多媒体网络环境下大学英语阅读教学模式构建

利用体压分布测量系统,采用主观评价与客观测试相结合的方法分析了沙发靠背高度与坐姿舒适性、及压力分布指标之间的关系,为从人体工程学的角度优化沙发靠背面的设计以及沙发舒适性的评价提供了理论依据。试验研究表明,沙发靠背面的高度较大时,坐姿总体舒适性会较高,但较高的靠背面会影响颈部的舒适性。     

日光温室葡萄滴灌灌溉制度试验研究

根据葡萄不同物候期的需水特征,选择灌水量和灌水周期作为试验因素,开展日光温室葡萄滴灌灌溉制度试验.葡萄年生长周期持续352d,适宜的灌水次数为31次,平均灌水周期为12d,平均灌水定额为200m3/hm2,适宜的灌溉定额为6 200m3/hm2.照此灌溉制度进行灌水管理,葡萄产量可达3.75×104 kg/hm2以上.     

Identification of a gene responsible for the 60-day delay in flowering time of Arabidopsis

Identification of genes related to flowering-time in Arabidopsis is very important and meaningful contribution to the flowering process control. One late flowering mutant plant, which exhibits 60-day delay in flowering, was screened from Arabidopsis library of T-DNA insertion. Southern blotting was used to confirm the single copy of exogenetic T-DNA in the genome of the mutant. The flanking sequence of T-DNA insert was obtained by TAIL-PCR and then analyzed by BLAST to confirm that the insertion site locates at the sixth exon of AT2G19520.1 (FVE gene). FVE is considered as a classical flowering time gene in Arabidopsis. It is a component of the autonomous pathway that encodes AtMSI4, which is a putative retinoblastoma-associated protein. The late-flowering mutant is named as fve-4, which is similar to fve-3 of Columbia and allelic with fve-1 and fve-2 of Landsberg erecta. The fve-4 mutant’s delay of flowering was longer than that of fve-3 mutant, whose T-DNA insertion is located at the first exon of FVE gene, suggesting that the sixth exon of FVE gene may play a more important role in the control of floral transition.     

四川省规模化养猪场污染物排放清单

为了摸清楚四川省规模化生猪养殖污染物排放量及分布,为后续污染治理政策研究提供支持,基于四川省2013年的规模化养猪场生猪饲养量的统计和四川省规模化养猪场的产排污系数调研,计算了四川省2013年规模化养猪业污染物产排放量。经计算,四川省2013年规模化养猪场产生的粪便量总共达317.38万t,尿液达759.475万t。四川省规模化养猪场排放的污染物化学需氧量达到18.0679万t,排放的总氮达到1.6665万t,排放的总磷为0.1734万t。四川省生猪养殖污染物排放量最大的5个市分别是南充、广元、成都、绵阳和德阳,是今后四川省畜禽养殖污染控制重点地区。     

Effects of stocking density on survival,growth and biochemical composition of cultured mussels (Mytilus galloprovincialis,Lamarck 1819) from an offshore submerged longline system

This study examined an offshore submerged mussel longline system, in the Black Sea, from May 2009 to May 2010. The system was allowed 1 year for spat collection. After a 1‐year spat collection period, some spat collectors were left untouched (NS), and some spat collectors were grazed and socked (S) for a grow‐out study in May 2009. The effects of stocking density on the growth and survival of the S and NS mussels were examined. The biochemical composition of the mussels was also determined. Environmental factors including temperature, salinity, chlorophyll a, total suspended matter, inorganic matter and organic matter were monitored monthly during the experimental period. In May 2010, the mean length and live weight of the S and NS mussels were 60.46 ± 0.60 mm and 53.34 ± 0.37 mm, respectively, and 20.50 ± 0.50 g and 13.11 ± 0.26 g respectively. Mean moisture and ash were 82.35 ± 0.47% and 6.67 ± 0.44% respectively. Mean carbohydrate, protein and lipid were 27.74 ± 2.40%, 57.68 ± 2.15% and 7.91 ± 0.68% respectively. These results indicate that a submerged offshore mussel culture system in the Black Sea can be commercially convenient. In addition, stock management via thinning out of the spat can considerably increase the marketable size of mussels, reduce harvest time and produce better growth.     

Numerical study of airflow distribution in air-conditionedtrain in Qinghai-Tibet Railway

To obtain the influence of outer environmental condition on the indoor airflow distribution for the 25T air-conditioned train in Qinghai-Tibet, the Realizable k-ε model is adopted to numerically analyze the indoor temperature and velocity fields of the running train. The results indicate that solar radiation has great effect on the indoor temperature field and it is meaningful for improving the thermal comfort to adjust the air supply parameters with the outer environmental condition. Under different air supply conditions, it is the conjugating relation between the indoor temperature field and velocity field that leads to different thermal comfort in different regions of the running train. In addition, the operating modes exchange under different outdoor environmental conditions is also discussed and some additional functions of the using air-conditioning system are put forward too.     

水芹大棚基质栽培试验初报

以鄂水芹1号为试材,以泥炭、蛭石、菇渣和土为基质材料,进行了8种不同配方基质栽培水芹的试验研究,结果表明,50%泥炭+50%菇渣配方下栽培的水芹产量最高,667m2达6510.6kg,可推荐为大棚水芹基质栽培的理想配方。从营养成分测试结果来看,露地大田种植的水芹营养成分含量较高,大棚基质栽培的水芹营养价值稍逊,但更加水嫩。     

Planting spacing affects canopy structure,biomass production and stem roundness in poplar plantations

To improve the productivity and wood quality of poplar plantations, effects of four planting spacing on canopy characteristics, biomass production and stem roundness in poplar plantations were evaluated over 8 years. Planting spacing influenced canopy characteristics of the plantations, and further affected the understory vegetation and plantation productivity. Understory vegetation biomass and Shannon-Wiener index were negatively correlated with leaf area index, but both diversity indexes and aboveground biomass of understory vegetation were higher in stands with a wider spacing. Tree diameter growth increased with increasing planting spacing, while the increment in plantations of square configurations (5?×?5 m and 6?×?6 m) was higher than those with rectangular configurations (3?×?8 m, 4.5?×?8 m). The highest poplar biomass production was achieved in the plantation with 5?×?5 m spacing at age 8. Moreover, poplar trees showed a tendency with better stem roundness in a square configuration. The results suggest that planting spacing not only affect canopy characteristics, understory vegetation and tree growth but also wood quality, and square configurations (5?×?5 m and 6?×?6 m) could be a better option for poplar plywood timber production at similar sites.     

Effects of O<Subscript>3</Subscript> stress on physico-chemical and biochemical properties and composition of main microbial groups of a soil cropped to soybean

Tropospheric O₃ (ozone) stress can negatively affect forest productivity and crop yields. Yet, relatively little attention has been paid to the effects of O₃ stress on belowground system. Here, a pot experiment was conducted in open top chambers to monitor the response of physico-chemical properties, main microbial groups, and potential enzyme activities of a soil cropped to soybean (Glycine max; a highly sensitive species to O₃) and exposed to background O₃ concentration (45?±?5 ppb, control) and O₃ stress (80?±?10 ppb, O₃+ and 110?±?10 ppb, O₃++) with sampling at branching, flowering, and podding stages. The growth of soybean was significantly inhibited by O₃ stress, which showed significant effects on soil microbial biomass C and pH during the whole growth of soybean at the highest concentration. The O₃++ stress significantly decreased soil pH at flowering stage, and increased soil pH at podding stage; the O₃+ stress and growth stage?×?O₃+ stress showed significant influences on the potential activities of acid phosphomonoesterase, invertase, and amylase. The O₃ stress significantly reduced the abundances of total PLFAs (phospholipid fatty acid), bacterial PLFAs, and AMF (arbuscular mycorrhizal) PLFAs at branching and podding stages. Our results suggest that the main soil microbial groups might be indirectly affected by the O₃ stress through the alteration of soil physico-chemical properties with changes in the potential enzyme activities of soil.     

Variation of soil enzyme activity and microbial biomass in poplar plantations of different genotypes and stem spacings

To improve the productivity of poplar plantations, a field experiment of split-plot design with four tree spacings and three poplar clones was established, and four soil enzyme activities and microbial biomass were monitored in the trial.Soil enzyme activities, in most cases,were significantly higher in topsoil(0–10 cm) than in lower horizons(10–20 cm).Soil cellulase, catalase and protease activities during the growing season were higher than during the non-growing season, while invertase activity followed the opposite trend.Soil invertase, cellulase and catalase activities varied by poplar clone but soil protease activity did not.Cellulase and protease activities in the plantation at 5×5 m spacing were significantly higher than in the other spacings.The highest catalase activity was recorded at 6×6 m spacing.At the same planting density, invertase activity was greater in square spacings than in rectangular spacings.Soil microbial biomass was also significantly affected by seedling spacing and poplar clone.The mean soil MBC was significantly lower in topsoil than in the lower horizon, while MBN showed the opposite pattern.Significantly positive correlations were observed among soil cellulase, protease and catalase activities(p0.01), whereas soil invertase activity was negatively and significantly correlated with cellulase, protease and catalase activities(p0.01).Soil microbial biomass and enzyme activities were not correlated except for a significantly negative correlation between soil MBC and catalase activities.Variations in soil enzyme activity and microbial biomass in different poplar plantations suggest that genotype and planting spacing should be considered when modeling soil nutrient dynamics and managing for long-term site productivity.