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Potassium-ion batteries (PIBs) have received much attention as next-generation energy storage systems because of their abundance, low cost, and slightly lower standard redox potential than lithium-ion batteries (LIBs).

In the middle or late stage of oilfield exploitation in China, the storage speed of oil well does not match pumping speed, resulting in pumping unit in the state of “non-full pumping” or “empty pumping”, which wastes lots of electricity. This paper used overdetermined equation and neural networks to predict liquid production after eliminating dimensional influence among oil well feature data with normalization method. Comparing the results with the regression equation, the effect of neural network is better than the other two methods in the case of large amounts of data. Even under the same training set, the results of the two neural networks are quite different. According to the prediction results of regular data, the effect of neural networks are significantly affected by the characteristics and quantity of the sample data. Therefore, appropriate prediction method in the prediction of liquid production can provide reference for oilfield management.

After a long period of continuous exploitation, most of oil fields in China have been in a low-permeability or ultra-low-permeability state. In order to grasp the liquid level state of oil wells in real time, the submergence depth model of oil well pumping is constructed by using the law of dynamic liquid level change during the pumping process and the working mode of oil pump. On this basis, according to the relative stability of the parameters, the stroke pumping oil model is transformed into a continuously pumping model with time as a variable. The submergence depth model of pumping oil can be divided into two types according to oil well state, namely the submergence depth model of pumping oil in full pumping state and the submergence depth model of pumping oil in non-full pumping state. The model is applicable to the pumping process of ultra-low permeability oil fields, as well as to the liquid pumping process of straight container. Combined with pumping speed and continuous pumping model, the submergence degree of oil well can be obtained in real time which provides an effective application method to implement reasonable exploitation of the oil field.

To understand the characteristics of winter fine aerosol pollution in Beijing, we conducted continuous measurements of the atmospheric trace gas ammonia (NH3), PM2.5, and inorganic ions in PM2.5 at an urban site in Beijing from February 13 to March 17, 2015. The hourly average concentration of NH3 throughout the campaign was 15.4 ± 17.5 ppb. NH3 concentrations correlated well with NH4+ in PM2.5, indicating the dominant precursor role of NH3 on NH4+ formation. The diurnal profile indicated an increase in NH3 concentrations during the morning rush hours, which was likely due to vehicle emissions. The mean ammonium conversion ratio (NHR) was 0.26, with the highest value of 0.32 in the afternoon. Elevated NHR, nitrate oxidation ratio (NOR), and NH4+ coincided with the significant increase in O3 levels in the afternoon, indicating the large daytime formation of NH4NO3 via photochemical reactions. Moreover, higher NHR values occurred under higher relative humidity (RH >60%) and lower temperature (0–10 °C). NHR increased during the nighttime and correlated well with RH, indicating the dominant role of heterogeneous reactions on gas-particle partitioning. The sulfate oxidation ratio (SOR) and NOR showed positive correlations with RH, which suggests that the conversions of SO2 to SO42− and NO2 to NO3− were sensitive to changes in RH. The sustained increase in SO42− concentrations at RH >60% suggests that RH had a higher influence on SO42− formation than on NO3− formation. As the sole precursor of NH4+, NH3 significantly enhanced daytime NH4NO3 formation via homogeneous gas-phase reactions and also promoted sulfate formation via both homogeneous and heterogeneous reactions. Moreover, the back trajectory results inferred a high contribution of southwestern air masses to atmospheric NH3 and NH4+ aerosol variations in Beijing. The result suggests the need for controlling the vehicle emissions to reduce the high levels of NH3 and alleviate PM2.5 pollution in winter in Beijing.

Severe PM2.5 pollution was observed frequently in Beijing. We conducted highly time-resolved measurements of inorganic ions associated with PM2.5 at an urban site in Beijing from 10 February to 19 March, 2015. The average PM2.5 mass concentrations during the six haze episodes ranged from 113.0 μg/m3 to 182.6 μg/m3, which were more than 8 times higher than those observed in clean periods. The secondary inorganic species (NH4+, SO42− and NO3−) in PM2.5 sharply increased during the haze episodes, indicating more extensive formation of SO42− and NO3−. The sulfur oxidation ratios (SOR) and the nitrogen oxidation ratios (NOR) in haze episodes were higher than those in clean periods, which indicated that secondary transformation in haze episodes was more significant than those in clean periods. No correlations between SOR and the oxidants (O3 and HONO) and the temperature were found, whereas a high correlation between SOR and relative humidity (RH) was found in haze episodes, which implied that sulfate was mainly produced by the aqueous-phase oxidation of SO2 rather than the gas-phase conversion of SO2 to sulfate. The conversion of SO2 to SO42− was observed to be sensitive to changes in RH. Furthermore, the SOR sharply increased at RH > 60% with the highest value of 0.88 at RH around 80% during complicated pollution. NO2 played an important role in the rapid sulfate formation with high RH and NH3 neutralization conditions in haze episodes in Beijing. The impact of RH was less apparent for nitrate than for sulfate. Nitrate was found to be produced mainly by photochemical and heterogeneous reactions, while heterogeneous reactions had a greater influence on NOR at nighttime. The NO3−/SO42− ratio indicated that mobile sources contributed more to the formation of PM2.5 than stationary sources. The result suggested the need for control of vehicle emissions to reduce the high levels of NOx and nitrate and the severe PM2.5 pollution in Beijing.

To explore the effectiveness of anterolateral thigh fasciocutaneous flap for repair of skin and soft tissue defect and simultaneous Achilles tendon reconstruction with modified methods of ilio-tibial bundle suture.Between October 2009 and June 2011, 10 cases of Achilles tendon and soft tissue defects were treated. There were 7 males and 3 females, aged from 5 to 60 years (median, 40 years). Injury was caused by spoke in 5 cases, by heavy pound in 3 cases, and by traffic accident in 2 cases. The time between injury and admission was 2-24 hours (mean, 8 hours). The size of wound ranged from 11 cm x 7 cm to 18 cm x 10 cm; the length of Achilles tendon defect was 4-10 cm (mean, 7 cm). Three cases complicated by calcaneal tuberosity defect. After admission, emergency debridement and vacuum sealing drainage were performed for 5-7 days, anterolateral thigh fasciocutaneous flap transplantation of 11 cm x 7 cm to 20 cm x 12 cm was used to repair skin and soft tissue defects, and improved method of ilio-tibial bundle suture was used to reconstruct Achilles tendon. The flap donor site was closed directly or repaired with skin grafting to repair.All flaps and the graft skin at donor site survived, healing of wounds by first intention was obtained. All patients were followed up 6-18 months (mean, 10 months). The flap was soft and flexible; the flap had slight encumbrance in 3 cases, and the others had good appearance. At last follow-up, two-point discrimination was 2-4 cm (mean, 3 cm). The patients were able to walk normally. The range of motion (ROM) of affected side was (24.40 +/- 2.17) degrees extension and (44.00 +/- 1.94) degrees flexion, showing no significant difference when compared with ROM of normal side [(25.90 +/- 2.33) degrees and (45.60 +/- 1.84)degrees] (t = 1.591, P = 0.129; t = 1.735, P = 0.100). According to Arner-Lindhoim assessment method for ankle joint function, all the patients obtained excellent results.A combination of anterolateral thigh fasciocutaneous flap for repair of skin and soft tissue defects and simultaneous Achilles tendon reconstruction with modified methods of ilio-tibial bundle suture is beneficial to function recovery of the ankle joint because early function exercises can be done.

The vapor emission control of citywide service stations in Beijing has completed in 2008. 40 service stations have been tested according to China national standards between year 2008 to 2010, and 5 service stations have been tested in 2010 time after time. The result shows that in 2008 the acceptance test attainment rates of air tightness, dynamic back pressure, and air to liquid volume ratio (A/L) of vapor recovery system were 65.0%, 95.3% and 81.5%, which is better than the initial control level of Germany and America. The air tightness failure is due to the leakage of manhole covers, gauge hatches, P/V valves of underground tanks, etc. The dynamic back pressure failure is due to small diameter and inadequate slope of the vapor pipelines, etc. The A/L is failed because the vacuum pump failure, A/L control valve off, etc. The annual test attainment rates of air tightness, dynamic back pressure, and A/L of vapor recovery system raised to 82.5%, 85.0% and 84.8% in 2009, which is about the same in 2010. It also indicates that the attainment rate of distributed vapor recovery system is slightly higher than centralized system. The attainment rate of A/L is positively correlated with dynamic back pressure (R2=0.26), and is negative correlated with the average gasoline amount dispersed by all fueling nozzles of each station (R2=0.04). The exceeded A/L value rate of fueling nozzles, which is about 50% non-attainment of A/L, is less than 10%. Four times of test in every half year can raise the attainment rates of these three indicators of vapor recovery system from 65% to 90%. On-line monitoring systems were suggested to install in designated service stations according to GB 20592 as early as possible.