干酪流变学的研究

干酪是一种黏弹性物质,对其进行流变学特性的研究,主要从时间规模作用和干酪分子间化学键等方面进行,干酪的流变学特性与干酪的质构和生产工艺密切相关,是其质量评价中的重要体系之一。     

The influencing factors of N2O emission and denitrification in the soil of water-level-fluctuation zone in the Three Gorges Reservoir area

In order to study the influences of water filled pore space (WFPS), temperature, the addition of nitrate (NO -3) and carbon source on N2O emission and denitrification in the soil of water-level-fluctuation zone in the Three Gorges Reservoir area, C2H2 in hibition incubation experiments are applied. Results from experiments in laboratory and in situ field are analyzed. Results show that the WFPS is a main factor determining N2O emission and denitrification. Denitrification rate increases while the WFPS increases, and the maximum denitrification rate and the maximum N2O emission rate appear when the WFPS is 100% and 60%, respectively. In addition, while the temperature is between 10 ℃ and 40 ℃, the increase of temperature contributes to the increase of the N2O emission and denitrification rates. Furthermore, it is found that the N2O emission and denitrification rates are significantly and positively correlated with temperature. The addition of carbon source could increase denitrification performance in soil. However, the addition of nitrate has a negative impact on the denitrification performance, because nitrogen source is not the main factor determining denitrification performance and excessive nitrate could inhibit the denitrification in these experiments. The addition of glucose, which is a carbon source easily be utilized by denitrifying bacteria, could significantly increase the denitrification rate in soil, and the maximum denitrification rate takes place while the carbon content in per kilogram soil is 240 mg.     

Expression Patterns of the Serine Protease Gene AlSP 3 in Apolygus lucorum (Hemiptera: Miridae) at Different Temperatures

As an important digestive enzyme gene, the serine protease gene AlSP 3 plays a key role in Apolygus lucorum for digesting conventional cotton. To understand the effect of different temperatures on the expression level of AlSP 3, we analyzed the expression patterns of AlSP 3 in A. lucorum reared at different temperatures using real-time polymerase chain reaction. The results showed that at the normal temperature of 24 ℃, the expression of AlSP 3 in A .lucorum at different nymphal stages was similar. The expressions of AlSP 3 in the female adult at the pre-mating stage and the male adult at post-mating stage were 19.71- and 7.16-fold higher than their control at the 1^st nymphal stage, respectively, which were significantly higher than at any other stages. However, expression in the 4^th to 5^th A. lucorum at the nymphal stage increased with rising temperature in the range of 21～30 ℃. At 30 ℃, the expression of AlSP 3 in the 2nd to 5^th A. lucorum was the highest. The expression levels of AlSP 3 in adult A. lucorum reared at different temperatures during the new emergence and pre-mating stages were significantly higher than that of the control reared at 24 ℃ (P < 0.01), while the expression during the post-mating stage at 18℃ was higher than that at other temperatures. When incubated at extreme temperatures (4 ℃ and 40 ℃), the expression of AlSP 3 in female and male adult A. lucorum was significantly higher than that at 24 ℃ (P < 0.01). Taken together, our results showed that the external environment temperature and the internal stage of A. lucorum or its sex all had significant effects on the expression of AlSP 3 in A. lucorum (P < 0.01), and that there was some interactions between them. Therefore, AlSP 3 is very important for the female adult A. lucorum to obtain nutrition at the early stages and temperature is an important limiting factor for the expression of AlSP 3.     

一种富含花青素的固体饮料的工艺研究

以黑米、黑芝麻、黑豆、黑玉米、黑木耳、黑枣、麦芽糊精、木糖醇和乳粉为原料,针对中老年人群,开发出一款富含花青素的固体饮料。首先,将黑米、黑玉米、黑芝麻和黑豆进行预处理,以花青素保留率、淀粉糊化率、溶解度和膨胀度为指标,优化烘烤条件。结果表明,四者的烘烤条件分别为150℃,15 min;210℃,7 min;140℃,9 min;130℃,15 min。在此基础上,以感官品质为评价指标,通过单因素试验,初步探讨麦芽糊精添加量对产品黏稠度和稳定性的影响,以及木糖醇、乳粉、黑米、黑芝麻、黑豆和黑玉米添加量对产品的影响。在此基础上,选择黑米、黑芝麻、黑豆和黑玉米为主要因素,进行配方的L₉(3⁴)正交试验,各组分添加量为黑芝麻23.33%,黑豆11.67%,黑玉米16.67%,黑米11.67%,黑木耳3.33%,黑枣3.33%,木糖醇13.33%,麦芽糊精10%,乳粉6.67%。     

灌浆初期低温对春玉米产量构成的影响研究

旨在研究东北地区低温冷害对春玉米灌浆的影响,确定春玉米灌浆期间冷害影响农业气象指标。用人工气候室通过模拟自然低温（平均15℃、17℃、19℃）方法,对灌浆初期盆栽春玉米进行（3、5、7天）胁迫处理。结果表明：春玉米在灌浆初期经不同天数的低温处理后,穗粒数减少,穗粒重、百粒重和叶绿素降低,成熟期延迟,果穗秃尖长度和籽粒含水量增加,作物产量呈不同程度的下降。温度越低,持续时间越长,对玉米产量的影响越严重。其中在15℃低温下处理7天后,玉米产量下降最大,较对照穗粒重减少了32.4%,百粒重减少9.2%。可见,灌浆初期低温对春玉米产量结构影响最大的因素是结实率和籽粒干物质含量的双重降低。     

微生物预处理秸秆纤维浆结构、形态及成膜性研究

为研究生物预处理对秸秆纤维解离作用,促进制浆过程纤维分丝帚化及成膜性,采用实验室模拟发酵法,探讨微生物接种量及发酵时间对秸秆纤维化学组分、纤维形态及膜力学性质的影响。结果表明,与对照相比,接种1%外源菌处理稻秸14天时降解率达到20%,纤维降解适中,细小纤维占比仅59.63%~67.91%,纤维间交织力增强,纤维的疏解与拆分效应提升,打浆能耗降低71.54%。且随发酵时间的延长,纤维膜的抗张强度先升高再降低,第7和14天时分别提高7.6%和4.64%;3%接菌量处理14天时,浆料重均和质量加权增幅最大至28.57%和49.36%,膜撕裂度最高达240.9 mN。抗张强度与纤维质量间无明显相关性,耐破强度与纤维质量加权长度间呈负相关,撕裂强度与纤维数均长度、重均及纤维长宽比间呈显著正相关。该研究为生物降解秸秆纤维地膜的开发应用可行性提供技术支撑。     

水肥一体化条件下不同灌水量对甜菜产质量的影响

通过对甜菜在苗期、叶丛繁茂期、块根糖分增长期和糖分积累期的生理所需进行控水灌溉,研究不同灌水量对甜菜产质量的影响,确定少水、多糖、高产的最佳灌水方案,为甜菜节水灌溉提供理论依据,指导甜菜生产科学灌溉。试验设置3312.75、4005.30、4697.85、5390.40、6082.95、6775.50 m³/hm²等6个灌水梯度,在苗期、叶丛繁茂期、块根糖分增长期和糖分积累期分别按各生长期需水比例灌入不同水量,收获时测定甜菜含糖率、产量和产糖量,分析水分利用效率(WUE)和灌溉水分利用效率(IWUE)。结果表明,灌水量对甜菜含糖率、产量和产糖量影响明显,全生育期灌水量为3312.80 m³/hm²时甜菜的产质量处于较低水平,随着灌水量的逐渐增加,甜菜的含糖率、产量和产糖量呈现上升趋势,全生育期灌水量为4697.90 m³/hm²时甜菜的含糖率、块根产量和产糖量均为最高,但当灌水量高于4697.90 m³/hm²时甜菜的含糖率、块根产量和产糖量开始下降,在灌水量为6775.55 m³/hm²时,甜菜的含糖率、块根产量和产糖量均为最低。因此在新疆石河子地区甜菜全生育期灌水7次时,总灌水量在4697.90 m³/hm²,可以使甜菜含糖率、产量和产糖量达到最佳。     

贵州省露地菜椒生产的能量效益和碳足迹评价——以锦屏县为例

为探明贵州省调减玉米种植后改种辣椒经济作物的生态效益,本研究以锦屏县为例,基于对80个小农户及4家合作社的调查数据,采用生命周期评价法,对该地区辣椒生产的能量流和碳足迹进行定量评价。结果表明：（1）辣椒生产的能量输入为53431.8 MJ,远大于产出的9000 MJ,净能量效益为-44431.8 MJ;其中,化肥和农膜占有能量投入的最大比重,分别是53%和16%;能量利用效率、单位产品能量比和单位能量生产率分别为0.17、4.75 MJ/kg和0.21 kg/MJ;（2）碳足迹结果为碳排放大于碳固定分别是5450.9 kg CO₂eq和2227.3 kg CO₂eq;净碳效率(0.41)小于1,属温室气体排放贡献源;化肥生产运输环节和农作肥料施用环节对农田碳排的贡献最大分别为44.7%和32.07%;有机耗碳比、单位面积碳足迹、单位产品碳足迹和单位经济效益碳足迹分别为0.07、0.55 kg CO₂eq/m²、0.48 kg CO₂eq/kg、2.91元/kg CO₂eq。可见,在该地区,产业结构调整后辣椒种植存在潜在的生态风险。因此,优化农资投入结构,减少化肥施用,增加有机质投入占比,发展清洁能源,加强良种选育是今后锦屏县域辣椒生产提能效、减碳排,实现生产与生态共赢的关键。     

山东省青州市西南部山区土壤硒元素特征

利用潍坊市土地质量地球化学调查与评价（青州市）取得的大量数据,绘制了硒元素地球化学图,在硒元素高值区布设了100件表层土壤样品和5条垂直土壤剖面样品,研究青州市典型地区土壤硒元素特征。结果表明：表层土壤样品硒含量平均值为0.28 mg/kg,硒元素有效度为1.76%~14.21%,平均为5.70%。pH与全量硒呈一定程度的负相关,与水溶态硒呈正相关;磷、氮、有机质、镉与全量硒、水溶态硒呈正相关;全量硒与铅、锌、镍、砷、汞也具有一定的正相关性。表层土壤中硒元素强有机结合态(38.22%)>残渣态(34.82%)>腐殖酸结合态(21.05%)>碳酸盐结合态(3.20%)>离子交换态(1.54%)>水溶态(1.00%)>铁锰氧化物结合态(0.17%)。研究区硒的富集与有机质关系非常密切,垂向上表现为上高下低的表聚型。     

不同用量化肥和猪粪对优质强筋小麦产量和品质的影响

研究不同用量化肥和猪粪对优质强筋小麦产量和品质的影响,以不同氮肥类型和用量长期定位试验为平台(猪粪氮与化肥氮分别为0、60、120、180、240、300、360、420、500、600 kg/hm2),分析评价猪粪氮和化肥氮不同用量对优质强筋小麦'烟农19'产量和品质的影响.结果 表明:氮肥类型和用量对小麦产量和品质...