施肥与盖膜微集雨集成技术对土壤性状及木薯产量的影响

【目的】探索木薯施肥与盖膜微集雨集成技术,为改善土壤质量、提高木薯产量提供科学依据。【方法】开展田间试验,处理1为施用木薯加工废弃物研制的生物有机肥＋测土配方肥＋盖膜微集雨技术（在行距畦面上利用农膜覆盖收集雨水进入木薯种植行沟的盖膜模式,盖膜行距畦面高于木薯种植行沟2-3 cm,行距畦面宽80 cm）,处理2为习惯施肥栽培（对照,不盖地膜）,每个处理施肥量以NPK总养分为900.0 kg/ha计。测定不同处理对木薯生长指标、产量及土壤理化性状的影响。【结果】处理1的土壤速效N、P、K,有机质、含水量、总孔隙度分别比处理2提高9.19%、9.17%、3.32%、8.25%、32.21%、9.60%,容重降低6.25%,可改善土壤p H。处理1木薯叶片叶绿素和叶片干物质、木薯杆茎径、木薯块根茎径、木薯块根长、单株块根条数、单株块根重、木薯块根鲜重、经济效益分别比处理2增加51.36%、11.14%、18.48%、21.57%、18.76%、34.88%、40.04%、31.89%、9033.8元/ha,差异均达显著（P〈0.05）或极显著水平（P〈0.01）。【结论】采用生物有机肥＋测土配方肥＋盖膜微集雨技术,可为木薯高产稳产的生长发育提供及时、持续、平衡的养分供应与水肥条件,并可显著改善土壤理化性状。     

A comparison of 3-T magnetic resonance imaging and computed tomography arthrography to identify structural cartilage defects of the fetlock joint in the horse

Articular cartilage defects are prevalent in metacarpo/metatarsophalangeal (MCP/MTP) joints of horses. The aim of this study was to determine and compare the sensitivity and specificity of 3-Tesla magnetic resonance imaging (3-T MRI) and computed tomography arthrography (CTA) to identify structural cartilage defects in the equine MCP/MTP joint. Forty distal cadaver limbs were imaged by CTA (after injection of contrast medium) and by 3-T MRI using specific sequences, namely, dual-echo in the steady-state (DESS), and sampling perfection with application-optimised contrast using different flip-angle evolutions (SPACE). Gross anatomy was used as the gold standard to evaluate sensitivity and specificity of both imaging techniques.CTA sensitivity and specificity were 0.82 and 0.96, respectively, and were significantly higher than those of MRI (0.41 and 0.93, respectively) in detecting overall cartilage defects (no defect vs. defect). The intra and inter-rater agreements were 0.96 and 0.92, respectively, and 0.82 and 0.88, respectively, for CT and MRI. The positive predictive value for MRI was low (0.57). CTA was considered a valuable tool for assessing cartilage defects in the MCP/MTP joint due to its short acquisition time, its specificity and sensitivity, and it was also more accurate than MRI. However, MRI permits assessment of soft tissues and subchondral bone and is a useful technique for joint evaluation, although clinicians should be aware of the limitations of this diagnostic technique, including reduced accuracy.     

ASYMMETRIC NASAL MUCOSAL THICKENING IN HEALTHY DOGS CONSISTENT WITH THE NASAL CYCLE AS DEMONSTRATED BY MRI AND CT

The nasal cycle is a physiological phenomenon that causes regular cyclical congestion and decongestion of the venous sinusoids lining the nasal mucosa. The purpose of this prospective study was to describe magnetic resonance imaging (MRI) and computed tomographic (CT) features of the normal nasal cycle in a group of dogs. Five dogs were recruited that met the following criteria: 8 to 15 months old, nonbrachiocephalic breed, no clinical signs or history of nasal disease, and undergoing anesthesia for problems unrelated to the nasal cavity. Nasal MRI (n = 5) and CT scans (pre‐ and postcontrast, n = 5) were acquired. Images were evaluated subjectively by two board‐certified radiologists and objectively by a diagnostic imaging intern using regions of interest placed on each side of the nasal cavity. Findings were compared using Cohen's kappa coefficient and Students t‐test on log‐transformed data. All dogs showed diffuse unilateral mucosal thickening of the rostral part of the nasal cavity in both MRI and CT studies. This mucosal thickening shifted sides between examinations in three dogs. Changes appeared most marked on T2‐weighted scans. No asymmetric mucosal changes were seen in the mucosa of the ethmoturbinates, vomer–nasal septum, hard palate or the frontal sinuses in any patient on MRI or CT. Computed tomographic contrast enhancement of the thickened mucosa was not statistically significant (P‐value < 0.08). In conclusion, the normal nasal cycle may cause asymmetrical mucosal changes in the rostral part of the nasal cavity that mimic MRI and CT characteristics previously reported for inflammatory disease in dogs.     

MULTIDETECTOR ROW COMPUTED TOMOGRAPHY AND ULTRASOUND CHARACTERISTICS OF CAUDAL VENA CAVA DUPLICATION IN DOGS

Caudal vena cava duplication has been rarely reported in small animals. The purpose of this retrospective study was to describe characteristics of duplicated caudal vena cava in a large group of dogs. Computed tomography (CT) and ultrasound databases from two hospitals were searched for canine reports having the diagnosis “double caudal vena cava.” One observer reviewed CT images for 71 dogs and two observers reviewed ultrasound images for 21 dogs. In all CT cases, the duplication comprised two vessels that were bilaterally symmetrical and approximately the same calibre (similar to Type I complete duplication in humans). In all ultrasound cases, the duplicated caudal vena cava appeared as a distinct vessel running on the left side of the abdominal segment of the descending aorta and extending from the left common iliac vein to the left renal vein. The prevalence of caudal vena cava duplication was 0.46% for canine ultrasound studies and 2.08% for canine CT studies performed at these hospitals. Median body weight for affected dogs was significantly lower than that of unaffected dogs (P < 0.0001). Breeds with increased risk for duplicated caudal vena cava were Yorkshire Terrier (odds ratio [OR] = 6.41), Poodle (OR = 7.46), West Highland White Terrier (OR = 6.33), and Maltese (OR = 3.87). Presence of a duplicated caudal vena cava was significantly associated with presence of extrahepatic portosystemic shunt(s) (P < 0.004). While uncommon in dogs, caudal vena cava duplication should be differentiated from other vascular anomalies when planning surgeries and for avoiding misdiagnoses.     

模糊综合评价在评估岩滩水库 水质周年变化中的应用

用模糊综合评价方法评价岩滩水库4个类型监测区水质周年变化。结果表明,各监测区周年水质均为芋类。影响水质的主要因子是TN,TN 超标倍数（WTN）分析表明,在相同水质等级（芋类）内,汉达监测区水质最好,TN 超标倍数（WTN）值处于0.096~0.883 范围;江栋监测区水质最差,TN 超标倍数（WTN）值处于0.557~1.358 范围。水质周年变化与大水面养殖状况关系密切,建议在大水面开展鱼类养殖、促进库区移民增收的同时,充分保护养殖水域环境,提高大水面资源综合、可持续利用水平。     

苹果内部品质的CT成像结合傅里叶变换方法检测

通过对苹果的CT扫描灰度图像进行傅里叶变换,在变换后的频域图像中提取16个参数,并结合苹果的可溶性固形物质量分数、可滴定酸度、pH值和含水率,采用主成分回归和偏最小二乘回归的方法建立模型,预测苹果的内部品质。结果表明,采用主成分回归分析建立模型,主成分的累计贡献率选取99%的情况下,F检验的P均小于0.05,预测效果良好。采用偏最小二乘回归时潜变量的个数为12时,各模型的误差平方和最小,预测效果良好。对两个模型进行误差率验证表明主成分回归的模型略优于偏最小二乘回归模型。     

微阅读环境下高校图书馆服务大学生就业策略研究

当前大学生就业问题已成为关系我国社会民生的战略性核心问题。高校图书馆应肩负起其社会责任,发挥自身优势,积极参与到大学生就业服务中。随着网络技术的快速发展,微阅读已经成为当代大学生获取信息的重要渠道。本文结合高校图书馆参与大学生就业服务的现状调查及国内高校图书馆开展微阅读服务的现状分析,探究了高校图书馆应如何积极应对微阅读时代的读者需求,创新大学生就业服务工作。     

森林碳储量估算方法综述

介绍样地清查法、微气象学法、箱式法、模型模拟法、遥感估算法等森林碳储量的主要估算方法。在对各种方法的主要原理及应用实例进行分析的基础上,指出了各方法的适用性和不足之处,认为在研究大尺度的森林生态系统碳汇储量时,多学科融合、各种方法综合运用是准确估算森林碳储量的有效手段。     

石油污染胁迫下植株根区土壤微生物多样性分析

【目的】研究在不同石油污染胁迫水平下,适合陕西延安气候与土壤条件的4种耐性植株根区土壤微生物多样性的变化。【方法】采用室外盆栽模拟法,在含0,5,10,15和20g/kg石油的土壤中栽植油松、沙棘、刺槐、紫穗槐4种植株,待苗木生长6个月后采集其根区周围土壤,采用微生物平板培养法、酸碱滴定法及Biolog微平板法,从微生物区系、呼吸强度及功能多样性角度,对不同石油污染胁迫水平下植株根区土壤的微生物多样性进行分析。【结果】栽植4种植株均能促进根区土壤微生物的生长,增加根区土壤微生物多样性;在高水平石油污染胁迫下,4种植株对根区土壤微生物的多样性具有保护作用,其中刺槐植株表现最为明显;5~10g/kg石油污染胁迫水平能刺激植株根区土壤微生物的生长,促进植株根区土壤微生物对碳源的利用;15~20g/kg石油污染胁迫水平对部分土壤微生物具有毒害作用,对根区土壤微生物的碳源利用有抑制作用,其中20g/kg石油污染胁迫水平的毒害及抑制作用最强。主成分分析结果显示,第1主成分将10g/kg石油污染胁迫水平与0,20g/kg石油污染胁迫水平的土壤微生物功能多样性明显区分开来,第2主成分将0g/kg石油污染胁迫水平与其他石油污染胁迫水平的土壤微生物功能多样性区分开来,其中影响第1主成分的碳源主要为多聚物类和氨基酸类,影响第2主成分的碳源主要为碳水化合物类。【结论】4种植株均能有效提高石油污染胁迫下根区土壤微生物的多样性;5~10g/kg石油污染胁迫水平能提高土壤微生物多样性;15~20g/kg石油污染胁迫水平降低了土壤微生物多样性,对微生物生长具有毒害作用。     

Analysis of I/O Component of ICT Control Software Based COM

To implement the reuse of industrial CT control software, make the product easily maintained and upgraded, the control software of industrial CT based COM is researched. With the characteristics of language irrelevancy, reuse of binary codes, expansion, the industrial CT control software are divided into several components according to the control function of industrial CT, and the I/O component is developed. Better effects and open characteristic are achieved while this component is communicating with the Client program.