地膜覆盖对烤烟的生长发育和产质量影响研究进展

对近年来国内外有关地膜覆盖对烤烟的生长发育以及产质量的影响的研究进展作了综述.     

湘西山区主要气候事件对烟叶产质量的影响

根据2005～2009年湘西主要产烟区烟叶收购统计数据,分析了烟叶生长期主要气候事件(春寒、倒春寒、5月低温、连阴雨、雨季结束时间、日最高气温≥35℃高温的日数、日最高气温≥35℃连续天数、干旱)对烟叶产质量的影响.结果表明,湘西主要产烟区出现在3月中旬的春寒或倒春寒天气过程可能对烟叶的产质量造成严重影响;4月轻度春寒或倒春寒,轻度5月低温对烟叶产质量的负面影响较小;在雨季结束日期不明显的年份,8月份的干旱有利于烟叶产质量的提高;7、8月份高温期间,温度、湿度、日照、云量、日较差等综合气象因素可能是湘西高品质烟叶生产的重要因素;日最高气温≥35℃的高温日数偏少对烟叶产质量有负面影响,日数偏多则有利于烟叶产质量的提高;5月低温与重度连阴雨同时出现时,烟叶的产质量严重下降,6月连阴雨对烟叶的产质量影响较小,7月连阴雨有助于烟叶的生长.     

不同氮用量对烤烟中性香气成分及感官质量的影响

[目的]探讨氮用量对烤烟质量的营养调控技术.[方法]设置6个施氮处理(施纯氮45.0、52.5、60.0、67.5、75.0、82.5 kg/hm2),进行田间小区试验,研究不同氮用量对烤烟中性香气成分和评吸质量的影响.[结果]施纯氮量不高于75.0 kg/hm2时,提高氮肥用量有利于烤烟香气成分的形成,其中以施纯氮75.0 kg/hm2时效果最好;施纯氮量高于75.0 kg/hm2 时,烤烟的品质均下降.评吸结果表明,施纯氮75.0 kg/hm2处理的烟叶香气较丰富,饱满;杂气较轻;余味微滞,品质最佳.[结论]施纯氮75.0 kg/hm2处理的烟叶中性香气成分最高,感官评吸质量表现最好;其次是施纯氮67.5 kg/hm2和施纯氮82.5 kg/hm2的处理.     

集中采收对不同烤烟品种上部烟叶理化性状的影响

[目的]探讨不同烤烟品种上部烟叶采用集中采收的适用性.[方法]对不同烤烟品种(K326、云87和粤97)采取集中一次性采收的效果进行了比较.[结果]各品种在不同评价指标中具有各自的优势.集中采收方式下,云87和粤97烟叶开片较好,含梗率和叶厚度相对较小,化学成分较协调;K326品种单叶重和叶密度相对较小,烟碱含量较高,总糖和还原糖含量较低,整体表现较差.[结论]集中采收上部烟叶在不同烤烟品种上的适宜性大小为云87≥粤97>K326.为提高上部烟叶质量提供了理论依据.     

不同化控措施对烤烟生长和烟叶氮·磷·钾含量的影响

[目的]研究不同化控措施对烤烟生长和不同生长时期烟叶氮、磷、钾含量的影响.[方法]通过土培盆栽试验,在烤烟旺长期、现蕾前期及打顶期叶面喷施7种化控物质,设清水对照.[结果]氯吡脲(KT-30)+磷酸二氢钾+氨基酸+黄腐酸处理(T5)、萘乙酸钠+胺鲜酯(DA-6)+KT-30+磷酸二氢钾+氨基酸+黄腐酸处理(T7)可有效促进烤烟的生长;T5处理可降低烤烟后期中、上部叶氮含量,提高烟叶的磷含量,使烟叶的氮、磷含量最接近优质烟叶的氮、磷含量标准;T5、萘乙酸钠+DA-6+磷酸二氢钾+氨基酸+黄腐酸(T6)、T17处理均能有效地提高烤烟上、中、下部烟叶的全钾含量.[结论]T5处理在促进烤烟生长,改善烟株氮、磷营养,提高烟叶全钾含量方面的综合效应最好.     

壳聚糖对长豆角品质和产量的影响

[目的]为生产长豆角无公害寻找有效的生长调节剂.[方法]在长豆角现蕾前,采用1.2和1.6 mg/ml壳聚糖溶液喷洒长豆角植株,研究其豆荚品质和产量的变化.[结果]壳聚糖有效减少了长豆角虫害的发生,提高了长豆角豆荚可溶性蛋白含量、可溶性糖含量和维生素C含量,降低粗纤维含量,并增加了单果重量、单株结荚数和单位面积产量.[结论]壳聚糖作为一种植物生长调节荆,显著增加作物产量和改善作物营养品质.     

Influence of Partitioning Effects on the Retained Austenite Content and Properties of Martensitic Stainless Steel

The effect of a quenching and partitioning (Q&P) heat treatment with a quenching temperature (T_Q) range from 20 to 190 °C is investigated for two martensitic stainless tool steels X40Cr14 and “X25CrN13”, focusing on microstructural evolution, hardness, and toughness. The influence on the retained austenite (RA) content, when replacing part of carbon with nitrogen, is of core interest. The amount of RA is analyzed by X-ray diffraction and is additionally proved with electron backscatter diffraction, and the RA content is thermodynamically calculated. Subsequently, the effect of the microstructure on toughness and hardness is investigated. For both steels, the toughness maximum is reached in the region of the RA maximum. The “X25CrN13” attains higher toughness at higher RA contents. Higher RA contents do not benefit X40Cr14. Furthermore, the effect of double tempering at higher tempering temperatures after Q&P on the steels is investigated. Besides RA contents and hardness, dilatometer curves are used to evaluate the formation of fresh martensite in the microstructure. The secondary hardness maximum of “X25CrN13” is reached at 500 °C and that of X40Cr14 is at 480 °C. For double tempering temperature at 520 °C, T_Q has little effect on toughness, and “X25CrN13” shows better values.     

Effects of Cold Rolling Reduction on Retained Austenite Fraction and Mechanical Properties of High-Si TRIP Steel

 Transformation-induced plasticity-aided steel ［TRIP steel (0. 4C-1. 5Si-1. 5Mn)］ was rolled at room temperature to different thickness reductions (0, 4%, 10%, 20%, 40%, and 60%). The mechanical properties, microstructure and austenite fractions of the rolled samples were measured by tensile test, electron back scattered diffraction (EBSD) and X-ray diffraction (XRD) for each rolling. The deformation behavior was studied based on the analysis of the mechanical properties and microstructure of steel after tensile deformation, aiming at understanding the effects of cold rolling reduction on the decay behavior of the austenite and the change of mechanical properties of the TRIP steels. It was found that increasing rolling reduction increases the yield stress gradually but decreases the total elongation significantly. It is very interesting that after 10% rolling reduction the yield stress is about 1000 MPa but still with 20% total elongation, which gives an excellent combination of yield strength and ductility. Based on the XRD results, it was revealed that in both rolling and tension the austenite volume fraction monotonically decayed with the increase of rolling strain, but the decaying rate is faster in tension than in rolling, which may be ascribed to the higher temperature in rolled specimens than in the tensioned ones during deformation. Experimental results and theoretical reasoning indicate that the decreasing trend of austenite volume fraction with strain can be formulated by a unique equation.     

Effects of Various Irrigation Regimes on Soil Water Balance, Yield, and Fruit Quality of Drip-Irrigated Peach Trees

The aim of this research was to determine the amount of irrigation water, irrigation interval, and water consumption that gave the greatest yield, to determine the effect of irrigation on fruit quality characteristics, and to investigate variations in soil moisture in Redhaven peaches irrigated by drip irrigation in the Aegean region of Turkey. The study was performed in 2003 and 2004 on split plots in randomized blocks with three replications. Main treatments were 3 and 6?days between irrigations, and subtreatments comprised four different pan coefficients (Kp1.25, Kp1.00, Kp0.75, and Kp0.50). According to the 2-year averages of peach yields, the effect on yield of the amount of irrigation water was found to be significant (p<0.01), but the effect of the irrigation interval was found not to be significant. Total yield varied between 5,966 and 16,340??kg?ha-1, and marketable yield between 5,349 and 14,164??kg?ha-1, according to irrigation treatments. A maximum average yield of 14,101??kg?ha-1 was obtained from treatment Kp1.00. Average irrigation water amount for this treatment was 482?mm, average water consumption was 705?mm, and the Kpc value was 0.785. Maximum water-use efficiency (WUE) of 2.02??kg?m-3 was obtained from Kp1.00. The yield response factor (ky) was found to be 1.2. Weight of individual fruit varied between 203 and 253?g, height varied from 6.3–6.6?cm, diameter from 7.2–7.7?cm, soluble dry matter from 10.8–14.5%, and juice pH from 4.14–4.37. In the years of the study, the declining trend of soil moisture was greater in the treatments that received little irrigation water than in those that received more. After irrigation was ended, soil moisture decreased rapidly and eventually reached the wilting point. To conclude, when setting up a drip-irrigation program for fully grown peach trees in the Aegean region, the irrigation interval may be 3 or 6?days. The amount of water to be applied at each irrigation can be determined by correcting the total evaporation from a Class-A evaporation pan over the chosen irrigation interval by a coefficient of 0.785.     

Effects of Austenitization Temperature and Compressive Stress During Bainitic Transformation on the Stability of Retained Austenite

The effects of stress and austenitization temperature on the carbon content and morphology of retained austenite (RA) have been investigated. The stability of RA has been analyzed. An interesting finding is that the increase in the amount of bainite is not accompanied by the increase in the carbon content in RA under the effect of stress. This does not match with what is expected from the bainitic transformation theory. The amount of bainitic transformation and stress both affect the carbon content in RA. In addition, the stress during bainitic transformation helps to increase the stability of RA by decreasing the amount of blocky RA, whereas it has little effect on the carbon content in RA. Moreover, the increase in austenitization temperature is beneficial to increasing the stability of RA, whereas it has no significant effect on the morphology of RA.     

中间包底吹氩水模型试验及冶金效果

通过水模型试验和工业试验,研究了中间包底吹氩参数对中间包流场的影响。水模型试验结果表明:中间包底吹气可以改善中间包流场,较佳的吹气参数是透气砖距离冲击区765 mm,吹气量在0.06~0.10 m3/h。工业试验结果表明:中间包采用底吹氩后,T[O]降低了26.67%;大型夹杂物总含量由0.430 mg/kg降至0.079 mg/kg,降低了81.82%。     

煤场底煤质量分析及再利用实践

在炼焦生产过程中，由于“精细配比”工艺的改进，造成原料煤场各单种煤堆放位置频繁变更，导致煤场底煤成分复杂。将底煤分为4层，通过常规分析进行细分类后，采取“降级使用”、“特殊配比”和“微量配比”等措施对煤场底煤进行了全部再利用，质量检测数据表明，配合煤和焦炭的质量指标均没有出现大幅波动，可满足生产需要。     

不同施肥方式对澳洲坚果产量的影响

[目的]研究不同施肥方式对澳洲坚果产量的影响.[方法]以澳洲坚果H2品种为试材,连续3年调查不同施肥方式对澳洲坚果产量的影响.[结果]年施3次肥的单株产量高于年施2次肥的,施水肥的单株产量最高,其次为沟施,撒施最差.[结论]在施用普通肥料情况下,增加肥料用量,减少施肥次数,澳洲坚果不能获得增产.     

提高球团矿产量和质量的生产实践

介绍和分析南钢2×8 h球团竖炉的生产现状,影响球团矿产量、质量的因素。提出了对工艺设备改造和生产管理改进的措施,确保了球团矿生产的稳步提高。