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阔叶树小径材热压干燥工艺的研究 总被引:2,自引:0,他引:2
通过对荷木和米槠两种华南地区常用阔叶树小径材薄板材热压干燥工艺的研究,探讨热压干燥工艺参数对小径材板材干燥质量(包括密度,厚度压缩率,尺寸稳定性及部分力学性能)的影响,试验结果表明,热压干燥工艺可以大大改善小径材的物理力学性能。 相似文献
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Vegetation dynamics in previously burnt shrublands dominated by gorse (Ulex gallii) in north-west Spain were studied during 4 years under different grazing managements with sheep (Gallega breed) and goats
(Cashmere or local breed). Initially (Period 1), treatments consisted of sheep or goat grazing on four plots (two replicates).
After two grazing seasons, the plots were split in two and the treatments were reversed in four of the subplots; sheep were
placed in subplots previously grazed by goats and vice versa (Period 2). The results from Period 1 showed that goats control
the regrowth of gorse (from 19.6 to 14.2% of cover) more effectively than sheep (17.8 to 27.0% cover; P < 0.05), favouring the increase in herbaceous plants (from 21.5 to 42.1% of cover under goat grazing and from 22.1 to 26.6%
under sheep grazing; P < 0.01). In Period 2, after changing treatments, there was a clear effect of the previous management (P < 0.01), conditioning the dynamics of the different plant components. Where the same animal species were maintained for 4 years,
the differences between sheep or goat grazing on gorse and herbaceous plant dynamics increased (24.4% of gorse and 35.2% of
herbaceous plant cover under goat grazing vs 43.8% of gorse cover and 19.1% of herbaceous plant cover under sheep grazing).
Animal species change buffered the differences between sheep and goats during the second Period. 相似文献
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The road effect on small rodent population is investigated at 8 fragmented forest areas in the Baekdudaegan moun-tain range, South Korea in September 2001, We especially focused on the distribution and body condition of small rodents near the roads, Korean field mouse (Apodemus peninsulae) seems to be more sensitive to the existence of a road than striped field mouse (Apodemus agradus), Korean field mouse prefers interior forest area to around road. Striped field mouse is a habitat generalist and has wide distributional range around road, but Korean field mouse is forest-inhabiting species and their distribu-tion is limited in forest area. These results suggest the effect of road is different on each small rodent species and their habitat preferences. 相似文献
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Sven Buchholz Peter Neumann Katharina Merkel H. Randall Hepburn 《Journal of pest science》2006,79(4):251-254
Small hive beetles, Aethina tumida Murray, are parasites and scavengers of honeybee colonies, Apis mellifera L., and have become an invasive species that can cause considerable damage in its new distribution areas. An effective subspecies of Bacillus thuringiensis Berliner (=Bt) would provide an alternative to chemical control of this pest. Therefore, we tested three different Bt strains [B. thuringiensis, var. aizawai (B401®), B. thuringiensis var. kurstaki (Novodor®) and B. thuringiensis var. San Diego tenebrionis (Jackpot®)] and Perizin® (3.2% coumaphos), each applied on combs with a pollen diet fed to pairs of adult beetles. This evaluates the products for the suppression of successful small hive beetle reproduction. While none of the tested Bt strains showed a significant effect on the number of produced wandering larvae, we could confirm the efficacy of coumaphos for the control of small hive beetles. We further show that it is also efficient when applied with a lower concentration as a liquid on the combs. We suggest the continued search for efficient Bt strains naturally infesting small hive beetles in its endemic and new ranges, which may become a part of the integrated management of this pest. 相似文献
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Withthesmallsawlogwidespreadused,theuncut-boardsandslabsarecutbythemulti-bitrippingedgerinthejhoberindustw.AfersawingripPed,theunedgedboedaccuratelyvolumeisfAnotherparametCrsaredefinitebyadrawing,theaPProimatevolumeforn1ulateofunedgedboardistx,y,~inatC,x'… 相似文献
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【目的】 研究沙葱及其提取物对小尾寒羊生产性能、胴体特征,肉品质及血清生化指标的影响,为舍饲肉羊饲料添加剂的开发提供试验依据。【方法】 选取3月龄、体重相近的小尾寒羊公羊60只,随机分为4组,每组3个重复,对照组(CK)饲喂基础日粮,试验组分别在基础日粮中添加沙葱粉(AMR),沙葱水提物(AWE)和沙葱醇提物(AFE),添加剂量分别为10、3.4和2.8 g/(只•d)。试验持续75 d,其中预饲期15 d,正饲期60 d。正饲期内测定小尾寒羊生产性能,正饲期结束空腹颈静脉采血测定血清生化指标,随后每个重复随机选2只羊进行屠宰,立即测定胴体特征(胴体热重、屠宰率、肾周脂肪重、皮下脂肪厚度及硬度),取胴体左侧背最长肌测定肉品质,取肾周脂肪、尾部脂肪、背部皮下脂肪和大网膜脂肪测定脂肪肉色。【结果】 与对照组相比,①沙葱醇提物组的平均日采食量显著降低(P=0.001),饲料转化率显著升高(P=0.039),平均日增重无显著性变化(P>0.05);②日粮添加沙葱粉及水提物能够显著降低羊肉的剪切力(P=0.029);③沙葱粉组、水提物组和醇提物组肾周脂肪的黄度值(b*)无显著性差异(P>0.050),醇提物组肾周脂肪(P=0.096)和大网膜脂肪(P=0.087)的b*值与沙葱粉组相比有升高的趋势,而红度值(a*)(P=0.044)和饱和度(C*)(P=0.021)显著高于沙葱粉组;④添加沙葱及其提取物能够显著升高血清总蛋白(P=0.006)的含量,沙葱及其醇提物能够显著提高血清白蛋白(P=0.006)的含量,沙葱醇提物能够显著降低血清尿素氮(P=0.024)的含量。【结论】 沙葱及其提取物对舍饲小尾寒羊胴体特征和脂肪肉色无显著影响;日粮中添加沙葱醇提物能够显著提高小尾寒羊饲料转化率,沙葱粉及水提物能够显著降低羊肉的剪切力,提高羊肉嫩度;同时沙葱及其醇提物能够显著提高血清中总蛋白和白蛋白的含量,促进肉羊对蛋白质的吸收。 相似文献
60.
基于“大国小农”的国情,促进小农户和现代农业有效衔接是推动中国农业现代化发展进程以及实现乡村振兴战略的主要着力点。虽然当前小农户参与现代农业发展存在老龄化、女性化和兼业化“三化”并重的锁定效应、耕地禀赋的刚性效应以及市场准入的壁垒效应,但重新审视小农户的生命活力与现代农业发展的包容性可以发现,小农户和现代农业之间存在相容性关系。进一步提出,实现小农户和现代农业衔接的关键在于建立新型农业服务主体激励相容机制、社会网和利益网“双重”网络机制以及小农户自我发展能力提升机制。 相似文献