Study on Factors Affecting the Structure of High SpeedSteel Ingot Produced by ESR

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大剂量Si-Mn复合孕育剂在铸铁中的应用

从例证和机理两方面来说明通过大剂量Si Mn复合孕育在铸铁中的应用 ,使Mn的作用得到充分发挥 ;Mn13是提高铸铁组织中珠光体量和性能的理想元素 ;通过调节大剂量Si Mn复合孕育剂中Mn的比例来稳定和提高基体组织中的珠光体量 ,达到稳定和提高铸铁性能的目的 ,它的可操作性比通过控制化学成分来稳定和提高铸铁的性能更好更容易 ,冲天炉熔炼效果更明显。     

Φ840 mm自动轧管机回送辊的研制

介绍了Φ840mm自动轧管机回送辊的工况条件,该轧辊成分选择原则、铸造工艺、球化孕育处理工艺等。研制出的自动轧管机回送辊综合指标符合GB/T1504—91标准,轧辊的强韧性、耐磨性好,达到同类产品较好水平。     

畜禽粪便快速微生物发酵生产有机肥的研究

利用优选获得的微生物菌剂快速发酵畜禽粪便生产有机肥,并进行温室及大田的肥效试验.结果表明,经优选的微生物菌剂可有效提高发酵温度,缩短发酵腐熟时间(基本腐熟时间仅为25 d),且腐熟质量佳.温室试验和大田试验均表明,施用经微生物菌剂发酵制备的有机肥较非菌剂发酵有机肥更能促进作物生长,增加产量,有利于改善作物品质(降低作物硝酸盐、亚硝酸盐含量),且可在一定程度上增加作物的抗病性.     

Laboratory silo type and inoculation effects on nutritional composition,fermentation, and bacterial and fungal communities of oat silage

The objectives were to evaluate (1) the use of 2 types of experimental silos (S) to characterize whole-crop oat (Avena sativa L.) silage with or without addition of an inoculant (I), and (2) the effect of inoculation on the microbial community structure of oats ensiled using only plastic bucket silos (BKT). From each of 6 sections in a field, oats were harvested, treated (INO) or not (CON) with inoculant, packed into 19-L BKT or vacuum bags (BG), and ensiled for 217 d. The inoculant added contained Lactobacillus buchneri and Pediococcus pentosaceus (4 × 10⁵ and 1 × 10⁵ cfu/g of fresh oats, respectively). The experimental design was a complete randomized design replicated 6 times. Treatment design was the factorial combination of 2 S × 2 I. Some differences existed between BG versus BKT at silo opening (217 d), including a decreased CP (7.73 vs. 7.04 ± 0.247% of DM) and ethanol (1.93 vs. 1.55 ± 0.155) and increased lactic acid (4.28 vs. 3.65 ± 0.241), respectively. Also, WSC and mold counts were reduced in BG versus BKT for CON (1.78 vs. 2.70 ± 0.162% of DM and 0.8 vs. 2.82 ± 0.409 log cfu/fresh g) but not for INO (～1.53 and 1.55), respectively. Application of INO increased DM recovery (96.1 vs. 92.9 ± 0.63%), aerobic stability (565 vs. 133 ± 29.2 h), acetic acid (2.38 vs. 1.22 ± 0.116% of DM), and reduced NDF (65.0 vs. 67.0 ± 0.57), ADF (36.7 vs. 38.1 ± 0.60), ethanol (0.63 vs. 2.85 ± 0.155), and yeast counts (1.10 vs. 4.13 ± 0.484 log cfu/fresh g) in INO versus CON, respectively. At d 0, no differences were found for S and I on the nutritional composition and background microbial counts. Leuconostocaceae (82.9 ± 4.27%) and Enterobacteriaceae (15.2 ± 3.52) were the predominant bacterial families and unidentified sequences were predominant for fungi. A higher relative abundance of the Davidiellaceae fungal family (34.3 vs. 19.6 ± 4.47) was observed in INO versus CON. At opening (217 d), INO had a lower relative abundance of Leuconostocaceae (42.3 vs. 95.8 ± 4.64) and higher Lactobacillaceae (57.4 vs. 3.9 ± 4.65) versus CON. Despite several differences were found between BKT and BG, both techniques can be comparable for characterizing effects of INO on the most basic measures used in silage evaluation. The use of inoculant improved oat silage quality partially by a shift in the bacterial community composition during ensiling, which mainly consisted of an increased relative abundance of Lactobacillaceae and reduction of Leuconostocaceae relative to CON.     

新型型内孕育块的研究

通过对几种不同的型内孕育块成型工艺特点的分析对比，提出了压力成型型内孕育块工艺，并对其成型参数作了介绍。试验表明，采用压力成型的孕育块具有良好的孕育效果，满足薄壁铸态铁索体球铁的生产要求。     

用长效孕育剂改善球墨铸铁的力学性能

介绍了差速器壳体的铸件结构及技术要求,详细阐述了解决珠光体-铁素体混合基体球铁综合性能不达标问题的措施。采用湿型粘土砂造型,化学成分设计为:w(C)3.5%~3.9%,w(Si)2.2%~2.8%,w(Mn)≤0.4%,w(P)≤0.07%,w(S)≤0.025%,w(RE)0.02%~0.04%,w(Mg)0.03%~0.06%;利用3 t中频感应电炉熔炼,采用喂丝球化处理方法,球化剂加入量为1%,球化处理温度为1 500℃。原工艺采用促进珠光体型孕育剂,结果力学性能达不到技术要求,后来在其它工艺条件不变的情况下,通过采用含有Ba、Sr、RE的长效孕育剂,使铸件金相组织和力学性能均符合技术要求。     

The ability of common mastitis-causing pathogens to survive an ensiling period

A forage-based study was conducted to examine the ability of enterococci, streptococci, and gram-negative bacteria to survive a 3-wk ensiling process. Harvested grass and corn forages were each divided into 3 treatment groups consisting of 2 commercially available silage inoculants and 1 negative control group. Within 24 h of harvest, a uniform amount of forage was added to each of 18 vacuum-sealable freezer bags. Inoculants 1 and 2 were applied to each of 6 bags and the remaining 6 bags were not inoculated (negative control). All bags were sealed using an industry-grade vacuum sealer to create a pillow pack. At wk 1, 2, and 3 of the ensiling process, 6 bags were opened, 2 from each of the 3 groups. Dry matter (DM), pH, and bacterial enumeration were determined on the forage before ensiling, as well as at wk 1, 2, and 3 of ensiling. The pH of grass and corn samples decreased to 5.2 and 4.1, respectively, by the end of the ensiling period. Inoculant 2 (7.3 log₁₀ cfu/g of DM) resulted in a greater enterococcal count in grass samples than did inoculant 1 (4.2 log₁₀ cfu/g of DM) at 3 wk of ensiling and both were greater than the negative control (1.2 log₁₀ cfu/g of DM). Counts of streptococci in grass samples at wk 3 were greater in inoculated samples (inoculant 1, 7.6 log₁₀ cfu/g of DM; inoculant 2, 7.0 log₁₀ cfu/g of DM) compared with the negative control (4.3 log₁₀ cfu/g of DM). Treatment differences were observed following 1 wk of ensiling in corn samples. Enterococcal counts on corn samples following the 3-wk ensiling were not significantly different between inoculant 1 (4.3 log₁₀ cfu/g of DM) and inoculant 2 (4.4 log₁₀ cfu/g of DM). However, counts in both inoculated groups were greater than in the negative control group (4.0 log₁₀ cfu/g of DM). No significant treatment differences were observed for streptococci counts at wk 3. Counts for gram-negative bacteria were not detectable by wk 3 of ensiling in either grass or corn samples. The addition of a silage inoculant led to greater counts of enterococci and streptococci in grass silage compared with the negative control at the end of a 3-wk ensiling period. The application of a silage inoculant led to increased enterococci counts, but not streptococci counts, in corn samples following the ensiling period. These data indicate that enterococci and streptococci are able to survive the pH decrease observed during ensiling.     

Effect of long-term application of animal slurries to grassland on silage quality assessed in laboratory silos

The effect on silage quality of slurry type (pig or cow), rate of application of slurry (50, 100 or 200 m³ ha^?1 year^?1) and use of a bacterial silage inoculant, was assessed on grass from a long-term slurry experiment ensiled in laboratory silos. There was no significant effect of slurry type or the quality of silage made from grass re growths. However, on the basis of ammonia-N, lactate and volatile fatty acid contents, spring (first cut) grass treated with cow slurry in both years of the study produced significantly poorer fermentation (P < 0.001) than silage from grass treated with pig slurry. The quality of silage made from slurry-treated swards compared favourably with that from swards treated with granular fertiliser. Although increasing the rate of slurry application was shown to reduce fermentation quality in most treatments, this was seen as an effect of increasing the total-N content of the herbage rather than of slurry application per se. From a study, in selected treatments, of the bacterial flora at harvest, it was also observed that slurry application had little impact on either the composition or diversity of herbage enter bacteria at harvest, and therefore probably upon subsequent fermentation. No evidence was found for the occurrence of clostridia on herbage from slurry-treated swards. Use of a bacterial inoculant (Ecosyl; ICI plc) improved fermentation quality significantly (P < 0.001) even where high rates of slurry (200 m³ ha^?1 year^?1) had been applied to swards. The high acetate and butyrate contents typical of laboratory silages untreated with additive were not seen in the inoculated silages.     

高铬铸铁复合变质剂的研究

通过实验室和生产条件下的试验,研制出一种适用于高铬白口铁的含Ｚｎ,Ｍｇ等元素的多元复合变质剂———Ｚｎ变质剂．采用Ｚｎ变质剂处理的高铬白口铸铁,初生奥氏体细小,碳化物孤立、圆钝,材料的冲击性αＫ≥８Ｊ／ｃｍ２,ＨＲｃ≥６０,其效果相当或优于ＶＴｉ变质剂,悬殊成本低廉．采用ＳＥＭ,ＥＤＡＸ和ＥＰＡ等手段对Ｚｎ变质剂的变质作用进行了分析．