DIFFUSION OF LONG CHAINS THROUGH A POROUS THIN GEL NETWORK

Using a core （142 nm） made of linear polystyrene （PS） chains as a seed, we further polymerized a thin layer of cross-linked PS shell （7 nm） on it in water to form a core-shell particle. Such a particle swells in toluene, which enables linear PS chains inside the core to gradually diffuse out through the porous shell. Using a combination of static and dynamic laser light scattering, we examined the chain diffusion process by following the change of the scattering intensity （i.e. the average molar mass of the particles）. For the first time, we have revealed that the diffusion exhibits three stages. In the first stage, the chain diffusion through the shell is even faster than their translational diffusion in a dilute solution. The three stages respectively correspond to the change of the solution in the core from concentrated to semidilute and then from semidilute to dilute.

Applications of MEMS devices in nanosatellite

micro-electro-mechanical system （MEMS） device has the advantages of both electronic system and mechanical system. With the development of MEMS devices for satellite, it is possible to establish much lighter and smaller nanosatellites with higher performance and longer lifecyele. The power consumption of MEMS devices is usually much lower than that of traditional devices, which will greatly reduce the consumption of power. For its small size and simple architecture, MEMS devices can be easily integrated together and achieve redundancy. Launched on April 18, 2004, NS - 1 is a nanosatellite for science exploration and MEMS devices test. A mass of science data and images were acquired during its running. NS - 1 weights less than 25 kg. It consists of several MEMS devices, including one miniature inertial measurement unit（MIMU） , three micro complementary metal oxide semiconductor （CMOS）cameras, one sun sensor, three momentum wheels, and one micro magnetic sensor. By applying micro components based on MEMS technology, NS - 1 has made success in the experiments of integrative design, manufacture, and MEMS devices integration. In this paper, some MEMS devices for nanosatellite and picosatellite are introduced, which have been tested on NS -1 nanosatellite or on the ground.

Search for a lighter neutral custodial fiveplet scalar in the Georgi-Machacek model

Many researches from both theoretical and experimental perspectives have been performed to search for a new Higgs Boson that is lighter than the 125 GeV Higgs boson,which was discovered at the LHC in 2012.In this study,we explore the possibility of constraining a lighter neutral custodial fiveplet scalar H_(5)^(0) in the GeorgiMachacek(GM) model using the latest results of the search for a lighter Higgs boson decaying into two photons from LHC data.The custodial-singlet mass eigenstate h or H is considered to be the LHC observed 125 GeV Higgs boson.A new set of constrained parameters that is favoured by low-mass H_(5)^(0) is proposed to generate events efficiently.The production of H_(5)^(0) from a scan based on the constrained parameters is compared to the latest results of the search for a lighter Higgs boson decaying into two photons by the CMS Collaboration after applying theoretical constraints from the GM model and constraints from all existing relevant experimental measurements,including the recent results of the Higgs boson searches by the LHC.Numerical analyses of the surviving GM parameter space are performed.The tendencies and correlations of the GM input parameters from phenomenological studies are summarized.In addition,the discovery potential of the other interesting decay channels of this low-mass neutral custodial fiveplet scalar are discussed.

Search for a lighter Higgs boson in the Next-to-Minimal Supersymmetric Standard Model

Following the discovery of the Higgs boson with a mass of approximately 125 GeV at the LHC, many studies have been performed from both the theoretical and experimental viewpoints to search for a new Higgs Boson that is lighter than 125 GeV. We explore the possibility of constraining a lighter neutral scalar Higgs boson hi and a lighter pseudo-scalar Higgs boson al in the Next-to-Minimal Supersymmetric Standard Model by restricting the next-to-lightest scalar Higgs boson h2 to be the one observed at the LHC after applying the phenomenological constraints and those from experimental measurements. Such lighter particles are not yet completely excluded by the latest results of the search for a lighter Higgs boson in the diphoton decay channel from LHC data. Our results show that some new constraints on the Next-to-Minimal Supersymmetric Standard Model could be obtained for a lighter scalar Higgs boson at the LHC if such a search is performed by experimental collaborations and more data. The potentials of discovery for other interesting decay channels of such a lighter neutral scalar or pseudo-scalar particle are also discussed.

Panel Says Lighter Cgarettes May Be No Safer

近年来一些烟草商推出所谓“安全柔和型香烟”,称这种新一代产品“焦油和尼古丁含量较低”,不会对身体带来危害,也不易成瘾。这种香烟因而在美国市场大行其道。本文告诉读者,这种所谓“安全柔和型”香烟同样可以导致心脏病和肺癌等各种疾病,而且由于烟草商的误导,吸烟者因此可能会加大使用量,从而给身体带来更大的危害。