塞流式沼气池气动搅拌装置的研究

针对我国现存塞流式沼气池结构简单、产气效率低、无气动搅拌装置的问题,设计了一种强制回流沼气搅拌装置。该装置利用小功率电动风机,把沼气池内新鲜沼气重新打回到沼气池中。该装置已在山西阳泉牛家峪村沼气工程中投入使用。通过16次配对比较试验,结果表明:当搅拌装置每天搅拌10min时,沼气池产气效率可提高38%～100%。与国内现有的气动搅拌相比,本气动搅拌装置动力强、耐腐蚀、操作简单。

混合—塞流式小型高效沼气装置的研究

以粪便为原料的沼气发酵工艺可以归纳为两大类。第一类是经过产酸发酵之后,除去进料中的固形物,用 AF、UASB 等高效装置处理以可溶性有机物为主的液态原料,其产气率很高,但一般农户无法使用。第二类是原料不经固液分离直接入池产气。目前广泛采用的又分为塞流式和混合式。

全地下塞流式沼气集中供气站运行管理办法——以庄浪县野赵村为例

为加强沼气站运行管理,倡导农民使用清洁能源,本文以庄浪县野赵村的沼气集中供气工程为例,重点介绍了集中供气的管理办法,旨在提升农民生活质量,保障沼气集中供气工程顺利运行。

西北严寒地区全地下塞流式沼气工程技术改进优化研究

针对庄浪县通化镇野赵村全地下塞流式沼气工程在运行过程出现的问题和不足,对该县南湖镇石阳村全地下塞流式沼气工程在发酵池结构设计、发酵池内增温等工程技术方面进行了改进,达到了养殖企业粪污处理彻底、节能减排增效、环境保护及发展绿色循环农业的预期效果。通过运行和对比分析,效果显著。

多环芳烃生物恢复技术的研究进展

多环芳烃是一大类广泛存在于环境中的有机污染物。本文介绍了多环芳烃生物恢复的三种不同方法 :就地耕作法 ,场外耕作法和塞流式污泥生物反应器 ,并对其研究现状和最新研究成果进行了归纳。

Flow mixing model of liquid phase in an internal airlift loop reactor

Residence time distribution (RTD) analysis of liquid phase was conducted in an internal airlift loop reactor (AL) and a bubble column (BC) with the tracer response technique. These data were simulated and compared through several flow mixing models. The modeling results of two-parameter model indicated that there were higher ratio of full mixing zones and lower ratio of bypass flow in AL than in BC. Then a completely mixed-plug flow parallel combined (four-parameter) model was established. Modeling results show that it is more precise and more obvious than two-parameter model.

Computational Study of Performance Characteristics for Truncated Conical Aerospike Nozzles

Aerospike nozzles are advanced rocket nozzles that can maintain its aerodynamic efficiency over a wide range of altitudes. It belongs to class of altitude compensating nozzles. A vehicle with an aerospike nozzle uses less fuel at low altitudes due to its altitude adaptability, where most missions have the greatest need for thrust. Aerospike nozzles are better suited to Single Stage to Orbit （SSTO） missions compared to conventional nozzles. In the cur- rent study, the flow through 20% and 40% aerospike nozzle is analyzed in detail using computational fluid dy- namics technique. Steady state analysis with implicit formulation is carried out. Reynolds averaged Navier-Stokes equations are solved with the Spalart-AUmaras turbulence model. The results are compared with experimental results from previous work. The transition from open wake to closed wake happens in lower Nozzle Pressure Ratio for 20% as compared to 40% aerospike nozzle.

Leakage research on supercritical carbon dioxide fluid in rolling piston expander

The leakage research on supercritical carbon dioxide fluid in rolling piston expander was investigated experimentally.Using expander instead of throttle valve is an important way to improve the efficiency of carbon dioxide refrigeration system.However,the supercritical fluid leakage in expander is serious and is the main factor affecting the expander's efficiency.This paper presented and compared four classic leakage models.The analysis indicated that laminar leakage model is suitable in leakage simulation of expander.A leakage test system,including the leakage test part which has two types of leakage specimens with different gaps ranging from 5 to 15 m,was established.The experimental results indicated that lubricant film played an important role.When the leakage clearance of cylindrical specimen was 5 m,the mass flow rate of leakage was about 0.88 g s-1.The data was 3.638 g s-1 with leakage clearance being 10 m and 7.11g s-1 with leakage clearance being 15 m.A modified leakage model was developed,whose average deviation was within 10% compared with the experimental data.At last,this paper simulated the leakage in rolling piston expander presented by Tian et al.(2010).The leakage between rolling piston and cylinder was the most serious part with the value up to 0.04 kg s-1.

Inhibitive effect on apoptosis in splenic lymphocytes of mice pretreated with Lingzhi (GanodermaLucidum) spores

OBJECTIVE： To investigate how the pretreatment of mice with Ganoderma spores affected the apop- tosis of their splenic lymphocytes induced by dexa- methasone after 19 days treatment. METHODS： Sixty Kunming mice were randomly di- vided into six groups： blank control groupdrenched with normal saline; a drug control group drenched with 150 mg/mL Ganoderma spores; a model group treated with saline; a low dose group with S0 mg/mL Ganoderma spores; a moderate dose group with 100 mg/mL Ganoderma spores; and a high dose group with 150 mg/mL Ganoderma spores. The effect of Ganoderma spores on apoptosis in spleen lymphocytes was analyzed. All groups were treated for 19 days. On day 20, the model group and the 3 treatment groups were intraperitoneally injected dexamethasone to induce apoptosis. Splenic index and apoptosis indes were employed to measure cell apoptosis RESULTS： The results showed that Ganoderma spores reduced the splenic index to different de- grees in each group and the best effect was seen in the high dose group （P〈0.05）. Terminal dexynucleo- tidyl transferase （TdT）-mediated 2＇-Deoxyuridine 5＇-Triphosphate nick end labeling staining revealed that the apoptotic index in all groups administered Ganoderma spores differed significantly from the model group, and a dose-response was observed. Flow cytometric analysis indicated that spleen lym- phocyte apoptosis in the model group was exten- sive. Each dose of Ganoderma spores inhibited dexamethasone-induced apoptosis in spleen lym- phocytes, and a dose-response was observed as well. The highest dose of Ganoderma spores de- creased Malondialdehyde content in serum in- duced by dexamethasone （P〈0.05）. CONCLUSION： The findings imply that the pretreat- ment of the mice with Ganoderma spores could re- duce the apoptosis rate induced by dexametha- sone in their splenic lymphocytes.