[en] Highlights: • High-density (98.4%) W–20 wt.%Cu composites were low-temperature fabricated. • A highly pure Cu network and a homogenous microstructure formed in the composites. • The interfaces between W and Cu are well bonded with no spaces. • The composites have excellent thermal properties. -- Abstract: High-density W–20 wt.%Cu composites containing a Cu-network structure and exhibiting good thermal properties were fabricated by low-temperature hot-press sintering from high-purity copper-coated tungsten powders. The relative density of W–20 wt.%Cu composites sintered at 950 °C–100 MPa–2 h was 98.4%. The low-temperature densification of W–Cu composites occurs because the sintering mode of the coated particles involves only sintering of Cu to Cu, rather than both Cu to W and Cu to Cu, as required for conventional powder particles. The microstructure shows that a network of high-purity Cu extends throughout the composites, and that the W is distributed homogeneously; the interfaces between W and Cu show good contact. The composites have excellent thermal conductivity (239 W/(m K)) and a relatively low coefficient of thermal expansion (7.4 × 10⁻⁶/K), giving them some of the best properties reported to date for thermal-management materials. The excellent performance is mainly because of their structure, which arises from the characteristics of the high-purity copper-coated tungsten powders

[en] Diffusion bonding of two dissimilar materials, Ti–6Al–4V (TC4) and oxygen-free copper (OFC), was investigated at low temperature. A 30-µm silver foil was used as interlayer and the bonding was carried out at various bonding temperatures and times. The diffusion bonded joint microstructures were studied using an S-4800 field emission scanning electron microscope, JXA-8100 electron probe micro-analyzer, and Rigaku Ultima II X-ray diffractometer. Joint tensile strengths were measured by tensile tests. The silver interlayer prevented the formation of Ti–Cu compounds, AgTi and AgTi₂ were generated at the TC4/Ag interface and a solid solution formed at the Ag/OFC interface. The tensile strength of the TC4/Ag/OFC joint increased first and decreased with bonding temperature or bonding time. The joint bonded at 700 °C for 120 min at 10 MPa showed a maximum tensile strength of 161.9 MPa. Fracture morphology showed that ductile fracture initiation and propagation took place at the Ag/OFC interface, which was the weak point of the joint

[en] Highlights: • Highly pure copper-coated tungsten powders were prepared in fixed quantities. • Effect of 2,2′-dipyridyl on plating process and coated Cu was studied. • The approximate concentration of 2,2′-dipyridyl in the bath is 20–40 mg/L. • The composite powders can be used to fabricate high-performance W–Cu composite. - Abstract: Highly pure copper-coated tungsten powders were successfully prepared in fixed quantities using electroless plating, via the addition of an appropriate amount of 2,2′-dipyridyl to the plating bath. The effect of 2,2′-dipyridyl on the plating Cu rate, microstructure and performance of the coated Cu layer was studied systematically. Changing the concentration of 2,2′-dipyridyl had significant effects on the plating Cu rate, surface morphology, average grain size, purity and quantity of coated Cu. With a 2,2′-dipyridyl concentration of approximately 20–40 mg/L, the coated Cu was highly pure, with very little oxygen content (less than 0.1 wt.%). The complexation of the 2,2′-dipyridyl with cuprous ions and the absorption of the 2,2′-dipyridyl on the coated Cu surface can explain these findings. With increase in the concentration of 2,2′-dipyridyl in the plating bath, the plating Cu rate, microstructure and performance of the coated Cu layer changed steadily, indicating that the complexation and absorption of 2,2′-dipyridyl gradually approached a saturation level. High thermal performance W–Cu composite can be fabricated by using these composite powders

[en] In the present paper, the relationship between characteristic wave impedance and compositions was mainly investigated in order to find a suitable theoretical model for predicting the impedance value of Ti-Mo system composites and FGM. At first, dense Ti-Mo composites with different weight fractions of Mo were prepared. Then the transverse and longitudinal wave velocities of the samples were measured and the characteristic wave impedance values were obtained. A mixture model was adopted to estimate the characteristic wave impedance value of Ti-Mo composites. Comparisons between the estimated and experimental results demonstrated that the suggested model was sufficiently accurate to predict the characteristic wave impedance value of Ti-Mo system composites and FGM. (orig.)

[en] Objective: To study the therapeutic efficacy of radioimmunotherapy of ¹³¹I-human anti-HBsAg Fab via different routes of administration. Methods: The human hepatoma bearing nude mice we reinjected with ¹³¹I-human anti-HBsAg Fab intra-tumor (IT) and intra-peritoneum (IP). Biodistribution was measured on the 5th day. The tumor growth inhibition rate was determined by measurement of tumor volume. Results: In the IT-treated mice, tumor uptake of ¹³¹I-human anti-HBsAg Fab was four-fold greater than in the IP-treated mice, and normal organ uptake was half of that in the IP-treated mice. At the 3rd week after the infusion, the tumor growth inhibition rate in IT-treated mice was higher than that in the IP-treated mice. Conclusions: Intratumoral administration of ¹³¹I-human anti-HBsAg Fab makes high level of radioactivity retained in tumor with significantly lower radioactivity retained in normal tissues, and provides a more effective regional therapy

[en] Highlights: • La₂Co_xNi_1-xMnO₆ epitaxial films are originally fabricated by pulsed laser deposition. • Co-doping effect on the structure and magnetic property arestudied. • La₂Co_0.2Ni_0.8MnO₆ displays the highest B-site ordering degree, which improves the magnetic performance. Novel La₂Co_xNi_1-xMnO₆ (LC_xNMO, x = 0–0.4) thin films were prepared by pulsed laser deposition, and the influences of Co-doping content on the crystallographic structure, chemical structure as well as magnetic property were studied. The AFM and SEM images revealed a uniform film growth and smooth surfaces for all the films. The (HR)XRD analysis and their RSM results testified for the formation of pseudocubic perovskite films epitaxially grown onto LAO(00l) substrate. The in-plane lattice parameter increased with increasing proportion of Co substituting for Ni sites, as expected due their ionic radii differences. In our work, a change of Mn³⁺ + Ni³⁺/Co³⁺ → Mn⁴⁺ + Ni²⁺/Co²⁺ was found, and the mechanism in the enhancement of the magnetic property was demonstrated. It proposed that the performances of all the films can be enhanced and regulated by controlling the Co-doping content. Among all the films, LC_0.2NMO film possessed the maximum Mn⁴⁺ ion concentration (80%) and displayed the highest B-site ordering degree. As a consequence, LC_0.2NMO was achieved to exhibit a high Curie temperature (278.4 K) and the best saturation magnetization (513.72 emu/cm³), on account of the combined effects of the strong B-site cation ordering and the structural distortion after Co-doping.

[en] A novel transparent conducting oxide based on the ATO/graphene multi-layered thin films has been developed to satisfy the application of transparent conductive electrode in solar cells. The ATO thin films are prepared by pulsed laser deposition method with high quality, namely the sheet resistance of 49.5 Ω/sq and average transmittance of 81.9 %. The prepared graphene sheet is well reduced and shows atomically thin, spotty distributed appearance on the top of the ATO thin films. The XRD and optical micrographs are used to confirm the successfully preparation of the ATO/graphene multi-layered thin films. The Hall measurements and UV-Vis spectrophotometer are conducted to evaluate the sheet resistance and optical transmittance of the innovative structure. It is found that graphene can improve the electrical properties of the ATO thin films with little influence on the optical transmittance.

[en] Highlights: • LSMO films were crystallized using post-annealing after room-temperature deposition. • The out-of-plane lattice parameter decreased with decreasing sputtering pressure. • The T_C and T_MI for LSMO film deposited at 1.0 Pa were close to room temperature. • The LSMO films showed significant magnetoresistance around room temperature. Epitaxial La_0.9Sr_0.1MnO₃ thin films were crystallized using post-annealing after deposited at room temperature, and the effect of sputtering pressure on the structural, magnetic and electrical properties was investigated. It is interesting to note that the out-of-plane lattice parameter decreases with decreasing sputtering pressure, which is attributed to the reduction of Mn³⁺/Mn⁴⁺ ratio. Differing from the corresponding bulk material, all the films show metal-insulator (MI) transition with a significantly enhanced Curie temperature (T_C). And the film deposited at 1.0 Pa shows the maximum T_MI and T_C resulted from the strongest double exchange interaction. Most significantly, the largest magnetoresistance around room temperature (−53% at 3 T and 295 K) is also observed in this film, showing great potential in application.

[en] Dense SnO₂-based electrode ceramics have extensive application prospect in glass electric-melting industry due to the excellent electrically-conductive and chemical property in high temperatures and oxidation environment. In this paper, dense SnO₂-based electrode ceramics doped with MnO₂ and Sb₂O₃ were prepared by pressureless sintering method and the corrosion rate in soda-lime glass liquid as well as the microstructure evolution was mainly investigated. The results suggested that SnO₂-based ceramics had good corrosion resistance, and the minimum value was only 2.54x10^-4 mm/h when MnO2 content is 1.0% and Sb₂O₃ content is 0.1%. Composition Elements of Glass liquid were detected in the grain boundary and some intergranular pores. It was found that SnO₂ grains remained unchanged, whereas MnO₂ was easily dissolved into molten glass liquid. SnO₂-based electrode ceramics with dense structure and few amounts of additives had excellent corrosion resistance to the molten glass.

[en] High carbon-rich boroncarbonitride thin films have been grown by pulsed laser deposition (PLD) technique with using BN-C dual-targets. Fourier-transform infrared (FTIR) spectroscopy results presented B-N, B-C and C-N bonds, indicating the as-deposited thin films were new ternary compounds. B-N, B-C and C-N bonding structures were also detected by X-ray photoelectron spectroscopy (XPS), and carbon content fell into a large range of 45.8 to 85.9%. The films exhibited good thermalstability in vacuum, whereas were oxidized at 600 "oC in air