【正文】 te class covers a vast range of particle sizes, from dust large enough to be visible to the eye to submicroscopic particles that elude most filters. Particles may be liquid, solid, or have a solid core surrounded by liquid. They are present in the atmosphere at concentrations ranging from 100 particles/cm3 in the cleanest environments to millions per cubic centimeter in polluted urban environments. 顆粒類，涵蓋了從粉塵顆粒大小廣闊的范圍，足夠大的眼睛躲避大多數(shù)過濾器的微觀粒子，可見。Air contaminants are generally either particles or gases. The distinction between particles and gases is important when determining removal strategies and equipment. Although the motion of particles is described using the same equations used to describe gas movement, even the smallest of particles (approximately 1 nm) are much larger than individual gas molecules, have a much greater mass, and a much lower diffusion rate. 空氣污染物一般是顆?；驓怏w。這個(gè)定義葉開放的心態(tài)或滿意的狀況是什么意思，但它正確地強(qiáng)調(diào)，舒適的判斷是一個(gè)認(rèn)知的過程，涉及物理，生理，心理，和其他進(jìn)程影響了許多投入。Thermodynamic wetbulb temperature t* is the temperature at which water (liquid or solid), by evaporating into moist air at a given drybulb temperature t and humidity ratio W, can bring air to saturation adiabatically at the same temperature t* while the total pressure p is maintained constant. This parameter is considered separately in the section on Thermodynamic WetBulb and DewPoint Temperature.熱力學(xué)濕球溫度T *是在水（液體或固體），潮濕的空氣中蒸發(fā)，在一個(gè)給定的干球溫度t和濕度比W的溫度，可以使空氣飽和絕熱在同一溫度T*而總壓力p保持不變。Basic Parametersn Humidity ratio W (alternatively, the moisture content or mixing ratio) of a given moist air sample is defined as the ratio of the mass of water vapor to the mass of dry air in the sample: W = Mw/Mda (7) The humidity ratio W is equal to the mole fraction ratio xw/xda multiplied by the ratio of molecular masses: W = 98 xw /xda (8)n Specific humidity γ is the ratio of the mass of water vapor to total mass of the moist air sample: γ = Mw/(Mw + Mda) (9a)基本參數(shù)濕度比W（另外，水分含量或比例混合），一個(gè)給定的潮濕空氣樣品是干燥的空氣質(zhì)量比樣品中的水蒸汽的質(zhì)量定義為：W = MW/ MDA（7）濕度比W是相等的摩爾分?jǐn)?shù)比XW/ XDA分子群眾的比例乘以：公式（1）在x方向的熱流率q是成正比的溫度梯度DT/ DX和橫截面積一個(gè)正常的熱流。Equation 1 states that the heat flow rate q in the x direction is directly proportional to the temperature gradient dt/dx and the crosssectional area A normal to the heat flow. The proportionality factor is the thermal conductivity k. The minus sign indicates that heat flow is positive the direction of decreasing temperature. Conductivity values are sometimes given in other units，but consistent units must be used in Equation 1 . Equation 1 states that the heat flow rate q in the x direction is directly proportional to the temperature gradient dt/dx and the crosssectional area A normal to the heat flow. The proportionality factor is the thermal conductivity k. The minus sign indicates that heat flow is positive the direction of decreasing temperature. Conductivity values are sometimes given in other units，but consistent units must be used in Equation 1 . 公式（1）在x方向的熱流率q是成正比的溫度梯度DT/ DX和橫截面積一個(gè)正常的熱流。When fluid currents are produced by external sources (for example, a blower or pump), the solidtofluid heat transfer is termed forced convection. If the fluid flow is generated internally by nonhomogeneous densities caused by temperature variation, the heat transfer is termed natural convection or free convection.When fluid currents are produced by external sources (for example, a blower or pump), the solidtofluid heat transfer is termed forced convection. If the fluid flow is generated internally by nonhomogeneous densities caused by temperature variation, the heat transfer is termed natural convection or free convection.當(dāng)流體的電流是由外部來源（例如，一個(gè)鼓風(fēng)機(jī)或泵），固 液傳熱被稱為強(qiáng)迫對(duì)流。電導(dǎo)電液體和固體，它被認(rèn)為是造成晶格結(jié)構(gòu)的縱向振蕩。傳熱之間的能源運(yùn)輸?shù)默F(xiàn)象，其中包括傳質(zhì)，動(dòng)量傳遞或流體摩擦和導(dǎo)電。在暖通空調(diào)行業(yè)（如，水，空氣，大部分制冷劑）牛頓流體可以作為治療。Vi