共查询到20条相似文献，搜索用时 250 毫秒
1.
为了有效防止褐变,从菇体内因素水平pH值、氧气和水分含量考虑,研究了电生功能水、真空充氮、水浸泡3种前处理,同时结合沸水烫漂对双孢菇颜色的影响。结果表明,3种前处理均可以在一定程度上抑制菇片的褐变,其最佳处理分别为菇体pH值4.02,0.09 MPa条件下真空充氮和水浸泡1 h。其中,真空充氮结合沸水烫漂处理防褐变效果最好,最大褐变抑制率为(17.52±0.45)%。 相似文献
2.
基于液-液萃取机理的新型环境样品前处理方法研究进展 总被引：2，自引：0，他引：2
新型环境样品前处理技术已经逐步取代传统液-液萃取。液相微萃取、液膜萃取和逆流色谱技术均是集采样、萃取和浓缩于一体的环境友好型环境样品前处理技术。液相微萃取、液膜萃取实质上是微型化的液-液萃取;逆流色谱结合了液液萃取和分配色谱的优点,是一种新型色谱分离技术。3种技术均对环境样品中的痕量/超痕量污染物质有高效的富集、净化效果。笔者综述了液相微萃取、液膜萃取和逆流色谱技术的优缺点及在环境样品前处理中的应用。 相似文献
3.
玉米弯孢菌叶斑病是玉米生产上的重要病害之一。［目的］为获得一株有效的抗玉米弯孢菌叶斑病的生防细菌,［方法］本研究采用生防细菌包衣处理玉米种子的方法,将前期田间初筛得到的4株生防促生细菌进行室内和田间防效评估,获得一株防效最好的菌株。进一步通过室内和田间试验验证该菌株对玉米的促生和增产作用,并采用形态学、生理生化和分子生物学分析方法对其进行鉴定。［结果］结果表明,4株生防细菌中,菌株Sneb2249对玉米弯孢菌叶斑病的防效最好,盆栽防效为55.04%,田间防效为39.36%。室内促生和田间测产试验结果显示,菌株Sneb2249能够显著促进玉米植株生长,其株高、地上部干重和千粒重分别比对照提高24.89%、49.15%和 7.9%。经鉴定菌株Sneb2249为恶臭假单胞菌(Pseudomonas putida)。［结论］恶臭假单胞菌Sneb2249是一株优良的植物根际促生菌,既可抗弯孢叶斑病菌,又对玉米具有促生增产作用。利用有益微生物处理种子防控病害将是一种新型的植保措施,具有重要的研究意义。 相似文献
4.
《农产品加工．学刊》2016,(16)
"食品工厂设计"是食品科学与工程专业重要的必修课程,具有很强的实践性和综合性。在多年讲授该课程的基础上,结合教学计划安排和同学们的需求,将实习与课程讲授结合起来,在企业进行现场教学与实践,对传统"食品工厂设计"的教学模式进行改革,并就企业现场教学中存在的问题进行分析,提出了进一步的改进方法。 相似文献
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6.
李仪祉是中国由古代科学技术进入近代科学技术治河的开路人。在中国近代水利事业发展史上,他不仅大量引进、传播西方先进水利科学技术,也努力继承和发展中国传统治水理论。他肯定了中国传统堤防的作用,提出“学术筑堤”;注重堤防的治导作用,将河道整治工程作为筑堤防洪的外延;强调植物固堤护滩要避其松土之短,扬其助淤之长;他还希望全面改进传统堤防的施工管理和基础科学研究,建设防洪、治导、灌溉、交通一体化的堤防。 相似文献
7.
不同干燥处理对马齿苋总酚含量及其抗氧化性的影响 总被引：2，自引：0，他引：2
分别采用热风干燥法、真空微波干燥法和真空冷冻干燥法处理马齿苋,测定马齿苋粉甲醇提取液的总酚含量、总抗氧化能力、还原能力、DPPH·清除能力、羟自由基清除能力和超氧阴离子自由基清除能力,研究不同干燥方法对马齿苋粉总酚含量和抗氧化性的影响。结果表明,真空冷冻干燥法制得的马齿苋干粉样品中总酚含量显著高于真空微波与热风干燥样品;不同的干燥方法对马齿苋粉的抗氧化性有明显影响,真空冷冻干燥法制得的马齿苋粉甲醇提取液的总抗氧化能力、还原能力、DPPH·与羟自由基清除能力显著高于真空微波和热风干燥法制得的马齿苋粉(P0.05),但真空冷冻干燥样品与真空微波干燥样品对O_2~-·的清除率无显著差异,综合考虑产品品质与加工成本,采用真空微波干燥法更为合理。 相似文献
8.
本试验选用22.4%螺虫乙酯悬浮剂(Spirotetrama)、TTP200SC、倍内威（溴氰虫酰胺10% OD）3种新型杀虫剂,对番茄地烟粉虱进行了田间药效试验,结果表明：7个施药处理在药后1~7天药效持续增强,7~21天药效逐渐减弱,药效持续期可达21天。TTP+螺虫乙酯,每公顷用量为199.5 mL+417 mL时,在药后1、3、7、14、21天,5个时间段都是效果最好的处理,当该处理施药7天时综合防效达到最好,若虫和成虫虫口防效都极显著高于其他处理,此时烟粉虱若虫虫口防效为93.06%、成虫虫口防效为92.19%。该施药处理对烟粉虱的综合防效及持效期防效最佳。 相似文献
9.
《农药市场信息》2013,(8)
<正>近日,由中科院华南植物园完成的"一种菜心贮藏保鲜方法"获得国家发明专利授权(专利号:ZL201110154408.0)。该发明公开了一种菜心贮藏保鲜方法。它是挑选适期采收、无机械损伤、病虫害的菜心,预冷,然后将切口用抗菌剂和防褐变剂处理;将处理后的菜心装入保鲜袋中,用0.530毫克/千克的1-甲基环丙烯处理,立即扎紧保鲜袋口,置于1℃30毫克/千克的1-甲基环丙烯处理,立即扎紧保鲜袋口,置于1℃2℃下贮藏,在贮藏过程中保鲜袋处于密闭状态至少12小时以上。本发明将菜心先进行预冷,再经特定的防腐和防褐处理,然后用保鲜袋包装,再结合菜心的生物学特性,在低 相似文献
10.
郭港 《农产品加工．学刊》2008,(11):38-38
山东省金乡县通过推广“蒜片加工废水的M—MIT多级处理及综合利用新技术”,解决了蒜片加工的污染问题。金乡县联合省大蒜技术工程研究中心和有关大学的专家教授,开展了“蒜片加工废水的M—MIT多级处理及综合利用新技术”项目专题攻关。该项目采用国际先进的分子印迹分离技术和膜分离技术,结合传统的物理处理方法, 相似文献
11.
Ventilating vacuum method can overcome the clogging problem which often occurs on the traditional vacuum method dewatering dredged clays with high initial water contents. However, how to analyze the anti-clogging behavior of ventilating vacuum method is an important issue in practical engineering. A radial drainage model was established based on the filtration theory developed by Ruth. The vanity of the model was verified using the test results of ventilating vacuum, and the change law in average radical dewatering resistance of dewatering layer which reflects the filtration performance was investigated during the dewatering process. It is indicated that the dewatered layer is compacted by traditional vacuum method during the dewatering process. Its corresponding pore structure is unstable, thus the drainage pipeline often clogs. While the technique of ventilating vacuum provides a powerful way to overcome the clogging problem, and the pore structure is stable during the dewatering process. 相似文献
12.
The ground treatment method for very soft soil do not satisfy the enineering needs presently. This paper studies the drain and consolidation mechanism for ground treatment method improvement of the super soft soil. It aims to obtain some varying laws of engineering properties during the super soft soil consolidated. By quantities of test data, the varying laws of the porosity, permeability, compressibility, consolidation properties and pore pressure, and their varying micro_mechanism during the seepage and consolidation of super soft soil are initially studied. Some mechanism of permeation and consolidation of super soft soil are ascertained. It concludes that the varying laws of above engineering properties is related each other, and the governing mechanism are the varying laws of the porosity and the pore pressure. 相似文献
13.
A number of lands were occupied by discarding the dredged sludge in the yard as waste materials.The Aeration Vacuum rapid Mud Water Separating (AVMWS) technique was appropriate for discarding yard with high water content and high clay particle content sludge.This technique could quickly reduce the volume of the sludge and accelerate the turnover use of the yard.In addition,the technique could overcome the clogging problem when pumping water from high water content, high clay particle content dredged sludge.Through the sampling particle size distribution tests after AVMWS and conventional vacuum pumping model tests, it was found that in the AVMWS tests the fine grained soil run off, coarse particles accumulated, and arching structure layer was formed.However, in the conventional vacuum pumping tests, fine particles did not lost and there was clogging without arching structure layer.The layer could protect the internal loss of the fine particles and ensure a high permeability of the soil at the same time.And the mechanism was explained as well. 相似文献
14.
Based on traditional consolidation theory, the soft ground settlement is calculated and one-, two-, and three-dimensional consolidation of reinforced soft foundation with sand drain is studied. The calculation method of average sand drain and the new modified method are discussed. The results can serve as a guide to subgrade design of soft ground. 相似文献
15.
Because of the existence of initial hydraulic gradient in clay, non Darcy equation with initial hydraulic gradient was modified with classical consolidation theories of sand drained ground.And the approximate solution in the instance of vacuum preloading was presented.Based on this, the effect of initial hydraulic gradient on the seepage front, the pore water pressure and the average degree of consolidation were investigated.It was found that the spread of vacuum pressure was delayed because of initial hydraulic gradient, resulting in the dissipation of pore water pressure and the speed of soil layer consolidation.The hysteresis became more and more evident with the increase of initial hydraulic gradient.In addition, initial hydraulic gradient also caused some residual pore water pressure which could not reach vacuum pressure.Thus, the ultimate average degree of consolidation was less than 100%, which decreased with the increase of initial hydraulic gradient. 相似文献
16.
Follow in precursory relating documents, several equations of one dimension Large Strain Consolidation (LSC) and consolidation coefficients were discussed firstly. Based on this, a Finite Difference Method (FDM) equation was derived, which was the physical described LSC equation with variable displacement. Moreover, the initiate and boundary condition were dispersed by FDM, and the boundary of different layers of super soft soil was disposed of continuity. Finally,nonlinear group equations of LSC FDM solution was deduced for multi layers super soft ground by repeated method, and a FDM program of 1D nonlinear LSC analysis was compiled. Finally, a case showed a satisfied analysis result by LSCFDM. 相似文献
17.
Zhu Zuorong Hu Zhenying 《保鲜与加工》1990,(4)
This paper describs a case study of foundation engineering for forming sand and oval stone piles through the action of quaking, water striking,pouring and packing by a pile driver. The piles and packking mud are combined, forming a compound foundation to support the upper loads. This paper introduces the design and construction of this engineering. In order to check this method for consolidating the soft foundation,the loading test and the settlement observation in site are made. After the construction work,there has been an organized technical identifying meeting. The result out of the identification is positive. 相似文献
18.
基础尺寸对碎石土地基扩底基础上拔承载力影响的现场试验研究 总被引：2，自引：0，他引：2
影响基础上拔承载能力的因素包括地基土物理力学参数及基础尺寸参数,而确定混凝土方量最小、基础上拔承载力最大的基础参数配比是基础优化设计的关键。以戈壁滩碎石土地基中的原状土扩底基础为研究对象,采用正交设计方法,以立柱直径、深宽比、扩展角为影响因素,以基础上拔承载力为分析指标,设计出9组尺寸的足尺基础。通过现场试验,获得了各试验基础的荷载位移曲线和上拔承载力值,提出了采用渐变率的概念表征荷载位移曲线的非线性变化特征,通过分析发现基础荷载位移曲线渐变率与承载能力呈负相关。结合正交试验分析结果,得出立柱直径、深宽比、扩展角3个因素中对碎石土地基原状土扩底基础抗拔承载能力的影响程度由大到小依次为深宽比、立柱直径、扩展角,表明在戈壁滩碎石土地基基础的工程设计中增加深宽比能提高基础抗拔承载能力。 相似文献
19.
A clogging segment mechanical model is established on gas extraction horizontal borehole. Based on the air pressure extremes pmax of the construction site, we solve the corresponding critical clogging length L0 and find clogging will occur when L> L0. With the clogging segment mechanical model, we analyze the calculation method of the retreat drilling rod resistance in borehole. The influence rule of clogging length and air supplying system pressure on retreat drilling rod resistance is analyzed. Analysis results show that the main reason for difficult drilling clogging and retreat drilling rod is the higher pressure in borehole clogging segment. The retreat drilling rod resistance is especially sensitive to the change of air supplying system; therefore, the effective method of reducing the retreat drilling rod resistance is reducing the air supplying system pressure in borehole. The drilling construction status in Jiulishan coal mine is analyzed by using the clogging segment mechanical model, and three technical measures are put forward, including increasing slagging space, reducing slagging resistance and increasing drilling rod strength. When the improving measures are adopted, the pipe-sticking phenomena decreases, the drilling rod broken phenomenon are averted and the drilling efficiency increases by 17%. 相似文献
20.
The study on automatic balance of the rotor was made both from theory and ap-plication.In the light of the feature of automatic balancing,new analysis about the mechanical modelof vibratory system was done,and the result is that the accurate model of system can be gained bycompensation method and the traditional principle errors of balance machine both for soft and hardbearing can be overcome.The autornatic balance testing theory was proposed.The automatic balancesystem has been developed a nd the fu n ction a nd techn ical key are also discussed in detail. 相似文献