一波三折 腾挪跌宕——关汉卿《救风尘》冲突艺术赏析

关汉卿无疑是元杂剧作家群星中最璀璨的一颗。当时戏曲界称他为“梨园领袖”,“杂剧班头”,享有极高的文学地位。其戏曲作品或揭露黑暗社会的各种丑恶现象,或抨击封建礼教对广大妇女的摧残,或歌颂英雄人物的高尚情操。其剧中的人物更是丰满逼真。

Informational digital diagrams applied to predict spring wind,snow,and sandstorms

Using informational digital diagrams, we analyzed the snow event that occurred on Feb 26, 2006 and the sandstorm on Apr 11, 2006 in Xi＇an. Results indicate that, under similar weather circumstances, different events evidently exhibit unique vertical structure features. Informational digital diagrams provide a method for transitional weather prediction, a problem for present extrapolative analysis system.

Assemblage characteristics of clay minerals and its implications to evolution of eolian dust input to the Parece Vela Basin since 1.95 Ma

To understand the provenance and evolution of eolian input in the last 1.95 Ma in the Parece Vela Basin in the eastern Philippine Sea, the clay mineral assemblage of a gravity core PV090510 from the basin was investigated using paleogeomagnetic dating and X-ray diffraction. The assemblage of the core mainly consisted of smectite （-46%） and illite （-40%）, with some chlorite （-10%） and kaolinite （-4%）. Analysis of the provenance of these minerals suggested that smectite was mainly derived from volcanic rocks of the Mariana Arc, while illite, chlorite, and kaolinite were mainly transported as eolian dust by the East Asian monsoon from central Asia. We used the ratio of （illite＋chlorite＋kaolinite）/smectite as a proxy for Asian eolian input to the Parece Vela Basin since 1.95 Ma. This ratio followed glacial and interglacial cycles and was consistent with the intensity of the East Asian monsoon and aridity of central Asia since 1.95 Ma. The changes of the ratio reflected three different stages of the East Asian monsoon and provenance climate.

Development of dust collection and removal technology of comprehensive mechanized excavation face

To solve the problem of excavation face dust control,the theory of dust removal after collection was put forward.Through a large number of theoretical and experimental researches,a new wind screen dust-collection system which was applied to comprehen- sive excavation face was developed.To set a wind dam in jet stream box,achieve the function of multi-stage and multiple-level regulation,lots of experimentation was carried out to obtain higher jet stream velocity with the minimum loss of energy.Experiments show that the slit width in the exports of wind screen dust-collection system should be 10 to 15 mm.For the general excavation roadway,after wind attenuation,the velocity can be greater than 3 m/s at the roof which meets the requirements of respirable dust control.

Aerosol Data Assimilation Using Data from Fengyun-3A and MODIS:Application to a Dust Storm over East Asia in 2011

Aerosol optical depth （AOD） is the most basic paxalneter that describes the optical properties of atmospheric aerosols, and it can be used to indicate aerosol content. In this study, we assimilated AOD data from the Fengyun-3A （FY-3A） and MODIS meteorological satellite using the Gridpoint Statistical Interpolation three-dimensional variational data assimilation system. Experiments were conducted for a dust storm over East Asia in April 2011. Each 0600 UTC analysis initialized a 24-h Weather Research and Forecasting with Chemistry model forecast. The results generally showed that the assimilation of satellite AOD observational data can significantly improve model aerosol mass prediction skills. The AOD distribution of the analysis field was closer to the observations of the satellite after assimilation of satellite AOD data. In addition, the analysis resulting from the experiment assimilating both FY-3A/MERSI （Medium-resolution Spectral Imager） AOD data and MODIS AOD data had closer agreement with the ground-based values than the individual assimilation of the two datasets for the dust storm over East Asia. These results suggest that the Chinese FY-3A satellite aerosol products can be effectively applied to numerical models and dust weather analysis.

Two Different Dust Storms in Northeast China:the Sources and Influences in East Asia

There are two different dust storms in Northeast China, normal dust and alkali dust, from Kerqin sand land and Songnen saline land. As well as visible damages of the dust storms, there are some invisible influences. The authors provide evidences that the bacteria carried by dusts from remote area should not be ignored, but the damages of the alkali dusts are still not clear.

Research on Mine Fan Speed Control System Based on the PLC control network

This paper designs a set of ventilation and dust removal in coal mine test device and PLC monitoring system. The ventilation and dust removal test device has a set of ventilation and dust removal functions, can automatically monitor air volume, air pressure, resistance and other performance parameters of ventilator and precipitator. The PLC monitoring system can remotely start and stop the variable frequency speed control on the ventilation machine and dust collector, and it can real-time monitor operation state, such as the running current and the parameters of ventilator and dust collector. The paper simulate and realize computer remote centralized monitoring of underground ventilation for mine ventilation system. The actual application shows that： the system is stable and reliable, simple operation, strong scalability.

Respiratory Risk Associated with Indoor Air Pollutants in the Form of Settled House Dust

Asthma and allergies are considered by many physicians as being triggered by different substances in the air that people breathe. The lung is the most common site of injury by airborne pollutants. Acute effects, however, may also include non-respiratory signs and symptoms, which may depend upon toxicological characteristics of the substances and host-related factors. The studying of indoor air quality can provide a method for appropriate remedial action. Research suggests that SHD （Settled House Dust） may be a significant source for indoor exposure to different substances. This research study consisted of sampling dust from homes in different area codes. The dust samples were collected from August 2006 thru March 2007 and analyzed using GC/MS （Gas Chromatography/Mass Spectrometry）. The purpose of this research study will display how sampling household dust is a powerful tool for identifying chemicals that contribute to poor indoor air quality.

Simulation study of blast fume diffusion characters of driving face

Based on FLUENT software, studied the blast fume diffusion characteristics of a driving face under 8 situations, and analyzed the influence to fume diffusion of different drift length and different ventilation pipe outlet positions. Through regression analysis, functions of ventilation time to the drift length and ventilation pipe outlet position was obtained.

Simulation on dissolute and dust dispersion in comprehensive mechanized heading face with forced-exhaust ventilation

According to the characteristics of comprehensive mechanized heading face, established the mathematical model of single-phase air flow with κ-ε two equations model, and have established κ-ε-θ-κp mathematic model to solve two-phase flow of gas and particles in dust space with eulerian-eulerian method and eulerian-lagrangian method. Numerical solution of gas-particle two-phase flow was put forward based on collocated grid SIMPLE algorithm. Moreover, numerical simulation of dust concentration in fully mechanized caving face was carded out by using Fluent software. Finally, when in forced-exhaust ventilation circumstance, drawer type fan drum have less dust absorption, and most of dust spread to the other site; the dust concentration is inversely proportional to the distance from tunneling head, and the dust concentration has already diffused to decrease below 102 mg/m3 at the position ofx=12 m. Dust are more focused on relative side（in the range about y from 0 to 2 meter） of roadway space of press-ventilated fan drum, especially between tunneling place and drawer type fan drum; the roadway with road header have a higher dust concentration. These conclusions provide reliable theory basis for the dust prevention in comprehensive mechanized heading face.

Influence of dust aerosols on eastern Pacific tropical cyclone intensity

The thermodynamic state of the tropical atmosphere plays an important role in the development of tropical cyclone(TC)intensity.This study reports new results that demonstrate a negative association between eastern Pacific TC intensity in offshore regions and dust aerosol optical depth(AOD)for the years 1980–2019.At the same time,a negative response of cloud water in the lower troposphere to dust AOD is reported by analyzing MERRA-2 reanalysis data and GCM simulations from CMIP6.This response can be explained by the dust semi-direct effect,in which dust aerosols absorb solar radiation,promoting the evaporation of clouds.In principle,this aerosol-driven vaporization modification could affect the enthalpy of the air surrounding a TC.Using potential intensity theory,the authors demonstrate that change in TC intensity related to dust AOD conditions is a consequence of the anomalous enthalpy of the air surrounding a TC caused by the dust semi-direct effect.

Review of Determination of Minimum Ignition Energy of Combustible Gases or Dusts

MIE is an important parameter to be used to rank the ignition risk of the combustible materials.Commonly used electric circuits for generating spark have been reviewed and their features are analyzed in detail.Attention to avoiding test errors is stressed.Ranking of ignition risk is suggested based on MIE data.

Research and application of inertia-gravity dedusting and noise reduction technology in mine airshaft outlet

Massive dust of exhausted airflow easily diffuses to the industrial square while hoisting shaft is used as return shaft in the retrograde ventilation,and certainly there is a problem of dust scattering and noise exceeding standard. In order to solve the problem,the coupled technology of dedusting and noise reduction in airshaft outlet was investigated and the device with the function of Dedusting and noise Reduction(DR) was originated. The device is named as DR diffuser,which comprehensively utilizes mechanisms of inertia-gravity dedusting and absorption-insulation sound. The DR diffuser has been applied to Xingdong Coal Mine,and the testing results show that:a. the resistance of DR diffuser is lower than 60 Pa;b. the noise level reaches to 49.2 dB(A);c. the dedusting efficiency of above 50 μm is higher than 85 %;d. dynamic pressure recovered from the outlet of main fan is larger than 50 Pa. The above measured data illustrates that comprehensive benefit of the DR diffuser is good,and the device is worth of applying to engineering site.

Urban Boundary-Layer Stability and Turbulent Exchange during Consecutive Episodes of Particle Air Pollution in Beijing,China

Based on measurements at the Beijing 325-m Meteorological Tower,this study reports an analysis of atmospheric stability conditions and turbulent exchange during consecutive episodes of particle air pollution in Beijing(China),primarily due to haze and dust events(15–30 April 2012).Of particular interest were relevant vertical variations within the lower urban boundary layer(UBL).First,the haze and dust events were characterized by different atmospheric conditions,as quite low wind speed and high humidity are typically observed during haze events.In addition,for the description of stability conditions,the bulk Richardson number(RiB) was calculated for three different height intervals: 8–47,47–140,and 140–280 m.The values of RiB indicated an apparent increase in the occurrence frequency of stably-stratified air layers in the upper height interval—for the 140–280-m height interval,positive values of RiB occurred for about 85% of the time.The downward turbulent exchange of sensible heat was observed at 280 m for the full diurnal cycle,which,by contrast,was rarely seen at 140 m during daytime.These results reinforce the importance of implementing high-resolution UBL profile observations and addressing issues related to stably-stratified flows.

Dust Diffusion Simulation in the Third Layer Construction of Underground Powerhouse

Under forced ventilation,the dust diffusion of underground powerhouse construction is investigated using a 3D high Reynolds number k-ε model.The interfacial momentum transfers and the wall roughness in the wall function are considered.Ventilation in the third layer of underground powerhouse of Xiangjiaba hydropower station is used as a case.The geometric structure has a decisive effect on the airflow distribution.It is concluded that the dust concentration decreases gradually with the increase of the ventilation time.However,iso-concentration curves have the same tendency after 1 800 s.The dust concentration meets the ventilation and dust-prevention health standard after 2 300 s.The prediction by the present model is confirmed by the experimental measurement by Nakayama.

Effect of floor level slit exhaust ventilation system on distribution of house dust

Based on the fact that the house dust usually falls on the ground, the floor level slit exhaust ventilation system including inlet located at the ceiling and outlet of slit exhaust installed at comer between wall and floor was considered. Experiments and simulations were performed to investigate the flow and diffusion fields that are affected by this floor level slit exhaust ventilation system. The characteristics of airflow with experiments and computation fluid dynamics （CFD） are generally similar except airflow at the location of impinging flow and the location right below the inlet. Riboflavin particles were used as the house dust. For the spatial distribution of riboflavin particles in the ventilation system before operation, due to the influence of gravity, different sizes of particles show smooth decay curve. After floor level slit exhaust ventilation system is operated, the decay rate of the particles becomes faster than that after the ventilation system is powered on, and the particles with diameter of 0.5-3.0 μm in the experimental data and calculated values show good agreement.

The effect of exposure of iron and its oxide dust to the body

Iron overload is closely related to many diseases. Iron overload is a risk factor that triggers a series of health problems. The toxicity of iron is that iron can catalyze the formation of oxygen free radicals and can be used as a nutrient necessary for the growth of microorganisms and tumor cells. The sensitivity of human cells to iron toxicity varies widely. Causes of iron overload include genetic factors, behavioral factors and environmental factors. With the rapid development of modem industry, iron and its compound dust distribution industry and the increasingly widespread, in the iron pigment production, mechanical casting, iron ore mining and iron smelting operations will produce a lot of iron and its compound dust, Its impact on the human body has been of concern. Long-term exposure to iron and its compounds can cause different degrees of damage to the respiratory system, resulting in iron in vivo disorder. The relationship between iron metabolism and lung injury has also begun to be concerned, and maintaining iron homeostasis is important for lung injury and its protection.

风尘之上

他浅浅地笑说至少他的命运在他手上我说我的命运不在我的手上,在风尘之上好像是子夜了,我没有睡着,隐约听见大堂深处飘来的钢琴声。我在电梯里有些发晕,电梯门一开,我就看见他又坐在那儿了。