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OX2 (X=halogen) molecules was studied theoretically. Calculation results show that delocalized [Formula: see text] bonds exist in their electronic structures and O atoms adopt the sp2 type of hybridization, which violates the prediction of the valence shell electron pair repulsion theory of sp3 type. Delocalization stabilization energy is proposed to measure the contribution of delocalized [Formula: see text] bond to energy decrease and proves to bring extra-stability to the molecule. These phenomena can be summarized as a kind of coordinating effect.

The construction and the operation of multi-reservoir has severely altered the downstream design flood. This paper quantified the flood frequency modifications caused by multi-reservoir regulation with recorded data and a numerical model composed of peaks-over-threshold (POT) samples and time-trend models. The whole research was carried out in Dongjiang River Basin, Southern China. Results showed that (1) Sampling with the POT method could eliminate fake changes in change detection and prevent the underestimation of the design floods with an exceeding probability over 90% and the overestimation of the design floods with an exceeding probability less than 80%; (2) Multi-reservoir regulation severely reduced design flood when the exceeding probability was greater than 1% and smaller than 95%. The 10-year floods were mitigated the most. However, when the exceeding probability was over 95%, the impact was insignificant; (3) Flood mitigation was positively correlated to the number of reservoirs, but negatively correlated to the distance between the affecting reservoir and the affected station. However, when multiple reservoirs took effect on the design flood in one station, the closest reservoir did not necessarily take the most effect. The results of this research will amplify the theoretical basis for flood protection and the planning of regulation.

To compare the modified Qing Long Bai Wei needling method and ordinary acupuncture method in the effects of improving the levels of interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α in the treatment of knee osteoarthritis (KOA), and to determine the advantage of the modified Qing Long Bai Wei needling method for KOA. One hundred KOA patients were randomized into a treatment group and a control group by using the random number table, with 50 cases in each group. The treatment group was intervened by the modified Qing Long Bai Wei needling method, and the control group was given ordinary acupuncture. The two groups were observed before and after the treatment to determine the changes in the levels of IL-1β, IL-6 and TNF-α in synovial fluid, and the clinical efficacies were compared between the two groups. The total effective rate and clinical recovery rate were 97.9% and 52.1% respectively in the treatment group, versus 85.1% and 25.5% in the control group, and the between-group differences were statistically significant (both P

To summarize and analyze the acupoint selection rules in acupuncture-moxibustion for stable angina pectoris. Clinical studies and literature on acupuncture-moxibustion for stable angina pectoris with definite acupoint selection were included through retrieving China National Knowledge Infrastructure (CNKI), Wanfang Database and VIP in order to analyze the characteristics and rules of acupoint selection in acupuncture-moxibustion treatment for stable angina pectoris. It has been found that the acupoint selection of acupuncture-moxibustion prescriptions for stable angina pectoris focused on specific acupoints. The top 5 acupoints with the highest using frequency included Neiguān (内关PC 6), Danzhōng (膻中CV 17), Xīnshū (心俞BL 15), Zusānlĭ (足三里ST 36) and Sānyīnjiāo (三阴交SP 6). Acupuncture-moxibustion treatment of stable angina pectoris involved 12 meridians, mainly including the hand-jueyin pericardium meridian, the foot-taiyang bladder meridian, conception vessel, the foot-yangming stomach meridian, the foot-taiyin spleen meridian, and the hand-shaoyin heart meridian, etc., embodying the characteristics and rules of acupoint selection such as "highlighting the special treatment effect of acupoints" "selecting acupoints along the pericardium meridian, bladder meridian and conception vessel, combining the anterior and the posterior acupoints", "selecting the distal acupoints of spleen and stomach meridians, and focusing on specific acupoints", etc.

Contamination in a wafer transportation box [e.g., a front-opening unified pod (FOUP)] can influence device yield and performance. Additional precautions might be required to prevent outside contamination during FOUP door opening. This paper experimentally examines moisture evolution in a pre-purged FOUP with an open door in a mini-environment. Air curtains of different widths ( ${W}_{A}$ ) were employed to prevent outside moisture intrusion, and their performance was compared with that of a conventional purge method. Clean dry air was used as the supplied gas in experiments. A moisture prevention index (MPI) was further introduced as a tool for interpreting results. When the conventional purge method was used, moisture in the mini-environment was rapidly transferred into the FOUP, and relative humidity (RH) reached approximately the same levels as the mini-environment, indicating poor moisture prevention performance. RH values were much lower when the air curtain was used. The best moisture prevention performance was observed for a system using an air curtain with ${W}_{A}\,\,{=}\,\,50$ mm. The MPIs for the conventional purge method were approximately 8.0%–8.4%, whereas those for the air curtain application ranged from 40%–100%. Most importantly, the MPIs for ${{W}}_{A} {=} {{50}}$ and 70 mm reached or exceeded 90%.

Heterogeneity caused by seasonality could lead to the estimation error of the design flood level (DFL). This research intended to examine the existence of seasonality in the extreme water levels in a tidal reach and to quantify its impact on the DFL estimation. The mixed-distribution, a commonly used method for design value estimation with heterogeneous samples, was tested. A case study was carried out in the Pearl River Delta, South China. Results showed that a significant seasonality existed in the extreme water levels that were generated from the flood-tide interactions in the delta. If the DFL was estimated with a single distribution, the DFL with a return period smaller than 1.1 years would be underestimated and more information of the non-flood season would be lost. The mixed-distribution was superior in its consideration of seasonality, however, when the return period was over 10 years or smaller than 5 years, the DFL estimation results of this approach were only shifted by

The stationarity assumption of hydrological processes has long been compromised by human disturbances in river basins. The traditional hydrological extreme-value analysis method, i.e., &ldquo, extreme value theory&rdquo, which assumes stationarity of the time series, needs to be amended in order to adapt to these changes. In this paper, taking the East River basin, south China as a case study, a framework was put forward for selection of a suitable distribution curve for non-stationary flood series by using the time-varying moments (TVM). Data used for this study are the annual maximum daily flow of 1954&ndash, 2009 at the Longchuan, Heyuan and Boluo Stations in the study basin. Five types of distribution curves and eight kinds of trend models, for a combination of 40 models, were evaluated and compared. The results showed that the flood series and optimal distribution curves in the East River basin have been significantly impacted by a continuously changing environment. With the increase of the degree of human influence, the thinner tails of distributions are more suitable for fitting the observed flow data, and the trend models are changed from CP (mean and standard deviation fitted by parabolic trend model) to CL (mean and standard deviation fitted by linear trend model) from upstream to downstream of the catchment. The design flood flow corresponding to a return period of more than 10 years at the Longchuan, Heyuan and Boluo Stations was overestimated by more than 28.36%, 53.24% and 26.06%, respectively if the non-stationarity of series is not considered and the traditional method is still used for calculation. The study reveals that in a changing environment, more advanced statistical methods that explicitly account for the non-stationarity of extreme flood characteristics are required.