根－土界面区域磷酸盐的分布和移动: Ⅱ. 土壤水分含量和磷酸盐施用量的影响

The phosphate in the soil-root interface zone under various soil water contents and application rates of phosphate was still of depletion distribution which could be described by a power function in the form of C/Co= ax^b(C/Co is the relative content of fertilized phosphate in a distance from the root surface x, a and b are the regression constants). The depletion rate of phosphate in soil near the root surface was higher and the depletion range was narrower under lower soil moisture. On the contrary, at higher soil water content the depletion range was wider, generally. The application rate of phosphate led to the greater depletion intensity of phosphorus was higher in the heavier texture soils. In general, the depletion intensity in the soils, which decreased with increasing clay content or increasing buffering power of soil, decreased in the order as loessal soil and black lou soil > lou soil > yellow cinnamon soil when 50 or 100 mg of phosphorus were applied in the form of KH₂PO₄. This result indicated that the phosphate distribution and its movement in the soil-root interface zone closely related with the buffering capacity of soil.     

根-土界面的微生态过程与有机污染物的环境行为研究

土壤-植物系统是地球生态系统中与人类生存与健康关系最为密切的亚系统。该系统中有机污染物的运移必须历经根-土界面多层次的微生态过程的控制。这些微生态过程涉及到系统中许多生物、生物化学和物理化学反应机理,与土壤中污染物迁移转化及其归宿等环境行为具有密切的关系。理解这些微生态过程及其对有机污染物环境行为的影响,对提高作物生长、改善土壤环境质量和提高农产品品质安全具有直接的理论和实践指导意义。     

Prevalence of antibodies to Brucella spp. and individual risk Factors of Infection in Traditional Cattle, Goats and Sheep Reared in Livestock–Wildlife Interface Areas of Zambia

A cross-sectional study was performed in the livestock–wildlife interface areas of Lochinvar and Blue Lagoon National Parks and the non-interface area of Kazungula to determine the prevalence of antibodies to Brucella spp. in domestic ruminants and identify individual animal risk factors of infection. A total of 1245 cattle from 124 herds and 280 goats and sheep from 29 flocks were tested sequentially for Brucella antibodies using the Rose Bengal test (RBT) and competitive ELISA. In cattle, individual seroprevalence ranged from 14.1% to 28.1%, while herd sero–prevalence ranged from 46.2% to 74.0% in the three study areas. No goat or sheep tested positive for Brucella antibodies. Three types of cattle grazing strategies were encountered: locally grazed herds (LGH), transhumantly grazed herds (TGH) and river flood plain grazed herds (FGH). Brucella seroprevalence was seen to vary according to area and grazing strategy: Lochinvar and transhumant grazed herds recorded the highest figures, respectively. Age, sex and history of abortion were found to have independent effects on individual seroprevalence. This study establishes that brucellosis is endemic in domestic animals in the livestock–wildlife interface areas of Blue Lagoon and Lochinvar national parks and the disease is also present in Kazungula. We observed that type of grazing strategy had significant impact on cattle Brucella seroprevalence and that transhumant herds were at high risk of being infected.     

iSCSI虚拟服务器盘阵在图书馆终端机群中的应用

分析了安庆师范学院图书馆的硬、软件资源,并提出了运用iSCSI技术将普通服务器虚拟成SCSI服务器,运用Software RAID方法将普通硬盘组建成磁盘阵列,在客户服务终端机上调用虚拟SCSI服务器RAID盘阵上的服务程序,从而模拟其在真实SCSI盘阵上的高效运行和存储效果,以提高服务器、终端机群以及维护人员的工作效率,降低维护成本。     

公私合作模式下农地整治项目组织界面管理研究

农地整治是保障国家粮食安全和实现耕地总量动态平衡的重要手段,但目前仍存在资金缺乏、效率低下等问题。在农地整治项目中引入公私合作模式,是解决当前我国农地整治项目一系列问题的主要途径。分析了公私合作模式下的农地整治项目存在的组织界面问题,提出了WBS矩阵与DSM集成,有助于项目的界面管理,提高农地整治项目效率。     

青藏高原东北部黄土区灌木柠条锦鸡儿根—土界面剪切特性

[目的]分析不同因素对根—土界面抗剪强度指标和抗剪强度的影响,为深入探讨青藏高原东北部黄土区灌木根系固土护坡机制提供理论依据。[方法]以区内优势灌木植物柠条锦鸡儿(Caragana korshinskii)为研究对象,通过根—土界面直剪试验,分析根径级别为2.20±1.00～32.00±1.80 mm以及土体含水量、干密度和含盐量分别为6.00%～22.00%,1.20～1.60 g/cm³,0.59%～2.50%的条件下,各因素对柠条锦鸡儿根—土界面抗剪强度指标和抗剪强度的影响规律。[结果]在其他影响因素恒定的情况下,根径对根—土界面抗剪强度指标和抗剪强度无显著影响(p>0.05)。随着土体含水量由6.00%增大到22.00%,根—土界面黏聚力呈先增大后减小的趋势,当土体含水量达到14.00%时黏聚力达到峰值6.74 kPa;根—土界面摩擦角由21.40°降低至15.75°,呈线性函数降低趋势;根—土界面抗剪强度呈线性函数降低趋势。随着土体干密度由1.20 g/cm³增长至1.60 g/cm³,根—土界面黏聚力由...     

我国苜蓿产业过去10年发展成就与未来10年发展重点

纵观我国苜蓿(Medicago sativa)60多年的发展历程,可分为5个阶段。近十几年,随着苜蓿的社会地位和作用不断提高与增强,苜蓿科技驱动力亦不断提升,产业结构不断明晰,种植面积不断扩大,生产加工企业不断涌现;同时,苜蓿供需矛盾也在持续加剧,科技创新不足的压力与日俱增,资源约束的压力越来越大,生态安全的压力明显增强,苜蓿界面耦合的压力日趋明显;今后应着力提升苜蓿持续发展的战略地位,强化苜蓿科技创新、新品种培育和种子产业发展,推进苜蓿产业现代化发展进程,提升苜蓿-奶牛一体化发展水平,大力发展苜蓿生物技术及其生物经济。     

稀土元素示踪法在土壤侵蚀与泥沙来源研究中的应用

[目的]掌握稀土元素(REE)示踪土壤侵蚀和泥沙来源的方法,明确其不确定性来源,对正确运用该方法获得可靠的侵蚀速率和泥沙源地贡献结果具有重要意义。[方法]基于前人运用REE示踪土壤侵蚀速率和泥沙来源的研究成果,总结了REE示踪土壤侵蚀的基本技术路线及其在水蚀、风蚀和泥沙来源研究中的应用,探讨了REE示踪土壤侵蚀和泥沙来源研究中的不足。[结果]分析认为REE虽是理想的示踪剂,但REE示踪法仍存在影响示踪土壤侵蚀和泥沙来源准确性的关键方面需要改进,包括REE与土壤结合方式与机理、长期监测或复杂环境下随淋溶、径流的迁移以及植被吸收利用等。在未来研究中应重点关注大量释放REE对土壤、植物、环境健康的影响以及REE示踪法与复合指纹识别法的结合运用等。[结论]研究结果为提高REE示踪土壤侵蚀结果的准确性,运用该方法开展其他侵蚀类型研究,与复合指纹识别法结合辨别大区域的泥沙来源奠定基础。     

多露石石漠化区岩面流对岩-土界面土壤的冲蚀效应

岩面流在基岩出露的喀斯特石漠化区普遍存在,其容易受岩面形状影响以汇聚或分散的方式对岩—土界面处土壤进行冲刷侵蚀,这是喀斯特石漠化区土壤侵蚀/漏失发生的重要物理过程。为分析不同岩面形状下岩面流对岩—土界面土壤颗粒分布的影响,揭示岩面流对岩—土界面土壤的冲蚀效应,选择具有典型石漠化特征的休耕地(1年岩面流冲刷作用),在其中选取3种典型岩面形状(平直型、外凸型和内凹型岩面)为研究对象,采用激光粒度仪分析法,分析距岩—土界面不同水平距离(0～2,2～4,4～6,6～8,8～10,20 cm)及不同土层(0—10,10—20 cm)处土壤的颗粒分布特征。结果表明：(1)不同岩面形状下岩面流对岩—土界面处土壤的冲蚀影响依次为内凹型>平直型>外凸型;内凹型岩—土界面处土壤中黏粒含量最低,外凸型岩—土界面处土壤中黏粒含量最高;(2)岩面流对岩—土界面土壤冲蚀作用主要集中在距岩—土界面水平距离0～2 cm范围内,在其范围内内凹型岩—土界面土壤的砂粒含量均显著高于外凸型和平直型,而在距岩—土界面其他水平距离处土壤颗粒分布情况无显著性差异;(3)在岩面流影响下岩—土界面土壤颗粒分形维数均值排序依...     

口蹄疫疫苗免疫效果跟踪试验报告

本试验用中农威特生物科技股份有限公司生产的猪O型口蹄疫灭活苗免疫两个不同的猪场,其中一个猪场由于母源抗体水平较高,免疫效果不理想,另一个猪场在免疫后36d、51d跟踪检测抗体,合格率为90%;用中农威特生物科技股份有限公司生产的O型-亚Ⅰ型口蹄疫二价灭活苗免疫两个不同的奶牛场,O型抗体水平明显高于亚Ⅰ型抗体水平。