异冰片基氧丙酮及4－异冰片基氧－2－丁酮的合成

将莰烯分别与１，２－丙二醇及１，３－丁二醇加成所得产物１－［（１，７，７－三甲基双环［２，２，１］庚－２－基）氧］２－丙醇及４－［（１，７，７－三甲基双环［２，２，１］庚－２－基）氧］－２－丁醇，氧化得到两只新型的可用作香料的萜醚酮，１－［（１，７，７－三甲基双环［２，２，１］庚－２－基）氧］丙酮，与４－［（１，７，７－三甲基双环［２，２，１］庚－２－基）氧］－２－丁酮。     

早熟西瓜新品种晋抗4号的选育

晋抗4号是山西省农业科学院园艺研究所以自交系99-20为母本、Ja-126为父本配制而成的西瓜一代杂种。早熟,全生育期约97d,果实发育期28d。果实圆形,黑皮,皮厚1.4cm,硬韧,耐贮运;瓜瓤大红色,质地脆沙,中心可溶性固形物11.5%。平均单果质量5kg,667m2产量3000kg。田间表现对枯萎病有一定抗性,对炭疽病抗性强。适宜于山西省及周边地区早熟栽培。     

一种制备(3R,4R)-4,7,7-三甲基-6-氧杂二环[3.2.1]辛烷-3,4-二醇的新方法

在催化剂过氧磷钨酸十二烷基吡啶盐(Cat-PW4)的作用下,α-蒎烯与H2O2反应生成主要产物(3R,4R)-4,7,7-三甲基-6-氧杂二环[3.2.1]辛烷-3,4-二醇。不同反应条件对反应转化率和选择性的实验结果表明,最佳反应条件为:12.8 mmolα-蒎烯、5 m L溶剂三氯甲烷、0.2 g催化剂、3.3 m L 30%H2O2,反应温度40℃,反应时间3 h,α-蒎烯转化率和产物的选择性分别为94.7%和39.8%。反应结束后,该产物存在于水相和有机相中,通过萃取和重结晶分离提纯,得率11%,纯度达到98%;其分子结构通过红外光谱、紫外光谱、1H核磁共振谱、13C核磁共振谱、低分辨率质谱及高分辨率质谱确证。     

不同药剂浸泡处理对山桃稠李种子发芽的影响

为了促进山桃稠李种子萌发,提高山桃稠李种子繁殖的发芽率,以清水作为对照,采用不同浓度的高锰酸钾、过氧化氢、赤霉素对山桃稠李种子进行处理,比较不同药剂、不同浓度及不同处理时间对山桃稠李种子发芽的影响。结果表明:不同药剂处理的种子发芽率有显著差异,不同处理时间之间没有显著差异,各药剂处理按照发芽率由高到低的顺序排列依次为高锰酸钾、赤霉素、过氧化氢、水处理。对发芽促进效果最佳的组合是0.7%的高锰酸钾浸泡处理48h,发芽率可达88%。     

1,1—二甲基—7—异丙基—1,2,3,4—四氢萘—6—磺酸钠的合成

文章探讨了１，１－二甲基－７－异丙基－１，２，３，４－四氢萘－６－磺酸钠合成的磺化工艺。通过实验室的试验，确定了适宜的工艺条件，１，１－二甲基－７－惜内基－１，２，３，４，－四四氢萘与浓度硫酸的配比为１：１０．５（ｍｏｌ比），反应温度９０±２℃，反应时间２０ｍｉｎ，产品得率达８０．３％。同时测定了产物表面活性性能，可用作表面活性剂。     

New monoterpene glycosides from Paeonia lactiflora

Three new monoterpene glycosides named 4-O-methyl-paeoniflorin (1), isopaeoniflorin (2), and isobenzoylpaeoniflorin (3), together with two known monoterpene glycosides, paeoniflorin (4) and benzoylpaeoniflorin (5), were isolated from the roots of Paeonia lactiflora. Their structures were established on the basis of spectral and chemical evidence.     

Seasonal dynamics of mineral N pools and N-mineralization in soils under homegarden trees in South Andaman,India

Agroforestry trees are now well known to play a central role in the build up of nutrients pools and their transformations similar to that of forest ecosystem, however, information on the potential of homegarden trees accumulating and releasing nitrogen (mineralization) is lacking. The present study reports seasonal variations in pool sizes of mineral N (NH₄⁺-N and NO₃⁻-N), and net N-mineralization rate in relation to rainfall and temperature under coconut (Cocos nucifera L.), clove (Eugenia caryophyllata Thunb) and nutmeg (Myristica fragrans Houtt. Nees) trees in a coconut-spice trees plantation for two annual cycles in the equatorial humid climate of South Andaman Island of India. Concentration of NH₄⁺-N was the highest during wet season (May–October) and the lowest during post-wet season (November–January) under all the tree species. On the contrary, concentration of NO₃⁻-N was the lowest in the wet season and the highest during the post-wet season. However, concentrations of the mineral N were the highest under the nutmeg and the lowest under the coconut trees. Like the pool sizes, mean annual mineralization was the highest under the nutmeg (561 mg kg⁻¹ yr⁻¹) and the lowest under the coconut trees (393 mg kg⁻¹ yr⁻¹). Rate of mineralization was the highest during the post-wet season and the lowest during the dry season (February–April) under all the tree species. High rainfall during the wet season, however, reduced the rate of nitrification under all the tree species. The mean annual mineralization was logarithmically related with rainfall amount and mean monthly temperature.     

Simple method for synthesizing phenolicβ-O-4 dilignols

A modified synthetic method for phenolic-O-4 lignin substructure model dimers was developed involving protection of the phenolic hydroxyl group of acetophenons with benzoyl chloride, bromination with 4-dimethylaminopyridiniumbromide perbromide, condensation with phenols in the presence of 18-crown-6-ether, condensation with paraformaldehyde, reduction with NaBH₄ and debenzoylation. This method results in shorter reaction times and increasing yields without the application of strict anhydrous and drastic conditions or chloric solvents. This alternative route could be applied to the-O-4 dilignol syntheses of four combinations of guaiacyl and syringyl derivatives.     

稻田转为菜地初始阶段温室气体排放特征

【目的】近年来,随着我国社会经济的快速发展和人们生活水平的提高及膳食结构的改善,越来越多的稻田被转为蔬菜种植,影响了土壤碳氮转化过程及其引起的温室气体排放。因此有必要探究稻田转为蔬菜种植,特别是该土地利用方式转变初始阶段的温室气体（CH₄和N₂O）排放特征及其关键影响因素。【方法】试验选取了长期种植水稻的双季稻田,将其中一部分转为蔬菜种植,另一部分继续种植水稻,每个处理设置了3个重复,按照当地常规模式进行管理。采用静态暗箱—气相色谱法连续3年进行田间原位观测,比较分析稻田和由稻田转变的菜地CH₄和N₂O排放特征及其年际变化差异,明确稻田转为菜地初始阶段CH₄和N₂O排放的关键影响因素。【结果】稻田是重要的CH₄排放源,其第一年的排放强度（183.91 kg CH₄-C·hm^-2?a^-1）明显低于后续两年（241.56—371.50 kg CH₄-C·hm^-2?a^-1）,这主要归功于后两年降雨量的增加引起了土壤水分含量的升高。稻田转为菜地显著减少了CH₄排放,减少量相当于稻田CH₄年累积排放量的83%—100%。菜地第一年的CH₄累积排放量（31.22 kg CH₄-C·hm^-2）显著高于第二年（0.45 kg CH₄-C·hm^-2）和第三年（0.89 kg CH₄-C·hm^-2）,表明稻田转菜地对CH₄排放的影响具有时间滞后效应。稻田是弱的N₂O排放源（1.35—3.49 kg N₂O-N·hm^-2?a^-1）,其转为菜地显著增强了N₂O排放。菜地第一年的N₂O累积排放量（95.12 kg N₂O-N·hm^-2）显著高于第二年（38.28 kg N₂O-N?hm^-2）和第三年（40.07 kg N₂O-N·hm^-2）。菜地土壤异养呼吸对N₂O排放的影响在第一年明显高于第二、三年,表明稻田转为蔬菜种植的第一年,有机质矿化对N₂O排放有重要贡献。在100年尺度CO₂当量下,稻田转为蔬菜种植第一和第二年的综合增温潜势（GWP）相对于稻田分别显著增加了390%和98%,主要是由于增加的N₂O增温潜势超过了减少的CH₄增温潜势。但是,稻田转为菜地的第三年,菜地的GWP（(16.72±3.25) Mg CO₂-eq·hm^-2）与稻田（(14.84±1.39) Mg CO₂-eq·hm^-2）相比无显著差异,主要是由于减少的CH₄ 增温潜势完全抵消了增加的N₂O增温潜势。这些研究结果表明稻田转菜地对GWP的影响主要集中在该土地利用方式转变的第一年。【结论】稻田转为菜地显著减少了CH₄排放,增加了N₂O排放,增强了菜地第一和第二年的综合增温潜势。有机质矿化过程对新转菜地第一年较高的N₂O排放有重要贡献。这些研究结果表明了评价土地利用方式转变初始阶段温室气体排放特征的重要性,便于及时采取有效管理措施缓解温室气体排放,实现环境友好型农业可持续生产。