三种类型化妆品灌装间卫生学调查

作者对广东省三种主要类型化妆品灌装间进行卫生学调查,结果表明,生产车间空气卫生质量与一般的卫生状况密切相关;紫外线消毒对生产车间空气细菌总数减少有明显效果;车间空气尘埃粒与细菌总数呈正相关。调查结果还说明,除了车间卫生状况外,通风和空气净化方式还在很大程度上影响室内空气卫生质量,通过三种类型车间的比较,其空气卫生质量高低依次为空气过滤型>空调机型>排气扇型。

空气净化间长期使用与间断性使用洁净度监测对比的观察

药品、生物制品、血液制品是用于临床，作为解除患者疾苦的一种必需品，制品质量的优劣直接关系到临床用药安全、可靠、有效，因此在生产过程中从生产环境、生产仪器设备、生产人员都要按照“GMP”(药品生产和质量管理规范)进行管理监督。

Effect of Particle＇s Size on the Structural and Dynamical Properties in 2D Dusty Plasma

In a two-dimensional （219） dusty plasma system, the size of particles is considered under two different interparticle potentials （Yukawa potential and Dressed potential）. The structural and dynamical characters are investigated by molecular dynamics simulation respectively. The results show that the 2D systems via Yukawa and Dressed potentials have a different critical coupling constant F corresponding to the systems beginning to coagulate and exhibit different crystal configurations. Also we find that the size of particles has little influence on the 2D system＇s structure characters.

Dust Acoustic Solitary Waves in Saturn F-ring's Region

Effect of hot and cold dust charge on the propagation of dust-acoustic waves （DAWs） in unmagnetized plasma having electrons, singly charged ions, hot and cold dust grains has been investigated. The reductive perturbation method is employed to reduce the basic set of fluid equations to the Kortewege-de Vries （KdV） equation. At the critical hot dusty plasma density Nho, the KdV equation is not appropriate for describing the system. Hence, a set of stretched coordinates is considered to derive the modified KdV equation. It is found that the presence of hot and cold dust charge grains not only significantly modifies the basic properties of solitary structure, but also changes the polarity of the solitary profiles. In the vicinity of the critical hot dusty plasma density Nho, neither KdV nor mKdV equation is appropriate for describing the DAWs. Therefore, a further modified KdV （fmKdV） equation is derived, which admits both soliton and double layer solutions.

我和一粒尘埃相见甚欢

露水中有一个稳坐的佛陀 泪水落下千万个完整的菩萨 膝盖里的庙宇 跪向慈悲 喧哗的蝉声包裹人世的安静 韭菜教我生死 蟾蜍教我念经

Effects of Adiabatic Dust Charge Fluctuation and Particles Collisions on Dust-Acoustic Solitary Waves in Three-Dimensional Magnetized Dusty Plasmas

Taking into account the combined effects of the external magnetic field, adiabatic dust charge fluctuation and collisions occurring between the charged dust grains and neutral gas particles （dust-neutral collisions）, the dust-acoustic solitary waves in three-dimensional uniform dusty plasmas are investigated analytically. By using the reductive perturbation method, the Korteweg-de Vries （KdV） equation governing the dnst-aconstic solitary waves is obtained. The present analytical results show that only rarefactive solitary waves exist in this system. It is also found that the effects of the wave vector along the z-direction, dust charge variation, collisional frequency, the plasma density, and temperature ratio can significantly influence the characteristics of low-frequency wave modes. Moreover, for the collisional dusty plasmas, there is a certain critical value μc of the plasma density ratio μ, if μ 〈 μc, the width of the waves increases with μ, otherwise the width of waves decreases with μ.

Effect of Polynomial Expressed Distribution Dust Particles for Unmagnetized Two-Ion-Temperature Dusty Plasma

Linear dispersion relation for linear wave and a Kadomtsev-Petviashvili (KP) equation for nonlinearwave are given for the unmagnetized two-ion-temperature cold dusty plasma with many different dust grain species.The numerical results of variations of linear dispersion with respect to the different dust size distribution are given.Moreover,how the amplitude,width,and propagation velocity of solitary wave vary vs different dust size distribution isalso studied numerically in this paper.

Effect of Sand and Dust Storms on Microwave Propagation Signals in Southern Libya

The propagation of electromagnetic waves in millimeter band is severely affected by rain, and dust particles in terms of attenuation and de-polarization. The computations of dust and/or sand storms require knowledge of electrical properties of the scattering particles and climate conditions at the studied region. To compute the effect of dust and sand particles on the propagation of electromagnetic waves, it is required to collect the sand particles carried out by the wind, measure the particles size, calculate the concentration, and carry chemical analysis of the contents, then the dielectric constant can be calculated. The main object of this paper is to study the effect of sand and dust storms on wireless communication, such as microwave links, in the southern region of Libya （Sebha, Ashati, Obari, Morzok, Ghat） by determining the attenuation. The result showed that there is some consideration that has to be taken into account in the communication power budget.

一粒尘埃飞扬的过程(外二首)

阳光下 我弹开的一节手指 沾着一滴乌声 搓开一粒种子 从内到外我始终看不到 一粒尘埃飞扬的过程 阳光与风安静无声

一粒尘埃,仰望星空

说到读书，其实我很惭愧，因为我的专业阅读起步很晚，从2005年踏上三尺讲台开始，从接触《教师博览》开始。那是学校每月发给我们的“福利”，在乡村每一个寂静的夜里，是《教师博览》陪我度过。在《教师博览》里我读到了很多老师的好文章，从而记住了他们的名字。

了不起的一粒尘埃

一粒尘埃在空中飘着，它总认为自己太没用太没用，很自卑。

Effect of an Arbitrary Dust Size Distribution Dust Particles for Vortex-Like Ion Distribution Dusty Plasma

In order to investigate the effect of an arbitrary dust size distribution for vortex-like ion distributiondusty plasma,we use a reasonable polynomial-expressed function to represent an arbitrary dust size distribution.Thenumerical results of linear dispersion relation,nonlinear solitary wave amplitude,width and velocity for polynomialexpressed dust size distribution dusty plasma with vortex-like ion distribution have been studied.

Sand dunes as potential sources of dust in northern China

While saltation bombardment of sand grains on a fine substrate can produce considerable dust, the well-sorted nature of sand dunes tends to preclude them from consideration as major dust sources. Recent research, however, has revealed that sand dunes can, in some cases, be large sources of dust. We used the PI-SWERL(Portable In-Situ Wind Erosion Laboratory) to measure in the field the potential of sand dunes and other desert landforms to emit particulate matter <10 μm(PM-10) dust in the Tengger, Ulan Buh, and Mu Us deserts of northern China. Combined with high resolution particle size measurements of the dune sand, an assessment of sand dunes as a dust source can be made. Large active transverse dunes tend to contain little to no stored PM-10, yet they produce a low dust flux. Coppice dunes stabilized by vegetation contain appreciable PM-10 and have very high dust emission potential. There is a positive correlation between the amount of PM-10 stored in a dune and its potential dust flux. Saltation liberates loose fines stored in dunes, making them very efficient dust emitters compared to landforms such as dry lake beds and washes where dust particles are unavailable for aeolian transport due to protective crusts or sediment cohesion. In cases where large dunes do not store PM-10 yet emit dust when active, two hypotheses can be considered:(1) iron-oxide grain coatings are removed during saltation, creating dust, and(2) sand grains collide during saltation, abrading grains to create dust. Observations reveal that iron oxide coatings are present on some dune sands. PI-SWERL data suggests that low dust fluxes from dunes containing no stored dust may represent an estimate for the amount of PM-10 dust produced by removal of iron oxide coatings. These results are similar to results from dunes in the United States. In addition, PI-SWERL results suggest that dust-bearing coppice dunes, which cover vast areas of China's sandy deserts, may become major sources of dust in the future if overgrazing, depletion of groundwater, or drought destabilizes the vegetation that now partially covers these dunes.

Dust levitation and transport over the surface of the Moon

Exposed to space plasma and solar radiation, electrostatic potential may build up in the lunar regolith, leading to a wealth of dust phenomena, including levitation, oscillation, and transport over the surface. Based on plasma sheath theory,the global near-surface plasma environment is modeled, and the dynamics of charged dust are investigated. Results show that sub-micron sized dust particles can be levitated by the electric field over the surface, forming a dust belt that changes in position and thickness depending on the solar zenith angle. On the dayside of the Moon, stably levitated particles are about ten times smaller, and collect in a thinner belt closer to the surface than do those on the nightside. Although the size and charge of stably levitated dust particles are dependent on ambient plasma conditions, initial charge and velocity, which are closely related to the dynamics of dust particles including charging, oscillation, and damping, will determine whether, or not, a particle can attain stable levitation. Horizontal electrostatic dust transport near to the terminator region may lead to net deposition of dust from the dark into the sunlit hemisphere. Finally, because of different charging processes that result due to rotation of the Moon, before precipitation,dust particles in the dusk terminator region may be transported much longer distances and oscillate to much higher altitude than these in the dawn terminator.

Shock Structures in Charge Variable Dusty Plasmas with Effect of Strongly Coupled Dust Particles

A theoretical investigation has been carried out to study the effect of strong electrostatic interaction on the dust acoustic shock structures in strongly coupled dusty plasma with dust charge fluctuations.The fluid approach is employed,in which the strong electrostatic interaction is modeled by effective electrostatic temperature.A Burger-like equation,the coefficients of which are significantly modified by effects of strong coupling and dust charge Ructuation,is derived.It is shown that the combined effects of dust charge Ructuation,the ion/electron temperature,the ion/electron population,and strong coupling effect modify the basic properties of the dust acoustic waves in such a strongly coupled dusty plasma.The results of this work are compared with those observed by some laboratory experiments.

Modified Potential Around a Moving Test Charge in Strongly Coupled Dusty Plasma

The theory of dynamical （wa＆e） potential behind a moving test charge in a weakly coupled dusty plasma is extended to that including of strong interaction between dust grains. Such strong interaction is included in the dielectric response function by a generalized hydrodynamic （GH） fluid model. It is shown that the strong interaction between dusts including the lattice spacing correction has a significant effect on the wake potential in dusty plasma. This may be used to investigate basic features of phase transition and possibility of lattice formation of dusty plasma.

Influence of Non-Maxwellian Particles on Dust Acoustic Waves in a Dusty Magnetized Plasma

In this paper an investigation into dust acoustic sofitary waves （DASWs） in the presence of superthermM electrons and ions in a magnetized plasma with cold dust gains and trapped electrons is discussed. The dynamic of both electrons and ions is simulated by the generalized Lorentzian （κ） distribution function （DF）. The dust grains are cold and their dynamics are studied by hydrodynamic equations. The basic set of fluid equations is reduced to modified Korteweg-de Vries （mKdV） equation using Reductive Perturbation Theory （RPT）. Two types of solitary waves, fast and slow dust acoustic soliton （DAS） exist in this plasma. Caiculations reveal that compressive solitary structures are possibly propagated in the plasma where dust grains are negatively （or positively） charged. The properties of DASs are also investigated numerically.

Spherical Kadomtsev-Petviashvili Solitons in a Suprathermal Complex Plasma

The nonlinear aspects of nonplanar dust acoustic (DA) solitary waves are investigated in an unmagnetized complex plasma comprising of cold dust grains,kappa-distributed ions as well as electrons.The nonplanar DA solitons are studied based on the reductive perturbation technique.It is shown that the evolution of DA solitons is governed by a spherical Kadomtsev-Petviashvili (sKP) equation and then the impact of suprathermality on the spatial structure as well as the nature of DA soliton is studied.It seems that the properties of DA solitons in nonplanar geometry are quite different from that of the planar solitons.