Extreme Pressure Property of Rare Metal Zirconium

2013 ◽  
Vol 712-715 ◽  
pp. 70-73
Author(s):  
Hui Li Yu ◽  
Yan Wei Wang

This article studies through experiments the anti-wearing property of the organic compound of rare metal zirconium as extreme pressure (EP) additive for lube oil. It proves the extreme pressure (EP) anti-wearing property of the rare metal zirconium is far better than that of traditional lead. We have developed a new type innocuous and highly efficient EP anti-wearing additive the organic compound of metal zirconium.

1986 ◽  
Vol 76 ◽  
Author(s):  
John B. Warren

ABSTRACTCollaborative work between Brookhaven and Los Alamos National Laboratories is developing a new type of linear accelerator that uses a high-power, picosecond pulse CO2 laser to irradiate a specialized form of grating with a pitch of 10.6 microns. The electromagnetic field that results can be used to accelerate electrons at field gradients of several GeV/m with potential efficiencies much better than current accelerators. The grating must be conductive to minimize resistive losses, be able to withstand high fields without damage, and requires dimensional tolerances in the sub-micron range. These requirements focus attention on grating material selection, microfabrication methods, and metrological methods used for quality control. At present, several types of gratings have been manufactured by reactive ion etching of fused silica in CHF 3/Ar or etching silicon with KOH/H 2O or ethylenediamine-pyrocatechol solutions. Metrological analysis of the gratings has begun with a Tracor Northern 5700 digital image analyzer.


Author(s):  
Yi Xie

Heterogeneous network is supposed to be the dominant network architecture of the fifth generation (5G) cellular network, which means small cells are overlaid on the macrocell. The beamforming (BF) and cell expansion are two important approaches to serve users in small cells. Furthermore, non-orthogonal multiple access (NOMA) is a new type of multiple access multiplexing which improves system performance without taking up extra spectrum resources. Therefore, it becomes one promising technique in 5G. In this paper, NOMA is applied in a 5G heterogeneous network with biased small cells. The BF strategy and the multiuser scheduling method are proposed. The main user in NOMA is scheduled inside the original coverage of the small cell while the side user is chosen from the biased expansion area. The BF strategy that is executed depends on the channel of main user. The multiuser scheduling method is to maximize the rate performance. The proposed method can provide performance benefits. Simulation results show that the proposed methods can be well applied in heterogeneous networks. The achieved performance gain is approximately twice better than traditional OMA and has 10% improvement to the stochastic schedule method. In addition, the average rate of cell edge users is improved.


2020 ◽  
Vol 34 (4) ◽  
pp. 387-394
Author(s):  
Soodabeh Amanzadeh ◽  
Yahya Forghani ◽  
Javad Mahdavi Chabok

Kernel extended dictionary learning model (KED) is a new type of Sparse Representation for Classification (SRC), which represents the input face image as a linear combination of dictionary set and extended dictionary set to determine the input face image class label. Extended dictionary is created based on the differences between the occluded images and non-occluded training images. There are four defaults to make about KED: (1) Similar weights are assigned to the principle components of occlusion variations in KED model, while the principle components of the occlusion variations have different weights, which are proportional to the principle components Eigen-values. (2) Reconstruction of an occluded image is not possible by combining only non-occluded images and the principle components (or the directions) of occlusion variations, but it requires the mean of occlusion variations. (3) The importance and capability of main dictionary and extended dictionary in reconstructing the input face image is not the same, necessarily. (4) KED Runtime is high. To address these problems or challenges, a novel mathematical model is proposed in this paper. In the proposed model, different weights are assigned to the principle components of occlusion variations; different weights are assigned to the main dictionary and extended dictionary; an occluded image is reconstructed by non-occluded images and the principle components of occlusion variations, and also the mean of occlusion variations; and collaborative representation is used instead of sparse representation to enhance the runtime. Experimental results on CAS-PEAL subsets showed that the runtime and accuracy of the proposed model is about 1% better than that of KED.


2012 ◽  
Vol 512-515 ◽  
pp. 377-381 ◽  
Author(s):  
Jin Rong Lu ◽  
Yang Zhou ◽  
Yong Zheng ◽  
Shi Bo Li ◽  
Zhen Ying Huang ◽  
...  

In this paper, a new type of Ti3SiC2/Cu composites with the volume fractions of 30% Ti3SiC2 particle was prepared by hot pressing and vacuum sintering respectively. The effects of sintering temperature and holding time on the density, resistance and Vickers hardness of Cu-30vol%Ti3SiC2 composite were investigated. The results show that the mechanical properties of the composites prepared by hot pressing are better than that prepared by vacuum sintering. The relative densities of Cu-30vol% Ti3SiC2 composites are rather high in suitable sintering conditions. It achieved 100% for the composites prepared by hot pressing at 930°C for 2h, and 98.4% for the composites prepared by vacuum sintering at 1250°C for 1h. At the same time, the maximum Vickers hardness reached 1735MPa at 900°C by hot pressing. The resistance and Vickers hardness of the composites decreased with an increase in sintering temperature, whereas the density increased. Scanning electron microscope (SEM) and energy-dispersive spectroscopy (EDS) were used to observe the microstructure of the composites. The relationship between microstructure and mechanical properties was discussed.


2013 ◽  
Vol 409-410 ◽  
pp. 668-672
Author(s):  
Yong Mei Xu ◽  
Jian Tang ◽  
Jun Han ◽  
Chu Qin Lin

Aimed at a new type of ventilation - stratum ventilation, air distributions at a breathing-zone in a model office were measured under kinds of air changes, the measure parameters in the experimental studies included temperatures, wind speeds and pollutant concentrations, based on which the thermal comfort at a breathing-zone were studied. Experimental results show that, the temperature, pollutant concentration and wind speeds in a breathing-zone under 5 times air changes are better than those under 6 times air changes. The calculating results of PMV and PPD indicate that the thermal comfort at a breathing-zone under 5 times air changes is better. The experimental study is instructive for the development of the ventilation.


2018 ◽  
Vol 5 (15) ◽  
pp. 2345-2348 ◽  
Author(s):  
Deng-Jie Zhu ◽  
Wen Ding ◽  
Dong-Hui Wang ◽  
Min Xue ◽  
Yong Yang

A new type of carbazole-based sulfonamide macrocycle was synthesized efficiently in one single step.


2021 ◽  
Vol 143 (5) ◽  
Author(s):  
Jin Li ◽  
Xiaoli Fu ◽  
Shenglin Yan

Abstract Based on the study of leakage characteristics of labyrinth seal structure (LSS), a new type of combined seal structure (CSS) consisting of the labyrinth structure and the nozzle structure has been proposed. The sealing characteristics of CSS and LSS are compared by means of numerical simulation and experiments, and the effects of the internal resistance of the device, structural geometric parameters and other factors on the leakage characteristics of CSS are studied. The results illustrate the following conclusions: (a) When the inlet flow is 12 m3/h and the internal resistance of the device is 2000–4000 Pa, the leakage rate of CSS decreases by 30%–40% in comparison with that of LSS, which indicates that the performance of CSS is much better than that of LSS. (b) The leakage rate increases as the internal resistance of the device increases. When the internal resistance of the device increases from 2000 Pa to 8000 Pa, the leakage rate increases from 26% to 72%. (c) When the internal resistance of the device is constant, the larger the inlet flow, the smaller the leakage rate. (d) The choice of nozzle radius in structural geometric parameters is more important for the leakage rate than the tooth height and teeth numbers. When the nozzle radius decreases, ΔPAB (pressure difference between the labyrinth structure and the nozzle structure) and the leakage rate decrease accordingly.


2019 ◽  
Vol 55 (38) ◽  
pp. 5467-5470 ◽  
Author(s):  
Wen-Da Zhang ◽  
Xiaodong Yan ◽  
Tao Li ◽  
Yong Liu ◽  
Qiu-Ting Fu ◽  
...  

Ultrathin metal hydroxide nanosheets derived from metal–organic layers serving as electrocatalysts displayed highly efficient oxygen evolution even better than commercial IrO2.


Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1522 ◽  
Author(s):  
Ningning Hu ◽  
Xiuheng Zhang ◽  
Xianghui Wang ◽  
Na Wu ◽  
Songquan Wang

In the present work, the relationship curve of the coefficient of friction (COF) with varying loads of different morphology WS2 lubricating additives in the friction process at various sliding speeds was studied. On this basis, wear marks and elements on the wear surfaces after friction were analyzed, and then the anti-wear and mechanism effects of WS2 of different forms in the lubrication process were discussed. Meanwhile, the Stribeck curve was used to study the lubrication state of the lubricating oil in the friction process. It was revealed that the COF of lubricating oil containing lamellar WS2 decreased by 29.35% at optimum condition and the minimum COF was concentrated at around 100 N. The COF of lubricating oil containing spherical WS2 decreased by 30.24% and the minimum coefficient was concentrated at 120 N. The extreme pressure property of spherical WS2 was better than that of lamellar WS2, and the wear resistance of spherical WS2 was more stable when the load was over 80 N. The different morphology of WS2 additives can play anti-wear and anti-friction roles within a wide range of sliding speeds.


2004 ◽  
Vol 35 (6) ◽  
pp. 919-928 ◽  
Author(s):  
MICHAEL B. FIRST

Background. The objective of this paper is to describe and conceptualize an unusual and probably rare condition: the intense longstanding desire to have an amputation.Method. Structured interviews were conducted by telephone of 52 subjects (mean age: 48·6, range 23–77 years; 47 male, 4 female, 1 intersexed) self-identified as having had a desire to have an amputation.Results. Seventeen per cent (n=9) had an arm or leg amputated with two-thirds using methods that put the subject at risk of death and one-third enlisting a surgeon to amputate their healthy limb. The most common reported reason for wanting an amputation was the subject's feeling that it would correct a mismatch between the person's anatomy and sense of his or her ‘true’ self (identity). None were delusional. For all but one subject age at onset was during childhood or early adolescence. For those who had psychotherapy or medication there was no change in the intensity of the desire for amputation. The six subjects who had an amputation at their desired site reported that following the amputation they felt better than they ever had and no longer had a desire for an amputation.Conclusions. These preliminary results suggest the existence of an extremely unusual clinically distinct condition characterized by a lifelong desire to have an amputation of a particular limb. The condition is associated with serious negative consequences: amputation attempts, impairment and marked distress. Reflecting similarities between Gender Identity Disorder and this condition, the author suggests that it may be conceptualized as an unusual dysfunction in the development one's fundamental sense of anatomical (body) identity.


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