Experimental investigation on micro-dynamic behavior of gas explosion suppression with SiO_2 fine powders

To study the effect of inert dust on gas explosion suppression mechanism,SiO_2 fine powders were sprayed to suppress premixed CH_4-Air gas explosion in a 20 L spherical experimental system.In the experiment,high speed schlieren image system was adopted to record explosion flame propagation behaviors,meanwhile,pressure transducers and ion current probes were used to clearly record the explosion flame dynamic characteristics.The experimental results show that the SiO_2 fine powders suppressed evidently the gas explosion flame,and reduced the peak value of pressure and flame speed by more than 40%.The ion current result shows that the SiO_2 super fine powders were easy to contact with and absorb free radicals near the combustion reaction region,which greatly reduced the combustion reaction intensity,and in turn influenced the flame propagation and pressure rising.

Performance assessment of water mist applied in gas burning suppression in underground coal mine

The main objective of the present study was introduced water mist suppressiontechnology to prevent and control gas burning which occurred during drilling at Wu20160working-face in No.10 coal mine of Pingdingshan Ltd..Based on the self-developed ex-periment platform,a series of fire suppression tests to evaluate the performance of a watermist system were conducted.The detailed measurements of the spray characteristics,i.e.,the Sauter Mean Diameter(SMD),the velocity and spray angle which are the main pa-rameters considered in the Study,were obtained by using LS-2000 Sizer.The amount ofwater consumed and the water flux density distribution over the cross section downstreamthe nozzle exit were measured by cup collector method.The operating pressure of thewater mist nozzle is set to 0.5 MPa,the droplet SMD of 104 pm,the water flux density dis-tribution from 0.71 to 8.47 L/(m^2.min),the average velocity of 2.14 m/s.The experimentalresults show that the averaged time required for extinguishment is 3.14 s,and the corre-sponding amount of water used during fire test is about 0.11 kg.The gas fire suppressionsystem reduces the temperature in combustion chamber of the experimental apparatusbelow the ignition point of the gas,which can effectively avoid the occurrence of the gasfire in coal mine.

Experimental study on gas explosion suppression based on ferrocene

In order to study the gas explosion suppression performance based on ferrocene, the self-constructed experimental facility was used to accomplish the experiment of gas explosion suppression. By means of thermogravimetric analysis, the thermal characteristics of ferrocene have been gotten and the gas explosion suppression mechanism of ferrocene has been analyzed. The results show that ferrocene had good effects on gas explosion suppression, and the explosion pressure and flame propagation speed declined obviously. When ferrocene concentration is 0.08 g/L and methane volume concentration is 9.5%, the maximum explosion overpressure and maximum flame propagation speed of methane-air respectively decreased by about 59.5% and 19.6%, respectively. TG and DSC curves showed that the mass loss of ferrocene consists of two processes, which are sublimation and lattice fracture. The temperature of mass loss ranged from 128 ℃ to 230 ℃. The results showed profoundly theoretical significance to gas explosion suppression by ferrocene in coal mines.

Effects of Heat Clearing and Stasis Resolving Method on PTS,Inflammatory Factors and T-lymphocyte Subsets in Peripheral Blood of URM Patients with Suppressed Internal Heat

[Objectives]To explore the effects of heat clearing and stasis resolving method on prethrombotic state,inflammatory factors and T-lymphocyte subsets in peripheral blood of unexplained recurrent miscarriage(URM)patients with suppressed internal heat.[Methods]Thirty cases of URM patients with suppressed internal heat and 30 normal women were collected,and characteristics of changes in peripheral serum D-dimer(D-D),fibrin degradation product(FDP),fibrinogen(FIB),IL-6,IL-10 and TNF-α,CD,CD,CD,CD,CDlevels were detected.URM patients were treated with traditional Chinese medicine for clearing heat and resolving blood stasis for 3 menstrual cycles,and the changes of indicators before and after treatment were observed.[Results]Compared with normal women,the peripheral serum levels of D-D,IL-6,TNF-αand CDin URM patients with suppressed internal heat were increased(P<0.05),while the IL-10 lymphocyte level was significantly decreased(P<0.05);compared with that before treatment,the contents of D-D,IL-6,TNF-αand CDdecreased after 3 menstrual cycles(P<0.05),while the contents of IL-10 and CDT lymphocytes increased significantly(P<0.05).[Conclusions]The heat clearing heat and stasis resolving method can effectively improve the prethrombotic state of URM,and the action mechanism may be related to the regulation of immune and peripheral blood inflammatory factors.

Acoustic Resonance in Exhaust Gas Economizer Tube Bundles Prediction and Suppression of Resonance

The tendency for air column resonance generation in structures with a constant volume behind a tube array like that of an exhaust gas economizer has been reported, but many points remain unclear with respect to the mechanism and conditions that generate acoustical resonance. When acoustical resonance is generated, in reality, prevention and suppression measures are implemented by inserting a baffle plate into the ducts through a process of trial and error. The purpose of this study is to clarify the mechanism of generation of acoustical resonance, and to establish an appropriate measure to prevent such resonance. Noise generated in an exhaust gas economizer was correlated with the flow inside the tube array and experimentally analyzed, and the mechanism for resonance generation was considered. In addition, the effectiveness of a baffle plate positioned in order to prevent resonance was investigated. We have successfully employed a single baffle plate to suppress resonance.

Combined effects of obstacle and fine water mist on gas explosion characteristics

Combined effects of obstacles and fine water mist on a methane-air explosion of a semi-closed pipe were investigated experimentally.In this study,the diameter of the water mist,the location,and the number of obstacles was considered.The results demonstrated that 5 μm water mist present a significant suppression affected while 45 μm shows a slight promotion effected on a gas explosion of the condition without obstacles.In the presence of an obstacle,however,the inhibitory effect of 5 μm water veils of mist dropped significantly during flame propagation,and the effect of 45 μm water veils of mist changed from the enhancement of inhibition,and its inhibitory effect was significant.The inhibitory effect of 45 μm water veils of mist on gas explosion weakened firstly and then enhanced with the increasing distance between obstacle location from the ignition location as well as in several obstacles.

Comparative experimental study on inhibiting gas explosion using ABC dry powder and diatomite powder

Using a 20 L spherical explosion suppressing test system, the largest gas explosion pressure and maximum pressure rising rate with additives of ultra-fine ABC dry powder and diatomite powder were tested and compared, and the explosion suppression effect of the two kinds of powder was analyzed. Experimental results show that both powders can suppress gas ex- plosion and ABC dry powder is superior to diatomite powder. Adding two powders under the same experimental conditions, when methane concentration is 7.0%, the maximum explosion pressure decreased 39% and 4%, respectively, while the rising rate of the maximum pressure decreased 80% and 53%, respectively. When methane concentration is 9.5%, the maximum ex- plosion pressure decreased 14% and 12%, respectively, the rising rate of maximum pressure decreased 62% and 27%, respec- tively, the maximum explosion pressure decreased 23% and 18%, respectively, while the rising rate of the maximum pressure decreased 77% and 70%, respectively. When methane concentration is 12.0%, the explosion suppression effect of ultra-fine ABC dry powder is not affected by the methane concentration, and the explosion suppression effect of diatomite powder under high methane concentrations is more obvious.

Hard Photons from a Non-Equilibrated Quark-Gluon Plasma with Finite Baryon Density at a Two-Loop Level

We study hard photon production from a two-loop level （bremsstrahlung and annihilation with scattering） in a chemically equilibrating quark-gluon plasma at finite baryon density based on Jüttner distribution of partons of the system. We find that the photon yield from the two-loop level increases obviously with the increasing initial quark chemical potential.

Active protection of work area against explosion of dust-gas mixture

Potentially explosive atmosphere can occur not only in the production systems of the food,energy,chemical and petrochemical industries but also in the production processes of the mining industry.Gases,vapours,mists and dusts arise can escape in an uncontrolled way during production,processing,transportation and storage of flammable substances.In combination with oxygen,they create explosive atmospheres that,if ignited,lead to an explosion causing catastrophic damage to peopled lives and property.To protect against the results of hazardous dust-gas mixtures explosions in a confined work space,where employees can stay,various control and protection mechanisms are used in the form of an active explosion-proof system.The article presents the results of tests on an active system for limiting the effects of ignition of gas and/or dust based on a highly efficient explosion suppression system-equipped with an ignition detection system,high-pressure fire extinguisher and a power supply and trigger system.Smokeless powder was used as the explosive charge and sodium bicarbonate as the suppressive material.Tests of the effectiveness of the active explosion suppression system were carried out on two devices:a small-size dry dust collector and a zone extinguishing system adapted for direct explosion suppression in closed working spaces.In both cases,the explosion suppression process took place through the action of extinguishing powder blown out of the fire extinguisher after membrane perforation by compressed combustion products.

从肝胃论治肉芽肿性乳腺炎伴抑郁焦虑状态

肉芽肿性乳腺炎(GLM)是临床常见乳腺疾病之一,GLM患者常合并抑郁焦虑状态,身心同病。从中医角度分析,GLM伴抑郁焦虑状态与肝、胃关系密切,且以肝气郁结、胃热壅盛为基本病机。在治疗上,当以泄肝清胃、抑木扶土为基本治法,辅以心理疏导、饮食疗法。系统论述从肝胃论治GLM伴抑郁焦虑状态,并附医案一则,以供临证参考。

黄力教授益气活血、平肝潜阳、清热解毒法治疗高血压的临床经验总结

高血压是临床常见心血管疾病,发病率较高,严重威胁人类健康。中医学将高血压归为“眩晕”“头痛”等范畴,病位主要在肝、肾,并与心、脾相关,病理因素包括风、火、痰、瘀、虚。黄力教授临证经验丰富,善于治疗心血管疾病,认为高血压病机为本虚标实,其中本虚为气虚,甚者阳虚,标实为痰湿、痰瘀、痰火、热毒,治疗应以益气活血、清热解毒为原则。该文总结整理了高血压病因病机和黄力教授治疗高血压的临证经验,以期为临床治疗高血压提供参考。

A new design of foam spray nozzle used for precise dust control in underground coal mines

In order to improve the utilization rate of foam,an arc jet nozzle was designed for precise dust control.Through theoretical analysis,the different demands of foam were compared amongst arc jets,flat jets and full cone jets when the dust source was covered identically by foam.It is proved that foam consumption was least when an arc jet was used.Foam production capability of an arc jet nozzle under different conditions was investigated through experiments.The results show that with the gas liquid ratio(GLR)increasing,the spray state of an arc jet nozzle presents successively water jet,foam jet and mist.Under a reasonable working condition range of foam production and a fixed GLR,foam production quantity increases at first,and then decreases with the increase of liquid supply quantity.When the inner diameter of the nozzle is 14 mm,the best GLR is 30 and the optimum liquid supply quantity is0.375 m^3/h.The results of field experiments show that the total dust and respirable dust suppression efficiency of arc jet nozzles is 85.8%and 82.6%respectively,which are 1.39 and 1.37 times higher than the full cone nozzles and 1.20 and 1.19 times higher than the fiat nozzles.

Bi-Level Bidding and Multi-Energy Retail Packages for Integrated Energy Service Providers Considering Multi-Energy Demand Elasticity

How to effectively use the multi-energy demand elasticity of users to bid in the multi-energy market and formulate multi-energy retail packages is an urgent problem which needs to be solved by integrated energy service providers(IESPs)to attract more users and reduce operating costs.This paper presents a unified clearing of electricity and natural gas based on a bi-level bidding and multi-energy retail price formulation method for IESPs considering multi-energy demand elasticity.First,we propose an operating structure of IESPs in the wholesale and retail energy markets.The multi-energy demand elasticity model of retail-side users and a retail price model for electricity,gas,heat and cooling are established.Secondly,a bi-level bidding model for IESPs considering multi-energy demand elasticity is established to provide IESPs with wholesale-side bidding decisions and retail-side energy retail price decisions.Finally,an example is given to verify the proposed method.The results show that the method improves the total social welfare of the electricity and natural gas markets by 7.99%and the profit of IESPs by 1.40%.It can reduce the variance of the electricity,gas,and cooling load curves,especially the reduction of the variance of the electricity load curve can which reach 79.90%.It can be seen that the research in this paper has a positive effect on repairing the limitations of integrated energy trading research and improving the economics of the operation of IESPs.

人工影响天气工程系统

文章介绍了人工影响天气 (人工增雨、防雹、消雾等 )的基本科学原理、国内外的发展历史、现状、科技水平、效益以及国内的需求、组织、规模等概况。描述了我国典型的人工影响天气工程系统及其各组成部分 ,即天气云况监测预测、催化技术、数值模拟、通信指挥和效果评估等分系统。强调了科研支持系统的重要性 ,提出了当前有关应用基础和技术开发的主要研究课题 。

清热五号合剂抗流感病毒作用的研究

目的 探讨中药“清热五号合剂”抑制流感病毒的效果。方法 用MDCK(狗肾细胞)组织培养技术和血凝试验方法。结果 清热五号合剂抑制流感病毒的最低浓度为5mg/ml。结论 清热五号合剂有明显的抑制流感病毒致细胞病变作用,通过血凝试验也证实了该药可以阻断流感病毒在细胞内复制。

建瓴汤治疗高血压脑出血术后

高血压脑出血术后,常出现难以控制的高血压症状,处理好术后高血压危象是围手术期中最重要的一环。高血压脑出血术后病标在脑、心、胃、肺、肾,病本在肝胆,其性为风火,乃风火相煽,挟气血上犯冲脑而致。治当清火平肝,引血下行,方选张锡纯清火、平肝、引血下行之建瓴汤(方药:怀牛膝、生白芍、山药、生赭石、生龙骨、生牡蛎、生地黄、柏子仁等)随症加减。

《血证论》甘淡滋脾法在贫血治疗中的应用

《血证论》重脾阴的思想以血病津伤累气为理论基础,应用甘淡养阴滋脾益气为治疗大法,固护脏腑津液,并结合清心宁血、心脾兼治、培土疏木、抑火生血、宁血止血的治疗法则,达到滋阴生血益气的治疗效果。《血证论》甘淡滋脾治疗贫血的理论,摆脱了现代医学对中医思路的限制,以中医传统阴阳气血水火理论为基础,顾及到血虚患者津伤病气,同时容易发生火性炎上、肝郁不疏、心血不宁的病理表现。为中医治疗贫血提供有益的治疗思路。

王净净教授治疗小儿抽动障碍的经验

国家级名中医王净净认为小儿体质为“阳常有余,阴常不足”,抽动障碍(tic disorders,TD)本质为阴不制阳,基本病机为阴虚阳亢,与肝肾关系最为密切,外风引动为发病关键,常兼脾虚痰聚;治疗当以滋阴息风为大法贯穿始终,并遵循“风火虚并治”,平肝息风,清肝泻火,滋阴潜阳;并应适当兼顾脾胃,而勿使疾病传变。临床多用滋阴养血、平肝潜阳、息风止痉、疏风解表类药物,所创TD基本方——抽动方,全方宗滋阴、潜阳、祛风为一体,并佐以少量调和脾胃药物,根据不同证型及兼证加减用药,临床具有较好的治疗效果。

Metal Particle Contamination in Gas-insulated Switchgears/Gas-insulated Transmission Lines

Metal particle contamination in a gas-insulated switchgear(GIS)or a gas-insulated transmission line(GIL)is an important factor leading to the decline of insulation performance.Exploring the deterioration mechanism and suppression measures of metal particles on insulation is a key technical problem in enhancing the dielectric strength of GIS/GIL equipment.In this paper,the charge and motion characteristics of metal particles are first introduced.The gas gap breakdown caused by free metal particles and the surface flashover caused by metal particles near or adsorbed on the insulator are then analyzed according to different particle motion patterns and spatial locations.Subsequently in terms of operation managements,the existing methods of particle detection are analyzed.In addition,the main inhibition methods of metal particles are introduced from three aspects:particle trap,insulator surface treatment and electrode coating.Finally,the prospects in the future research on particle pollution in GIS/GIL are also pointed out.

鲁伯嗣治疗小儿急惊风四法

总结鲁伯嗣治疗小儿急惊风平肝、清心、健脾、滋肾四法:急则治标,截风定搐,治之在肝;清热安神,定惊止抽,治之在心;豁痰除涎,祛邪止惊,治之在脾;滋补真阴,固本止抽,治之在肾。