The constant-volume method is used to determine the solubility of CO 2 in methanol, ethanol, n-propanol, n-butanol, n-propanol, ethylene glycol, propylene glycol, acetone, 2-butanone, ethylene glycol monomethyl ether, and ethylene glycol monoethyl ether under the pressure of 6 MPa and the temperature variations from (288.15 to 318.15) K in this paper. It is found by contrast that ketones have a greater ability to dissolve CO 2 than alcohols, ethers, and glycols, which also indicate that both the carbonyl group and the ether bond in solvents can promote the CO 2 absorption, but hydroxyl group will inhibit the CO 2 absorption.
This paper presented a novel flue gas desulfurization (FGD) process. In this method, organic amine was used to absorb sulfur dioxide in flue gas. The vapor-liquid equilibrium model of absorption of sulfur dioxide in the flue gas by an organic amine was established, and the vaporliquid equilibrium of the sulfur dioxide-ethylenediamine-phosphoric acid-water system was first predicted. For a 0.3 mol‚L -1 ethylenediamine buffer solution system, the predicted results fit the experimental results well. It is indicated that the model is preferable to predict vaporliquid equilibrium under the experimental conditions. Using an ethylenediamine-phosphoric acid aqueous solution as the absorbent, some technology conditions such as the temperature, gas-liquid ratio, pH value, concentration of the desulfurization reagent, and liquid flow rate in absorption and deabsorption were experimentally researched on the L 30 mm × 600 mm packed tower in the laboratory. The optimized conditions were finally specified after experiments. The novel FGD method presented in this paper has advantages such as high desulfurization efficiency and low investment and unit FGD expense. It is suggested that this novel method be applied to the FGD process in power plants using high sulfur coal as the fuel.
This study investigated Zn-bearing zeolite clinoptilolite (Zn-ZCP) as a Zn supplement on performance, organ or tissue development, Zn accumulation in tissues, and gene expression of Zn transporters in the duodenum of broilers. A total of 300 1-d-old Arbor Acres chickens were randomly allocated to 5 dietary treatments with 6 replicate cages of 10 birds per treatment for a 21-d feeding period. The treatments comprised a basal corn–soybean meal diet without supplemental Zn (the control) or similar diets supplemented with 80 mg/kg Zn from ZnSO4 or 20, 40, or 80 mg/kg Zn from Zn- ZCP, respectively. Supplementation of Zn-ZCP had a positive effect on G:F (linear, P < 0.05) and had tendency difference on ADG (linear, P < 0.1) of broilers during 1 to 21 d. Incremental Zn-ZCP inclusion in the diet increased the fresh weight of the pancreas (linear, P < 0.05) and tibia (linear, P < 0.05) in broilers on d 14. The same trend to the fresh weight of the tibia (linear, P < 0.05) and pancreas (linear, P < 0.05) was observed on d 21. Increasing Zn-ZCP level showed a linear response on Zn concentration in the liver (linear, P < 0.001), pancreas (linear, P < 0.05), and tibia (linear, P < 0.05) on d 14. The same trend of Zn concentrations in pancreas (linear, P < 0.05) and tibia (linear, P < 0.001) was observed on d 21. The mRNA levels of Zn transporter 2 (ZnT-2) and Zn transporter 5 (ZnT-5) in the duodenum of chicks fed the diet with 80 mg/kg Zn from Zn-ZCP did not differ from those of chicks fed the control diet, but both were lower (P < 0.05) than those of chicks fed ZnSO4 diet. Metallothionein (MT) mRNA levels of broilers fed the diet supplemented with 80 mg/kg Zn from Zn-ZCP or ZnSO4 was higher (P < 0.05) than that in the control group. Dietary treatments did not affect the mRNA expression of Zn transporter 1 (ZnT-1) or metal response element-binding transcription factor-1 (MTF-1). In conclusion, as a Zn supplement, Zn-ZCP was comparable to ZnSO4 for enhancing Zn accumulation and growth performance of broilers during 1 to 21 d. Broilers fed the diet with 80 mg/kg Zn from Zn-ZCP had different expressions of ZnT-2 and ZnT-5 in the duodenum compared with those fed the ZnSO4 diet.
Organic−inorganic hybrid metal−oxide clusters have been pursued for many years, benefiting from their abundant structures and prominent performances. Upon our exploration, a family of unusual mixed-heteroatom (Sb III , P III )-directing lanthanoid (Ln)-inserted h eteropolyoxotungstates ( Ln-HPOTs),functionalized by 1,2,3-propanetricarboxylic acid (H 3 ptca) was a c h i e v e d . T h e i n t r i g u i n g t r i m e r i c [ L n 4 ( H12− polyanion was established by two trivacant [B-α-Sb III W 9 O 33 ] 9− segments mounted on both sides and one rare [HP III W 4 O 18 ] 8− segment at the bottom, which are bridged via an organic−inorganic hybrid [W 4 Ln 4 (H 2 O) 12 O 10 (H 2 ptca) 2 ] 14+ central moiety. Such Ln-HPOTs involving dual-heteroatom-directing mixed building blocks, and even simultaneously modified by tricarboxylic ligands, are rather unseen in polyoxometalate chemistry. Moreover, the detection of 17β-estradiol through a 1-based electrochemical biosensor has been explored, demonstrating a low detection limit (7.08 × 10 −14 M) and considerable stability.
This study was conducted to investigate the effect of zinc-bearing zeolite clinoptilolite (Zn-ZCP) on performance, growth performance, nutrient retention, digestive enzyme activities, and intestinal function in broiler chickens. A total of 180 1-day-old Arbor Acres chickens were randomly divided into three groups with six replicates of ten birds for a 21-day feeding period. Birds were fed a basal corn-soybean meal diet (29.1 mg of Zn per kilogram of diet) without supplemental zinc (control) or the same diet supplemented with 80 mg/kg zinc from ZnSO4 or Zn-ZCP. Zn-ZCP and ZnSO4 treatments had lower feed: gain ratio than that of control group (P < 0.05). Addition of Zn-ZCP increased (P < 0.05) the apparent retention of organic matter and ether extract during 14-17 days, and increased (P < 0.05) pancreatic lipase activity at 14 and 21 days as well as amylase activity at 21 days. Addition of Zn-ZCP increased the villus heights and villus height to crypt depth ratio at the duodenal (P < 0.05) and jejunal (P < 0.05) of broilers at 14 days. Broilers fed the diet supplemented with 80 mg/kg Zn from Zn-ZCP had higher villus heights and villus height to crypt depth ratio of duodenum (P < 0.05) and jejunum (P < 0.05) than those fed with control diet on day 21. Zn-ZCP treatment increased (P < 0.05) IgG and sIgA concentrations in jejunum at 21 days. The results indicated that Zn-ZCP supplementation which might have modified the release of Zn further down in the intestinal tract with the controlled-release characteristic, modulated digestive enzyme activities and intestinal structure and function, increased nutrient retention, and improved feed efficiency.
From June 11, 2020, a surge in new cases of coronavirus disease 2019 (COVID-19) in the largest wholesale market of Beijing, the Xinfadi Market, leading to a second wave of COVID-19 in Beijing, China. Understanding the transmission modes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the personal behaviors and environmental factors contributing to viral transmission is of utmost important to curb COVID-19 rise. However, currently these are largely unknown in food markets. To this end, we completed field investigations and on-site simulations in areas with relatively high infection rates of COVID-19 at Xinfadi Market. We found that if goods were tainted or personnel in market was infected, normal transaction behaviors between sellers and customers, daily physiological activities, and marketing activities could lead to viral contamination and spread to the surroundings
via
fomite, droplet or aerosol routes. Environmental factors such as low temperature and high humidity, poor ventilation, and insufficient hygiene facilities and disinfection practices may contribute to viral transmission in Xinfadi Market. In addition, precautionary control strategies were also proposed to effectively reduce the clustering cases of COVID-19 in large-scale wholesale markets.
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