柠条裂解产品的化学成分和性质

为探索柠条裂解机理以及在特定温度下裂解产物的结构特征,文中以柠条为原料研究其裂解过程的产物分布,并利用氮吸附法、GC/MS等方法分析500℃条件下的裂解产品。结果表明:柠条炭产率随着裂解温度的升高而降低,但柠条炭中固定碳含量随着温度的升高而逐渐增加。柠条炭具有较高的全N(2.5%)和灰分含量(14.1%),比表面积为265m2/g,其中介孔占56%。XRD、FTIR分析显示柠条炭已具有一定的构造,其表面具有羰基、酯基、醚等各种官能团。GC/MS定性分析得到,柠条焦油中共检出85种化合物,相对含量91.3%,其中脂肪族化合物54种,相对含量52.9%,芳香族化合物有31种,相对含量38.4%;焦油中相对含量大于3%的化合物有杂氧环十七烷、4-乙基-2-甲氧基苯酚和棕榈酸。     

茉莉酸甲酯处理的油用牡丹干旱下的光合及生理特性

以油用牡丹‘凤丹’为材料,整株喷施4种浓度(50、100、200、400μmol/L)的茉莉酸甲酯(MeJA),以喷施清水处理为对照(CK),连续喷施3 d后进行干旱处理再复水,在‘凤丹’到达中度、重度干旱2 d及复水2 d后取样,测定‘凤丹’叶片的渗透调节物质含量、丙二醛(MDA)含量、光合色素含量,同时对光合指标进行测定。结果表明：200μmol/L MeJA处理后,中度干旱的‘凤丹’幼苗的脯氨酸含量最高,较CK显著提高250.34%,净光合速率、气孔导度和蒸腾速率最大,较CK分别提高25.73%、68.0%、43.04%;‘凤丹’的叶绿素a、叶绿素b和类胡萝卜素含量在400μmol/L MeJA处理下达到最高,较CK分别提高了33.33%、26.09%、34.48%;喷施200μmol/L MeJA后,重度干旱的‘凤丹’幼苗可溶性糖含量达到最大值,净光合速率最大,较CK提高了41.73%;蒸腾速率和胞间CO₂浓度在400μmol/L Me JA处理下最高,分别较CK提高了74.07%和13.44%;复水后,适宜浓度的MeJA处理使光合生理指标均得到不同程度的...     

农户对病虫害综合防治技术的行为选择——基于辽宁省蔬菜产地的问卷调查

在充分借鉴已有文献的基础上,结合辽宁两市的实地调研数据,从农户自身因素、生产经营条件、认知水平、风险态度以及政策环境5个方面深入分析病虫害综合防治技术的发展现状,并采用定量研究方法,运用二元Logit模型进行实证分析。结果表明,在调查样本中有69.5%的农户知道病虫害综合防治技术,但仅有36.9%的农户最终使用了这项技术。另外,家庭规模、健康程度、是否知道该技术、风险态度对农户使用病虫害综合防治技术有显著的正向激励作用,而耕地面积扩大具有显著的负面作用。     

草鱼白介素10基因的克隆表达及其双抗体 夹心ELISA检测方法的建立

为建立检测草鱼白介素10(CiIL-10)的双抗体夹心 ELISA方法,首先克隆CiIL-10基因、构建与表达原核表达重组质粒pET-32a-CiIL-10,并对表达产物进行纯化,以获得重组CiIL-10(rCiIL-10)纯化蛋白.然后,以纯化的rCiIL-10蛋白为免疫原制备兔源及鼠源抗rCiIL-10的多克隆抗体,并对其进行纯化与酶标记.最后,以纯化的鼠抗rCiIL-10抗体为捕获抗体,rCiIL-10纯化蛋白为夹心抗原,HRP标记的兔抗CiIL-10纯化抗体为检测抗体,通过优化反应条件,建立双抗体夹心 ELISA检测方法.结果显示,该方法的优化反应条件包括,捕获抗体的最佳包被浓度为20μg·mL-1,检测抗体的最佳稀释度为1 ∶ 3 200,最佳封闭条件是使用5％脱脂奶粉,37℃封闭1.5 h,样品反应时间为2 h,以OD450值≥0.174作为阳性判定标准.该方法的板内及板间重复性变异系数小于10％,最低检测限量为24.29 ng·mL-1,与草鱼白介素6、草鱼肿瘤坏死因子、小鼠白介素10、小鼠干扰素和小鼠单核细胞趋化蛋白均无交叉反应.结果表明,建立的双抗体夹心ELISA方法具有较好的特异性、重复性和灵敏度,可用于草鱼白介素10的快速检测.     

邓庄农业科技园区蔬菜产业化发展的SWOT分析及战略构想

运用“SWOT”分析方法,探讨了邓庄农业科技园区主导产业—蔬菜产业化发展的区位、规模、科技、机制、信息5大优势和自身存在的劣势,以及发展过程中面临的机会和挑战。并在此基础上,分别从名牌战略,科技进步,渠道疏通,企业壮大,政策扶持,产业链条延长等方面提出了如何推进邓庄园区蔬菜产业化发展的战略构想。     

河北省果品出口贸易研究

果品是劳动密集型产业 ,在河北省果品面积和产量的高速发展与国内居民消费水平的缓慢增长矛盾日益突出和面临加入WTO的新形势下 ,应把出口贸易作为果品业发展的重点。在深入分析河北省发展果品出口贸易的潜力和优势、果品出口贸易现状、果品出口面临的问题与障碍的基础上 ,全面论证了河北省发展果品出口贸易的目标、定位及战略 ,提出了应用性、可操作性较强的进一步发展果品出口贸易的思路及对策。     

云南广南天然蒜头果可培养内生及根际真菌多样性分析

为探讨蒜头果内生、根际真菌与其存活、生长及生境的关系,在云南广南县蒜头果天然分布区选取3个代表不同生境的样地,采集蒜头果根、茎、叶和根际土进行内生、根际真菌的分离鉴定及其群落结构多样性分析。结果表明：3个样地共分离获得蒜头果内生、根际土壤真菌276株,涉及3个门8个纲35个属,其中木霉属,间座壳属和青霉属为优势菌属。不同部位中茎部内生菌种类和数量最为丰富,共93株,24个属,且多样性、均匀度及丰富度指数最高。此外,根部内生菌和根际真菌的群落组成相似性系数最高,而叶部内生菌最低。在相同海拔条件下,裸露石灰岩山地（DY）与石灰岩林地（DB）的蒜头果内生、根际真菌群落组成具有一定的相似性,但前者较后者丰富;石灰岩林地中,低海拔生境（DB）的蒜头果内生、根际真菌群落组成较高海拔生境（NZ）丰富,且二者群落结构差异较大。不同生境间蒜头果内生、根际真菌多样性与丰富度指数为裸露石灰岩山地（DY）> 低海拔石灰岩林地（DB）> 高海拔石灰岩林地（NZ）,而优势度与均匀度指数则相反。由此表明,裸露石灰岩山地（DY）的蒜头果内生、根际真菌群落更为丰富,而高海拔石灰岩林地（NZ）的单菌属优势突出,菌落结构较为单一。     

Nutritive value of selected grasses in North Sumatra, Indonesia

The nutritive values of seven native grass species collected in North Sumatra, Indonesia, during dry and rainy seasons were evaluated. The chemical composition, in vitro dry matter digestibility (IVDMD), in vitro organic matter digestibility (IVOMD), in vitro crude protein digestibility (IVCPD), macro mineral concentrations of calcium, phosphorus and magnesium, in vitro gas production profile and metabolizable energy (ME) content of the grasses varied greatly among species and seasons. The crude protein content ranged from 6.6 (Andropogon gayanus) to 16.2% dry matter (Cynodon plectostachyus) in the rainy season, with a significant (P < 0.05) reduction in the dry season. Data on the fiber fraction showed that the grasses contained more neutral detergent fiber (NDF) and acid detergent fiber (ADF) in the dry season and it significantly (P < 0.05) decreased in the rainy season, except for Panicum maximum and Pennisetum purpureum for NDF content and C. plectostachyus, P. maximum and Brachiaria decumbens for ADF content. Data on the mineral concentration showed that C. plectostachyus in the dry and rainy seasons had a higher calcium content than those of other species. The overall means of the seven grasses for IVDMD, IVOMD and IVCPD were significantly higher (P < 0.05) in the rainy season than in the dry season. The in vitro gas production and ME concentration were numerically higher in the rainy season than in the dry season. In conclusion, the nutritive value of the observed grasses in North Sumatra was relatively higher during the rainy season compared with the dry season. Among the species of grass, P. purpureum and C. plectostachyus had a higher nutritive value in both the dry and rainy seasons.     

大米蛋白胃蛋白酶酶解物体外抗氧化作用的研究

本试验采用正交设计,以羟自由基清除率为评定指标,用胃蛋白酶酶解大米蛋白,旨在确定其酶解物体外抗氧化作用最佳的酶解条件。试验结果表明:当酶解温度为37℃时,影响大米蛋白胃蛋白酶酶解物抗氧化效果的因素大小排序为:pH酶浓度底物浓度酶解时间;最佳酶解条件为:pH1.4、酶浓度5%、底物浓度8%、酶解120min,此条件下酶解物的羟自由基清除率为72.78%,多肽浓度为5.49mg/mL,水解度为15.62%。     

Effects of Bacillus subtilis on jejunal integrity,redox status,and microbial composition of intrauterine growth restriction suckling piglets

The present study used intrauterine growth restriction (IUGR) piglets as an animal model to determine the effect of Bacillus subtilis on intestinal integrity, antioxidant capacity, and microbiota in the jejunum of suckling piglets. In total, 8 normal birth weight (NBW) newborn piglets (1.62 ± 0.10 kg) and 16 newborn IUGR piglets (0.90 ± 0.08 kg) were selected and assigned to three groups. Piglets were orally gavaged with 10-mL sterile saline (NBW and IUGR groups), and IUGR piglets were orally gavaged with 10-mL/d bacterial fluid (B. subtilis diluted in sterile saline, gavage in the dose of 2 × 10⁹ colony-forming units per kg of body weight; IBS group; n = 8). IUGR induced jejunal barrier dysfunction and redox status imbalance of piglets, and changed the abundances of bacteria in the jejunum. Treatment with B. subtilis increased (P < 0.05) the ratio of villus height to crypt depth (VH/CD) in the jejunum, decreased (P < 0.05) the plasma diamine oxidase (DAO) activity, and enhanced (P < 0.05) the gene expressions of zonula occludens-1 (ZO-1), occludin, and claudin-1 in the jejunum of IUGR piglets. Treatment with B. subtilis decreased (P < 0.05) the concentration of protein carbonyl (PC) and increased (P < 0.05) the activities of catalase (CAT) and total superoxide dismutase (T-SOD) in the jejunum of IUGR piglets. Treatment with B. subtilis also increased (P < 0.05) gene expressions of superoxide dismutase 1 (SOD1), CAT, and nuclear factor erythroid 2-related factor (Nrf2), as well as the protein expressions of heme oxygenase-1 (HO-1), SOD1, and Nrf2 in the jejunum of IUGR piglets. Treatment with B. subtilis also improved the abundances and the community structure of bacteria in the jejunum of IUGR piglets. These results suggested that IUGR damaged the jejunal barrier function and antioxidant capacity of suckling piglets, and altered the abundances of bacteria in the jejunum. Treatment with B. subtilis improved the intestinal integrity and antioxidant capacity while also improved the abundances and structure of bacteria in the jejunum of suckling piglets.