通辽地区总水资源动态模拟评价     

刘廷玺  刘小燕  史小红  冀蒙利  张旭  鲍金风 《内蒙古农业大学学报(自然科学版)》2002,23(2):110-114

文中提出了水资源的动态模拟评价观点及其系列评价方法和过程，认为，水资源不是一种静态, 而是一种动态资源，它随着人力干及周围环境的变化而变化，也就是说，水资源不但存在着时空变异性，而且是一种随时间，空间不断动态变化的资源，文中还提出了水资源的周期评价观点，即评价水资源时应以大周期作为评价时段，那种以任一时段间隔作评价期的作法是造成评价水资源偏大或偏小的重要原因，根据上述新观观点，我们论述了各项地下水资源，地表水资源有其地表水－地下水相互转化资源量的动态变化规律，并根据各项水资源的评价结果对它们进行了动态模拟评价。  相似文献   

奥硝唑等药物对慢性子宫内膜炎的疗效观察          下载免费PDF全文

麦达兴  张玉西 《中国牛业科学》2022,48(3):93-96

摘要： 为提高水牛慢性子宫内膜炎的治愈和配种受胎率,笔者应用奥硝唑注射液、甲硝唑、头孢拉定粉针和奥硝唑+头孢拉定四组药物对水牛慢性子宫内膜炎进行治疗和疗效观察。结果①在药物有效率上,用药1dh后,四组的药物有效率分别46.67%、44.44%、31.25%和51.43%,IV组优于I、II、III组,差异显著（P＜0.05）依次为I、II组、III组,差异显著（P＜0.05）;用药2d后,四组的药物有效率分别73.33%、66.67%、43.75%和82.86%,IV组优于I、II、III组,差异显著（P＜0.05）,依次为I、II组、III组,差异显著（P＜0.05）;用药3d后,四组的药物有效率分别77.42%、70.37%、50%和88.57%, IV组优于I、II、III组,差异显著（P＜0.05）,依次为I、II组、III组,差异显著（P＜0.05）。②在发情率上,4组药物分别为73.33%、74.07%、68.75%和77.14%,奥硝唑+头孢拉定联合用药组显著高于其余3组（P＜0.05）,奥硝唑、甲硝唑次之,头孢拉定组再次之;③在治愈率上,4组分别为66.67%、59.26%、56.25%和74.29%,奥硝唑+头孢拉定联合用药组显著高于其余3组（P＜0.05）,疗效最好,依次为奥硝唑、甲硝唑、头孢拉定;④在配种受胎率上,4组分别为63.64%、55%、54.55%和70.37%,奥硝唑+头孢拉定联合用药组显著高于其余3组（P＜0.05）,奥硝唑次之,甲硝唑、头孢拉定再次之;⑤在产活犊率上,4组分别为92.86%、81.82%、83.33%和94.74%,奥硝唑+头孢拉定联合用药组显著高于其余3组（P＜0.05）,奥硝唑次之,甲硝唑、头孢拉定再次之。试验结果表明,临床治疗母牛慢性子宫内膜炎以奥硝唑+头孢拉定联合用药效果最好,奥硝唑单独用药次之,甲硝唑和头孢拉定再次之。由此表明,奥硝唑、甲硝唑、头孢拉定、奥硝唑+头孢拉定对慢性子宫内膜炎对水牛慢性子宫炎的治疗均有效,其中以奥硝唑+头孢拉定联合用药效见效最快,疗程短,是最理想的药物组合;奥硝唑次之,甲硝唑再次之,头孢拉定最后。  相似文献   

自然生长与栽培种中国水仙的切片观察     

许荣义  郑天本 《福建农林大学学报(自然科学版)》1989,(1)

对闽浙沿海岛屿发现的自然生长的中国水仙和漳州栽培的中国水仙的根、叶、花序轴进行切片观察,三者结构相同。其生长发育期也基本相同,作者认为二者属于同一个种 Narcissustazetta var.chinensis  相似文献   

世界唯一棕白色大熊猫“丹丹”部分组织的光镜观察     

郑月茂  周宏超  华进联  张雅蓉  张涌 《勤云标准版测试》2005,(8)

对世界唯一一例人工圈养的棕白色大熊猫“丹丹”的肝胀、脾胀、子宫、癌变皮和口皮部分组织进行光镜观察。结果表明:肝窦和脾窦不同程度扩张,其中有大量红细胞和枯否氏细胞,可见大量黄褐色的含铁血黄素颗粒。部分肝细胞变性、坏死;大量肝细胞肿胀,胞浆内可见许多大小不一的脂肪空泡;肝细胞胞核浓缩、碎裂、溶解甚至消失。白髓淋巴小结里淋巴细胞增多。子宫的固有膜由富有血管的胚性结缔组织构成。癌变皮的棘细胞出现不典型增生,未见恶性细胞团向深层组织生长浸润。口皮的棘细胞未出现增生。  相似文献   

Digital assessments of soil organic carbon storage using digital maps provided by static and dynamic environmental covariates     

Fatemeh Rahbar Alam Shirazi  Farzin Shahbazi  Hossein Rezaei  Asim Biswas 《Soil Use and Management》2023,39(2):948-974

Understanding the vertical and lateral distribution of soil organic carbon (SOC) and soil organic carbon density (SOCD) is indispensable for soil use and environmental management because of their vital role in soil quality assessments. Primarily, they are needed in calculating soil organic carbon storage (SOCS). The objective of this research was to provide digital maps of SOC and SOCD variation as well as their uncertainties at multiple standardized depths (H1: 0–5, H2: 5–15, H3: 15–30, H4: 30–60 and H5: 60–100 cm) using a parsimonious model with optimized terrain-related attributes and satellite-derived data. SOCS were evaluated at soil subgroup levels. An area of about 808 km² with varying elevation, plant cover and lithology from the Miandoab region, West Azerbaijan Province, Iran was selected as a case study area. A total of 386 soil samples were collected from 104 profiles comprising various soil genetic horizons. A continuous spline function was then fitted to the target properties in advance of creating a dataset at five standard depth intervals (following the GlobalSoilMap project). These were then grouped into three classes including top (H1), middle (H2, H3 and H4) and bottom (H5) depths to ease interpretation. Static and dynamic covariates (30-m resolution) were derived from a digital elevation model (DEM) and a suite of Landsat-8 spectral imageries, respectively. Four candidate models including stepwise multiple linear regression (SMLR), random forest (RF), cubist (CU) and extreme gradient boosting (XGBoost) Tree were tested in this study. Finally, the digital maps at 30-m resolution of SOC and SOCD and their uncertainties were prepared using the best-fit model and the bootstrapping method, respectively. Four soil subgroups (Gypsic Haploxerepts, Typic Calcixerepts, Typic Haploxerepts and Xeric Haplocalcids) were identified across the study area. The covariates had variable contributions on the evaluated models. The XGBoost Tree model generally outperformed other models for prediction of SOC and SOCD (R² = 0.60, on average). Regardless of soil subgroups, the uncertainty analysis showed that the SOCD map had a low prediction interval range value indicating high accuracy. Additionally, the highest SOCS and SOCD was observed at the top followed by middle and bottom depths in the study area. All subgroups exhibited a decreasing trend of SOCD with increasing depth. A similar trend was also observed for SOCS. The highest SOCD (on average) was observed in Gypsic Haploxerepts (4.71 kg C/m²) followed by Typic Calcixerepts (4.46 kg C/m²), Typic Haploxerepts (4.45 kg C/m²) and Xeric Haplocalcids (4.40 kg C/m²). Overall, the SOCS normalized by area within soil order boundaries was greater in Inceptisols than Aridisols across the study area. The findings of this study provide critical information for sustainable management of soil resources in the area for agricultural production and environmental health in the Miandoab region of Iran.  相似文献   

考虑非一致性的黄土高原区旱涝复合事件的演变特征及其动态变化     

高月娇  黄生志  王韩叶  王志霞  郭雯雯  穆振侠  陈刚  黄强 《农业工程学报》2023,39(8):133-143

受气候变化和人类活动的双重影响,传统水文序列的一致性假设受到破坏,在考虑非一致性的条件下探究相邻季节间旱涝复合事件的动态变化及主导因子,对区域的粮食安全与旱涝灾害防御意义重大。为探究非一致性条件下旱涝复合事件的动态演变特征及其主导因子,该研究以黄土高原为研究对象,基于广义可加模型拟合单季节标准化降水指数的边缘分布,构建二维Copula模型分析旱涝复合事件（中、重和极端情景下）的发生概率,并利用变量投影重要性准则探究复合事件动态变化的主导因子。结果表明：1）1982-2015年间正常转旱、旱转正常、正常转涝和涝转正常事件分布广泛且发生频次较高（高于22次）;2）春-夏内蒙古持续干旱、夏-秋青海持续干旱、秋-冬宁夏持续干旱、冬-春山西持续干旱、夏-秋陕西持续洪涝、夏-秋甘肃持续洪涝事件的发生概率较大;3）春-夏由旱转涝、夏-秋持续洪涝、秋-冬由涝转旱、秋-冬持续干旱和冬-春季持续干旱事件的发生概率显著上升,对该区域社会经济与生态将产生不利影响;4）复合事件发生概率动态变化的主导因素为北极涛动指数和太阳黑子指数。研究成果将为黄土高原地区旱涝复合事件的精准防御提供科技支撑。  相似文献   

蚯蚓作用下土壤化学组成和性状的动态变化   总被引：5，自引：0，他引：5  

王斌  李根  陈欢  焦加国  刘满强  蒋洋杨  胡锋  李辉信 《水土保持学报》2013,27(3)

通过室内培养试验研究赤子爱胜蚓(Eiseniafoetida)和威廉环毛蚓(Metaphire guillelmi)对土壤化学组成和性状的动态影响.结果表明:接种蚯蚓可显著提高土壤pH和电导率;蚯蚓作用49 d后土壤化学组成也发生明显变化,接种赤子爱胜蚓和威廉环毛蚓处理的土壤碳水化合物含量分别比对照增加43.22,44.76 mg/kg,酸解氨基酸含量分别增加15.34,12.52 g/kg,植物激素GA3含量分别增加11.21,13.68mg/kg,IAA含量分别增加8.99,8.81mg/kg,而多酚含量却显著降低了7.79,7.48mg/kg.不同处理土壤化学组成和性状随时间变化趋势各有不同,2种蚯蚓作用下,土壤pH和碳水化合物含量均在前7d急剧增加,之后变化趋于平缓;而土壤多酚含量在前7d显著降低,此后也趋于平缓;土壤植物激素GA3含量在前35 d持续增加,而后无显著变化;土壤植物激素IAA、电导率和氨基酸含量随培养时间增加而持续增长,直至培养结束(49 d).  相似文献   

不同生境果园梨小食心虫各代成虫高峰期差异     

沈志杰  房明华  洪文英  刘涛  沃林峰  孙媛  蓝陈仪航  邓建宇 《植物保护》2021,47(3):222-225

梨小食心虫Grapholita molesta (Busck)是桃、梨果园中最重要的食心害虫之一,仅依据往年的发生期和田间为害特征来指导防治具有滞后性。而性信息素具有高效、专一性强的特点,可用于准确监测其成虫发生情况,以此推测成虫的卵高峰期和幼虫初孵期,科学地指导防治。本研究在3个不同生境果园中,利用性信息素监测梨小食心虫成虫周年发生动态。结果表明:2019年在杭州余杭地区3个不同生境果园,包括越冬代在内,平地桃园和平地梨园的梨小食心虫成虫发生7代,而坡地桃园只有6代。成虫始见于3月中旬,终见于10月下旬;3个果园由于生境不同,同一世代梨小食心虫高峰期发生时间和各世代高峰期间隔时间不尽相同。因此在不同生境果园利用性信息素监测梨小食心虫成虫发生动态,有助于指导果园的适期防治。  相似文献   

油菜体内及土壤中咪鲜胺的残留检测与消解动态   总被引：7，自引：0，他引：7  

柳训才  陈平  程运斌  李胜清  陈浩  吴谋成 《中国油料作物学报》2006,28(3):354-357

采用固相萃取( SPE) - 高效液相色谱紫外检测(HPLC - UV)建立了油菜中咪鲜胺的残留量检测方法,并 进行咪鲜胺消解动态研究。提取液经石墨碳和C18固相萃取柱净化、浓缩后测定。咪鲜胺在各样品中的添加回收 率为80. 1% ～91. 8% ,变异系数为1. 8%～9. 6%。咪鲜胺在油菜中消解较快,半衰期为4～6d; 30g制剂/666. 7m2 于油菜盛花期施药2 次,油菜收获时,油菜籽中咪鲜胺残留量最高为0. 20mg/kg,土壤中咪鲜胺残留量最高为 0. 49mg/kg。  相似文献   

Functional Properties of Wheat Gliadins. II. Effects on Dynamic Rheological Properties of Wheat Gluten   总被引：1，自引：0，他引：1  

B. S. Khatkar  R. J. Fido  A. S. Tatham  J. D. Schofield 《Journal of Cereal Science》2002,35(3):307

The effects of addition of purified total gliadin and its subgroups (α-, β-, γ- and ω-gliadins) on the dynamic rheology of gluten were investigated. The frequency sweeps of gluten with added α-, β-, γ- and ω2-gliadins showed unexpected increases in the magnitude of G′ and G′′, suggesting stiffening of the native gluten. Conversely, a reduction in the magnitude of G′ and G′′ occurred upon addition of the total gliadin fraction and the ω1-gliadin, implying softening of the gluten. Addition of individual gliadin fractions increased the values of slope log G′ vs log frequency, suggesting increased concentrations of uncrossed-linked material compared with the native gluten. There were significant differences in the slope values for individual gliadin fractions. The increasing order of slopes for different gliadins was: β- >γ- >α- =ω1>ω2, indicating that glutens containing ω- and α- gliadins are relatively less crossed-linked than those containing β- and γ-gliadins. The dynamic moduli, G′ and G′′, of cv. Hereward gluten showed significant positive relationships with Mixograph parameter peak dough resistance (PDR), and loaf volume for gliadin subgroups added to cv. Hereward flour.  相似文献