基于履带式底盘的改进型森林消防车通过性

通过对林区复杂地形和现有消防设备的分析,在第一代消防车(LY1102XFSG30)结构上对底盘及上装进行了优化改造,由4个支重轮增加到5个支重轮,设计了一台大型履带式消防车(LF1352JP)。采用CREO软件对整车结构进行了三维设计与仿真,对消防车横向、纵向稳定性以及垂直越障和跨越壕沟进行了理论分析,分析表明,LF1352JP消防车满载时在斜坡上横向行驶所允许的最大斜坡角度为40.6°,空载时45.1°;纵向行驶时,满载时最大纵向上坡角度为52.0°,空载时60.9°,满载时最大下坡角度为47.2°,空载时45.8°;满载时越障高度为405 mm,空载时615 mm;满载时跨越壕沟宽度为1 248 mm,空载时983 mm。最后在试验场地进行了纵向爬坡、纵向下坡、跨越壕沟试验,试验验证了改造后整车牵引力和稳定性能方面都有了较大的提升,能够满足现阶段大型林区火灾作业的需求。     

对禾草源同型发酵和/或异型发酵乳酸菌发酵无芒雀麦青贮有氧稳定性的评价

本研究旨在评价禾草源同型发酵和/或异型发酵乳酸菌发酵对无芒雀麦青贮有氧稳定性的作用效果。将从禾本科牧草上分离筛选出的2株同型发酵植物乳杆菌(Lactobacillus plantarum)和蒙氏肠球菌(Enterococcus mundtti)及1株异型发酵布氏乳杆菌(Lactobacillus buchneri)制成发酵剂。选用开花期无芒雀麦,刈割切段至2~3 cm,根据所喷发酵剂菌株的不同,分为4个处理:1)对照处理(con处理),喷洒无菌去离子水;2)异型发酵处理(he处理),喷洒布氏乳杆菌液;3)同型发酵处理(ho处理),喷洒植物乳杆菌和蒙氏肠球菌混合液(2种菌1∶1混合);4)同型发酵+异型发酵处理(he+ho处理),喷洒布氏乳杆菌、植物乳杆菌和蒙氏肠球菌混合液(3种菌1∶1∶1混合)。各处理喷洒量均为10 m L/kg鲜牧草,喷洒总菌数约为5×105CFU/g鲜牧草,每个处理设5个重复。实验室常温发酵60 d后开封,通过测定无芒雀麦青贮营养成分、菌群数量及中心温度变化评价其有氧稳定性。结果显示:经60 d青贮发酵后,4个处理的p H均较青贮前显著降低(P0.05),所有处理发酵效果均较好(p H≤4.3),尤以ho处理效果最优。而在有氧暴露试验期间,con和ho处理的p H迅速增加,至第8天时达到7以上;he+ho处理p H增加幅度略低于con和ho处理,其p H至第8天时为6.3,显著低于con和ho处理(P0.05);he处理p H增加非常缓慢,至第8天时仅为4.4,显著低于其他处理(P0.05)。经60 d青贮发酵后,可溶性碳水化合物(WSC)含量以ho处理最高,显著高于其他处理(P0.05);con处理最低,显著低于其他处理(P0.05)。而在有氧暴露试验期间,WSC含量在ho处理中迅速降低,在he处理中缓慢降低;至第8天时,WSC含量以he处理最高,he+ho处理显著低于前者(P0.05),而con和ho处理则显著低于he和he+ho处理(P0.05)。青贮发酵后霉菌数量明显受到抑制,且以单独添加异型发酵乳酸菌和混合添加同型发酵和异型发酵乳酸菌时抑制效果较优,这2个处理均未检出霉菌,且he+ho处理在有氧暴露至第5天时仍未检出霉菌,he处理在有氧暴露至第8天时仍未检出霉菌。在有氧暴露第3和5天时,he和he+ho处理酵母菌数量显著低于con、ho处理(P0.05)。在有氧暴露第8天时,he+ho与he处理的乳酸、乙酸浓度均显著高于另2个处理(P0.05)。he、he+ho、con和ho处理的有氧稳定性依次降低,分别为194、126、62和58 h。综合评价结果得出:布氏乳杆菌单独或与同型发酵乳酸菌蒙氏肠球菌和植物乳杆菌联合接种可有效抑制无芒雀麦青贮的有氧腐败,保证无芒雀麦青贮有氧暴露期间品质的稳定,且前者更有效;接种同型发酵乳酸菌蒙氏肠球菌和植物乳杆菌未能在提高无芒雀麦青贮有氧稳定性方面表现出积极的作用。     

Impacts of wetting-drying cycles on short-term carbon and nitrogen dynamics in Amynthas earthworm casts

Effects of earthworm casts on soil nutrient dynamics and their responses to changing moisture availability in subtropical ecosystems remain poorly understood. This study aimed to examine short-term carbon(C) and nitrogen(N) dynamics and their interactions with wetting-drying cycles in three different structural forms(i.e., granular, globular, and heap-like) of Amynthas earthworm casts. The rates of C and N mineralization in the earthworm casts were examined under two different wetting-drying cycles(i.e., 2-d and 4-d wetting intervals) using a rainfall simulation experiment. After three simulated rainfall events, subsamples of the earthworm casts were further incubated for 4 d for the determination of CO_2 and N_2O fluxes. The results of this study indicated that the impacts of wetting-drying cycles on the short-term C and N dynamics were highly variable among the three cast forms, but wetting-drying cycles significantly reduced the cumulative CO_2 and N_2O fluxes by 62%–83% and 57%–85%, respectively, when compared to the control without being subjected to any rainfall events. The C mineralization rates in different cast forms were affected by the amount of organic substrates and N content in casts, which were associated with the food preference and selection of earthworms. Meanwhile, the cumulative N_2O fluxes did not differ among the three cast forms. Repeated wetting and drying of casts not only enhanced aggregate stability by promoting bonds between the cast particles, but also inhibited microbial survival and growth during the prolonged drying period, which together hindered decomposition and denitrification. Our findings demonstrated that the interactions between the structural forms, aggregate dynamics, and C and N cycling in the earthworm casts were highly complex.     

热处理浸渍杨木性能研究

【目的】探究不同固化温度对浸渍杨木力学性能、物理性能和甲醛释放量的影响,为浸渍木的加工与应用提供实践指导和理论依据。【方法】以毛白杨锯材径切板为试材,以不进行任何处理锯材为素材,以常压过热蒸汽为介质,选择120,140,160,180℃的固化温度对脲醛树脂浸渍杨木(浸渍材)进行树脂固化处理。【结果】经过高温固化处理的浸渍杨木力学性能相对于素材有所升高,相对于未经高温固化浸渍材有所降低。与素材相比,浸渍材和120,140,160,180℃固化浸渍材的抗弯强度(MOR)分别升高了49.60%,45.21%,43.40%,37.70,24.95%;弹性模量(MOE)分别升高了107.39%,106.83%,92.40%,85.20%,57.35%;硬度值分别升高了65.71%,59.41%,56.06%,50.98%,44.46%;冲击韧性分别降低了7.03%,10.77%,14.73%,16.40%,21.54%。素材、浸渍材以及120,140,160,180℃固化材的阻湿率分别为0,20.0%,26.0%,29.4%,30.0%,33.3%。随着固化温度的升高,固化浸渍材阻湿率升高,尺寸稳定性提高。未经高温固化浸渍材的甲醛释放量为1.66mg/L,120,140,160,180℃固化浸渍材的甲醛释放量分别为1.09,0.91,0.25,0.16mg/L,经过高温固化处理后浸渍材的甲醛释放量明显降低。【结论】热处理对浸渍木物量力学性能及甲醛释放量有明显影响,建议生产中选用160℃作为脲醛树脂浸渍杨木的固化温度。     

葡萄霜霉病菌对甲霜灵抗药性治理及其田间抗药菌株遗传稳定性分析

 为了明确葡萄霜霉病菌对甲霜灵的田间抗药性水平发展态势,于轮换用药前后,采用叶盘漂浮法测定了河北、山西、河南3省葡萄主要种植区11个葡萄园试验地葡萄霜霉病菌对甲霜灵敏感性变化动态。结果表明:田间采集的葡萄霜霉病菌对甲霜灵抗药的菌株其抗药性可以稳定遗传;不同地区轮换用药后,葡萄霜霉病菌对甲霜灵的抗药水平变化态势因用药流程的不同而发生相应的变化。采用不同作用机制的杀菌剂轮换或混合用药进行葡萄霜霉病菌对甲霜灵的抗药性治理时,需制定合理的施药流程,并根据抗药性治理的效果不断完善治理措施。     

玉米秸秆低温高效降解复合菌系GF-20的菌种组成及降解稳定性

【目的】探索不同温度及pH条件对玉米秸秆低温高效降解复合菌系的玉米秸秆分解稳定性及菌群结构稳定性的影响,完善菌系培养方法,促进其应用开发利用。【方法】以低温高效降解复合菌系GF-20为研究对象,在10℃条件下连续继代培养45代、不同温度和pH条件下连续继代培养15代,分别获得多组不同代数（F）、不同温度（T）和pH（P）条件下的菌系。测定各复合菌系发酵液pH、玉米秸秆降解率及纤维素酶活,评价复合菌系的玉米秸秆分解稳定性;利用PCR-DGGE技术结合主成分分析法对菌群组成结构的稳定性进行研究。【结果】在10℃条件下经连续继代培养40代和在温度4-30℃、pH 6.0-9.0条件下继代培养获得的不同复合菌系发酵液pH均随发酵时间的延长趋近中性;玉米秸秆降解率在27.59%-32.53%,除F40显著高于F5外,其余无显著差异;纤维素酶活性呈高代菌系大于低代菌系,温度4-10℃和pH 6.0-9.0条件下,对复合菌系产酶有促进作用,纤维素酶活为1.34-1.84 IU·mL^-1;复合菌系的纤维素酶在较低的温度和较宽的pH范围内具有良好的温度和pH稳定性,酶促反应温度15-30℃和pH 4.0-9.0内仍保持80%以上的纤维素酶活力;复合菌系F5-F45、T4-T30和P6.0-P9.0的DGGE条带差异不显著,表明菌系的菌种组成稳定;而在偏酸（pH=4、5）和偏碱性（pH=10）条件下继代培养,复合菌系秸秆降解率和纤维素酶活均显著降低,菌种组成发生变化,进而影响性质与功能稳定性。PCR-DGGE共检测到18个条带,其中关键菌株分别为Bacillus licheniformis、Azonexus hydrophilusd、Azospira oryzae、Arobacter cloacae、Cellvibrio mixtus、Bacillus tequilensis、Clostridium populeti subsp. Mixtus和Clostridium xylanolyticum。【结论】复合菌系GF-20在温度4-30℃、pH 6.0-9.0条件下经过多代继代培养,仍然保持了较高的玉米秸秆分解活性和菌种组成稳定性,具有良好的应用前景。     

三种护坡植物根-土复合体抗剪强度比较

以紫穗槐、胡枝子及狗牙根根系及其与土壤构成的根-土复合体为研究对象,通过对根-土复合体的室内直剪试验,比较分析了不同物种根系和不同含根量对根-土复合体的抗剪强度的影响。结果表明,根系的存在提高了土体的抗剪强度,根-土复合体的抗剪强度随着含根量的增加而增大,但当含根量达到一定值时根-土复合体的强度增加并不明显,即存在最佳含根量范围;与无根扰动土相比,根-土复合体内摩擦角无显著变化,但显著提高了黏聚力,其中紫穗槐、胡枝子、狗牙根黏聚力平均增幅分别为47.5%,39.2%和38.9%;紫穗槐、胡枝子和狗牙根根-土复合体对土壤的抗剪强度影响不同。在水土流失区种植乔灌木物种能有效增加坡体稳定性,降低土壤侵蚀。     

Combining Ability Analyses of Net Photosynthesis annuum Rate in Pepper （Capsicum annuum L.）

In perspective of breeding high-yield hybrid pepper varieties, combining ability analysis of net photosynthesis rate at different phases of flowering and fruit setting in pepper was made with 15 cross combinations from 6 parents by （1/2） n （n- 1） diallel crosses. There are relatively large differences not only in general combining ability （GCA） effect among different parents and at different phases of flowering and fruit setting, but also in specific combining ability （SCA） effect among different hybrids. There are relatively large GCA effects in late parents but relatively less GCA effects in early parents. No obvious laws have been found in the relationship between SCA effects and maturity of hybrids. Variances of SCA are larger than those of GCA. Heritability is less but influence of environment is larger. Correlation analysis of combining ability between net photosynthesis rate and agronomic character or resistances to main diseases has showed that correlation coefficients of GCA are relatively large at the medium phase and the late phase of flowering and fruit setting. Net photosynthesis rate is more relative to leaf characters and fruit characters. Correlation coefficients of SCA are relatively large at the early phase and the late phase of flowering and fruit setting. Net photosynthesis rate is more relative to leaf characters and plant characters at the early phase but to plant characters and fruit characters at the late phase. Correlation coefficients of SCA between net photosynthesis rate and resistances to main diseases are larger than those of GCA. The combining abilities of net photosynthesis rate at different phases of flowering and fruit setting are positively correlated with those of yield per plant. The combining ability is an important parameter of breeding of high photosynthesis hybrid pepper varieties.     

苹果汁加工和储藏中稳定性的研究

对苹果汁加工和储藏中稳定性的研究进行了综述.混浊苹果汁在加工和储藏过程中发生的非酶促褐变主要是由酚类的氧化聚合而引起,可通过低温储藏和添加0.006%Vc(W/V)加以控制.加胶或破碎时通蒸汽可改善苹果汁混浊稳定性.同时,对今后的研究重点进行了讨论.     

小麦高分子量麦谷蛋白亚基与品质性状的关系

对2002年国家黄淮南片区试参试小麦品系的蛋白质、湿面筋、沉降值和稳定时间等品质性状进行了测定,并运用SDS-PAGE分析了参试品系的高分子量(HMW)麦谷蛋白亚基组成及其与品质性状的关系。结果表明,在26个参试品系中,仅内乡188、郑农16达到强筋小麦标准;5+10亚基频率有所提高(53.8%),但具5+10亚基的品种间品质具有高度不稳定性,在品质改良中仅靠转育5+10亚基是不够的,要注重亚基组合的选育,其中以1,7+8,5+10和1,7+9,5+10亚基组合对品质的贡献最大,以14+15,5+10亚基组合对品质的贡献最小。