机械加工中有关积屑瘤的探讨

在机械加工过程中,常常见到工件的被加工表面上出现一轮轮划痕,有的表面还有细尖的毛刺等现象,再细心看刀尖的前面0的切刃处,就会发现被粘结着一小块金属的物质,好似是在刀刃上长了瘤一样,这一小金属瘤子平时人们称之为"积屑瘤"或刀瘤,就是这现象的出现从而影响机械加工的精度和表面光粗糙度的要求。文章就这一现象论述了在切削塑性材料过程中常见的积屑瘤的产生,消失、防止措施,以及在加工时怎样保证加工表面粗糙度等进行了探讨。

Research on the development and countermeasures for circular economy

Ecological economics and sustainable development economics are the basic theories to research on circulareconomy. Through the systemically research on the relationship of the three above, this paper thinks that the reuse andrecycle of circular economy is a way that the stall is mended after a sheep is lost. Although the reduction technicallycontrols the production process, it cannot solve the waste caused by blind production and excess competition. We haveexperienced variety obstacles when implementing the circular economy, whose main reason is the conflict between theindividual ration and the social ration. Therefore, only when the individual ration and social ration incline to conformity,the cooperating Nash equilibrium will be appeared. In order to realize the harmony of ecology, economy and society, wehave to explore effective evaluation theory. This paper cites the "five flows of wealth operation theory" from professorMa Chuandong to search operation mechanism of circular economy, makes clear the developing thoughts of circulareconomy based on the realities, and brings forward some countermeasures to develop circular economy based on theabove theoretical analysis.

Machine Interference Problem with Reliable Server under Single Vacation

The machine interference problem with reliable server under single vacation is considered here. There are M similar machines that are subject to fail or breaks down with a single server who is responsible for repairing or maintaining the failed machines. The machine fails completely at random with rate 2 and they are serviced in order of breaks down. More so, the machines operate independently but are subject to fail or break down. The service time distributions of the failed machines are assumed to be exponentially distributed with state dependent service rate #n, where n is the number of failed machines. By state dependent service rate we mean a situation where the rate of service depends on the number of failed machines present in the system. The Chapman-Kolmogorov differential equations obtained for the reliable server under single vacation model is solved through ODE45 （Runge-Kutta algorithm of order 4 and 5） in MATLAB programming language. The transient probabilities obtained are used to compute the operational measures of performance for the systems. The following time dependent operational measures of performance for the system are obtained： expected number of failed machines, expected number of operating machines, machine availability, expected idle period, expected busy period, operational utilization of the machine, the variance of the expected number of failed machine and variance of expected number of operating machine in the system. The effects of failure rate of machines, service rate of failed machines and the number of operating machines are investigated; it is observe that the rate at which machine fails and is serviced, affect the expected number of failed and operating machines in the system. The CPU time for obtaining the transient results for the systems and the variance of the systems are reported in this work.

Building Envelopes and Energy

In this paper, for a sustainable building in a Mediterranean climate areas, the relation between envelope and energy is discussed. The relation between envelopes and energy has been considered in all the phases of the life building （construction phase and during operation）. This has been made through global assessment of massive envelopes （with or without insulation） realized with blocks of different materials： natural stone, concrete and brick. For these types of envelope the thermal comfort of the rooms, the energy requirement for cooling and heating, economic and environmental aspects （costs and embodied energy） in the life cycle of the building have been studied.

Influence of Technological Operations in the Dissolved Oxygen Content of Wines

Oxygen plays a crucial role in oenology. The oxygen leads to changes in the chemical and sensory profile of wines. On one hand, the impact of moderate oxygen exposure of red wine has a positive effect in its colour, aromatic bouquet and mouth-feel properties. On the other hand, oxygen has a negative effect on white wine＇s quality, as well as the sensory and compositional levels. The purpose of this study was to quantify the dissolved oxygen in red and white wine, during different cellar operations such as racking, tartaric stabilization, filtering and bottling. The techniques that contribute most to the enrichment of oxygen in wine are： cold tartaric stabilization （2.29 mg/L, white wines）, bottling （1.38 mg/L red wines and 1.11 mg/L white wines） and bag-in-box filling （2.47 mg/L red wines; 2.22 mg/L white wines）. After identifying the most critical technical operations in wine making, preventive and corrective measures had to be taken to reduce the dissolved oxygen content of wines, as well as preventing their depreciation.

Mega Container Ships, Pros, Cons and Its Implication Recession

The size of container vessels has grown up in the past ten years and the trend prospect to be continued, according to analysis almost half of current ships order is for vessels exceeding 12,000 TEU＇s. Mega vessels have advantages to liners and for holding down the coast of ocean shipping but also raising concerns among vessel operation, insurance and they require for infrastructure adaptations and productivity level. Moreover further increase in ship size could result negative impacts and crises in recession.

通信枢纽楼能耗运行分析研究

如何在业务量不断增加,电源容量无法扩容的情况下,更好地解决供电能力紧张、机房装机位不足、机房散热等问题,是本论文的研究意义所在。本文通过对S省通信枢纽楼能耗运行分析,给出以上难点的合理化建议和建设指导原则。

Manipulating active layer morphology of molecular donor/polymer acceptor based organic solar cells through ternary blends

The development of molecular donor/polymer acceptor blend(MD/PA)-type organic solar cells(OSCs) lags far behind other type OSCs. It is due to the large-size phase separation morphology of MD/PAblend, which results from the high crystallinity of molecular donors. In this article, to suppress the crystallinity of molecular donors, we use ternary blends to develop OSCs based on one polymer acceptor(P-BNBP-f BT) and two molecular donors(DR3 TBDTT and BTR) with similar chemical structures.The ternary OSC exhibits a power conversion efficiency(PCE) of 4.85%, which is higher than those of the binary OSCs(PCE=3.60% or 3.86%). To our best knowledge, it is the first report of ternary MD/PA-type OSCs and this PCE is among the highest for MD/PA-type OSCs reported so far. Compared with the binary blends, the ternary blend exhibits decreased crystalline size and improved face-on orientation of the donors. As a result, the ternary blend exhibits improved and balanced charge mobilities, suppressed charge recombination and increased donor/acceptor interfacial areas, which leads to the higher shortcircuit current density. These results suggest that using ternary blend is an effective strategy to manipulate active layer morphology and enhance photovoltaic performance of MD/PA-type OSCs.