Refining grain structure and porosity of an aluminium alloy with intensive melt shearing

The official published version of the article can be obtained at the link below.Intensive melt shearing was achieved using a twin-screw machine to condition an aluminium alloy prior to solidification. The results show that intensive melt shearing has a significant grain-refining effect. In addition, the intensive melt shearing reduces both the volume fraction and the size of porosity. It can reduce the density index from 10.50% to 2.87% and the average size of porosity in the samples solidified under partial vacuum from around 1 mm to 100 μm.Financial support was obtained from the EPSRC and the Technology Strategy Board

Resonant sequential scattering in two-frequency-pumping superradiance from a Bose-Einstein condensate

We study sequential scattering in superradiance from a Bose-Einstein condensate pumped by a two-frequency laser beam. We find that the distribution of atomic side modes presents highly different patterns for various frequency difference between the two pump components. A novel distribution is observed, with a frequency difference of eight times the recoil frequency. These observations reveal that the frequency overlap between the end-fire modes related to different side modes plays an essential role in the dynamics of sequential superradiant scattering. The numerical results from a semiclassical model qualitatively agree with our observations.Comment: Submitted to PR

An Implementation of List Successive Cancellation Decoder with Large List Size for Polar Codes

Polar codes are the first class of forward error correction (FEC) codes with a provably capacity-achieving capability. Using list successive cancellation decoding (LSCD) with a large list size, the error correction performance of polar codes exceeds other well-known FEC codes. However, the hardware complexity of LSCD rapidly increases with the list size, which incurs high usage of the resources on the field programmable gate array (FPGA) and significantly impedes the practical deployment of polar codes. To alleviate the high complexity, in this paper, two low-complexity decoding schemes and the corresponding architectures for LSCD targeting FPGA implementation are proposed. The architecture is implemented in an Altera Stratix V FPGA. Measurement results show that, even with a list size of 32, the architecture is able to decode a codeword of 4096-bit polar code within 150 us, achieving a throughput of 27MbpsComment: 4 pages, 4 figures, 4 tables, Published in 27th International Conference on Field Programmable Logic and Applications (FPL), 201

Angle observation of laser peripheral iridoplasty for the treatment of acute angle-closure glaucoma which could not be controlled by drugs

AIM: To evaluate the effect of laser peripheral iridoplasty(LPIP)to treat acute angle-closure glaucoma(AACG)which could not controlled by drugs and with persistent ocular hypertension. <p>METHODS: Totally 67 patients(69 eyes)with AACG were performed LPIP when intraocular pressure(IOP)was still over 30mmHg after the medicine therapy for 3-6 hours. Visual acuity and intraocular pressure were under detection before laser treatment and 30 minutes, 60 minutes and 2 hours after laser treatment. We measured the anterior chamber depth, width of angle, iris thickness with ultrasound biomicroscope(UBM). Dynamic gonioscopy was used to evaluate the degree of peripheral anterior synechia(PAS).<p>RESULTS: Angle open distance(AOD)after iridoplasty was increased(<i>P</i><0.01). Trabecular-iris angle(TIA)was widen(<i>P</i><0.01)and the extents of PAS were reduced in some cases. IOP reduced at different levels in different time after laser treatment. The mean IOP before acute attack was(53.81±10.22)mmHg. The mean IOP were(33.81±9.22)mmHg,(21.93±7.19)mmHg and(15.16±3.07)mmHg at 30 minutes, 60 minutes and 2 hours after laser treatment respectively(<i>F</i>=151.79, <i>P</i><0.01). Visual acuity increased in all patients. <p>CONCLUSION: LPIP can deepen peripheral anterior chamber, increase the angle access and lower the IOP immediately. It is an important ongoing adjuvant treatment, which can reduce the patients suffering by lowering the IOP quickly, reduce the damage of visual function caused by long-term high intraocular pressure, avoid side effect of the drugs, and can improve the prognosis

catena-Poly[[(dichloridozinc)-μ-4,4′-bis­(1H-imidazol-1-yl)biphenyl-κ2 N 3:N 3′] 0.25-hydrate]

In the title one-dimensional coordination polymer, {[ZnCl2(C18H14N4)]·0.25H2O}n, the ZnII atom is coordinated by two chloride ions and two 4,4′-bis­(1H-imidazol-1-yl)biphenyl ligands, generating a distorted tetra­hedral ZnCl2N2 geometry. The dihedral angle between the benzene rings of the ligand is 51.0 (1)° and the dihedral angles between the benzene rings and their attached imidazole rings are 18.7 (2) and 45.9 (1)°. The bridging ligand leads to [10-1] polymeric chains in the crystal and the disordered water mol­ecule (occupancy 0.25) forms O—H⋯Cl hydrogen bonds