活性破片的动态压缩力学性能和反应性能

为了研究在冲击作用下烧结和未烧结工艺对活性破片的动态力学性能和反应性能影响,分别使用分离式霍普金森压杆和落锤加载装置对两种工艺的活性破片进行加载,并且对两种实验结果进行了对比。研究结果表明:烧结后的活性破片具有较好的力学性能,并且两种材料都具有明显的应变率效应,动态屈服强度约为静态屈服强度的2.8~3.3倍;落锤加载下烧结后的活性破片更容易发生反应,发生反应的临界落高为1.15 m。研究结果能够反映该材料的力学性能和反应性能。

模拟碳化塔中碳酸化反应合成碳酸钙晶须研究

在模拟碳化塔中进行了碳酸钙晶须合成的研究 ,发现压缩空气和CO 2 气体流量、温度、反应的液面高度对反应时间和碳酸钙晶须的生长具有很大影响 。

双膜式和多管式磺化反应器传质系数的比较

通过对双膜和多管膜式磺化反应器传质系数的计算与分析比较 ,表明传质系数的决定性因素是三氧化硫的扩散距离 ,其传质系数与实际情况较接近。又根据传质系数建立了反应高度与反应率的关系 ,分析了产品质量差异的原因 。

Recent advances in design of hydrogen evolution reaction electrocatalysts at high current density:A review

The electrolysis of water powered by renewable energy sources offers a promising method of"green hydrogen"production,which is considered to be at the heart of future carbon-neutral energy systems.In the past decades,researchers have reported a number of hydrogen evolution reaction(HER)electrocatalysts with activity comparable to that of commercial Pt/C,but most of them are tested within a small current density range,typically no more than 500 mA cm^(-2).To realize the industrial application of hydrogen production from water electrolysis,it is essential to develop high-efficiency HER electrocatalysts at high current density(HCD≥500 mA cm^(-2)).Nevertheless,it remains challenging and significant to rational design HCD electrocatalysts for HER.In this paper,the design strategy of HCD electrocatalysts is discussed,and some HCD electrocatalysts for HER are reviewed in seven categories(alloy,metal oxide,metal hydroxide,metal sulfide/selenide,metal nitride,metal phosphide and other derived electrocatalysts).At the end of this article,we also pro-pose some viewpoints and prospects for the future development and research directions of HCD electrocatalysts for HER.

Preparation of high purity ruthenium nitrosyl nitrate from spent Ru-Zn/ZrO_(2)catalyst

Preparation of high purity ruthenium nitrosyl nitrate using spent Ru-Zn/ZrO_(2)catalyst was studied,including melting and leaching to obtain potassium ruthenate solution,reduction,dissolving,concentrating and drying to obtain ruthenium trichloride,nitrosation and hydrolysis to obtain ruthenium nitrosyl hydroxide,removing of K^(+)and Cl^(-),and neutralization with nitric acid.The effects of temperature,concentration,time and pH on the yield and purity of intermediates and final product were studied,and the optimum process conditions were obtained.The yield of ruthenium nitrosyl nitrate is 92%,the content of ruthenium in high purity product is 32.16%,and the content of Cl^(-)and K^(+)are much less than 0.005%.The reaction kinetics of ruthenium nitrosyl chloride to ruthenium nitrosyl hydroxide was studied.The reaction orders of Ru(NO)Cl_(3)at 40,55 and 70℃are 0.39,0.37 and 0.39,respectively,while those of KOH are 0.16,0.15 and 0.17,respectively.The activation energy is-2.33 k J/mol.

In-situ reactive compatibilization of HDPE/GTR blends by dicumyl peroxide and phenolic resin without catalyst

In-situ reactive compatibilization of high-density polyethylene （HDPE）/ground tire rubber （GTR） blends by dicumyl peroxide （DCP） and HY-2045 - a kind of thermoplastic phenolic resin without catalyst was investigated by studying the mor-phology, stress and strain behavior, dynamic mechanical properties and crystallization performance of the blends. Scanning e-lectron microscopy （SEM） results show that there are a lot of fibrous materials distributing in the interface, which connects the dispersed phase with the matrix and obtains better interfacial strength for prominent mechanical properties. The addition of compatibilizers results in the decrease of crystallinity of the blends and the disappearance of an obvious yield phenomenon, which was proved by the differential scanning calorimeter （DSC） test and X-ray diffraction （XRD） characterization Although the crystallinity of the blends decreases,the tensile strength and tensile strain of the blends significantly increases, especially for the HDPE/GTR/DCP/HY-2045 blends, which is possibly attributed to the good compatibility of the blends owing to the in-situ interface crosslinking. In addition, it is found that the compatibilizing HDPE/GTR blends shows a higher tan^ peak temperature and a broaden transition peak for GTR phase.

弹性填料处理河道污水实验研究

采用弹性填料曝气生物膜法对污染的河道水体进行处理的实验研究,结果表明,在2m/h的流速、水温为16℃～18℃、气水比为1：1的条件下,采用弹性填料的生物膜处理系统运转正常,不易发生堵塞或系统短流,系统此时的水力停留时间为3.5h左右,污水中的COD和NH3-N去除率稳定,其均值分别为49.4%和19.1%.

Impact of salinity on treatment of saline wastewater by sequencing batch biofilm reactor process

High salinity industrial wastewater is difficult to treat using biological treatment system because of the high concentrations of salt.The potential of a sequencing batch biofilm reactor(SBBR)process in treating synthetic high salinity wastewater was evaluated at laboratory scale during a 110-day operation.The reactor was operated in a 12 h cycle,and each cycle consisted of 0.25 h influent addition,8 h aeration,3 h anoxic reaction,0.5 h sedimentation and 0.25 h effluent withdrawal.Gradual increase in salinity gradient was applied during the acclimatization period.The acclimated SBBR system was demonstrated to be an effective process to remove organic compounds and ammonia nitrogen under high salinity conditions with chemical oxygen demand(COD)and ammonia nitrogen(NH3-N)removal efficiencies of 88% and 80%,respectively.The microscopic examination indicated that rather than rotifers or vorticella,the zoogloea,filamentous fungus mingled with a small quantity of swimming infusorians were dominant bacteria in SBBR system.The removal efficiencies close to 80% in COD and 75% in NH3-N were achieved at an organic loading rate(OLR)of 0.96 kg COD/(m3·d),pH of 7.0,salinity of 14 g/L and NH3-N of 30 mg/L.

Atherosclerosis： from biology to pharmacological treatment

A recent explosion in the amount of cardiovascular risk has swept across the globe. Primary prevention is the preferred method to lower cardiovascular risk. Lowering the prevalence of obesity is the most urgent matter, and is pleiotropic since it affects blood pressure, lipid profiles, glucose metabolism, inflammation, and atherothrombotic disease progression. Given the current obstacles, success of primary prevention remains uncertain. At the same time, the consequences of delay and inaction will inevitably be disastrous, and the sense of urgency mounts. Pathological and epidemiological data confirm that atherosclerosis begins in early childhood, and advances seamlessly and inexorably throughout life. Risk factors in childhood are similar to those in adults, and track between stages of life. When indicated, aggressive treatment should begin at the earliest indication, and be continued for many years. For those patients at intermediate risk according to global risk scores, C-reactive protein, coronary artery calcium, and carotid intima-media thickness are available for further stratification. Using statins for primary prevention is recommended by guidelines, is prevalent, but remains under prescribed. Statin drugs are unrivaled, evidence-based, major weapons to lower cardiovascular risk. Even when low density lipoprotein cholesterol targets are attained, over half of patients continue to have disease progression and clinical events. Though clinical evidence is incomplete, altering or raising the blood high density lipoprotein cholesterol level continues to be pursued. The aim of this review is to point out the attention of key aspects of vulnerable plaques regarding their pathogenesis and treatment.

Leaching kinetics of low-grade copper ore with high-alkality gangues in ammonia-ammonium sulphate solution

The leaching kinetics of low-grade copper ore with high-alkality gangues was studied in ammonia-ammonium sulphate solution.The main parameters,such as ammonia and ammonium sulphate concentrations,particle size,solid-to-liquid ratio and reaction temperature,were chosen in the experiments.The results show that the increase of temperature,concentrations of ammonia and ammonium sulphate is propitious to the leaching rate of copper ore.The leaching rate increases with the decrease of particle size and solid-to-liquid ratio.The leaching rate is controlled by the diffusion through the ash layer and the activation energy is determined to be 25.54 kJ/mol.A semi-empirical equation was proposed to describe the leaching kinetics.

镁法海绵钛爬壁钛生成量的初探

在海绵钛的还原生产过程中,反应器的上部器壁会生成大量环状的爬壁钛,一炉产品爬壁钛的生成量少则500kg左右,多则达800kg^1000kg,爬壁钛不仅产品取出困难,增加操作人员劳动强度,而且其质量较差,经济损失大。本文分析了海绵钛爬壁钛的形成机理及生产过程中爬壁钛增多的原因,提出了还原中后期最大加料速度限制,以缓解反应剧烈程度和控制反应液面高度在1#范围内小幅波动,防止形成新的活性中心,是生产过程中减少爬壁钛生成量的主要途径。

Investigation of Nitration Processes of iso-Octanol with Mixed Acid in a Microreactor

In this paper, the nitration characteristic of alcohols with mixed acid for the synthesis of energetic mate-rials in a stainless steel microreactor was investigated experimentally. The nitration of iso-octanol with HNO3-H2SO4 mixed acid was chosen as a typical model reaction which involved fast and strong exothermic liquid-liquid heterogeneous reaction process. The influences of mixed acid composition, flow rate, organic/aqueous flow ratio and reaction temperature have been investigated. The results indicated that the reaction could be con-ducted safely and stably in the microreactor at 25-40°C, which are enhanced compared to 15°C or below for safe operating conditions in the conventional reactors. Moreover, the 98.2% conversion of iso-octanol could be obtained and no by-products were detected in all cases.

Effect of Different Sources of Dietary Fibre on Oxidative Stress in Laboratory Rats

The objective of the present study was to determine the effect of different sources of dietary fibre on the oxidative stress induced by a high fat diet in laboratory rats. Thirty two laboratory rats were penned individually and divided into four groups： CONT （high fat diet）, G （70 g guar gum/kg）, P （70 g apple pectin/kg） and WB （155 g wheat bran/kg）. After 11 or 13 days of treatment DNA damage of blood leukocytes was measured by Comet assay and lipid peroxidation was studied by determining the malondialdehyde （MDA） concentration in liver and in urine. In comparison with group CONT, the degree of DNA damage was significantly lower in group WB. In groups G and P DNA damage was also reduced but not significantly. Similar results were also obtained for the liver MDA concentration. All three studied groups showed reduced liver MDA concentrations but only group WB was significant compared to group CONT. In comparison with group CONT, the groups WB and P had significantly reduced 24-hour urine MDA excretion, hut not group G. The results of the experiment confirmed that wheat bran intake effectively reduces oxidative stress induced by a high fat diet.

The diagnostic value of tumor abnormal protein and high sensitivity C reactive protein in screening for endometrial cancer with endometrial thickness less than 8 mm

Objective This study aimed to combine tumor abnormal protein(TAP) and high-sensitivity C-reactive protein(hs-CRP) level detection to diagnose endometrial cancer in patients with endometrial thickness less than 8 mm, and to provide a reference for clinical screening and diagnosis. Methods Clinical data from 19 cases of endometrial cancer, diagnosed on the basis of pathological findings, were collected from September 2014 to December 2015. The inclusion criteria were as follows: the patients were first diagnosed with endometrial thickness less than 8 mm and were all in menopause. Perimenopausal patients(n = 26) with uterine fibroids seen during the same period were selected as a control group. Serum TAP and hs-CRP levels of the patients in the two groups were simultaneously determined on admission. Results We found that both TAP and hs-CRP levels in the experimental group were higher than those in the control group [(182.95 ± 72.14) μm^2 vs.(133.19 ± 55.18) μm^2, P = 0.019;(7.52 ± 19.03) mg/L vs.(1.66 ± 2.31) mg/L, P = 0.136]. The sensitivity of TAP for the diagnosis of endometrial cancer was 73.68%, the specificity was 69.23%, and the Youden index was 0.4291. The diagnostic sensitivity and specificity of hs-CRP was 15.79% and 100%, respectively, and the Youden index was 0.1579. After plotting the receiver operating characteristics curves, the optimal cut-off value for TAP in diagnosing endometrial cancer was found to be 160.662 μm^2 and that for hs-CRP was 1.07 mg/L. Conclusion For patients suspected of having endometrial cancer with endometrial thickness less than 8 mm, combined detection of TAP and hs-CRP levels can be used as a screening tool and can provide new ideas regarding clinical diagnosis and treatment.

无症状高原反应区室内光环境舒适性影响因素的研究

论文主要研究无症状高原反应区低气压环境下影响视觉舒适度的3个因素:照度水平、光源的相关色温及压力变化。实验中采用3个压力工况分别为1.0 MPa、0.9 MPa、0.8 MPa,所涉及的压力环境属无高原反应症状区域;采用120lx、600 lx和1 000 lx3个照度水平;采用两种光源相关色温分别为3 200 K(暖光)和6 400 K(冷光),有24名在校大学生参与本实验问卷调查。论文通过对参与者在实验过程中所做的各项主观评价,确定在不同压力下照度和相关色温对评价指标中的照明水平、光的明暗比和颜色真实性有显著性影响;并通过拟合回归确定照度与视觉舒适度在不同压力和不同色温下的表达式。

Investigation on 1-Heptene/Air Laminar Flame Propagation under Elevated Pressures

The laminar flame propagation of 1-heptene/air mixtures covering equivalence ratios from 0.7 to 1.5 is investigated in a constant-volume cylindrical combustion vessel at 373K and elevated pressures (1, 2, 5, and 10 atm). Laminar flame speed and Markstein length are derived from the recorded schlieren images. A kinetic model of 1-heptene combustion is developed based on our previous kinetic model of 1-hexene. The model is validated against the laminar flame speed data measured in this work and the ignition delay time data in literature. Modeling analyses, such as sensitivity analysis and rate of production analysis, are performed to help understand the high temperature chemistry of 1-heptene under various pressures and its influence on the laminar flame propagation. Furthermore, the laminar flame propagation of 1-heptene/air mixtures is compared with that of n-heptane/air mixtures reported in our previous work. The laminar flame speed values of 1-heptene/air mixtures are observed to be faster than those of n-heptane/air mixtures under most conditions due to the enhanced exothermicity and reactivity.

Modeling and Simulation of the Hydrodynamic Behavior in a High-Density Downer Reactor

The hydrodynamic behavior in a high-density downer reactor was studied. A two-fluid model based on the kinetic theory of granular flow with a k-ε turbulent model was developed to simulate the flow behavior in the system. This simulation achieved an averaged solid fraction in the bed as high as 18% in this operating regime. The flow development in high-density downer consists of 3 regions, which are first acceleration, second acceleration, and fully developed regions. In the fully developed region, the lateral distribution of the solid volume fraction is low and almost uniform in the center region with a high density peak near the wall region. Gas and solid velocities gradually increase toward the wall and form a peak near the wall region. In addition, the solid volume fraction, gas and solid velocities increase with solid circulation rate.

Practical Performance of High Bulk Modulus Oil

Although hydraulic drives have an advantage of high power density, volumetric shrinkage of hydraulic fluids due to pressure causes various disadvantages such as delay of hydraulic response and compression energy loss. Hydraulic fluids of new concept, high bulk modulus oils, have been developed as a new approach to improve the performance of a hydraulic servo system and verified. In this paper, practical performances of high bulk modulus oil, such as oil temperature rise during pump test, air bubbles generation by ultrasonic wave vibration, oxidation stability and anti-wear property, were studied. And the new oil was confirmed to have excellent practical performances besides advantages in pressure response and volumetric efficiency of pumps. Various new applications of the new oil are promising.