水压机垫板裂纹的焊接修复

我厂生产的3150t水压机的垫板,材质为ZG5CrMnMo,板厚400mm,重约7.6t,热处理状态为正火+回火。在产品试装阶段发现垫板表面有三道裂纹,裂纹最大深度20mm,裂纹长度分别为200mm和30mm,垫板及缺陷情况如下图所示。

IMPACT OF ENSO ON THE PRECIPITATION OVER CHINA IN WINTER HALF-YEARS

In this paper, the impact of ENSO on the precipitation over China in the winter half-year is investigated diagnostically. The results show that positive precipitation anomalies with statistical significance appear over southern China in El Nio episodes, which are caused by the enhanced warm and humid southwesterlies along the East Asian coast in the lower troposphere. The enhanced southwesterlies transport more water vapor to southern China, and the convergence of water vapor over southern China increases the precipitable water and specific humidity. In La Nia episodes,although atmospheric elements change reversely, they are not statistically significant as those in El Nio periods. The possible physical mechanism of the different impact of ENSO cycle on the precipitation over southern China is investigated by analyzing the intraseasonal oscillations(ISOs) in El Nio and La Nia winter half-years, respectively. By comparing the characteristics of ISOs in El Nio and La Nia, a physical mechanism is proposed to explain the different responses of the precipitation over China to ENSO in the winter half-year. In El Nio episodes, over western North Pacific(WNP) and South China Sea(SCS) the ISOs are inactive and exert little effect on water vapor transport and convergence, inducing positive precipitation anomalies with statistical significance over southern China in El Nio episodes. In La Nia episodes, however, the ISOs are active, which weaken the interannual variation signals of ENSO over WNP and southern China and lead to the insignificance of the interannual signals related to ENSO. Therefore, the different responses of precipitation over China to ENSO in the winter half-year are possibly caused by the difference of intraseasonal oscillations over WNP and SCS between El Nio and La Nia.

Theoretical and Experimental Investigations of Solar Heating Systems at Specified Output Conditions of Hot Water

The theoretical analysis discussed in this work is a suitable mathematical tool by which the performance of the proposed collector can be predicted. The obtained experimental results coincide with the obtained theoretical data obtained from the devised computer program. Controlled output temperature can be obtained from the proposed system. The performance of the tested collector under the proposed intermittent flow conditions overcomes that of the conventional thermosyphone flow collector.

Stochastic Modeling of Total Ground Irradiance of Horizontal Surface

This paper describes relatively simple stochastic model of the total ground irradiance of horizontal surface. For this purpose clearness index is modeled as a stochastic signal. The parameters of clearness index stochastic signal are chosen to fit values of daily mean insolation for each month for the location of Zagreb, Croatia. Complete model has been done in MATLAB. This model can be used for Monte Carlo simulations of technical solar systems such as photovoltaic systems or solar thermal energy systems.

Long-Term Effects of Inorganic and Organic Amendments on Organic Carbon in a Paddy Soil of the Taihu Lake Region,China

A long-term experiment set up in 1980 compared the effects of applying manures and chemical fertilizers on a paddy soil in the Taihu Lake region, China. Of the fourteen randomly distributed treatments consisting of different combinations of organic manure, inorganic nitrogen （N）, phosphorus （P）, and potassium （K）, and rice straw, eight were selected for the present study in 2007. Application of organic manure plus straw significantly increased soil organic carbon （SOC） content of the topsoil （0-10 cm） compared to that of chemical fertilizers alone. The content of SOC was relatively stable in the 10-30 cm layer in the chemical fertilizer treatments and in the 20-40 cm layer in the manure treatments. The stable carbon isotope ratio （513C） ranged from -24% to -28% and increased gradually with depth. The content of SOC was significantly （P 〈 0.05） negatively correlated with 513C. In the 0-20 cm layer, the 513C value significantly decreased in the treatments of manure alone （M）, manure and chemical N and P fertilizers （MNP）, manure and chemical N, P, and K fertilizers （MNPK）, manure, rice straw, and chemical N fertilizer （MRN）, and chemical N fertilizer and rice straw （CNR）, as compared with the no-fertilizer control. In the 30-50 cm layer, however, the ratio significantly increased in all the treatments except Treatment CNR. Mineralization of organic C peaked in the first 2-4 d of incubation and gradually leveled off thereafter over the first 3 weeks, being faster in the manure treatments than the chemical fertilizer treatments. The average rate of mineralization varied from 55.36 to 75.46 mL CO2 kg-1 d-1 and that of stable mineralization from 10 to 20 mL CO2 kg-1 d-1. In eight weeks of incubation, cumulative mineralization was always higher in the manure treatments than the chemical fertilizer treatments, being the highest in Treatment MRN. Combined humus in the soil was mainly （over 50%） composed of tightly combined fraction. The loosely combined humus and its ratio of humic acid （HA） to fulvic acid （FA） significantly increased with long-term application of organic manure and chemical fertilizers. It could be concluded that the cycle of organic C in the paddy soil ecosystem studied was stable over the long-term application of fertilizers and continued cultivation.

Inorganic material passivation of defects toward efficient perovskite solar cells

Surface passivation with organic materials is one of the most effective and popular strategies to improve the stability and efficiency of perovskite solar cells(PSCs). However, the secondary bonding formed between organic molecules and perovskite layers is still not strong enough to protect the perovskite absorber from degradation initialized by oxygen and water attacking at defects. Recently, passivation with inorganic materials has gradually been favored by researchers due to the effectiveness of chemical and mechanical passivation. Lead-containing substances, alkali metal halides, transition elements, oxides,hydrophobic substances, etc. have already been applied to the surface and interfacial passivation of PSCs.These inorganic substances mainly manipulate the nucleation and crystallization process of perovskite absorbers by chemically passivating defects along grain boundaries and surface or forming a mechanically protective layer simultaneously to prevent the penetration of moisture and oxygen, thereby improving the stability and efficiency of the PSCs. Herein, we mainly summarize inorganic passivating materials and their individual passivation principles and methods. Finally, this review offers a personal perspective for future research trends in the development of passivation strategies through inorganic materials.