黄粉虫粪不同用量对制种黄瓜幼苗质量的影响

研究了营养土中不同黄粉虫粪搀入量对马坊营旱黄瓜幼苗生长的影响，结果表明：用黄粉虫粪与营养土按1：(160-320)(体积比)混配的基质进行黄瓜育苗，能促进幼苗生长，显著提高幼苗简单指标、相对指标和复合指标的值。     

基于主成分分析和聚类分析的贵州烟叶品质类型划分

本研究把烟叶外观质量评价和常规化学成分评价相结合,建立基于主成分分析和聚类分析的Fisher判别函数的烟叶质量评价模型,对贵州烤烟的品种类型进行划分,旨在为烟叶质量评价提供科学方法,并在生产上进行指导。     

松茸菌株对6种松树幼苗的感染及其菌根解剖学研究

利用我国滇产松茸9924菌株及日产松茸99606菌株，分别对云南松、华山松、马尾松、火炬松、湿地松及加勒比松6种松树幼苗实施人工菌根接种。研究结果表明，接种后90d的云南松和湿地松分别有75％和78．1％的幼苗受感染并形成菌根；接种后180d,6种松树幼苗分部都可形成菌根，菌根感染率分别达90．63％－100％，感染指数达50．00－84．68；菌根形态主要有棒状、二叉分枝状及多叉分枝状3种；随树种的不同，各类菌根形态所占比例也不同；不同树种根系上形成菌根的长度也有差异，以马尾松根系上的菌根最长，华山松的菌根最短；此外，各种组合之间在菌套厚度，哈蒂氏网结构上也略有差别。     

应用电导仪测定番茄灰霉病菌对多菌灵抗药性的初步研究

1.0 mg/L和5.0 mg/L多菌灵盐酸盐溶液处理灰霉病菌多菌灵敏感菌株和抗性菌丝体,用电导仪测定溶液电导率的动态变化,结果表明:在敏感菌株存在时,多菌灵盐酸盐溶液2 h后的电导率显著降低,而抗性菌株存在的溶液中电导率则未见下降。     

柴油机燃烧甲醇/生物柴油尾气颗粒物热解特性分析

采集了甲醇/生物柴油(5%、10%、15%)混合燃料在柴油机燃烧的尾气颗粒。采用热重分析仪和切线法、Flynn-Wall-Ozawa(FWO)热解动力学方法,研究颗粒挥发及氧化规律,分析了颗粒热解特征温度和活化能。结果表明:随着甲醇掺混量的增加,颗粒中H_2O的质量分数由2.6%增加到3.5%,可溶有机物(soluble organic fraction,SOF)质量分数由26.1%增加到32.5%,SOF的质量变化速率增大,对应的峰值温度后移;在O_2氛围中,SOF挥发阶段与在N2氛围中的表现基本一致,但质量变化速率明显增大;碳烟(soot)质量减小,由70.3%减少到63.8%,soot质量变化率峰值增大;SOF析出温度变化较小,soot起始燃烧温度明显降低,由488℃降低到458℃,SOF起始燃烧温度与燃尽温度均有所降低,颗粒的热解总反应时间缩短;颗粒的热解反应活化能由140.3 k J/mol降低117.3 k J/mol,颗粒的热解性能增强,颗粒更易被氧化。研究结果可为甲醇/生物柴油燃烧颗粒的处理及柴油机颗粒捕集器(diesel particulate filter,DPF)再生提供依据。     

Nitrous oxide emission as affected by changes in soil water content and nitrogen fertilization

Nitrous oxide emission was measured in laboratory incubations of an alluvial soil (58% clay, pH 7.4). The soil was amended with 40 mg N kg⁻¹ as NaNO₃ or NH₄Cl, or with NaCl as a control. Each fertilization treatment was adjusted to three different water contents: constant 60% WHC (water-holding capacity), constant 120% WHC, and water content alternating between 60 and 120% WHC. During an 8-day incubation period N₂O emission rates and inorganic nitrogen concentrations in soil (NH₄⁺, NO₂⁻, NO₃⁻) were determined at regular intervals. In the control and after nitrate application small N₂O emission rates occurred with only minor variations over time, and no differences between the water treatments. In contrast, with ammonium application N₂O emission rates were much higher during the first two days of incubation, with peaks in the constant 60% WHC and 120% WHC at day 1 and in the changing-water treatment at day 2, when the first wet period (120% WHC) was completed. This N₂O peak in the changing-water treatment was 4 to 9 times higher than with constant WHC and occurred when both, NH₄⁺ and NO₂⁻ concentrations declined sharply. Thus, this N₂O emission flush can be attributed to nitrifier denitrification. After the second rewetting of the NH₄⁺-amended soil no further N₂O emission peak was observed, being in accordance with small NH₄⁺ and NO₂⁻ concentrations in soil at that time. The unexpectedly small N₂O fluxes in the constant 120% WHC treatment after nitrate application were probably caused by the reduction of N₂O to N₂ under the prevailing conditions. It can be concluded that continuous wetting or flooding of a soil is an effective measure to reduce N₂O emissions immediately after the application of NH₄⁺ fertilizers.     

Expression of miRNA-22 in ovarian cancer and effect of miRNA-22 over-expression on SKOV-3 ovarian cancer cell proliferation,migration and invasion

AIM: To examine the expression of miRNA-22 in the ovarian tissues and the effect of miRNA-22 over-expression on the proliferation, migration and invasion in SKOV-3 cells. METHODS: The expression levels of miRNA-22 in different ovarian tissues and SKOV-3 cells were determined by qPCR. miRNA-22 was over-expressed by transfection of miRNA-22 mimic. The cell viability was examined by CCK-8 assay. The cell migration was measured by wound healing test. The cell invasion was analyzed by Transwell assay. The protein expression levels of VEGF and P53 were determined by Western blot. RESULTS: Compared with the normal ovarian tissue, the expression level of miRNA-22 was remarkably decreased in the ovarian tumor tissues. After transfection with miRNA-22 mimic, the expression level of miRNA-22 in the SKOV-3 cells was significantly increased, while the cell viability, migration and invasion were obviously decreased. Moreover, the protein expression of VEGF and P53 was dramatically inhibited after over-expression of miRNA-22. CONCLUSION: The decreased miRNA-22 expression may be correlated with the development of ovarian can-cer. Over-expression of miRNA-22 decreases the cell viability, migration and invasion by reducing the protein expression of VEGF and P53.     

用Nested-PCR检测广西黄皮与九里香黄龙病病原

摘要：运用nested-PCR技术对广西黄皮和九里香进行柑桔黄龙病（Citrus Huanglongbing, HLB）检测,结果表明：从部分黄皮和九里香样品抽提的DNA中,可扩增出一条特异性的400 bp条带,说明广西种植的黄皮和九里香均可感染黄龙病;在柑桔黄龙病疫区,黄皮和九里香黄龙病感染率分别为35.0%和40.0%。     

中国主要纸产品国际竞争力综合评价

文中在分析中国主要纸产品出口贸易现状的基础上,选取国际市场占有率、贸易竞争力指数和显示性比较优势指数测算中国主要纸产品2010-2019年的国际竞争力指数,并采用基于主成分分析的定权方法对纸产品国际市场竞争力进行综合评价。结果表明:主要纸产品国际竞争力较强的芬兰、瑞典和德国位居综合评价前3位,中国主要纸产品综合竞争力经过近10年发展已处于中等偏上水平,仍有改进和提升空间。基于上述研究成果,提出推进人工林速生材高效利用、促进科技创新能力提升和探索"出口转内销"等政策建议。     

大蒜主要农艺性状的相关与通径分析

对29个头蒜品种的13个农艺性状进行评价,并对其中12个农艺性状与单株产量进行相关与通径分析。相关分析表明,蒜头横径、蒜头高、叶宽、叶长、株高、外瓣数与单株产量的相关性达极显著水平,相关系数分别为0.95、0.92、0.84、0.71、0.61和0.47。通径分析表明,蒜头横径、蒜头高、叶宽与叶长4个性状对单株产量的影响较大。结合回归方程,确定蒜头横径、蒜头高与叶宽为影响单株产量的主要因素,可以作为大蒜高产育种的重要指标。