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ObjectiveTo investigate the effectiveness and limitations of multifetal pregnancy reduction (MFPR) on the improvement of pregnancy outcomes of triplet or twin pregnancies conceived by in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI).MethodsWe performed a cohort study of women undergoing IVF or ICSI from 2002–2016 in reproductive center, women’s hospital, Zhejiang University School of Medicine. The cohort included 502 women who underwent MFPR and 9641 non-reduced women. Pregnancy outcomes were gestational age (GA) at delivery, pregnancy loss, preterm delivery, low birth weight (LBW), very low birth weight (VLBW), and small for gestational age (SGA). Multiple linear regression and logistic regression models were used to compare pregnancy outcomes between groups.ResultsTriplets reduced to singletons had a longer median GA (39.07 vs 37.00, P

To understand the influences of emulsified fuel on ship exhaust emissions more comprehensively, the emissions of particulate matter (PM), nitrated, oxygenated and parent polycyclic aromatic hydrocarbons (PAHs) were studied on a ship main engine burning emulsified heavy fuel oil (EHFO) and heavy fuel oil (HFO) as a reference. The results demonstrate that EHFO (emulsified heavy fuel oil) exhibits notable abilities to significantly reduce emissions of particulate matter (PM) and low molecular weight PAHs (polycyclic aromatic hydrocarbons) in the gas phase, particularly showcasing maximum reductions of 13.99% and 40.5%, respectively. Nevertheless, burning EHFO could increase the emission of high molecular weight PAHs in fine particles and pose a consequent higher carcinogenic risk for individual particles. The total average (gaseous plus particulate) ΣBEQ of EHFO exhausts (41.5 μg/m3) was generally higher than that of HFO exhausts (18.7 μg/m3). Additionally, the combustion of EHFO (extra-heavy fuel oil) can significantly alter the emission quantity, composition, and particle-size distribution of PAH derivatives. These changes may be linked to molecular structures, such as zigzag configurations in C=O bonds. Our findings may favor the comprehensive environmental assessments on the onboard application of EHFO. [ABSTRACT FROM AUTHOR]

The TFe grade of the mixed magnetic concentrate from a Liaoning iron ore processing plant is 53.92%. The main iron minerals are magnetic/hematite and the main gangue minerals are quartz. TD-II collector is used for reverse flotation in tins concentrator, but the pulp temperature Is 40 °C, winch leads to waste of resources. In order to improve the production index, a new low temperature collector DZ with multipolar base independently developed by Northeastern University Is used for reverse flotation of the mixed magnetic concentrate in thus concentrator. The effects of DZ dosage, pulp pH value, flotation temperature, starch dosage and CaO dosage on the flotation behavior of the mixed magnetic separation concentrate were investigated. For the mixed magnetic concentrate with TFe grade 53.92%, a new low temperature collector DZ was used under the conditions of flotation temperature 15 ± 2 °C, pulp pH value 9, depressant starch dosage 750 g/t, collector DZ dosage 150 g/t, and no activator was added. The flotation lockedcycle test of "one roughing, two cleanings and three scavergings" showed that a flotation concentrate with TFe grade 65.24% and iron recovery of 93.03% can be obtained, whereas under the conditions of flotation temperature 40 ± 2°C, pulp pH value 11, starch dosage 900 g/t, CaO dosage 900 g/t and collector TD-II dosage 350 g/t, a flotation concentrate with TFe grade 65.47% and iron recovery 90.71% can be obtained through the lockedcycle flotation test of "one roughing, one cleanings and three scavengings". The product inspections for the flotation concentrates obtained from the new low-temperature collector DZ and from the field reagent TD-II were carried out. By comparing the flotation results with the product inspection, t can be found that the new low-temperature collector DZ is a high-efficiency and high-selectivity low-temperature flotation collector, which can effectively solve the problem of energy waste in the reverse flotation process of the concentrator, save the beneficiation cost and improve the resource utilization efficiency. [ABSTRACT FROM AUTHOR]

: In order to investigate the effect of the process conditions on the morphology and particle size of Ag hexagonal nanoplates prepared by liquid-phase reduction method, the Ag hexagonal nanoplates were prepared by stepwise liquid phase reduction method using AgNO3 as raw material, H2O2 as oxidizing etchant, NaBH4 and AA as reducing agents, TSC as morphology inducer. We investigated the influence law of process conditions such as H2O2 and NaBH4 dosage at the stage of crystal seeding, TSC dosage at the stage of growth, and solution pH on the morphology and particle size of nanosilver, and analyzed the influence mechanism. The results showed that the production of Ag hexagonal nanoplates was more favorable when the molar ratio of H2O2/AgNO3 in the growth phase was 50 : 1, the molar ratio of NaBH4/AgNO3 was 2 : 1, the molar ratio of TSC/AgNO3 in the growth phase was 2 : 1, and the pH of the reaction solution was 8, the average edge length of Ag hexagonal nanoplates was between 40 and 60 nm. The amount of H2O2 in the crystal seeding stage was the key factor affecting the morphology of the nano-silver, with the increase of H2O2, the morphology of the nanosilver experiences a transformation from sphere to flaky, and the excess of H2O2 can make the edge of sliver nanoplate experiences an etching effect. The pH of the reaction solution during the growth phase was a key factor affecting the particle size of the nanosilver, with the increase of the pH of the reaction solution, the average particle size of the nano- silver decreases. Sodium irate can undergo selective adsorption on the surface of nanosilver, which induced anisotropic growth of nanosilver and generates a lamellar structure. [ABSTRACT FROM AUTHOR]

As a mainstream equipment in the field of "more crushing and less grinding" and selective crushing application in the mining industry, high-pressure grinding mill has been widely used in both metal and non-metal industries due to is advantages of large ore processing capacity, high crushing efficiency, and line particle size of the crushed products. This paper briefly introduces the working principle and crushing process of high pressure grinding rolls, and analyzes the application, advantages and disadvantages of three crushing processes of high pressure grinding rolls in mines combined with practical cases. The typical application of high pressure grinding rolls in mineral processing industry Is introduced, the application of new technology of high pressure grinding rolls at home and abroad Is emphatically expounded, and the application of new technology in mineral processing industry !s prospected. The process of high pressure grinding rolls combined with agitating mill/tower mill, the process of high pressure grinding rolls combined with air classifier, the process of two high pressure grinding rolls in series, the technology of two high pressure grinders in parallel and the technology of double layer vibrating screen with high pressure rolls have obvious advantages in energy saving and consumption reduction, which is expected to provide a new scheme for efficient crushing of materials. [ABSTRACT FROM AUTHOR]