果树树冠静电喷雾的空间电荷效应分析

以风送静电喷雾机为例,描述了杀虫剂药液被气流剪切式喷嘴雾化时雾滴的诱导充电过程,建立了一个树冠静电喷雾过程的电子—机械简化模型,用于分析雾滴沉积过程中作用于荷电雾滴的静电力(镜像力、空间电荷力和空间电荷引力)和机械力(重力和拉力)。静电力的相对大小是通过与机械力的力比值作比较的,50μm和100μm两种充电雾滴的典型的力比值说明空间电荷引力在雾滴沉积过程中起着重要的作用。     

路灯照射对大豆生长发育和产量的影响

通过对淮北五马路沿线夏大豆的田间调查分析表明：受路灯照射的影响,夏大豆株高增加,开花期、成熟期推迟,底荚部位上升,单株生产力下降。且距离越近,植株越高,开花、成熟越晚,底荚部位越高,单株生产力越低。     

工艺加工对干法再造烟叶品质的影响

通过分析检测干法再造烟叶在制丝工艺过程中化学成分、烟气常规指标、烟气有害成分、致香成分以及感官质量的变化,考察工艺加工对干法再造烟叶品质的影响,为干法再造烟叶在卷烟中的应用提供科学依据。结果表明：经过松散回潮、加料贮叶、增温增湿、烘丝等处理,干法再造烟叶的总糖和还原糖含量有所增加,烟碱含量呈下降趋势;总粒相物、焦油、CO及各有害成分的释放量均呈下降趋势,危害指数降低了4．52％;工艺加工后大部分致香物质的总量略高于加工前,其中烟草中重要的致香成分巨豆三烯酮、β大马酮、新植二烯、β二氢大马酮、香叶基丙酮等的含量明显增加;再造烟叶感官质量明显提升,甜润感和烟气清晰度得到改善。上述结论表明,工艺加工过程对干法再造烟叶的内在品质有一定的提升作用,干法再造烟叶能很好地适应卷烟制丝线的工艺加工。     

豫东地区能源型甘薯品种的筛选

为选育适合豫东地区自然条件的高产高淀粉型甘薯品种,在河南省商丘市进行了生产试验,并测定各品种的鲜薯产量、薯干产量、干物质量、淀粉率及主要病虫害抗性。结果表明:徐薯22、商薯19和金玉3种能源生产专用型甘薯品种能更好地适应当地条件,其淀粉含量比当地主栽品种豫薯9号提高10%左右,产量提高5%～10%。大力发展能源型甘薯种植能使农民增收,使用生物质能源可有效减轻大气污染,经济效益、社会效益和生态效益明显。     

RADIOGRAPHIC CHARACTERIZATION OF PRIMARY LUNG TUMORS IN 74 DOGS

Primary pulmonary neoplasia is well recognized in dogs and prognosis depends upon the tumor type. The purpose of this retrospective study was to characterize the radiographic appearance of different primary lung tumors with the goal of establishing imaging criteria to separate the different types. Three‐view thoracic radiographs of 74 dogs with histologically confirmed pulmonary anaplastic carcinoma (n = 2), adenocarcinoma (n = 31), bronchioalveolar carcinoma (n = 19), histiocytic sarcoma (n = 21), and squamous cell carcinoma (n = 1) were evaluated. Radiographs were assessed for tumor volume, affected lobe, location within lobe, overall pulmonary pattern, presence of cavitation, mineralization, air bronchograms, lymphadenomegaly, and pleural fluid. Histiocytic sarcomas were significantly larger than other tumor types (271 cm³; P = 0.009) and most likely to be found in the left cranial (38%; 8/21) and right middle (43%; 9/21) lung lobes, whereas adenocarcinomas were most likely to be found in the left caudal (29%; 9/31) lung lobe. Fifty‐seven percent (12/21) of histiocytic sarcomas had an internal air bronchogram. Findings indicate that a large mass in the periphery or affecting the whole lobe of the right middle or left cranial lung lobe with an internal air bronchogram is likely to be an histiocytic sarcoma.     

Storage of biomass and net primary productivity in desert shrubland of Artemisia ordosica on Ordos Plateau of Inner Mongolia, China

Biomass and net primary productivity （NPP） are two important parameters in determining ecosystem carbon pool and carbon sequestration. The biomass storage and NPP in desert shrubland of Artemisia ordosica on Ordos Plateau were investigated with method of harvesting standard size shrub in the growing season （June-October） of 2006. Results indicated that above- and belowground biomass of the same size shrubs showed no significant variation in the growing season （p〉0.1）, but annual biomass varied significantly （p〈 0.01）. In the A. ordosica community, shrub biomass storage was 699.76-1246.40 g.m^-2 and annual aboveground NPP was 224.09 g-m^-2·a^-1. Moreover, shrub biomass and NPP were closely related with shrub dimensions （cover and height） and could be well predicted by shrub volume using power regression.     

国家尺度上基于地形因子的光温及气候生产潜力修正算法

【目的】光温/气候生产潜力作为农用地分等中的重要指标之一,直接影响分等结果的准确性。从理论上来说,不同地形地区的光温条件应各不相同,以目前这种一个县一种作物只具有一个生产潜力值的情况来看,当县内地形差异明显时,仅使用一个生产潜力值不能反应出光温条件在县内的异质性,从而使分等结果不能准确描述耕地质量的差异性。论文旨在解决这一问题。【方法】从地形对于光照、温度和降水等与生产潜力密切相关的因子具有严重关联性的角度入手,通过寻找地形因子与生产潜力的关系,利用地形因子对生产潜力进行修正。由于生产潜力是以国家级尺度的数据进行计算的,为了保证修正后生产潜力值的可比性,在国家级尺度上开展修正,以900 m×900 m的DEM数据为计算地形因子的数据来源,首先利用SPSS软件,分别对坡度、坡向、海拔与生产潜力做回归分析,筛选相关性最高的回归模型,确定不同地形因子与生产潜力的相关性;其次利用回归方程、县内平均地形因子值、平均生产潜力值和待修正区的地形因子值得出生产潜力修正公式;最后以不同地形因子与生产潜力的相关系数为权重,将单因子修正后的生产潜力值进行加权,得到最终的综合修正生产潜力值。【结果】以目前农用地分等中正在使用的生产潜力值和DEM数据生成的地形因子做回归分析,其中,参与修正光温生产潜力的样点共3 779个,参与修正气候生产潜力的样点共2 765个。回归分析结果表明,坡度和坡向与光温生产潜力的相关系数分别为0.0008和0.0002,说明在国家级尺度上,以900 m×900 m的DEM数据对坡度、坡向和生产潜力进行回归分析时,这两者与生产潜力的相关性过小,故暂不列为修正生产潜力的因子;海拔与光温生产潜力的相关系数达到0.835,与气候生产潜力的相关系数达到0.721,说明海拔与生产潜力具有高度相关性。根据海拔与生产潜力的回归方程得出,海拔对光温生产潜力的影响系数为1.479,对气候生产潜力的影响系数为1.095。论文以四川省长宁县为例进行了实例验证,结果表明,修正后的生产潜力值与海拔的趋势相同,体现出地势差异对光温条件的影响,并且海拔偏离县平均海拔越大的地区,生产潜力修正后偏离潜力的平均值越多。【结论】国家尺度范围内,海拔对于生产潜力具有重要的影响作用,并且海拔对于光温生产潜力的影响程度高于对气候生产潜力的影响程度,而坡度、坡向在该尺度内与生产潜力不具有明显的相关性。基于数据的限制,论文旨在侧重数学模型方法和修正思想的论述,与实际应用还有一定的距离,在未来研究中可探索利用国家级控制可比性、分区域利用更加精细的数据进行局部修正的方法进一步分析坡度、坡向对生产潜力的影响。     

PET/CT FOLLOWING INTENSITY-MODULATED RADIATION THERAPY FOR PRIMARY LUNG TUMOR IN A DOG

A primary lung tumor in a dog treated with intensity-modulated radiation therapy was imaged approximately 6 weeks and 1-year posttreatment with combined positron emission tomography (PET) and computed tomography, utilizing the radiotracers 18F-fluorodeoxyglucose and 18F-fluorothymidine. These two tracers allowed discrimination of tumor from inflammation, and demonstrated spread of tumor along airways over time after treatment. Fusion of functional imaging with anatomic imaging is a useful tool, particularly in the field of oncology, with the potential for PET markers that delineate tumor from normal or reactive tissue, and potential or actual response to therapy.     

科尔沁地区3类生产方式下的荒漠化问题研究

科尔沁地区作为我国荒漠化问题的重要研究区域,其荒漠化现状、发展趋势和形成原因一直存在争论.本研究采用野外调查方法,将调查区域分为偏农耕区、偏牧区及农牧混合区进行实地考察与研究,结果发现,近年来不同的生产方式下该区荒漠化形势依然严峻,若不改变现行不合理生产方式,区域荒漠化形势严峻趋势将难以逆转.从根本上说,近期科尔沁地区...     

Impact analysis of climate data aggregation at different spatial scales on simulated net primary productivity for croplands

For spatial crop and agro-systems modelling, there is often a discrepancy between the scale of measured driving data and the target resolution. Spatial data aggregation is often necessary, which can introduce additional uncertainty into the simulation results. Previous studies have shown that climate data aggregation has little effect on simulation of phenological stages, but effects on net primary production (NPP) might still be expected through changing the length of the growing season and the period of grain filling. This study investigates the impact of spatial climate data aggregation on NPP simulation results, applying eleven different models for the same study region (∼34,000 km²), situated in Western Germany. To isolate effects of climate, soil data and management were assumed to be constant over the entire study area and over the entire study period of 29 years. Two crops, winter wheat and silage maize, were tested as monocultures. Compared to the impact of climate data aggregation on yield, the effect on NPP is in a similar range, but is slightly lower, with only small impacts on averages over the entire simulation period and study region. Maximum differences between the five scales in the range of 1–100 km grid cells show changes of 0.4–7.8% and 0.0–4.8% for wheat and maize, respectively, whereas the simulated potential NPP averages of the models show a wide range (1.9–4.2 g C m⁻² d⁻¹ and 2.7–6.1 g C m⁻² d⁻¹ for wheat and maize, respectively). The impact of the spatial aggregation was also tested for shorter time periods, to see if impacts over shorter periods attenuate over longer periods. The results show larger impacts for single years (up to 9.4% for wheat and up to 13.6% for maize). An analysis of extreme weather conditions shows an aggregation effect in vulnerability up to 12.8% and 15.5% between the different resolutions for wheat and maize, respectively. Simulations of NPP averages over larger areas (e.g. regional scale) and longer time periods (several years) are relatively insensitive to climate data aggregation. However, the scale of climate data is more relevant for impacts on annual averages of NPP or if the period is strongly affected or dominated by drought stress. There should be an awareness of the greater uncertainty for the NPP values in these situations if data are not available at high resolution. On the other hand, the results suggest that there is no need to simulate at high resolution for long term regional NPP averages based on the simplified assumptions (soil and management constant in time and space) used in this study.