A note on the intermodulation performance of SCPC satellite links using a dominant carrier

The intermodulation performance of satellite links using a dominant carrier side-by-side with many small SCPC/FDMA carriers is considered. Closed-form expressions which are easy to evaluate are obtained for the amplitudes of the output carriers and intermodulation products. Using these expressions the carrier-to-intermodulation performance of the satellite link can be evaluated using personal computers or pocket calculators.     

Influence of absorber doping in a-SiC：H/a-Si：H/a-SiGe：H solar cells

This work deals with the design evaluation and influence of absorber doping for a-Si:H/a-SiC:H/a-SiGe:H based thin-film solar cells using a two-dimensional computer aided design (TCAD) tool. Various physical parameters of the layered structure, such as doping and thickness of the absorber layer, have been studied. For reliable device simulation with realistic predictability, the device performance is evaluated by implementing necessary models (e.g., surface recombinations, thermionic field emission tunneling model for carrier transport at the heterojunction, Schokley-Read Hall recombination model, Auger recombination model, bandgap narrowing effects, doping and temperature dependent mobility model and using Fermi-Dirac statistics). A single absorber with a graded design gives an efficiency of 10.1% for 800 nm thick multiband absorption. Similarly, a tandem design shows an efficiency of 10.4% with a total absorber of thickness of 800 nm at a bandgap of 1.75 eV and 1.0 eV for the top a-Si and bottom a-SiGe component cells. A moderate n-doping in the absorber helps to improve the efficiency while p doping in the absorber degrades efficiency due to a decrease in the V_OC (and fill factor) of the device.     

Crystallization kinetics and structure of poly(trimethylene terepthalate)/monolayer nano-mica nanocomposites

In this work, the structure of poly(trimethylene terepthalate) (PTT)/monolayer nano-mica (MNM) nanocomposites are investigated by wide angle X-ray diffraction (WAXD), small angle X-ray scattering (SAXS) and scanning electron microscope (SEM). In the PTT nanocomposites, the crystallization induces the segregation of MNM in which three morphologies, including interlamellar, interfibrillar, and interspherulitic segregations, are observed with changing the MNM content. Avrami analysis of isothermal crystallization demonstrates that MNM enhances the bulk crystallization rate in the nanocomposites. Moreover, the non-integral values of Avrami exponent n between 2 and 4 with increasing crystallization temperature indicate the mixed growth and nucleation mechanisms. The analysis of secondary nucleation theory for neat PTT and the PTT nanocomposites exhibit the same regime transition of crystallization behaviour in which the classical transition temperatures of regime I to II and regime II to III take place at 488 K and 468 K, respectively. The growth rate of spherulites of the PTT nanocomposites is twofold larger than that of neat PTT in regime III, implying that MNM plays an effective role as a nucleating agent, since the addition of MNM enormously reduces the activation energy of nucleation, folding surface free energy and average work of chain folding for PTT nucleation. However, experimental results show that the MNM content below 1 wt% is the most effective for nucleation of PTT crystallization.     

Light and temperature effects on shoot fruitfulness in Vitis vinifera L. cv. Sultana: Influence of trellis type and grafting

Fruit bud initiation in Sultana is more sensitive to climatic factors than fruit bud initiation in other cultivars. This paper considers historical findings regarding the influence of light and temperature on fruit bud initiation and fruitfulness in view of modern Sultana vineyard management practices.
Past results were reviewed and confirmed by experiments in which variability in vine size and structure was introduced by grafting and modifications of trellis design. Ramsey-grafted vines were consistently less fruitful than own-rooted Sultana, possibly because of a more shaded canopy interior due to greater vegetative growth of vines grafted to Ramsey rootstock. Carbohydrate reserves of node and internode tissue in late winter between node 2 and 18 followed a similar trend along the cane as fruitfulness in the following spring.     

Regulation of Autophagy Machinery in Magnaporthe oryzae

Plant diseases cause substantial loss to crops all over the world, reducing the quality and quantity of agricultural goods significantly. One of the world’s most damaging plant diseases, rice blast poses a substantial threat to global food security. Magnaporthe oryzae causes rice blast disease, which challenges world food security by causing substantial damage in rice production annually. Autophagy is an evolutionarily conserved breakdown and recycling system in eukaryotes that regulate homeostasis, stress adaption, and programmed cell death. Recently, new studies found that the autophagy process plays a vital role in the pathogenicity of M. oryzae and the regulation mechanisms are gradually clarified. Here we present a brief summary of the recent advances, concentrating on the new findings of autophagy regulation mechanisms and summarize some autophagy-related techniques in rice blast fungus. This review will help readers to better understand the relationship between autophagy and the virulence of plant pathogenic fungi.     

基于水溶性PEG/PMMA黏结剂的316L不锈钢注射成形研究

目的 针对316L不锈钢注射成形,研究一种环境友好型的水溶性黏结剂,并探究水脱脂温度对PEG脱除率的影响。方法 配置不同PEG/PMMA比例的黏结剂,通过成形后的形貌及SEM确定黏结剂的比例,对成形完整的生坯进行流变性能测试,最后将生坯放入水浴锅中脱脂,通过SEM观察形貌。结果 通过注射成形得出76%（质量分数,下同）PEG、79%PEG和82%PEG 3种喂料能够注出完整的生坯,同时根据SEM观察发现316L不锈钢粉末被黏结剂均匀包裹。在160℃、剪切速率102～105 s-1条件下,3种喂料黏度均低于1 000 Pa·s,符合注射成形的要求。在生坯脱脂过程中,PEG脱除率随着脱脂温度的升高而升高。PEG的脱除使生坯内部形成大量孔隙,有利于后续热脱脂与预烧结的进行。结论 与其他成分相比,成分为79%PEG+19%PMMA+5%SA的黏结剂喂料具有较好的流动性,适合注射成形,成形出的生坯形貌完整,内部孔洞较少,并且经过脱脂后仍能保持原始形状,无外部缺陷。生坯在60℃水温下脱脂,PEG脱除率最大,经过10 h脱脂后PEG脱除率达到80%。     

Material and method selection for efficient solid oxide fuel cell anode: Recent advancements and reviews

The energy crisis has reached to an alarming situation due to increase in population. To overcome the shortfall of energy, solid oxide fuel cell (SOFC) being cheap, clean, and efficient renewable energy source is getting attention for electricity generation. Out of the three main components as anode, electrolyte, and cathode; anode/fuel electrode is an important component of SOFC because it allows the flow of electrons via external circuit to cathode generating the electric current and hence requires high electrical conductivity. In this review, anode materials synthesized until now are reviewed and by careful analysis categorized on the basis of operating temperature, conductivity, electrode polarization resistance, and structure. This comparison and categorization will provide selection criteria for state‐of‐the‐art and highly efficient anode materials for SOFC. In addition, the synthesis methods have been reviewed on the basis of their pros and cons, which will further facilitate the researchers to select the best synthesis method so as to get optimized properties of materials.     

Synthesis,Characterization, Antibacterial Properties,and In Vitro Studies of Selenium and Strontium Co-Substituted Hydroxyapatite

In this study, as a measure to enhance the antimicrobial activity of biomaterials, the selenium ions have been substituted into hydroxyapatite (HA) at different concentration levels. To balance the potential cytotoxic effects of selenite ions (SeO₃²⁻) in HA, strontium (Sr²⁺) was co-substituted at the same concentration. Selenium and strontium-substituted hydroxyapatites (Se-Sr-HA) at equal molar ratios of x Se/(Se + P) and x Sr/(Sr + Ca) at (x = 0, 0.01, 0.03, 0.05, 0.1, and 0.2) were synthesized via the wet precipitation route and sintered at 900 °C. The effect of the two-ion concentration on morphology, surface charge, composition, antibacterial ability, and cell viability were studied. X-ray diffraction verified the phase purity and confirmed the substitution of selenium and strontium ions. Acellular in vitro bioactivity tests revealed that Se-Sr-HA was highly bioactive compared to pure HA. Se-Sr-HA samples showed excellent antibacterial activity against both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus carnosus) bacterial strains. In vitro cell–material interaction, using human osteosarcoma cells MG-63 studied by WST-8 assay, showed that Se-HA has a cytotoxic effect; however, the co-substitution of strontium in Se-HA offsets the negative impact of selenium and enhanced the biological properties of HA. Hence, the prepared samples are a suitable choice for antibacterial coatings and bone filler applications.