Direct photoelectrochemical nitrate synthesis in an acidic electrolyte from N_(2)by a hole coupled oxygen atom transfer process

Ammonia is an important chemical for pharmaceutical,agriculture,industry,as well as energy production et al.However,the industrial production of ammonia using the Haber-Bosch process is energy-intensive,which stimulates us to explore a cost-effective and low-carbon footprint way for the synthesis of ammonia[1–3].Electrochemical(EC)synthesis of ammonia from an aqueous N_(2)reduction reaction(NRR)has gained significant attention in recent years,while the high dissociation energy of the N≡N bond(941 kJ/mol),as well as higher over-potential than hydrogen evolution reaction(HER),cause a lower efficiency[4].

Oxygen Transfer and Hydrodynamics in a Flexible Fibre Biofilm Reactor for Wastewater Treatment

A flexible fibre biofilm reactor was developed for treatment of organic wastewaters.The hydrodynamic characteristics and mass transfer coefficients of oxygen were studied and compared with those of the conventional activated sludge processes.Tracer experiments were performed to obtain the residence time distributions of the reactors.The results indicated that both reactors could be treated as mixed flow reactors.The effects of flow rates of water and air on the overall mass transfer coefficient of oxygen were investigated,and the correlations between the mass transfer coefficient and the ratio of flow rates were obtained.Compared to the conventional activated sludge reactor,the mass transfer coefficients in the flexible fibre reactor were similar to but slightly lower,and less sensitive to the variation in the ratio of flow rates.It indicated that the fibre packing in the reactor hindered the oxygen transfer to some extent.

Effects of CeCl_3 on Energy Transfer and Oxygen Evolution in Spinach Photosystem Ⅱ

Due to 4f electron characteristics and alternation valence, cerium involved in an oxidation-reduction reaction in plant, closely relating to photosynthesis. Our studies proved that cerium could promote photosynthesis and greatly improve spinach growth. However, the mechanism of promoting energy transfer and conversion by cerium remains unclear. Here we reported that the effects of Ce^3＋ on energy transfer and oxygen evolution in photosystem Ⅱ （PS Ⅱ ） isolated from spinach, which was related to 4f electron characteristics and alternation valence in Ce molecule. The methods of absorption spectrum, fluorescence spectrum were used in the research. Results showed that Ce^3＋ treatment at low concentration could suitably change PS Ⅱ mieroenvironment, increase the absorbance of visible light, improve the energy transfer among amino acids within PS Ⅱ protein-pigment complex, and accelerate energy transport from tyrosine residue to chlorophyll a. In summary, the photochemical activity of PS Ⅱ （fluorescence quantum yield） and its oxygen evolving rate were enhanced by Ce^3＋.

Simulation of oxygen transfer in liquid lead under influence of nanoparticles by using lattice Boltzmann method

Oxygen transfer presents a serious challenge in the application of liquid lead as a nuclear coolant in advanced reactors. To mitigate corrosion by liquid lead in contact with steel, carefully controlling the oxygen concentration has been used as an effective way. Oxygen needs to mix in liquid lead uniformly and quickly. To enhance oxygen transport in liquid lead, nanoparticles are added to the liquid metal. In the current study, a lattice Boltzmann method is applied to investigate natural convection of copper/lead and aluminum oxide/lead in two-dimensional simplified container. Two thermal boundary cases are evaluated in order to check the effect of different natural convection flow patterns on oxygen transport. Some useful information are obtained such as improvement in natural convection and reduction in oxygen equilibrium time.

Oxygen Atom Transfer Reaction of Manganese-oxo Corrole toward Dimethyl Sulfide: a Density Functional Study

The effects of axial ligand on the oxygen atom transfer(OAT)reaction from 5,10,15-tris(pentafluorophenyl)corrole((tpfc)MnVO)to dimethyl sulfide(DMS)have been investigated by density functional theory(DFT)calculations.Imidazole(Im),4-methylimidazole(4-MI)and pyridine(Py)were selected as the axial ligands.The results revealed that the axial ligand can form coordinate bond with(tpfc)MnVO in the transition state(TS)of the OAT reaction.The axial coordination favored charge transferring from(tpfc)MnVO to DMS,and weakened the Mn≡O bond in both singlet and triplet states.Furthermore,axial coordination can reduce the energy barrier of neutral(tpfc)MnVO from 23.62 kJ·mol^-1 to less than 3 kJ·mol^-1 in the triplet state,which is significantly lower than in the singlet state.This makes(tpfc)MnVO tend to direct the OAT reaction via triplet state pathway.On the other hand,the energy barriers of[(tpfc)MnVIO]+species from disproportionation pathway increased from 1.26 to 33.95 kJ·mol^-1 in a doublet state.This suggests axial ligands were conducive for direct(tpfc)MnVO OAT reaction pathway.

Hydrodynamics and oxygen transfer in a novel extra-loop fluidized bed bioreactor

In this paper, the characteristics of fluid mixing time in a novel extra-loop fluidized bed were studied. The results showed that the mixing time was shortened with the increase of fluid velocity. All the discrete numbers of the reactor were above 0.2. The serial number n was 2.5 -3.0. It was judged accordingly that the reactor fluid state was continous stirred tank reactor （CSTR） mainly. When the inspiratory capacity increased the mixing time of the reactor was shortened. Thus the air input was beneficial for the fluid mixing. During the three phases mixing process, the mixing time of the reactor could be decreased by the n increase of carrier and air loading together, but the change was not significant. The parameters affecting the reactor fluid state were fluid velocity, inspiratory capacity and carrier. KLa could be increased with the air loading increase, and at the same gas/liquid ratio when the pressure drop was high, KL~ value was increased. The amount of carrier complex influence on KLa. As the carrier loading continued to increase, its value had been dropped but the changes was not significant, and optimization condition was found at above 800 1 000 g carrier loading （pouzzolane） or 600 g PVC. Under gas/liquid ratio of 0.8% -5.2%, KLa was （0.62-1.37）×10^-2· s^-1.

Heat Transfer Characteristics of Boiler Convective Heating Surface Under Pressurized Oxygen-fuel Combustion Conditions

增压富氧燃烧是一项极具前景的减排CO2新技术。对增压富氧燃烧条件下,对流受热面换热特性进行研究具有重要的意义。该文以一台实际300MW等级机组煤粉锅炉为计算对象,采用维里方程及Chun等的计算方法计算确定增压富氧燃烧烟气物性,采用宽带关联k模型计算富氧燃烧烟气辐射特性。进行了常规空气燃烧以及φ（O2）：φ（CO2）=21：79、φ（O2）：φ（CO2）=30：70两种比例的0.1、0.5、1.0、1.5、6 MPa五种压力下增压富氧燃烧各对流受热面的热力计算,分析了增压富氧燃烧条件烟气压力变化对各受热面换热特性的影响。研究结果表明：随烟气压力的升高,烟气流速下降,但烟气的Re却基本保持不变,对流换热系数有所增加。增压富氧燃烧烟气的辐射换热系数比空气燃烧烟气辐射换热系数大。实现同样的换热量,增压富氧燃烧条件下（φ（O2）：φ（CO2）=21：79、φ（O2）：φ（CO2）=30：70）对流受热面所需换热面积比常规空气燃烧条件下少。

The element transfer behavior of gas pool coupled activating TIG welding

This paper deals with a novel dual shield TIG welding method named gas pool coupled activating TIG( GPCA-TIG)welding. The welding method divides the shielding gas into two layers. Inert gas such as Ar is adopted as the inner layer gas to protect the tungsten electrode and the molten pool metal. Pure O_2,N_2 or mixture of them are used as the outer layer gas to increase the weld penetration and improve the low temperature toughness of weld metal. Through analyzing the interaction between outer gas and arc and the distributions and existing forms of oxygen and nitrogen elements,the transfer behaviors of nitrogen and oxygen from arc to pool were investigated. The results show that,the interaction between the outer gas and arc plasma makes the arc slightly constrict. The incoming oxygen enriches on the molten pool surface and exists in the form of iron oxide,chromium oxide,manganese oxide and silicon oxygen compounds. The incoming nitrogen evenly distributes in the molten pool and exists in the form of nitrogen atom.

STUDIES OF DISSOLVED OXYGEN IN PRODUCTION OF D-RIBOSE BY FERMENTATION

This paper mainly dealt with the dissolved oxygen in production of D-ribose by fermentation. The oxygen transfer coefficients of common flask, buffed flask and jar fermentor were determined.

Atmospheric Pressure Cold Argon/Oxygen Plasma Jet Assisted by Preionization of Syringe Needle Electrode

An atmospheric pressure nonequilibrium argon/oxygen plasma jet assisted by the preionization of syringe needle electrode discharge is reported. With the syringe needle plasma as its pre-ionization source, the hybrid barrier-jet was shown to generate uniform discharge with a lower breakdown voltage and a relatively low gas temperature varying from 390 K to 440 K, even when the vol.% oxygen in argon was up to 6%. Utilizing the actinometry method, the concentration of atomic oxygen was estimated to be about in an orders of magnitude of 10^17 cm^-3. The argon/oxygen plasma jet was then employed to clean out heat transfer oil, with a maximum cleaning rate of 0.1 mm/s achieved.

Useful and Unique Descriptions of Tropospheric Processes Which Produce Oxygen and Thereafter Give Birth to Equatorial Electro-Jets

Formation of negative static charges (e-) throughout troposphere is a natural phenomenon revealed by some weather events such as storms and lightning flashes that accompany thunderclouds. This climatic phenomenon (formation of negative charge in that case) has long been considered as physical phenomena of very small space-time scales. Now we have good reasons to say that this perception of troposphere electrical status is totally meaningless. Indeed, it is now easy to show that significant numbers of electrons are provided to troposphere at each appearance of a thunderstorm (or a lightning flash). Thereafter, movement implemented in the troposphere by winds (e.g., West African aerojet) contributes to the formation of low altitudes Electrojets (e.g., West African Equatorial Aerojet gives birth to West African Equatorial Electrojet). The existence of Low Layers Equatorial Electrojets (LL-EEJ) was totally unknown by the first theorists who have studied the Earth’s Ionosphere Plasma Physics and Electrodynamics. This mistake has led their followers to many questions unanswered in their attempt to explain the longitudinal and seasonal variations of observed EEJ. In this paper, we will provide many useful explanations on the manner in which clouds provide oxygen to troposphere and thereafter trigger negative static charges (e-) throughout both troposphere and ionosphere. Indeed, this paper also explains how, opportunely, the ITF (inter tropical front) plays the role of the tap which facilitates oxygen transfer from troposphere to ionosphere. Detailed studies on the Earth’s troposphere plasma physics and electrodynamics are impatiently awaited.

Experimental Study of Dissolved Oxygen Transport by Regular Waves Through a Perforated Breakwater

The perforated breakwater is an environmentally friendly coastal structure, and dissolved oxygen concentration levels are an important index to denote water quality. In this paper, oxygen transport experiments with regular waves through a vertical perforated breakwater were conducted. The oxygen scavenger method was used to reduce the dissolved oxygen concentration of inner water body with the chemicals Na2SO3 and COC12. The dissolved oxygen concentration and wave parameters of 36 experimental scenarios were measured with different perforated arrangements and wave conditions. It was found that the oxygen transfer coefficient through wave surface, K1α1, is much lower than the oxygen transport coefficient through the perforated breakwater, K2α2. If the effect of K1α1 is not considered, the dissolved oxygen concentration computation for inner water body will not be greatly affected. Considering the effect of a permeable area ratio a, relative location parameter of perforations 6 and wave period T, the aforementioned data of 30 experimental scenarios, the dimensional analysis and the least squares method were used to derive an equation of K2α2 （K2α2=0.0042aσ56δ2T1）. It was validated with 6 other experimental scenarios data, which indicates an approximate agreement. Therefore, this equation can be used to compute the DO concentration caused by the water transport through perforated breakwater.

MASS TRANSFER AND HYDRODYNAMICS IN AN AIRLIFT REACTOR WITH VISCOUS NON-NEWTONIAN FLUID

In an internal loop airlift reactor of 55L working volume,the gas-liquid volumetric oxygenmass transfer coefficient k_Lα,gas holdup ε_G and liquid circulation time t_c were measured with the sol-ution of carboxymethyl cellulose(CMC)to simulate the performance of a reactor with highly viscousbroth.Electric conductivity and oxygen probes were used to measure the local gas holdup,liquidcirculation time and oxygen mass transfer coefficient in the individual sections of the reactor(riser,downcomer and the gas-liquid separating section at the top of the reactor)and the total reactor,respectively.The values of k_Lα for the riser,downcomer and separation sections of the reactor were alsoestimated and compared with that for the total reactor.The results show that,both k_Lα and ε_G in-crease but t_c decreases with increasing gas velocity.Correlations and comparisons with works reportedin the literature are also presented.Data show that the methods developed for k_Lα measurements inthe individual section

Real Time Dynamic Study of Amperometric Exhaust Oxygen Sensors

Previously,we had identified the various dynamic mechanisms of a wide range air to fuel ratio sensor operated in the engine exhaust by using the transfer function approach.In this study,we utilized these results to model the real time sensor response to an engine exhaust excursion.In the fitting,we identified a new dynamic mechanism,which was not detected in the previous transfer function study.This new dynamic occurred at the stoichiometric point when the engine changed from rich to lean.This new mechanism involved the depletion of the adsorbed fuel species on the electrode surface by an oxidation process. The dynamics of this effect depends on the ratio of the diffusion flux of the sensor-coating layer to the total adsorbed gas species on the electrode surface.The smaller the ratio is,the slower the dynamic mechanism will be.

PN^(3)P-钳型镍硝酸根配合物的合成及光反应性质

PN^(P-)钳型镍硝酸根配合物2可通过其前体镍氯化物1与硝酸银复分解反应制备,产率高达95%;配合物2的结构通过核磁、红外、HRMS、X-射线单晶衍射等表征进行了确认,其中硝酸根以η^(1)-ONO_(2)的方式与金属镍配位。配合物2具有优异的光反应性质,通过控制光照时间,可分别转化为钳型镍硝基配合物3、氧原子分子内转移的硝基配合物4和配体磷完全氧化的镍双硝酸根配合物5。它们的结构均通过核磁和单晶表征证实,配合物3的结构还通过对比1与亚硝酸银反应生成产物的核磁数据进行了验证。

调控双钙钛矿中高熵组分促进高温析氧反应

固体氧化物电解池(SOEC)中阳极析氧反应动力学较为迟缓,限制了SOEC器件电催化转化能力,因此针对阳极材料的改性研究对于进一步提升SOEC电化学性能十分关键。高熵钙钛矿(HEP)在许多反应中表现出良好的催化活性,但在SOEC中的应用鲜有研究。本文通过在双钙钛矿的A位或A'位分别掺杂不同的稀土金属、碱土金属或碱金属离子,合成了(Pr_(0.2)La_(0.2)Sm_(0.2)Nd_(0.2)Gd_(0.2))BaCo_(2)O_(6-δ)(A-HEP)和Pr(Ba_(0.2)Sr_(0.2)Ca_(0.2)Na_(0.2)K_(0.2))Co_(2)O_(6-δ)(A'-HEP)两种高熵钙钛矿材料。由于掺杂离子平均半径和氧化态的差异,A-HEP保持四方双钙钛矿相结构而A'-HEP则转变为正交单钙钛矿相。物理化学表征结果表明,A-HEP中Co平均价态更高,Co 2p-O 1s杂化更强,从而增加了电子转移路径并降低了转移能垒。同时,A-HEP中表面氧空位浓度更高,可为阳极析氧反应提供更多的活性位点。因此,在具有A-HEP阳极的SOEC中,与氧输运、电子传输和表界面反应过程相关的阳极极化电阻显著降低,并在800℃下实现最高1.76 A·cm^(-2)的电流密度和200 h的稳定性。本工作为高熵钙钛矿材料在SOEC阳极中的应用提供了新的策略。

噻二唑衍生物的制备及性能评价

针对现有噻二唑衍生物制备工艺中废水化学需氧量(COD)极高的问题,探索以去离子水替代乙醇作为反应溶剂,并引入相转移催化剂促进固-液两相反应,开发了制备噻二唑衍生物的绿色环保新工艺;进而,采用红外光谱、液相色谱、质谱等手段对新工艺合成的产物进行了结构表征,采用铜片腐蚀试验和四球试验评价了合成产物的金属腐蚀抑制性能、极压性能和减摩性能。结果表明:采用新工艺合成产物过程中产生的废水COD为2000 mg/L,与传统工艺产生的废水COD(700000 mg/L)相比显著降低,说明新工艺符合绿色环保要求;采用传统工艺和新工艺分别合成了2,5-双(叔壬基二硫代)-1,3,4-噻二唑,其金属腐蚀抑制性能、极压性能、减摩性能相当,且优于市售噻二唑衍生物类金属减活剂T561。

夏冬两季AAO工艺微孔曝气系统性能测定与评价

以上海某城镇污水处理厂为研究对象,在夏冬两季通过好氧池沿程实地测试,对污染物去除效果和曝气系统性能进行系统测定与评价。结果表明,冬季水量负荷较夏季低,好氧池反应时间延长且充分曝气,抵消了低温对硝化的负面影响,因此,夏冬两季出水水质均达到《城镇污水处理厂污染物排放标准》(GB 18918—2002)一级A排放标准。与夏季相比,冬季生物处理工艺的需氧量更高,微孔曝气系统的氧传质效率更低,导致所需供气量更高,曝气效率更低。夏季和冬季供氧量比需氧量分别高38.99%和7.07%,夏季节能潜力较大。好氧池污染物浓度沿程下降,末端污染物浓度几乎不变,而末端溶解氧浓度远高于前端,说明末端的供氧并未用于COD_(Cr)氧化和氨氧化作用,存在过度曝气现象,因此,可适当降低好氧池末端供气量。

麻醉复苏室全麻患者院内转运脉搏血氧饱和度下降风险预测模型的构建与验证

目的构建预测麻醉复苏室(PACU)全麻患者转运脉搏血氧饱和度(SpO_(2))下降风险的列线图模型并进行临床评价,以期做到早期识别、降低转运危险。方法回顾性选取2021年3至9月浙江中医药大学附属第二医院791例PACU全麻患者作为建模组,2021年9月至2024年6月浙江中医药大学附属第二医院及杭州市中医院共419例PACU全麻患者作为验证组。根据SpO_(2)下降是否>5%进行分组,采用单因素分析、多因素logistic回归筛选PACU全麻患者发生SpO_(2)下降的独立影响因素,并构建预测模型,采用R软件绘制列线图并作验证。结果SpO_(2)下降发生率为29.1%,最终进入模型的影响因素有年龄、BMI、吸烟史、从手术室转运到PACU SpO_(2)下降情况、在PACU吸氧、早期预警评分、Ramsay镇静评分、PACU滞留时间、转运时间、转运人员职称、转运过程中与患者沟通。建模组的AUC、灵敏度、特异度、约登指数分别为0.878、0.822、0.793、0.615;验证组模型准确率为80.19%。结论列线图模型区分度、校准度较好,对识别PACU全麻院内转运患者发生SpO_(2)下降的风险有一定指导意义。

移动床生物膜反应器内典型水质因素对氧转移能力的影响

在污水处理节能降耗与“双碳”战略背景下,为进一步实现污水处理环节的提质增效与节能降碳,从提高氧转移能力的角度出发,在移动床生物膜反应器内,开展了水质因素对氧转移能力的影响研究,并从气泡Sauter平均直径、气泡平均上升速度和气含率等方面,定量分析了氧转移能力影响机制。结果表明:当十二烷基硫酸钠(SDS)浓度由0增大至10 mg/L时,不同载体填充率条件下的氧转移能力均降低;但当SDS浓度由12增大为20 mg/L时,氧转移能力逐渐提高;生物膜载体的存在削弱了SDS对氧转移能力的影响。当总溶解性固体(TDS)值由2000增大至12000 mg/L时,提高了氧转移能力;当TDS值大于12000 mg/L后,氧转移能力趋于不变。随着pH值增大,提高了氧转移能力。在实际污水处理过程中,根据不同水质条件下的氧转移能力变化,通过调节曝气强度等方式,可降低污水处理环节的能耗与成本。