Novel AlInAs/InP HEMT

The fabrication of the first AlInAs/InP HEMT is reported. This device has extrinsic transconductance of 40 mS/mm, gate-drain and drain-source breakdown voltages of 20 V and saturation drain current densities of 0.1 A/mm of gate width. These preliminary results show the potential of the AlInAs/InP heterojunctions for a wide variety of application including microwave power HEMTs.<>     

Highly stable microwave performance of InP/InGaAs HIGFETs

The fabrication and microwave performance of InP/InGaAs heterojunction insulated-gate FETs (HIGFETs) using plasma-enhanced chemical vapor deposition (PECVD)-deposited SiO₂ as the gate insulator are discussed. Extrinsic transconductances as high as 240 mS/mm were obtained. Although these devices had a drain current drift of 20% under DC bias, when operated at 5 GHz they exhibited negligible drain current drift. The observation of high transconductance and stable microwave performance makes these HIGFETs ideal candidates for microwave power applications     

Chemical etching of polyimide film

Chemical etching rates of BPDA/PDA/ODA/BMI polyimide film by an alkaline etching solution with the presence of different kinds of etchants were studied by film-thickness measurement and UV absorption spectroscopy of dispersible etching residue. The etching rate of polyimide film in alkaline ethylene diamine solution is highest among the etching solutions studied in the present experiment. If an external bias voltage was applied during etching, the etching rate was increased. The effects of temperature, solubility of the etchant, and ultrasonic vibration on etching rate are also discussed. The presence of a radical in the process of etching reveals that the etching reaction is a type of radical chain reaction. © 1995 John Wiley & Sons, Inc.     

Physicochemical properties of twenty-one Caribbean sweet potato cultivars

The physical, chemical and physicochemical properties of twenty-one Caribbean sweet potato cultivars were investigated. Hunter L a b colour parameters were measured, chroma, colour intensity and hue angle were calculated. Proximate composition, vitamin C, amylose, reducing and non-reducing sugars contents were determined using standard methods. Pasting properties were determined using Rapid Visco Analyser. Tuber size (length, r  = 0.72, n  = 21, P  < 0.0015; width, r  = 0.85, n  = 21, P  < 0.0002) was highly correlated with weight of the tubers. External colours of the tubers ( L =  28.7–63.1, a =  +5.9 to +18.0, b =  +3 to +19.3) were lower than the flesh colours ( L =  60.8–84.0, a =  −2.4 to +27.8, b =  +9.9 to +28.5). Proximate composition is typical of sweet potato cultivars but significant differences exist among cultivars. Total sugar, amylose and amylopectin contents ranged from 1.8 to 4.7%, 15.3–31.2% and 68.8–84.7%, respectively. Cooking profiles of the sweet potato flours showed similar trend. Pasting temperature, peak time, swelling power and solubility ranged from 78.3 to 93.0 °C, 3.3–4.8 min, 5.6–23.5 and 11.7–45.7%, respectively.     

电信运营商做好节能减排工作的建议

从国家战略和整体经济出发,分析了电信运营商进行节能减排的必要性和可能性,阐述了电信运营商作为超大规模的经济体节能减排对于国家和对于企业自己本身的重大意义。最后,提出了节能减排的原则思路和工作建议。     

上海某公司大型空调冷冻站设计

经过技术经济比较,某公司大型冷冰站选用15台直燃型溴化锂机组,空调水系统采用变流量二级泵系统;简要了水系统的控制方式,直燃机组的烟气排放、机房通风和防火防爆技术,总结了工程运行情况及设计经验教训。     

Extra virgin olive oil: A comprehensive review of efforts to ensure its authenticity,traceability, and safety

The growing demand for extra virgin olive oil (EVOO), appreciated for its unique organoleptic properties and health benefits, has led to various fraudulent practices to maximize profits, including dilution with lower value edible oils. The adulterated oils would be of poor nutritional quality, more readily oxidized, and may contain unhealthy substances formed during processing. Nevertheless, the range of available techniques to detect fraud in EVOO production has been growing. Reliable markers of EVOO adulteration include fatty acids and minor components such as sterols, tocopherols, triterpene alcohols, phenolic compounds, phospholipids, volatile compounds, and pigments. Additionally, increasing consumer interest in high-quality EVOO has led to the development of robust scientific methods for its traceability. This review focuses on (i) the usefulness of certain compounds as markers of EVOO adulteration; (ii) the potential health risks of consuming adulterated EVOO; and (iii) reliable methods for the geographical traceability of olive oil. In conclusion, fraudulent production practices need to be detected to preserve the beneficial health effects of EVOO and to avoid the potential risks associated with ingesting substandard oil. In this work, as EVOO certification and regulatory framework limitations have already been extensively reviewed, we focus our attention on biomarkers that guarantee both the authenticity and traceability of oil, and consequently its health properties. When it is unavailable to obtain a high-resolution mass spectrometry full fingerprint, stigmastadienes and the sterolic profile are proposed as reliable markers.     

Kink effect in submicrometer-gate MBE-grown InAlAs/InGaAs/InAlAsheterojunction MESFETs

The authors report the influence of the kink effect on the DC and microwave performance of i-InAlAs heterojunction doped-channel MESFETs lattice matched to an InP substrate with submicrometer gates. Kink effects were observed at room temperature as well as at 77 K in the DC measurement. The kinks seem to be related to deep-level electron trapping, and are not present at microwave frequencies. Measured results are presented showing that the existence of kinks at low operating frequencies does not seem to degrade the microwave performance of the devices     

Pharmacological Inhibition of mTORC2 Reduces Migration and Metastasis in Melanoma

Despite recent advances in therapy, liver metastasis from melanoma is still associated with poor prognosis. Although targeting the mTOR signaling pathway exerts potent anti-tumor activity, little is known about specific mTORC2 inhibition regarding liver metastasis. Using the novel mTORC2 specific inhibitor JR-AB2-011, we show significantly reduced migration and invasion capacity by impaired activation of MMP2 in melanoma cells. In addition, blockade of mTORC2 induces cell death by non-apoptotic pathways and reduces tumor cell proliferation rate dose-dependently. Furthermore, a significant reduction of liver metastasis was detected in a syngeneic murine metastasis model upon therapy with JR-AB2-011 as determined by in vivo imaging and necropsy. Hence, our study for the first time highlights the impact of the pharmacological blockade of mTORC2 as a potent novel anti-cancer approach for liver metastasis from melanoma.     

大数据和云技术在省级山洪监测预警中的应用

针对部分已建省、市级山洪监测预警系统功能较少、运行效率低、性能指标不达标的问题,结合县级防汛部门对监测数据可靠性和时效性需求,在现有山洪灾害防治体系的基础上,提出基于云计算、大数据等关键技术的省级山洪监测平台总体设计架构,分别从云架构基础设施、大数据资源中心、平台即服务和山洪灾害监测预警软件即服务等4个层次介绍云技术及大数据的具体应用方案,探索系统应用模式,展望应用效益,大数据和云技术为省级山洪监测预警平台建设提供强有力的技术支撑。