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The multiphase fluid mixing and bubble motion in a scale-down Isa smelting furnace with a top submerged lance were investigated through cold water model experiments. The mixing time in the liquid bath was determined by a novel criterion, and the bubble formation frequency and gas-liquid contact area were also measured by high-speed photographing. The empirical equations of mixing time (Tm) relating to mixing energy (ε) were ${T_{{\rm{m}},s}} = 913{\varepsilon ^{ - 0.5}}$ for solid tracer and ${T_{{\rm{m}},l}} = 624{\varepsilon ^{ - 0.48}}$ for liquid tracer, respectively. The mixing time trended down with the increasing of bubble formation frequency, affected slightly by the bubbles with small size and decreased obviously when increasing the gas-liquid contact area. The optimal conditions of gas flow rate, bath height, lance submerged height and lance diameter to guarantee high-efficiency mixing and low-level surface fluctuation/splashing were obtained.

Three new A-π-D-π-A type small molecules ( DIP-T , DIP-HT , and DIP-HTT ) employing diindole[3,2- b :4,5- b ′]pyrrole (DIP) as the electron-rich donor (D) block, indenedione as the electron-deficient acceptor (A) group, and thiophene, 3-hexylthiophene, or 4-hexyl-2,2′-dithiophene as the conjugated π-bridge, are designed, synthesized and characterized as donor materials for organic solar cells (OSCs). The effects of the length and steric hindrance of the thiophene-containing π-bridges on the molecular configuration, optical, electrochemical and charge-transport properties were investigated by theory calculations, UV–vis spectroscopy, cyclic voltammetry, and the space-charge-limited current method, respectively. These DIP-based small molecules (SMs) show excellent solubility and good thermal stability. DIP-T with thiophene as π-bridge shows wider and stronger absorption, higher-lying HOMO energy level, higher hole mobility and superior active layer morphology in comparison with that of DIP-HT and DIP-HTT with 3-hexylthiophene and 4-hexyl-2,2′-dithiophene as the conjugated π-bridge, respectively. As a result, the optimized OSC based on DIP-T exhibits an obviously higher power conversion efficiency (PCE) of 4.65% with relative to the other two SMs. So far, this is the first report of developing the A-π-D-π-A type SMs with a DIP donor core for application in organic electronic devices. Our results indicate that the pentacyclic DIP can be a potential and attractive donor building block for developing efficient A-π-D-π-A type SMs donor materials.

To obtain low-bandgap polymers paired well with fullerene and nonfullerene acceptors, here we adopted a D-A1-D-A2 motif to develop two new low-bandgap copolymers PTPTI-T-BDD and PTPTI-T-FBT, where thiophene was used as the D unit, thieno[2′,3′:5,6]pyrido[3,4-g]thieno[3,2-c]-isoquinoline-5,11(4H,10H)-dione (TPTI) was used as the A1 unit, and benzo[1,2-b:4,5-c′]dithiophene-4,8-dione (BDD) and 5,6-difluoro-2,1,3-benzothiadiazole (FBT) were employed as the A2 unit, respectively. Effects of the electron-withdrawing strength of A2 unit on optoelectronic and photovoltaic properties of the PTPTI-T-BDD- and PTPTI-T-FBT-based fullerene and nonfullerene polymer solar cells (PSCs) were systematically investigated. When blended with PC71BM and ITIC, PTPTI-T-FBT-based PSCs showed a power conversion efficiency (PCE) of 6.20% and 6.03%, respectively, both of which are higher than that of PTPTI-T-BDD-based PSCs. Furthermore, ternary PSCs based on PBDB-T:PTPTI-T-FBT:PC71BM exhibited an improved PCE of 7.92%. This work suggests that constructing D-A1-D-A2 copolymers is a promising strategy to develop low-bandgap copolymers for efficient fullerene and nonfullerene PSCs with a reduced energy loss.

Objectives This study compared the body contact pressure profiles of 2 types of mattresses: latex and polyurethane. Methods Twenty participants were required to lie down on the different mattresses in 3 different postures for 6 minutes, and their body contact pressure profiles were recorded with a pressure mat sensor. Results The data indicated that the latex mattress was able to reduce the peak body pressure on the torso and buttocks and achieve a higher proportion of low-pressure regions compared with the polyurethane mattress. Conclusions Latex mattress reduced peak body pressure and achieved a more even distribution of pressure compared with polyurethane mattress across different sleeping postures.

The compound trifluoroiodomethane can be activated to react with the electron donor, 1,4-dilithiotetraphenyl butadiene, by means of electron transfer catalysis (ETC). The structure of the product, 1,3-difluorotetraphenyl,benzene (1), was determined by MS, NMR, and X-ray single crystal diffraction. The conformations of compound 1 and its derivatives were analyized by molecular mechanics.

This paper presents an algorithm, which is used to find the shortest path between two given nodes in a grid with sparse polygon obstacles. Among these obstacles some of them may be bridged. The algorithm executes the search using a “don't change direction” heuristic along the line towards the target node. The path has eight searching directions, which are decided by the opposition of sources and target nodes. According to the result of many contrastive and on-the-fly experiments, the algorithm reduces the size of searching region. The path length is also shorter than those found by using traditional algorithms. Performance analysis shows that this algorithm is efficient.

The experimental advanced superconducting tokamak (EAST) is being constructed at the Institute of Plasma Physics of Chinese Academy of Sciences (CASIPP). The EAST project, approved by the Chinese government as a national mega project of science research is a fully superconducting tokamak. The most key component for EAST is the superconducting magnet coils (SMCs), which consists of 16 toroidal field coils (TFCs) and 14 poloidal field coils (PFCs). In 2003, three prototypes, one TFC and two PFCs, were successfully completed and passed a series of cryogenic tests. Batch production, needed for the SMCs has begun at CASIPP since 2002. Up to now, all 58 CIC conductors with a total length of 32 km, 12 TFCs out of 16 and 10 PFCs out of 14 have been fabricated. This paper emphasizes on the various technology issues that must be faced and solved for four R&D lines of SMCs after transforming to batch production. Quality control methods in process are also described.

The Toroidal Field (TF) coil case of the HT-7U superconducting tokamak device is made of austenitic stainless steel 316LN and is designed to operate at cryogenic temperature (4 K). 316LN can retain high strength and fracture toughness at 4 K. Feasibility study on technical process of welding has been experimentally considered as a hopeful joint method for suppression of post-welding deformation and reduction of over-heating. Meanwhile the final range of stress intensity and the stress intensity factor (K) for pre-cracks of welding structure have been determined by using J-integral. These related results are optimistic and have shown that there's no problem in strength and fracture toughness at the vicinity of the pre-crack tip. This paper introduces the welding structure of TF coil case in detail.

The toroidal magnet system of HT-7U is a very important part of the HT-7U superconducting tokamak device, which is consisted of sixteen D-shaped coils. In order to design the mechanical structure of the toroidal field (TF) system it is necessary to analyze the mechanical behaviors of the HT-7U TF coil system under normal and all possible fault operating conditions. The force distribution of the TF system in the equilibrium condition (all the coils energized) has been calculated [1]. In this paper, the fault conditions (one or more toroidal coils failed) have been analyzed based on the hypothesis that the current of all the other coils is kept constant when one or more coils failed. The aim is to provide necessary data for the stress analysis of TF structure.

A special winding machine with high accuracy has just been developed and applied to the construction of HT-7U Tokamak. It is one of the critical facilities for R & D of HT-7U construction. The machine mainly consists of five parts, including a CICC pay-off spool, a four-roller correcting assembly, a four-roller forming/bending assembly, a continuous winding structure and a CNC control system with three-axis AC servo motors. The facility is used for Cable in Conduit Conductor (CICC) magnet fabrication of HT-7U. The main requirements of the winding machine are: continuous winding to reduce joints inside the coils; pre-forming CICC conductor to avoid winding with tension; suitable for all TF & PF coils of various coil shapes and within the dimension limit; improving the configuration tolerance and the special flatness of the CICC conductor. This paper emphasizes on the design and fabrication of the special winding machine for HT-7U. Some analyses and techniques in winding process for trial D-shape coil are also presented.

The reputation mechanism in online auctions provides online auction participants with information about the past behaviour of other participants, in the form of a numerical rating. eBay, which is the most popular online auction website, uses a simple aggregation to summarize and demonstrate participants' reputations. This study proposes and investigates designs for multi-dimensional reputation mechanisms, with time and/or related transaction price information. A laboratory experiment was conducted to empirically test whether the time and price dimensions in a reputation mechanism have significant effects on bidding behaviour of online auction participants, and whether these help participants to better judge the trustworthiness of sellers with a higher level of confidence. A design with one treatment of five levels was adopted and 150 university students were recruited for the experiments. The results showed that the mechanisms with a weighted time and/or price dimension have some ability to enable bidders to better distinguish sellers of different reputation levels, and were perceived to be more helpful to bidders in making bidding decisions.