铅污染对土壤微生物及酶活性的影响

摘要：通过室内培养试验,研究了土壤铅污染对土壤微生物基础呼吸及土壤脲酶、脱氢酶、酸性磷酸酶的影响,结果表明,随着土壤铅添加浓度的提高,土壤微生物基础呼吸呈现出上升的趋势,土壤脲酶则随着铅浓度的增加呈现出不断下降趋势,土壤脱氢酶活性则在低浓度下上升而随着添加浓度的进一步提高迅速降低,可见,这两种酶对土壤铅毒害反应灵敏,可以作为土壤铅污染评价的指标,而土壤磷酸酶则对铅浓度的变化没有表现出明显的统计规律性,不适宜作为土壤铅污染评价的酶学指标。     

陆地棉体细胞胚的白化与植株再生的关系

通过对棉花体细胞胚胎发育过程的观察发现，其发育的四个时期即球形期，心形期，鱼雷期和子叶期均有白化现象。成熟期的白色叶胚比绿色子叶胚在成苗培养基上生长快，且形成再生植株的频率高。     

玉米秸秆全量还田下不同播种方式对土壤结构及小麦苗期生长的影响

在黄淮平原小麦玉米一年两熟、玉米收获后秸秆全量还田条件下,采用播量、播深和镇压三因素裂区试验,研究了不同播种方式对土壤容重、总孔隙度及小麦品种济麦22冬前出苗率、春季分蘖和单株次生根的影响。结果表明：播量极显著影响小麦次生根、分蘖数和出苗率,对以上指标作用力分别达到65.52%、54.02%和35.46%;镇压极显著影响出苗率,作用力达23.48%;播量、播深和镇压对土壤容重和总孔隙度的影响不显著。播深与镇压的交互效应表现为播量越大其交互作用越明显。     

Preparation and photocatalytic properties of Pt and Crco doped Nano TiO2 films 

Pt and Cr co doped Nano TiO2 film was prepared by the sol gel method. The film was characterized by AFM, XRD and UV Vis. The experiment showed that when the average TiO2 film diameter is 32 nm and the film thickness is 290 nm, the rate of photodegradation is 95% in 2.5 hours. Additionally, when the optimal co doping ratio for Pt Cr is n(Pt): n(TiO2) equals 0.03% and n(Cr):n(TiO2) equals 0.4%, the photodegradation of methylene blue for Nano TiO2 film can be enhanced. The photocatalytic properties of Pt and Cr co doped Nano TiO2 film is better than that of pure TiO2 and Pt, Cr separately doped TiO2 film.     

Effects of plastic film mulch and tillage on maize productivity and soil parameters

This paper determined the effects of mulching time for double furrows and ridges using plastic film on soil water status, grain yield of maize, soil quality, and economic benefits. The study was conducted in a typical semiarid area during two growing seasons of 2006–2007 with the following three treatments: (i) plastic film mulching at maize sowing with conventional tillage, and the film was removed at harvest (CK); (ii) mulching applied 30 d before sowing with conventional tillage, and the film was removed at harvest (T1); and (iii) mulching at sowing with no-tillage, and the film left on the field after harvest in the first season and used for mulching in the second season (T2). The T1 in both years and T2 in the second year (2007) improved soil water content (in the 0–60 cm layer) and temperature (10 cm) at sowing compared with CK. After the two seasons, the soil water content was significantly higher in the 0–80 cm soil layer in CK and T1, and in the 0–120 cm soil layer in T2; however, it decreased significantly in 140–200 cm soil layer in CK and T1, compared to their initial values at sowing in April 2006, and there was no significant change in T2. The rainfall storage in the 0–200 cm soil layer during the non-growing season (late September 2006 to late April 2007) was 18.2 mm in CK, 34.0 mm in T1, and 59.7 mm in T2, and the rainfall storage in 100–200 cm soil layer was 16.5 and 18.6 mm higher in T2 than in CK and T1, respectively. In 2006, there were no significant differences in yield and water use efficiency (WUE) in all treatments. In 2007, the yield in T1 was significantly higher than in T2, but yields in T2 and CK were not significantly different, and there was no significant difference in WUE among treatments. Soil organic carbon (SOC) (0–20 cm) decreased in CK and T1, but increased (by 2.7%) in T2 at harvesting in September 2007 from the initial value of sowing in April 2006. The ratio of output to input was 1.32:1 for CK, 1.40:1 for T1, and 1.67:1 for T2 averaged across the two seasons. Therefore, T2 was a more sustainable model for increasing water storage, producing greater economic benefit and maintaining SOC balance for maize production in semiarid area.     

芦笋罐头营养品质及抗氧化性研究

研究了芦笋罐头的营养成分及其抗氧化活性。结果表明,芦笋罐头的氨基酸质量分数为0.804%,黄酮质量分数为0.498%,清除DPPH自由基IC50值为0.74μg/mL,具有较强的抗氧化能力。     

优质稻核心种质青六矮1号及其衍生品种的性状相关性研究

对青六矮1号及其衍生品种(品系)的相关分析表明: 产量与有效穗数呈极显著正相关, 与每穗总粒数和每穗实粒数呈显著负相关; 倒三叶长与倒二叶长呈极显著正相关, 与着粒密度呈显著负相关, 与粒长呈显著正相关, 与垩白率呈显著负相关, 与垩白度呈极显著负相关, 与胶稠度呈显著正相关, 与直链淀粉含量呈显著负相关. 主成分分析表     

基于遥感数据同化的土壤含盐量估算方法

为探究同化遥感数据对监测区域尺度土壤含盐量时空信息的适用性,以河套灌区沙壕渠灌域为研究区,以高分一号卫星影像为数据源,通过灰度关联法筛选光谱指数,采用岭回归法构建不同深度的土壤含盐量反演模型,使用集合卡尔曼滤波同化算法将遥感数据应用于HYDRUS-1D模型中,开展区域尺度不同深度土壤含盐量的同化研究。结果表明,基于不同深度土壤含盐量的岭回归法模型,其R²均在0.64以上,RE为0.14～0.22,反演精度较高,得到的反演值较为准确;在单点尺度上,与模拟值、反演值相比,同化值更接近实测值,其EFF为0.84～0.93,NER为0.61～0.73,均为正数,且RMSE降低到0.006%～0.011%,提高了HYDRUS-1D模型模拟精度;在区域尺度上,不同深度同化值的r均为0.94以上,NER为0.61以上,优于模拟值和反演值,且同化精度随着深度的增加而降低。本文基于遥感数据和HYDRUS-1D模型的集合卡尔曼滤波同化研究,提高了土壤含盐量的模拟精度,对提高监测区域尺度土壤含盐量时空信息的精度具有一定的参考价值。     

挖拔式木薯收获机挖深液压控制装置的设计与试验

针对挖拔式木薯收获机在收获过程中带有一定倾角的挖掘铲有朝着深度方向行进的趋势,增加了挖土量及挖掘负荷等问题,提出了基于液压控制系统调整挖深的设计思路。为此,研制了一种挖深液压控制装置,主要由地表仿形机构、挖掘铲液压调节机构、液压系统及PLC控制系统4部分组成;同时,对液压系统的负载特性进行系统分析计算,选取了合适的执行元器件,并在此基础上进行土槽实验。结果表明:地表仿形机构,最大误差8.9%,平均误差3.5%;掘铲液压控制系统的响应时间为1.7s,1s内完成对挖出铲的角度与深度自动调节,测试效果能够满足精准挖深控制要求。     

旋耕式大蒜播种机关键部件优化及性能试验

为了提高旋耕式大蒜播种机对新疆大蒜种植模式的适应性,依据新疆蒜种外形尺寸优化蒜种勺参数,提高取种单粒率,降低空穴率及重播率。选择机具性能的主要因素(机具作业速度、大蒜种子外形尺寸、鳞芽长度),采用单因素试验分析进行田间试验,分析不同参数对大蒜播种机正芽率、空穴率、重播率的影响,得出各因素影响程度,为后期机具优化提供理论依据。