肉桂挥发油的提取与应用研究

以肉桂为材料,采用水蒸气蒸馏法提取肉桂挥发油,并对其挥发油的主要应用进行研究,分别考察了蒸馏时间和加水量两种因素对挥发油提取率的影响。并通过实验证明肉桂挥发油对大肠杆菌具有抑菌作用。     

Promotion of the seed germination and seedling growth of cabbage by root-colonizing fungi isolated from oat and Eucalyptus roots

(Jpn. J. Soil Sci.Plant Nutr., 77, 257–263, 2006)
The symptom of blighted leaves was observed for the melon plants grown on an isolated soil bed after steam sterilization (SS) in a greenhouse in Kochi Prefecture, Japan. To clarify the causes of this symptom, soil and plant analyses were conducted in the first experiment. Manganese concentrations in the leaves with the symptom were higher than 1,000 mg kg−1and exchangeable Mn in the soil was higher than 30 mg kg−1, which indicated the observed symptom was due to Mn excess. In the second experiment, formation of Mn oxide-dissolving substances after SS was examined for several organic amendments, because large amounts of palm chips had been supplied to the soil before SS in the first experiment. As a treatment similar to SS, palm chips, bark compost, and cattle feces manure were autoclaved. The water extracts were collected before and after the autoclave treatment and the Mn oxide-dissolving capacities of the extracts were evaluated. The Mn oxide-dissolving capacity of the water extracts after SS was remarkably higher than before SS, and the value was highest in palm chips, and followed by bark compost, and cattle feces manure. Fractionation and HPLC analysis of the water extracts after SS revealed that the main substance behind Mn oxide reduction in palm tips was arabinose and that in bark manure was malic acid. Further, Mn oxide-dissolving capacities of the water extracts were almost completely explained by the amounts of arabinose or malic acid found in these materials. From these results, it was considered that reducing substances such as arabinose were released by SS from the palm chips which had been applied in large quantity before SS and these reducing substances dissolved the soil Mn oxides and increased the amounts of available Mn, which led to the occurrence of Mn toxicity to the plants.     

具有节能作用的疏水器

简要阐述了疏水器的节能作用、种类及性能,并介绍了如何选择和维护管理疏水器。     

Soil Disinfestation with Steam: A Review of Economics,Engineering, and Soil Pest Control in California Strawberry

ABSTRACT

Increasingly stricter fumigant regulations will limit their use and require effective non-fumigant treatments if large-scale strawberry production is to continue in California. Steam has long been used for soil disinfestation in greenhouse soils where it controls most soil pests. The challenge of field-scale soil disinfestation with steam in place of fumigants is availability of machinery capable of treating a large acreage in a timely manner while making the most efficient use of fuel and water. Steam can be a component within an integrated set of fumigant and non-fumigant practices. Steam used together with other practices may permit technically and economically sustainable strawberry production into the future by allowing growers to adapt to more stringent fumigant use restrictions. It may be possible to overcome some of the limitations of steam because steam generator technology has advanced in recent years as well as recent developments in co-applications with steam, including exothermic compounds co-applied with steam and mustard seed meal co-applied with steam. Regarding steam generator technology, direct-fire steam generators are more energy efficient than traditional steam boilers and avoid the hazards of steam pressure vessels. Steam is arguably the most effective non-fumigant method of soil disinfestation and it likely has a role in a future California strawberry production system that is forced to use much less fumigant than it does at present.     

基于液气射流的负压蒸汽加热系统设计与试验

针对当前100℃以下的低温加热工艺在农业、化工、食品加工业中存在加热效率低、温度难以精确维持、自动化程度低、设备成本高等问题,集成射流泵抽空技术、PLC控制技术、控温调压技术,设计开发一种基于液气射流的负压蒸汽加热系统。该系统由智能控制系统、液气射流真空循环系统、降温调压系统和循环水调节系统组成,通过液气射流泵抽空提供蒸汽负压环境,结合减温减压装置和PLC智能控制系统对负压蒸汽进行控制,实现负压蒸汽对物料的精准自动化加热。详细阐述负压蒸汽加热系统的工作原理,确定关键部件射流泵设计结构和相关参数,并对其进行流体数值模拟的相关验证,模拟结果与实际误差在10%以内,表明射流泵设计合理可靠性高。对系统的加热性能进行试验,结果表明：基于液气射流的负压蒸汽加热系统可以精确控制蒸汽温度进行加热,同时加热温度曲线平缓,快速升温阶段真空度上下浮动0.003 MPa,平衡阶段真空度上下浮动0.002 MPa,加热温度浮动也在±1℃,更好地适应不同物料的加热温度,在加热效率方面优于水浴加热约2倍。该研究可解决传统水浴加热显热加热不均匀、控制精度差、加热过程缓慢、生产能力较低等问题,为农产品、化工产品深加工的...     

蒸汽预处理玉米秸秆酶水解速率下降的因素分析

为评价导致纤维素酶水解速率下降的因素,以底物质量浓度为50 g/L葡聚糖及酶用量为20 FPIU/g滤纸酶活和10 IU/g β-葡萄糖苷酶活的蒸汽预处理玉米秸秆酶水解为研究对象,探讨了影响酶水解速率的潜在因素,包括物料反应性能、纤维素酶非特异性吸附、酶失活及终产物抑制。结果表明：酶用量40 FPIU/g条件下酶水解6 h及12 h后,蒸汽预处理玉米秸秆的物料反应性能分别下降了16.0%及23.7%,然而,在酶用量为20 FPIU/g时,物料反应性能的下降对酶水解速率的影响极其有限;酶解木质素的添加使得1 h酶解上清液中酶蛋白浓度降低了20.8%,但初始酶水解速率并未显著降低,即木质素对纤维素酶的非特异性吸附对酶水解速率影响不大;两段酶水解中纤维素酶的更新使得7h酶水解速率由一段酶水解中的1.30 g/(L·h)提高至1.83 g/(L·h);两段酶水解中终产物的去除则使得7 h酶水解速率提高至4.76 g/(L·h),是一段酶水解中7 h酶水解速率的3.66倍。综合而言,酶失活及终产物抑制对酶水解速率影响较大,其中终产物抑制是导致蒸汽预处理玉米秸秆酶水解速率降低的关键因素。     

关于厨房排烟排汽问题的探讨

本文论述的关于厨房排烟、排汽问题是个常见的问题。但作者借鉴国外的作法在常规的问题上提出了自己的解决方法,按我国的现有的条件、设备结合实际情况,进行了较为细致的分析。     

利用蒸汽烘干塔干燥大豆的探讨：兼谈大豆干燥的最佳温度

采用蒸汽式烘干塔干燥高水分大豆。大豆出五塔时温度控制在３８℃至５０℃（最佳温度４５℃左右）,经适当冷却,可使蛋白质、含油量和出油率与烘干前基本相同。爆裂率控制在４％以内。     

蒸汽爆破法预处理木质纤维原料的研究

木质生物资源可以用来生产乙醇,但其结构与化学成分阻碍了纤维素对酶的可及性,因此必须对原料进行预处理,从而有效地酶解纤维素。蒸汽爆破法预处理木质生物资源。可有效去除半纤维素。分离出活性纤维。并且成本低,不用或少用化学药品。对环境无污染。