible faecal pellets per 24 h; the mean dry weight was 582 mg. The number and weight of the faeces was independent of mouse sex and weight. The defecation of UV‐visible faeces began at 2–3 h, peaked at 5–8 h and was complete at 17 h after bait ingestion. The detectability of the highly fluorescent faecal pellets using a small UV flashlight approached 100%, and no false positives were recorded. CONCLUSION: The tested formulation is of significant value for rodent pest monitoring because faeces that are highly visible by UV light are produced for 15 h by mice after ingestion, and their detection is easy and unambiguous. Copyright © 2011 Society of Chemical Industry     

测试条件对啶虫脒毒土柱防白蚁效果的影响

将预防性杀白蚁药剂施在土壤中形成毒土层是当前控制白蚁为害的主要方法之一。以黄胸散白蚁Reticulitermes flaviceps为对象,啶虫脒为供试药剂,在室内进行毒土柱防白蚁效果测定。结果表明,供试白蚁数量和食物供应与否均对药效试验评价结果有较大影响,毒土柱长度对测试结果的影响与土壤中药剂浓度有关。当毒土柱长度达到10 cm时,所测结果即可反应药剂对白蚁的阻杀效果。用毒土柱法测定预防药剂防白蚁的效果时,建议用10 cm长的毒土柱,每个重复的白蚁数为工蚁100头,并用湿润滤纸片作为供试白蚁的食物和水源。