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CO2 is an important carbon resource, which could be chemically utilized by carboxylation. In this paper, the carboxylation between benzene polycarboxylic acids (BPCAs) and CO2 was conducted using Cs2CO3 as a catalyst. The relationship between the product distribution and Mulliken charge at the reaction site of BPCAs was explored by combining experiments and quantum chemical calculations of molecular properties in the reaction of carboxylation between BPCAs and CO2. The negative Mulliken charge was found to facilitate carboxylation at the reaction site of BPCAs. Hydrogen abstraction was the rate-determining step for carboxylation, and its energy barrier was calculated for different C–H in the BPCA molecule. The results showed that the C–H bond with the more negative Mulliken charge was more easily deprotonated, which further verified the above conclusion. The study provides a convenient approach to predict a product distribution for carboxylation between BPCAs and CO2 according to the Mulliken charge of BPCAs. [ABSTRACT FROM AUTHOR]

This paper reviews a variety of dilute hydrochloric acid wastewater treatment processes, including desorption, rectification, combination, spray roasting, and emerging methods such as membrane separation and metal organic framework adsorption. The principles, processes, advantages and disadvantages and development prospects of various process methods are discussed. According to the existing technology, the concept of adding an azeotropic agent and adopting azeotropic distillation to regenerate dilute hydrochloric acid is proposed. [ABSTRACT FROM AUTHOR]

Coal gasification tar residue (CGTR) is a kind of environmentally hazardous byproduct generated in fixed-bed coal gasification process. The CGTR extracted by ethyl acetate was used to prepare powdered activated carbon (PAC), which is applied later for adsorption of phenol. The results showed that the PAC prepared under optimum conditions had enormous mesoporous structure, and the iodine number reached 2030.11 mg/g, with a specific surface area of 1981 m²/g and a total pore volume of 0.92 ml/g. Especially, without loading other substances, the PAC, having a strong magnetism, can be easily separated after it adsorbs phenol. The adsorption of phenol by PAC was studied as functions of contact time, temperature, PAC dosage, solution concentration and pH. The results showed a fast adsorption speed and a high adsorption capacity of PAC. The adsorption process was exothermic and conformed to the Freundlich models. The adsorption kinetics fitted better to the pseudo-second-order model. These results show that CGTR can be used as a potential adsorbent of phenols in wastewater. [ABSTRACT FROM AUTHOR]

Aiming at the problems of complex running environment of city tram, numerous constraint conditions and huge search space on train operation adjustment, this paper proposed the virtual platform, basing on which an optimized mathematic model of operation adjustment was established. By introducing the idea of the immune memory and the antibody concentration inhibition mechanism of the immune system, it used the immune particle swarm optimization algorithm to solve the model. Basing on the data from the test line of Haizhu city trams, it conducted the simulation. The result shows that the immune particle swarm optimization algorithm with virtual platform is able to solve the problems in city tram operation adjustment, and is more efficient than GA algorithm. [ABSTRACT FROM AUTHOR]

Calcium acetate and sodium hydroxide solution with different concentrations mixed with three demineralized low rank bituminous coals were boiled respectively in order to ion exchange with carboxyl and total acids functional groups. The titration end of carboxyl and total acids functional groups were controlled by the pH of calcium acetate solution and phenolphthalein indicator respectively. It showed that correct carboxyl content was obtained at 0.15 mol/L calcium acetate and 2 h boiling time; total acids functional groups were obtained at 0.25 mol/L sodium hydroxide and 1 h boiling time. The carboxyl content was lower than 2 mmol/g and the phenolic hydroxyl content was between 2 and 4 mmol/g; the oxygen in total acids functional groups was more than half in three low rank bituminous coals (dry ashes free basis). An accurate method for measuring acidic functional groups in low rank bituminous coals was obtained. [ABSTRACT FROM AUTHOR]

Extracting polycyclic aromatic structures (PASs)-enriched portion from direct coal liquefaction residue (DCLR) with an energy-efficient way is significantly important for the effective utilization of DCLR. In the investigation, dipropylamine (DPA) with weak polarity was used to extract DCLR as a CO 2 -triggered switchable solvent. When the extract solution was triggered by CO 2 , the extract automatically precipitated with the yield of 22.8% of DCLR. Furthermore, adding proper amount of NaOH could successfully achieve the recovery of DPA, and the recovered solvent could be reused for extracting DCLR. According to the characterization results of the extract by multiple analytical tools, the extract mainly consisted of PASs with over 4 rings, and the average molecular model of aromatic cluster could be represented by the derivative of coronene with 8 substituent groups. The investigation proved that extraction of PASs-enriched portion using DPA from DCLR was feasible, and tremendous energetic and environmental benefits could be potentially gained given that the separation of extract and solvent as well as solvent recovery could be achieved by the non-thermal CO 2 -trigger. [ABSTRACT FROM AUTHOR]

Objective: To investigate the effect of acupuncture on blood oxygen saturation in the patient of obstructive sleep apnea-hypopnea syndrome (OSAHS) in sleeping and to evaluate the therapeutic effect of acupuncture on this disease., Methods: Thirty cases with OSAHS were treated with acupuncture at Shanglianquan (Extra), Fengfu (GV 16), Yamen (GV 15), Fengchi (GB 20), etc. 3-5 sessions each week. After treatment of 30 sessions, apneahypopnea index (AHI), mean blood oxygen saturation (MSaO2), the lowest blood oxygen saturation (LSaO2), oxygen desaturation > or = 4% index (ODI4), the mean blood oxygen saturation of oxygen desaturation when SaO2 < 90%, the longest time of oxygen saturation > or = 4% were observed before and after treatment., Results: The effective rate of acupuncture was 23.3% for OSAHS. After acupuncture, AHI and ODI4 significantly reduced (P < 0.01); LSaO2 significantly increased (P < 0.01); MSaO2 and the mean blood oxygen saturation of oxygen desaturation when SaO2 < 90% significantly enhanced (P < 0.05); the longest time of oxygen saturation > or = 4% did not significantly change., Conclusion: The acupuncture treatment has intervenient effect on OSAHS and alleviates anoxia, so acupuncture is one of therapies improving anoxia in patients of OSAHS.