Rapid and accurate method for isolation of recombinant baculovirus with an expanded host range

A rapid positive screening system for identifying recombinant baculovirus with an expanded host range was developed by using an actin promoter-dependent fluorescent protein gene expression cassette. The expression of recombinant protein regulated by the polyhedrin promoter was not affected by the insertion of the cassette in the baculovirus genome.     

Performance enhancement of polybenzoxazine by hybridization with polysiloxane

Polybenzoxazine-polydimethylsiloxane (PBa-PDMS) hybrids were successfully prepared in situ by the ring-opening polymerization of benzoxazine (Ba) and the sol-gel process of diethoxydimethylsilane (DEDMS). The reaction conditions were optimized, and homogeneous opaque hybrid films were obtained up to 13 wt% of PDMS content by using p-toluenesulfonic acid as the catalyst for sol-gel process. The domain size of PDMS in the PBa matrix was examined by SEM. The tensile strength and elongation at break of the PBa-PDMS hybrid films were higher than those of pristine PBa, because of the toughening effect of PDMS. Dynamic viscoelastic analysis showed that the glass transition temperature of the hybrid was also higher than that of pristine PBa. Moreover, the decomposition temperatures and weight residue at 850 °C increased with the increase of PDMS content as evidenced by thermogravimetric analysis.     

Effect of in situ-formed polydimethylsiloxane on the properties of polyimide hybrids

Polyimide-polydimethylsiloxane (PI-PDMS) hybrids were synthesized by combining an in situ sol–gel reaction of diethoxydimethylsilane (DEDMS) and imidization of poly(amide acid) (PAA) prepared from pyromellitic dianhydride (PMDA) and 4,4′-oxydianiline (ODA). Transparent hybrid films were obtained with up to 3 wt.% PDMS content corresponding to the relatively small domain size of PDMS as confirmed by scanning electron microscopy. The hybrid films with up to 3 wt.% of PDMS content showed higher tensile modulus, strength and elongation at break than those of pristine PI, due to the in situ-formed PDMS. The thermal stability of the hybrids also increased with the increase of PDMS content, as evidenced by TGA.     

通过水溶液还原法用抗坏血酸制备纳米铜颗粒(英文)

通过水溶液还原法用抗坏血酸还原Cu2+制备纳米铜颗粒,并研究溶液pH和Cu2O平均粒径对纳米铜颗粒制备的影响。在溶液pH值为3、5和7时,可制得铜颗粒,并且在pH=7时制得的铜颗粒粒径最小。在溶液pH为9和11时无法制得铜颗粒。Cu2O的平均粒径能影响铜粉的粒径。Cu2O的平均粒径越大,得到的铜颗粒越大。通过对反应过程中不同时间点收集的样品进行XRD分析,可探索出反应的进程。在反应过程中,Cu(OH)2首先作为前驱体出现,然后被还原为Cu2O,最后被还原为铜颗粒。     

Exact optimal solutions of the minisum facility and transfer points location problems on a network

We consider hierarchical facility location problems on a network called Multiple Location of Transfer Points (MLTP) and Facility and Transfer Points Location Problem (FTPLP), where q facilities and p transfer points are located and each customer goes to one of the facilities directly or via one of the transfer points. In FTPLP, we need to find an optimal location of both the facilities and the transfer points while the location of facilities is given in MLTP. Although good heuristics have been proposed for the minisum MLTP and FTPLP, no exact optimal solution has been tested due to the size of the problems. We show that the minisum MLTP can be formulated as a p‐median problem, which leads to obtaining an optimal solution. We also present a new formulation of FTPLP and an enumeration‐based approach to solve the problems with a single facility.     

An Area-Effective Cell-Based Channel Decoder LSI For a Digital Satellite TV Broadcasting

A new channel decoder LSI, which will be used in digital satellite TV broadcasting Set-Top Boxes, has been designed. This LSI's functions include AD/DA conversion, QPSK demodulating, Viterbi decoding, frame synchronization, convolutional deinterleaving, Reed-Solomon (RS) decoding, and descrambling. We use a new method for Viterbi Decoding called the Tracking Survivor State Information (TSSI) method, which not only reduces power consumption, but also solves the problem of increasing memory size. To reduce the size of RS decoder circuit, we used a three-stage-pipeline structure as well as designed a new architecture to realize Euclid's algorithm. This device has been fabricated in a 0.35 µm 3-metal CMOS standard cell-based process and is composed of 670 K transistors. In this paper, we describe the TSSI method of the Viterbi Decoder and the Reed-Solomon Decoder's new 3-stage pipeline architecture.     

Measurement of cable resistance at high frequencies

Because of the presence of large capacitance, measuring the series resistance of a cable as a voltage drop is not an easy task especially at high frequencies. Considering this fact, this letter proposes a method to extract series resistance values of a single‐core cable at high frequencies from the measured frequency response of its open‐ended input impedance. The proposed method has been applied to the measurement of the series resistance of an existing 66‐kV underground cable, and the result is presented. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Plasma arc welding of pipelines: A study to optimise welding conditions for horizontal fixed joints of mild steel pipes

A plasma arc process was applied to the welding of mild steel pipes (thickness: 6·4 mm, outside diameter: 406·4 mm) and the effect of different welding parameters on the shape of welds and consistency of defects was studied in the flat, vertical and overhead positions.In conventional plasma arc welding conditions, full penetration and continuous bead formation were obtained in a range of conditions which tended towards lower plasma gas flow rates and higher travelling speeds as the welding current was increased. In the overhead position, the penetration bead presented deep continuous concaves.In the vertical-up position, it was not possible to obtain a range of welding conditions assuring full penetration and continuous bead formation.The experiment relating to the effect of the pulsating welding current on the shape and defects of welds disclosed that the use of pulse frequencies lower than 4 Hz makes the penetration bead less uniform than the use of higher pulse frequencies. It was also found that the use of high pulse frequencies results in a remarkable effect in the vertical-up position.Welding using argon gas back shielding made the penetration bead more uniform in height and width. By decreasing the atmospheric pressure inside the pipe, concaves in the penetration bead could be reduced, particularly in the overhead position.From the results described above, it is considered that pulsating welding current and the backing method are effective in obtaining a good bead over the entire circumference of mild steel by plasma keyhole welding.The experiment also revealed that when plasma arc welding is applied, mild steel pipes can be welded at four times the productivity that can be expected of the conventional GMA welding.Therefore plasma arc welding equipment and appropriate jigs will be made shortly for practical application.