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81.
以苯甲酸和草酸作为不同类别酸的代表,采用硫酸二甲酯(DMS)直接和羧酸反应制得羧酸甲酯的方法,进行气相色谱分析,研究DMS与其反应生成酯的转化率和色谱条件。结果表明:在100℃,30min时苯甲酸、草酸的成酯率分别为97%和96.9%。 相似文献
82.
Short Response of Spring Wheat to Tillage,Residue Management and Split Nitrogen Application in a Rice-Wheat System 总被引:1,自引:0,他引:1
Khalid Usman ;Ejaz Ahmad Khan ;Fazal Yazdan ;Niamatullah Khan ;Abdur Rashid ;Saleem Ud Din 《中国农业科学(英文版)》2014,(12):2625-2633
A ifeld experiment was conducted to study the impact of tillage, crop residue management and nitrogen (N) splitting on spring wheat (Triticum aestivum L.) yield over 2 yr (2010-2012) in a rice (Oryza sativa L.)-wheat system in northwestern Pakistan. The experiment was conducted as split plot arranged in randomized complete blocks design with three replications. Treatments comprised six tillage and residue managements:zero tillage straw retained (ZTsr), zero tillage straw burnt (ZTsb), reduced tillage straw incorporated (RTsi), reduced tillage straw burnt (RTsb), conventional tillage straw incorporated (CTsi), and conventional tillage straw burnt (CTsb) as main plots and N (200 kg ha-1) was applied as split form viz., control (no nitrogen&no splitting, N0S0);2 splits of total N, half at sowing and half at the 1st irrigation (i.e., 20 d after sowing (DAS)) (NS1);3 splits of total N, 1/3 at sowing, 1/3 at the 1st irrigation, and 1/3 at the 2nd irrigation (NS2);4 splits of total N, 1/4 at sowing, 1/4 at the 1st irrigation, 1/4 at the 2nd irrigation (45 DAS), and 1/4 at the 3rd irrigation (70 DAS) (NS3);and 4 splits of total N, 1/4 at the 1st irrigation, 1/4 at the 2nd irrigation, 1/4 at the 3rd irrigation, and 1/4 at the 4th irrigation (95DAS) (NS4) as sub plots. The results showed that the most pikes m-2, grains/spike, 1 000-grain weight, grain yield, and N use efifciency (NUE) were obtained at zero tillage, straw retained and 4 splits application of total N (i.e., at sowing 20, 45 and 70 d after sowing). The results indicated that ZTsr with application of 200 kg N ha-1 in 4 equal splits viz. at sowing 20, 45 and 70 d after sowing is an appropriate strategy that enhanced wheat yield (7 436-7 634 kg ha-1) and N efifciency (28.6-29.5 kg kg-1) in rice-wheat system. 相似文献
83.
Saeed El-Ashram Fathi Abouhajer Maged El-Kemary Guangping Huang Güngör Dinçel Rashid Mehmood Min Hu Xun Suo 《Veterinary research communications》2017,41(4):263-277
The interactions between gastric microbiota, ovine host, and Haemonchus contortus portray the ovine gastric environment as a complex ecosystem, where all factors play a pertinent role in fine-tuning each other and in haemeostasis. We delineated the impact of early and late Haemonchus infection on abomasal and ruminal microbial community, as well as the ovine host. Twelve, parasite-naive lambs were divided into four groups, 7 days post-infection (dpi) and time-matched uninfected-control groups; 50 dpi and time-matched uninfected control groups were used for the experiment. Six sheep were inoculated with 5000 H. contortus infective larvae and followed for 7 or 50 days with their corresponding uninfected-control ones. Ovine abomasal tissues were collected for histological analysis and gastric fluids were collected for PH value measurements, microbial community isolation and Illumina MiSeq platform and bioinformatic analysis. Our results showed that Haemonchus infection increased the abomasal gastric pH (P = 0.05) and resulted in necrotizing and inflammatory changes that were more severe during acute infection. Furthermore, infection increased the abomasal bacterial load and decreased the ruminal microbiome. A 7-day infection of sheep with H. contortus significantly altered approximately 98% and 94% of genera in the abomasal and ruminal bacterial profile, respectively (P = 0.04–0.05). However, the approximate altered genera 50 days after infection in the ovine abomasal and ruminal microbiome were about 62% and 69%, correspondingly (P = 0.04–0.05) with increase in some bacteria and decrease in others. Overall, these results indicate that Haemonchus infection plays a crucial role in shaping stomach microbial community composition, and diversity. 相似文献
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85.
Effect of various levels of dissolved oxygen on reactive oxygen species and cryocapacitation‐like changes in bull sperm 下载免费PDF全文
Beigh Y. Amin Jai K. Prasad Subrata K. Ghosh Shabir A. Lone Abhishek Kumar Abdul R. Mustapha Omer Din Ajay Kumar 《Reproduction in domestic animals》2018,53(5):1033-1040
The present investigation was carried out to study the effect of various levels of dissolved oxygen (DO) on reactive oxygen species (ROS) and cryocapacitation‐like changes in bull sperm. Egg yolk–Tris–glycerol (EYTG) extender was split into four subextenders; viz., Extender I (control; no flushing with liquid nitrogen (LN2)), Extender II, Extender III and Extender IV were flushed with LN2 for 40, 16 and 8 min, respectively. The DO levels were standardized to 11.7, 2, 4 and 8 ppm, respectively, in control (Extender I), Extender II, Extender III and Extender IV. Ejaculates with mass motility of ≥ 3+ were divided into group I (diluted with Extender I), group II (diluted with Extender II), group III (diluted with Extender III) and group IV (diluted with Extender IV) up to 80 × 106 sperm/ml. Extended semen samples were packed in French mini straws (0.25 ml), equilibrated and cryopreserved. Semen samples were evaluated at prefreeze and post‐thaw stage for various parameters (DO, progressive motility (PM), viability (VIB), acrosomal integrity (AI), hypo‐osmotic swelling (HOS) test, ROS, cholesterol (C) and phospholipid (P). The percentage of PM, VIB, AI, HOS test, cholesterol (C) and phospholipid (P) levels, and capacitated sperm were significantly (p < 0.05) higher in groups III and IV as compared to groups I and II. However, the acrosome‐reacted sperm (%; pattern AR) were significantly (p < 0.05) decreased in group III as compared to all other groups. Besides the proportion of sperm displaying tyrosine‐phosphorylated pattern, EA (fluorescence at both equatorial and anterior acrosomal regions, i.e. high capacitation level) was significantly (p < 0.05) reduced in group III compared to all other groups. In conclusion, varying DO levels in the extender significantly affect sperm quality, ROS production and capacitation‐like changes in bulls. 相似文献
86.
Hayat Ullah Sangam Shrestha Siraj Ud Din 《Archives of Agronomy and Soil Science》2017,63(9):1198-1209
In this study, we have attempted to investigate the effect of different water-saving cultivation techniques on root systems of two Thai rice varieties. The variables were two rice varieties (RD6 and RD10), two cultivation methods (dry direct seeding [DS] and transplanting [TP]) and two soil moisture regimes (field capacity [FC] and 50% FC). RD6 variety had higher root number, root length and root length density compared with RD10 under TP method at FC. Higher root number was observed for TP than dry DS method under FC at flowering stage with 543 and 415 roots plant–1 for RD6 and 392 and 362 roots plant–1 for RD10 cultivated under TP and dry DS methods, respectively. Root dry matter (DM) was the highest for RD6 cultivated through dry DS method compared with TP method at FC for both tillering and flowering stages. RD6 variety resulted in 25% and 50% higher root DM at FC for dry DS than TP at tillering and flowering stages, respectively. The performance of RD10 was poor under 50% FC and dry DS method. With proper selection of variety, dry DS method could be a better alternative for sustainable rice cultivation under water-limited environments. 相似文献
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89.
The aim of this study was to investigate the incidence of different teat lesions in cows that cause obstruction of milk flow. 18,400 teats were palpated in Konya slaughterhouse. From these 1000 hard milking or obstructed teats were found (5.4%). Based on the radiographical results, distal 1/3, proximal 2/3, complete teat lesions and congenital obstructions were found in 70.1, 16.6 and 0.7% respectively. 相似文献
90.
本文通过两年三点次,用10种激素不同浓度,在父本始穗至齐穗期喷施的试验结果。初步筛选出乙稀利1000~2000ppm与NAA100~200pm,有一定的推迟父本花时的效应,对异交结实率不仅无影响,尚似有提高的作用,其处理后授粉结实的F1生长发育正常。 相似文献