论体育教学与中学生人格精神塑造的关系

体育教学应由技术、身体的层面向人的精神层面拓展,注重对学生的个性塑造,促进学生身心的全面发展。     

Effects of greenhouse cooling method on growth,fruit yield and quality of tomato (Solanum lycopersicum L.) in a tropical climate

A tomato (Solanum lycopersicum L.) crop was grown in four greenhouses during the dry season 2005/06 in Central Thailand. Sidewalls and roof vents of two greenhouses were covered with nets and these greenhouses were mechanically ventilated when air temperature exceeded 30 °C (NET). The other two greenhouses were covered with polyethylene film and equipped with a fan and pad cooling system (EVAP). Overall mean air temperature was significantly reduced by 2.6 and 3.2 °C (day) and 1.2 and 2.3 °C (night) in EVAP as compared to NET and outside air, respectively. Temperature maxima in EVAP averaged about 4 °C lower than in NET and outside. The relative humidity was around 20 and 30% (day) and 10 and 15% (night) higher in EVAP than in NET or outside, respectively. Vapour pressure deficit averaged 0.25 kPa in EVAP, 1.03 kPa in NET and 1.48 kPa outside. The crop water-consumption was significantly lower in EVAP (1.2) than in NET (1.8 L plant⁻¹ day⁻¹), which is ascribed to reduced transpiration in EVAP. Total fruit yield was similar in NET (6.4 kg plant⁻¹) and EVAP (6.3 kg plant⁻¹). The quantity of undersized (mostly parthenocarpic) and blossom-end rot (BER)-affected fruits was reduced in EVAP. However, the proportion of marketable yield was significantly higher in NET (4.5 kg plant⁻¹) than in EVAP (3.8 kg plant⁻¹), owing largely to an increased incidence of fruit cracking (FC) in EVAP. Higher FC but lower BER incidence coincided with higher fresh weight and Ca concentration in the fruits in EVAP. It is concluded that in regions with high atmospheric relative humidity evaporative cooling without technical modifications allowing dehumidification will not improve protected tomato production.     

Mode of action of nitric oxide in inhibiting ethylene biosynthesis and fruit softening during ripening and cool storage of ‘Kensington Pride’ mango

The mode of action of nitric oxide (NO) in inhibiting ethylene biosynthesis and fruit softening during ripening and cool storage of mango fruit was investigated. Hard mature green mango (Mangifera indica L. cv. ‘Kensington Pride’) fruit were fumigated with 20 μL L⁻¹ NO for 2 h at 21 °C and allowed to ripen at 21 ± 1 °C for 10 d, or stored at 13 ± 1 °C for 21 d. During ripening and cool storage, ethylene production and respiration rate from whole fruit were determined daily. The 1-aminocyclopropane-1-carboxylic acid (ACC) content, activities of ACC synthase (ACS), ACC oxidase (ACO), and fruit softening enzymes such as pectin esterase (PE), endo-1,4-β-d-glucanase (EGase), exo- and endo-polygalacturonase (exo-PG, endo-PG) as well as firmness and rheological properties of pulp were determined at two- and seven-day intervals during ripening and cool storage, respectively. NO fumigation inhibited ethylene biosynthesis and respiration rate, and maintained higher pulp firmness, springiness, cohesiveness, chewiness, adhesiveness, and stiffness. NO-fumigated fruit during cool storage and ripening had lower ACC contents through inhibiting the activities of both ACS and ACO in the fruit pulp. NO-fumigated fruit showed decreased activities of exo-PG, endo-PG, EGase, but maintained higher PE activity in pulp tissues during ripening and cool storage. In conclusion, NO fumigation inhibited ethylene biosynthesis through inhibition of ACS and ACO activities leading to reduced ACC content in the fruit pulp which consequently, reduced the activities of fruit softening enzymes during ripening and cool storage.     

仙人掌提取物对断奶仔猪猪瘟抗体水平及其生长性能的影响

仙人掌提取物是一种新型中草药提取物,为研究其对断奶仔猪的免疫促进及其生产性能的作用,试验选用21日龄杜×长×大三元杂交断奶仔猪96头,随机分成4组,分别为对照组和3个试验组,试验期为42 d。在免疫前及免疫后第14、21、28、35和42天从前腔静脉采血,分离血清,间接方法测定猪瘟抗体,于第14天称重。采用在整个保育期饲料中添加不同剂量的仙人掌提取物和猪瘟疫苗颈部接种断奶仔猪,研究猪瘟兔化弱毒疫苗与不同剂量仙人掌提取物处理后对断奶仔猪免疫机能及生长性能的影响。结果表明,仙人掌提取物按400mg·kg-1剂量添加与猪瘟疫苗使用,能够显著提高断奶仔猪猪瘟抗体水平,促进疫苗的免疫效果。同时发现不同剂量的仙人掌提取物组均能不同程度提高断奶仔猪生长性能。     

人参果采后聚乙烯膜包装贮藏研究

以人参果为试材,设计自然贮藏和聚乙烯膜包装贮藏2种方式,研究聚乙烯膜包装贮藏下,对人参果失重率、可溶性固形物含量、腐烂率和病斑面积扩展速率的影响,为人参果贮藏中提供方便的贮藏技术.结果表明:聚乙烯膜包装处理明显的抑制了人参果采后的失重率上升,提高人参果贮藏9d内的可溶性固形物含量,能降低病果率,其中包装1个果实较包装多个果实抑制了腐烂率增加和病斑面积扩展有最佳效果.表明人参果采后常温贮藏应采取聚乙烯膜包装,且以单果包装最佳.     

论高校体育教学中的语言艺术

语言是人们交流思想、学习知识的工具,在高校体育教学过程中,要结合高校特点充分运用语言艺术,提高体育教学效果,做好教书育人的工作.     

免疫亲和层析纯化EGF-PE40

用PEG融合法建立了分泌抗EGF-PE40抗体的杂交瘤细胞株,并筛选了一杂交瘤细胞株D7.用此细胞株制备了高抗体含量的腹水,用辛酸-硫酸胺沉淀法纯化了抗体IgG,用ELISA法测定其与EGF-PE40的亲和常数2.24×109L/mol,并鉴定其亚类为IgG1.将纯化后的单抗IgG与CNBr活化的Sepharose 4B偶联,并用免疫亲和层析的方法纯化粗提物中的EGF-PE40,得到了大于80%的纯化率,且产物显示了良好的生物学活性,这为EGF-PE40的进一步纯化和大量生产提供了可能.     

绿脓杆菌ATCC27853外毒素PE40基因的扩增与测序

目的 扩增绿脓杆菌ATCC27853外毒素基因PE40，并对PCR产物进行测序鉴定，为获得用于构建分子导向药物的毒素弹头基因PE40奠定基础。方法 采用PCR技术，以绿脓杆菌ATCC27853基因组DNA为模板，扩增PE40基因并测序。用DNASTAR软件将测得的序列与GenBank中的国际标准产毒株PA103的PE40基因序列进行比较。结果 扩增出目的基因片断，长度为1231bp。测序表明，ATCC27853与PA103核苷酸同源性为98%，产生了7个碱基的突变，突变碱基导致第364位的天冬酰胺变成丝氨酸，第506位的丝氨酸变成色氨酸，第515位的丝氨酸变成甘氨酸。但产生变化的3个氨基酸均不是文献报道中的重要活性位点。结论 产生变化的3个氨基酸不会对PEA的酶活性及细胞毒性产生很大影响，绿脓杆菌ATCC27853的PE40基因可用作分子导向药物的弹头。     

PE微滤膜处理餐饮废水的试验研究

采用外压管式的PE微滤膜装置处理餐饮废水,研究了操作压差、料液流量、操作时间等操作条件对膜通量的影响,确定了最佳操作条件(操作压差为0.12MPa,料液流量为100L.h-1)。在最佳操作条件下对模拟餐饮废水进行了处理,结果表明,PE微滤膜对模拟餐饮废水有较好的处理效果,处理后水质达到了CJ3082—1999标准。同时,对膜污染的防治与清洗也进行了一定探讨,结果发现采用短时脉冲反冲洗效果较好。     

Study on Friction and Wear Performance of Ultra High Molecular Weight Polyethylene Plastic Composite Material

The friction and wear properties of Ultra High Molecular Weight Polyethylene(UHMW PE) composites filled with MoS 2,PTFE,carbon fiber,glass fiber and graphite are studied by using MPV-200 model friction and wear tester and caustic wear one. Experiment results show that graphite,MoS 2,PTFE reduce the friction coefficient of UHMW PE, but glass fiber increases the friction coefficient of UHMW PE, graphite not only reduces the friction coefficient of UHMW PE, but also can greatly reduce the wear of UHMW PE. At the same time, the effects of wear time,rate and load on the friction and wear characteristic of plastic alloy composite material are studied.