9种杀虫剂对玉米大豆带状复合种植大豆田甜菜夜蛾的防治效果

为了探究杀虫剂对玉米大豆带状复合种植大豆田甜菜夜蛾的防治效果,选取9种杀虫剂开展药剂筛选试验,结果表明,各处理试验药剂对大豆植株安全;喷施6%乙基多杀菌素SC 450 mL/hm^(2)、20%多杀霉素SC 450 mL/hm^(2)、5%溴虫氟苯双酰胺SC 450 mL/hm^(2)对玉米大豆带状复合种植大豆田甜菜夜蛾具有较好的防治效果,药后1 d对大豆田甜菜夜蛾的防效均达65%以上,药后3 d均达85%以上,药后7 d均达90%以上。以上3种处理药剂防治效果显著高于其他药剂处理,且这3种药剂处理药效迅速,可在短时间内显著减少甜菜夜蛾的种群数量。该研究监测了2022年8月滨淮农场地区甜菜夜蛾发生情况,为玉米大豆带状复合种植大面积生产科学防控甜菜夜蛾提供依据。

电子舌作用机理及其在肉品检测中的研究进展

电子舌作为一种新型的检测手段,具有检测快速、操作简便、精密度高等优点,受到了国内外学者的广泛关注。该文综述电位型、伏安型、阻抗谱型、光寻址型、声波型和生物传感器型电子舌的作用机理、影响电子舌作用效果的因素及其在肉品检测中的研究进展,以期为电子舌的应用和肉品检测技术的提升提供参考。

随机不确定性下Kriging辅助的谐波减速器柔轮疲劳寿命预测

柔轮作为谐波减速器核心传动件,在循环交变载荷作用下容易发生疲劳失效,其疲劳寿命直接影响谐波减速器的工作寿命。为揭示随机不确定性因素对谐波减速器柔轮疲劳寿命的影响规律,本文考虑材料属性和载荷等不确定因素对谐波减速器柔轮开展疲劳寿命预测研究,以期实现更客观地评估柔轮疲劳寿命。首先,建立柔轮的三维模型和有限元模型,通过有限元分析及寿命计算获得确定性条件下的柔轮寿命。然后,将材料属性及载荷考虑为随机变量,采用拉丁超立方抽样方法对柔轮进行试验设计。最后,基于主动学习Kriging模型和柔轮材料P-S-N曲线,通过逐一加点的方式对柔轮进行疲劳寿命分析,获得疲劳寿命统计结果,并与确定性条件下的柔轮疲劳寿命结果进行对比。结果表明,随机不确定因素影响下柔轮疲劳寿命预测结果与确定性条件下相比有所降低,对柔轮抗疲劳设计具有一定指导意义。

不同处理对猪毛角蛋白提取效果及功能特性的影响

目的探究不同处理方式对猪毛角蛋白提取效果及功能特性的影响。方法采取碱解法、酶解法、蒸汽爆破法、还原法4种处理提取猪毛角蛋白,研究不同处理对猪毛溶解率和可溶性蛋白含量以及角蛋白功能特性的影响。结果碱解和蒸汽爆破处理下猪毛溶解率较高,均为65%左右,而还原法处理的可溶性蛋白含量较高,为165 mg/g左右;不同处理对猪毛角蛋白的功能特性影响差异较大,溶解性和持水性较好的分别是碱解和蒸汽爆破处理得到的角蛋白,而还原法提取出的猪毛角蛋白持油性、冻融稳定性、乳化性及乳化稳定性较好。结论各处理方法均有利弊,需要根据角蛋白的用途选择合适的提取方法。本研究为猪毛角蛋白的提取及猪毛的充分利用提供了一定理论参考。

纳米二氧化钛抗菌热收缩膜的制备与性能研究

目的比较不同质量分数二氧化钛(TiO_(2))对抗菌热收缩膜的物理性能和抗菌效果。方法以线性低密度聚乙烯、乙烯–醋酸乙烯酯共聚物、聚偏二氯乙烯为原料,采用共挤压法制备纳米TiO_(2)质量分数分别为0%、2%、3%、4%的抗菌热收缩膜,并对其性能进行研究。结果纳米TiO_(2)颗粒在抗菌热收缩膜表面均匀分布,添加纳米TiO_(2)对热收缩膜的厚度和不透明度没有显著影响(P>0.05)。随着纳米TiO_(2)添加量的增加,纳米TiO_(2)抗菌热收缩膜的断裂伸长率和拉伸强度呈先升高后下降趋势。当纳米TiO_(2)质量分数为3%时,断裂伸长率和拉伸强度分别达到最大值238.48%和55.64 MPa。添加纳米TiO_(2)对热收缩膜的氧气透过量和水蒸气透过量没有影响(P>0.05)。纳米TiO_(2)抗菌热收缩膜对假单胞菌MN10、肉杆菌VE51、乳球菌VE58和乳杆菌VMR17表现出优异的抗菌性能,随着TiO_(2)添加量的增加,纳米TiO_(2)抗菌热收缩膜的抗菌效果越好,当纳米TiO_(2)质量分数为3%时,纳米TiO_(2)抗菌热收缩膜对4种株菌的抑菌效果分别达到了93.35%、98.46%、97.14%和100%。结论纳米TiO_(2)抗菌热收缩膜具有较好的物理性能和抗菌效果,具有应用于生鲜肉包装的潜力。

贵州台江县野生木本芳香植物资源调查与园林应用分析

【目的】为研究野生木本芳香植物资源状况和芳香特性,通过野外调查对贵州台江县野生木本芳香植物资源类群和园林应用评价进行了研究,以期为开发利用乡土芳香植物资源提供参考。【方法】在台江县种质资源普查的基础上,针对绿化观赏树种,在2019—2022年间,采用重复多次随机踏查和线路调查方法,对野生木本芳香植物资源进行了调查研究。【结果】台江县野生木本芳香植物大约有36科74属136种,其中:裸子植物1科1属1种,被子植物35科73属135种;从芳香特性来看,花期主要集中在春季,以3—5月为主,有109种,占总种数的80.15%;台江县有清香和芳香类野生木本芳香植物共47种,是清香和芳香类野生木本芳香植物的重要分布区。从园林用途看,以园林景观树和行道树用最多,有46种,占33.82%;台江县野生木本芳香植物开发潜力巨大的Ⅰ级有5种,开发潜力较大的Ⅱ级有64种,Ⅰ、Ⅱ级占总种数的50.74%。【结论】台江县野生木本芳香植物资源较丰富,开发潜力大。

碳硅泥岩型铀矿床钻孔水力开采相似律及相似材料研究

碳硅泥岩型铀矿床采用常规方法不易开采。依据钻孔水力开采工艺特点,结合二连盆地某碳硅泥岩型铀矿床的工程地质条件,在模型试验相似理论基础上进行了碳硅泥岩型铀矿床钻孔水力开采模型相似研究。基于所推导的模型试验相似准则,通过理论分析及试验,实现了模型试验的几何条件、边界条件、高压水射流荷载及材料相似。研究结果可为碳硅泥岩型铀矿床水力开采提供依据和试验基础。

宰后僵直和解僵过程羊肉风味品质分析

本文研究了4 ℃贮藏条件下,羊肉僵直和解僵过程中风味品质的变化。以羊背最长肌为研究对象,采用超快速气相电子鼻和气相色谱质谱联用技术(Gas Chromatography-Mass Spectrometer,GC-MS),测定宰后不同贮藏时间羊肉挥发性风味物质的差异。结果表明,宰后贮藏过程中共检测出挥发性风味物质6类51种,主要为醛类和醇类物质,随着贮藏时间的延长,熟制羊肉的醛类物质含量先增加后降低,醇类物质的含量先降低后增加,己醛、庚醛、辛醛、壬醛、1-戊醇、1-辛烯-3-醇和1-庚醇为宰后贮藏过程中羊肉的关键风味物质,宰后1 d与1 h羊肉的共有关键风味物质含量无显著差异(p>0.05),宰后 3 d 和 5 d羊肉的风味物质种类和含量降低;超快速气相电子鼻主成分分析结果与 GC-MS 结果相一致。因此,僵直前(宰后 1 h)和解僵初期(宰后 1 d)羊肉的共有关键风味物质种类和含量差异不显著,解僵后期(宰后 3 d 和 5 d)羊肉关键风味物质含量和种类明显降低。

食品生物胺安全控制关联的包装技术研究进展

目的综述包装技术在食品生物胺安全控制领域的研究现状及应用进展,为新型高效的食品生物胺控制包装的研发提供借鉴与参考,助力食品安全国家战略的实施。方法通过收集和整理相关文献,在概述食品中生物胺的形成机制和危害的基础上,探讨传统食品包装在控制生物胺形成方面的成效和局限性,重点总结近年来出现的新型生物胺控制包装技术(气调包装、抑脱羧酶活性包装及抑菌活性包装)及其研究进展,并对其未来发展方向进行展望。结论食品包装可实现生物胺的安全控制,研发新型、高效的生物胺安全控制包装技术对于保障消费者舌尖上的安全具有重要的现实意义。

音频大地电磁法和频谱激电法在黔西北某铅锌矿探测中的应用研究

黔西北铅锌成矿区具备寻找中、大型矿床的潜力。根据矿区地质背景和岩矿石电性特征,开展音频大地电磁法和频谱激电法测深,结合地质相关资料,查明该区岩矿体在深部空间上的电性特征,矿体的异常响应特征,划定构造格局,寻找深部隐伏矿体,突破找矿瓶颈。研究结果表明:两种物探方法在该区取得了良好的工作效果,并通过钻孔验证见矿,验证了电磁方法在寻找深部隐伏铅锌矿体中的有效性,该方法可以为同模式铅锌矿攻深找盲提供技术支撑。

砂岩铀矿床钻孔水力冲采模拟试验研究

针对中国北方大量胶结、低渗透砂岩铀矿资源难以采用常规方法和地浸方法开采的技术难题,提出钻孔水力开采的新思路。根据钻孔水力开采工艺技术特点,并结合某砂岩型铀矿床实际地质条件,对水力冲采过程中的高压水射流破岩机制进行探索,通过水力冲采模型试验相似率研究,建立了水力冲采试验模型。为了分析矿岩强度、水射流工作压力、喷头作业形式与水力冲采效率的关系,进行了三因素三水平正交试验,并采用极差分析法及方差分析法进行了分析,确定了较优的水力冲采工作条件,以期为砂岩铀矿床钻孔水力开采现场试验提供依据和试验基础。

The characterization of acid and pepsin soluble collagen from ovine bones (Ujumuqin sheep)

Ovine bones are the major by-products after slaughtered. The present study was conducted to extract and characterize acid soluble collagens （ASC） and pepsin soluble collagens （PSC） from ovine bones （Ujumuqin sheep）. Ovine bones collagen were identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis （SDS-PAGE） and liquid chromatography-tan- dem mass spectrometry （LC-MS/MS） as type I collagen. The results of Fourier transform infrared （FTIR） spectra analysis testified the existence of triple superhelical structure in both ASC and PSC, showing pepsin did not disrupt the triple helical structure of ovine bones collagen. Glycine, accounting for one-third of total amino acids, was the major amino acid for ovine bones collagen. Higher imino acid content was responsible for higher thermal denaturation temperature of ovine bones collagen compared to fish collagens. The isoelectric point of ASC was lower than PSC due to the higher content of acidic amino acids. Therefore, this study provides the potential reference for collagen extraction and application of ovine bones by-procduct.

ATP regulates the phosphorylation and degradation of myofibrillar proteins in ground ovine muscle

Phosphorylation post-translational modification plays an important role in postmortem muscle quality traits. Adenosine triphosphate(ATP) is an energy source and a key substrate of phosphorylation which provides the phosphatase groups to proteins in the presence of protein kinases. However, in postmortem muscle, the effects of ATP content on phosphorylation are poorly studied. The study investigated the effect of ATP on protein phosphorylation and degradation in postmortem ovine muscle. The ground muscle with/without additional ATP were treated/control groups and stored at 25 and 4℃, respectively. The ATP content led to different changes of p H value between the ATP-treated and control groups. The phosphorylation level of myofibrillar proteins was higher(P<0.05) in ATP-treated group compared to the control group at both temperatures, which suggested that ATP played a vital role in postmortem protein phosphorylation. A slower degradation rate of μ-calpain, desmin and troponin T was observed in the ATP-treated group which showed that there was a negative relationship between ATP level and the degradation of proteins. These observations clearly highlighted the role of ATP on the development of meat quality by regulating the phosphorylation and degradation of myofibrillar proteins in postmortem ovine muscle.

Changes of Intramuscular Fat Composition,Lipid Oxidation and Lipase Activity in Biceps femoris and Semimembranosus of Xuanwei Ham During Controlled Salting Stages

Fatty acid composition of neutral lipids （NLs）, phospholipids （PLs） and free fatty acids （FFAs） from intramuscular fat （IMF）, lipid oxidation and lipase activity in muscle Semimembranosus （SM） and msucle Biceps femoris （BF） of dry-cured Xuanwei ham during the 90-d salting stages were analysed. The salt content increased from 0.34 to 3.52%in BF and from 0.10 to 5.42%in SM during the 90 d salting stage, respectively. PLs of IMF in both BF and SM decreased 54.70%（P〈0.001） and 34.64%（P〈0.05）, furthermore, the saturated fatty acids （SFA）, monounsaturated fatty acids （MUFA） and polyunsaturated fatty acids （PUFA） of PLs in both muscles were hydrolysed almost isochronously. FFAs were increased from 0.46 g 100 g-1 lipids to 2.92 g 100 g-1 lipids in BF at the end of salting, which was lower than SM （from 1.29 g 100 g-1 lipids to 9.70 g 100 g-1 lipids）. The activities of acid lipase, neutral lipase and acid phospholipase all remained active in the 90 d. The thiobarbituric acid reactive substances （TBARS） was slowly increased to 1.34 mg kg-1 muscle in BF and to 2.44 mg kg-1 muscle in SM during the salting stage. In conclusion, the controlled salting process prompted the hydrolysis of PLs of IMF notably and increased the lipid oxidation of muscles within some limits.

长期不同施肥模式对茶叶产量与土壤肥力的影响

通过长期定位施肥试验,研究不同施肥模式对茶叶产量及土壤肥力的影响,旨在为茶园提供合理的施肥模式,从而提高茶叶产量及土壤肥力,为推进茶业的可持续发展提供科学依据。以连续10年长期定位试验为研究平台,设5种不同施肥模式:空白区、有机肥区、无机肥区、配方肥区、化肥减量区,测定茶叶产量及土壤肥力状况。结果表明,配方肥区和无机肥区均表现出持续提高茶叶产量的良好作用,且二者差异不显著。减量化肥区产量每年变化平缓,2013年开始呈上升趋势,到2016年,产量达到最大。各施肥处理的土壤有机质含量均呈逐年上升趋势,化肥减量区增幅最大,试验后比试验前增加了10.50 g/kg,提高43.75%。有机肥区对茶园土壤pH的提高幅度较大,配方肥区和化肥减量区将茶园土壤pH控制在适宜茶树生长的范围4.14~5.45。无机肥区和配方肥区明显提高了土壤碱解氮含量,分别比空白区提高了64.52%和41.98%。配方肥区土壤速效磷含量为68.64 mg/kg,比空白区和无机肥区分别提高了336.61%和20.86%。有机肥区和配方肥区速效钾含量较高,比空白区提高了43.51%和13.96%。因此,化肥与有机肥配施方式最为合理,有利于保持茶园土壤养分均衡,肥效长,后劲足,促进茶园生产力稳定。

The effect of dehydrogenase enzyme activity in glycolysis on the colour stability of mutton during postmortem storage

This study investigated the influence of activities of glyceraldehyde-3-phosphate dehydrogenase （GAPDH） and lactate dehydrogenase-B （LDH-B） on the colour stability of mutton. From 60 sheep （Bayannur mutton sheep）, 15 Iongissimus dorsi （LD） muscles were selected on the basis of colour stability （R630/580 and a＊ value） during the storage and classified into three groups （5 for each group） as high colour stability （HCS）, intermediate colour stability （ICS） and low colour stability （LCS）. The activities of GAPDH and LDH-B, muscle colour attributes, nicotinamide adenine dinucleuotide （NADH） concen- tration and lactate concentration were measured. The samples in HCS had higher activities of GAPDH and LDH-B than the samples in the LCS, and the samples in the HCS group also possessed higher NADH and lower lactate concentration. The higher activity of dehydrogenase enzyme may result in higher NADH concentrations and colour stability in muscle tissue. The results suggest that the activity of GAPDH and LDH-B may also play a role in maintaining colour stability.

工艺参数对双辊薄带铸轧中心层偏析影响

双辊薄带铸轧过程中工艺参数对中心层偏析有重大影响,针对双辊薄带铸轧机的特点,利用多相流技术建立完全耦合溶质场、流场、温度场的数学模型,对铸轧熔池中液相-液固两相-固相同时存在的复杂凝固过程进行模拟仿真,研究分析铸轧熔池中Mg、Si元素溶质场与流场分布特征,对比研究不同工艺参数(浇铸温度、辊缝宽度)对铸轧薄带中心层偏析的影响规律,并结合铝合金6061的铸轧实验对结论进行验证。

Phosphorylation of sarcoplasmic and myofibrillar proteins in three ovine muscles during postmortem ageing

This study aimed to examine changes in phosphorylation of sarcoplasmic and myofibrillar proteins from longissimus lumborum,semitendinosus,and psoas major muscles during postmortem ageing for 5 d.These sarcoplasmic and myofibrillar proteins were separated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and stained with phosphorous and protein specific stains.Myofibril fragmentation index,pH,the content of lactic acid and the relative activity of μ-calpain in three ovine muscles were measured.These results showed that the relative phosphorylation level of sarcoplasmic and myofibrillar proteins of psoas major muscle were lower compared with longissimus lumborum and semitendinosus muscles(P<0.05).The pH of psoas major muscle was the lowest at 0.5 h postmortem,and the highest after 12 h postmortem(P<0.05).In addition,the relative activity of μ-calpain was higher within 5 d postmortem and myofibril fragmentation index was higher after 1 d postmortem in psoas major muscle than those of longissimus lumborum and semitendinosus muscles(P<0.05).The sarcoplasmic protein phosphorylation may regulate the rate of pH decline to influence the μ-calpain activity and then proteolysis of proteins consequently.This study gives a new perspective of the mechanism of postmortem meat tenderization.

Effects of lairage after transport on post mortem muscle glycolysis, protein phosphorylation and lamb meat quality

The objective of this study was to investigate the effect of lairage after transport on post mortem muscle glycolysis,protein phosphorylation and lamb meat quality.Two preslaughter animal treatments,transport for 3 h and lairage for 0 h（T3L0）and transport for 3 h and then lairage for 12 h（T3L12）,were compared with a control treatment of 0 h transport and 0 h lairage.Data obtained showed that preslaughter transport had a significant effect on lamb meat quality.Loins from lambs of the T3L0 treatment showed higher（P=0.026）pH24 h and higher（P=0.021）pH48 h values,but lower（P〈0.001）drip loss and lower（P〈0.05）glycolytic potential at 0 h post mortem than those of the T3L12 and control groups.Muscle samples of the T3L0 group showed higher（P=0.046）shear force and lower（P=0.005）b＊ value than those of the T3L12 group.Muscle glycogen concentration at 0,2,4 h post mortem were lower（P〈0.05）in the T3L0 group than in control.No significant difference（P〉0.05）in most meat quality parameters was determined between the T3L12 group and control,showing lairage for 12 h allowed lambs to recover from the effects of transport for 3 h and resulted in similar meat quality characteristics compared to no transport.Lairage after transport did not affect most meat quality indices in comparison with control,but increased the meat drip loss and b＊value of lambs possibly through decreasing glycogen concentration and glycolytic potential.

核酸扩增技术在毛孢子菌检测和鉴定中的应用进展

核酸扩增技术是近年来应用最为广泛的一种分子诊断技术,在感染性疾病诊断中此类技术可快速高效扩增病原菌的特征性核苷酸序列,已在毛孢子菌感染的诊断中得到广泛应用。目前文献报道多集中于应用聚合酶链反应(PCR)及其衍生技术对毛孢子菌进行检测和鉴定的研究,同时亦有少量应用等温扩增技术的报道。核酸扩增技术一方面给毛孢子菌感染的诊断和菌种鉴定提供了宽广的发展空间,另一方面也依然存在一些瓶颈问题阻碍了毛孢子菌感染快速诊断的实现。该文将从上述两个方面对既往相关研究进行综述。