Electromechanical behaviour of violet phosphorene nanoflakes.

Violet phosphorene (vP), a two-dimensional structure with various unique properties, has attracted much attention recently. The electromechanical behaviour, a mechanical-electrical-thermal coupling failure behaviour, of supported and suspended vP nanoflakes has been investigated by the c-AFM nanoindentation method under different loads and bias voltages in this work. A bump due to the oxidation caused by electric current-induced local heating was observed for the supported vP on substrates under mild load and bias voltage. A concave morphology was observed when a load of 1500 nN and a bias voltage of 10 V were applied. No bump was observed for the suspended vP due to the larger contact area between the probe and the sample, resulting in a lower temperature. Fatigue damage was observed for the vP nanoflakes under constant load and a cycled bias voltage from 10 V to -10 V. The electromechanical behaviour of vP was also analyzed through its specific heat capacity and conductivity by density functional theory.

Thickness-Dependent Dielectric Screening in Few-Layer Phosphorus.

The dielectric screening plays a critical role in determining the fundamental electronic properties in semiconductor devices. In this work, we report a noncontact and spatially resolved method, based on Kelvin probe force microscopy (KPFM), to obtain the inherent dielectric screening of black phosphorus (BP) and violet phosphorus (VP) as a function of the thickness. Interestingly, the dielectric constant of VP and BP flakes increases monotonically and then saturates to the bulk value, which is consistent with our first-principles calculations. The dielectric screening in VP has a much weaker dependence on the number of layers. This could be ascribed to a strong electron orbital overlap between two adjacent layers of VP, resulting in a strong interlayer coupling. The findings of our work are significant both for fundamental studies of dielectric screening and for more technical applications in nanoelectronic devices based on layered 2D materials.

Lightweight similarity checking for English literatures in mobile edge computing.

With the advent of information age, mobile devices have become one of the major convenient equipment that aids people's daily office activities such as academic research, one of whose major tasks is to check the repetition rate or similarity among different English literatures. Traditional literature similarity checking solutions in cloud paradigm often call for intensive computational cost and long waiting time. To tackle this issue, in this paper, we modify the traditional literature similarity checking solution in cloud paradigm to make it suitable for the light-weight mobile edge environment. Furthermore, we put forward a lightweight similarity checking approach SC MEC for English literatures in mobile edge computing environment. To validate the advantages of SC MEC , we have designed massive experiments on a dataset. The reported experimental results show that SC MEC can deliver a satisfactory similarity checking result of literatures compared to other existing approaches.

Preparation of Montmorillonite Nanosheets with a High Aspect Ratio through Heating/Rehydrating and Gas-Pushing Exfoliation.

Montmorillonite (MMT) is an abundant silicate mineral with ultrahigh stability. The exfoliation of stacked MMT into high-aspect-ratio nanosheets is of crucial importance for various applications such as toxic gas suppression, barrier property enhancement, flame retardancy, and ion conduction. In this work, we develop a new heating/rehydrating and gas-pushing method that can successfully exfoliate MMT into nanosheets with aspect ratios (600-5000) far higher than the currently reported values (1-120). The MMT first goes through a "starvation pretreatment" under different heating temperatures to improve its hydrophilicity and is then rehydrated in a hydrogen peroxide solution. The hydrogen peroxide in the MMT interlayer space can decompose into water and oxygen bubbles, thus finally leading to the exfoliation via gas-pushing while preserving the large lateral size (mainly in the range of 1-6 µm) of the nanosheets. By changing the pretreatment temperature and pH value of the hydrogen peroxide solution, the exfoliation performance can be tuned. This simple and low-cost exfoliation method is promising to achieve the mass production of MMT nanosheets with a high aspect ratio and may promote its application in various fields such as energy conversion, drug delivery, and photocatalysis.

[Clinical observation of young, middle-aged and elderly women with endometrial carcinoma].

OBJECTIVE: To explore the clinical features, diagnosis, treatment and prognosis of endometrial carcinoma in young, middle-aged and elderly women. METHODS: We retrospectively analyzed the clinical data of 82 cases of endometrial carcinoma in young, middle-aged women and 33 cases of endometrial cacinoma in elderly women. RESULTS: The rates of adenocarcinoma in young, middle-aged and elderly groups were 74.4% and 75.5%, respectively. The young,middle-aged and elderly patients with Stage I endometrial cancer were 64.6% and 69.7%, and those with Stage III and IV were 15.9% and 15.2%, respectively. The histological Grade 1 carcinoma of endometrium in young,middle-aged and elderly women were 70.7% and 60.6%, respectively. The young, middle-aged women without myometrial invasion were more than the elderly women (42.8% vs 15.6%, P < 0.01). The young, middle-aged women with myometrial invasion more than half of myometrial wall were less than the elderly women (10.4% vs 40.6%, P < 0.01). The rate of chemical treatment after the surgery in the elderly women was more than that of the young, middle-aged women (P < 0.05). The 5-year survival rate of the young, middle-aged women was obviously higher than that of the elderly women (92.79% vs 72.21%, P < 0.05). CONCLUSION: Adenocarcinoma and well-differentiated cells are the main pathological characteristics of endometrial carcinoma both in the young, middle-aged and the elderly women. Most young, middle-aged and el-derly patients can be diagnosed and treated in the early stage. Early diagnosis and reasonable treatment can improve the prognosis. The prognosis of the young, middle-aged patients is obviously better than that of the elderly patients, and the myometrial invasion depth may be the main difference.