Rates of bacterial sulfate reduction and their response to experimental temperature changes in coastal sediments of Qi'ao Island, Zhujiang River Estuary in China

Subtropical sediment cores （QA09-1 and QA12-9） from the coastal zone of Qi’ao Island in the Zhujiang River Estuary were used to determine the rates of sulfate reduction and their response to experimental tempera-ture changes. The depth distribution of the sulfate reduction rates was measured from whole-core incu-bations with radioactive tracer35SO42-, and peaks of 181.19 nmol/（cm3·d） and 107.49 nmol/（cm3·d） were exhibited at stations QA09-1 and QA12-9, respectively. The profiles of the pore water methane and sulfate concentrations demonstrated that anaerobic oxidation of methane occurred in the study area, which result-ed in an increase in the sulfate reduction rate at the base of the sulfate-reducing zone. Meanwhile, the sulfate concentration was not a major limiting factor for controlling the rates of sulfate reduction. In addition, the incubation of the sediment slurries in a block with a temperature gradient showed that the optimum tem-perature for the sulfate reduction reaction was 36°C. The Arrhenius plot was linear from the lowest tempera-ture to the optimum temperature, and the activation energy was at the lower end of the range of previously reported values. The results suggested that the ambient temperature regime of marine environments prob-ably selected for the microbial population with the best-suited physiology for the respective environment.

Effect of CaO and CaCO3 on Reduction Rate of Iron Ore Pellets Containing Carbon

The effect of metallurgical fluxes CaO and CaCO3 on the reduction rate of iron ore pellets containing carbon in nitrogen atmosphere has been studied by a weight-loss thermal balance. The experimental results showed that adding CaO or CaCO3 can promote reduction reaction as the added CaO or CaCO3 probably decrease the apparent activation energy of iron ore concentrate-carbon-CaO or CaCO3 reaction, and the reduction rate constant changes with mass percent of CaO and CaCO3. The kinetic analysis also showed that the rate-controlling step of the reaction is inner gas diffusion.

Formulation of Reduction Rate for Ultimate Compressive Strength of Stiffened Panel Induced by Opening

The main objective of this study is to numerically investigate the characteristics of ultimate compressive strength of stiffened panels with opening and also to fit the design-oriented formulae. For this purpose, three series of well executed experimental data on longitudinally stiffened steel plates with and without opening subjected to the uniform axial in-pane load which is carried out to study the buckling and post-buckling up to the final failure are chosen. Also, a nonlinear finite element method capable of efficiently analyzing the large elasto-plastic deflection behavior of stiffened panels is developed and used for simulation. The feasibility of the present simulation process is confirmed by a good agreement with the experimental results. More case studies are developed employing the simulation process to analyze the influence of various design variables on the reduction rate of ultimate strength of stiffened panel induced by opening. Based on the computed results, two design formulae are fitted and the accuracy of design formulae is studied. Furthermore, the viability of the design formulae for practical engineering is proved.

Reduction Rate of Ferrous Oxide in Smelting Reduction

Reduction rate of ferrous oxide in smelting reduction with iron bath has been studied. The main affecting factors on reduction rate, such as composition of the melt, temperature of molten bath, basicity of slag and the way of supplying carbonaceous materials have also been investigated.

Bit Rate Reduction in Cloud Gaming Using Object Detection Technique

The past two decades witnessed a broad-increase in web technology and on-line gaming.Enhancing the broadband confinements is viewed as one of the most significant variables that prompted new gaming technology.The immense utilization of web applications and games additionally prompted growth in the handled devices and moving the limited gaming experience from user devices to online cloud servers.As internet capabilities are enhanced new ways of gaming are being used to improve the gaming experience.In cloud-based video gaming,game engines are hosted in cloud gaming data centers,and compressed gaming scenes are rendered to the players over the internet with updated controls.In such systems,the task of transferring games and video compression imposes huge computational complexity is required on cloud servers.The basic problems in cloud gaming in particular are high encoding time,latency,and low frame rates which require a new methodology for a better solution.To improve the bandwidth issue in cloud games,the compression of video sequences requires an alternative mechanism to improve gaming adaption without input delay.In this paper,the proposed improved methodology is used for automatic unnecessary scene detection,scene removing and bit rate reduction using an adaptive algorithm for object detection in a game scene.As a result,simulations showed without much impact on the players’quality experience,the selective object encoding method and object adaption technique decrease the network latency issue,reduce the game streaming bitrate at a remarkable scale on different games.The proposed algorithm was evaluated for three video game scenes.In this paper,achieved 14.6%decrease in encoding and 45.6%decrease in bit rate for the first video game scene.

Efficient Solvent- and Catalyst-Free Syntheses of Imine Derivatives Applying the Pressure Reduction Technique: Remarkable Change of the Reaction Rate with the Phase Transition

Because imines could be used as convenient starting materials in various fields, the development of an easy synthetic method of imine was strongly desired. In response to this demand, we thought that it would be an effective synthesis method if an aldehyde and an amine could be reacted to give an imine in good yield under solvent- and catalyst-free conditions. In fact, we tried the reaction of benzaldehyde with various amines under solvent- and catalyst-free conditions followed by removal of water that was produced in the reaction system by a vacuum pump, and desired imines could be obtained in good yields. Observation of this reaction using a nuclear magnetic resonance spectrometer revealed that the reaction rate was extremely fast at the initial stage but slowed over time. However, the reaction of benzaldehyde with aniline differed greatly, and the reaction rate dramatically improved in 47 - 48 minutes after the start of the reaction. At this time, we found that the reaction system underwent a phase transition from the liquid phase to the solid phase.

碳税分摊对供应链决策影响及社会福利研究

构建供应链博弈模型,讨论产品定价与减排策略随碳税率的变化规律,探讨政府如何调控碳税率与分摊率使社会福利最大化。研究表明,征收碳税会导致供应链成员均提高产品定价,且普通产品的价格变化比低碳产品变化更加明显,伴随碳税率的升高,低碳产品制造商的市场需求与利润变化较普通产品更具优势。将减排率制定在不同水平,制造商的获利能力存在很大差异。为了社会福利最大化,政府制定碳税率和分摊率必须控制在合理范围内,就此给出两者的最优显性解和隐性解。

节能技术助力实验动物设施环境控制与绿色低碳

在现场调研、检测北京、上海10多家实验动物设施环境控制及能耗水平的基础上,研究了实验动物设施净化空调系统的排风热回收、降低换气次数冗余度、新风集中+室内自循环净化机系统的昼夜不同运行模式,以及多功能四管制热泵冷凝热用于除湿再热和其他清洗用热等节能技术,并应用于北京、上海的2个典型实验动物中心,通过实时能耗监控平台的全年运行数据可知,全年节能率均超过30%。结果表明,该节能技术有效适用于实验动物设施,对实验动物设施的节能降耗提供了技术支撑,有助于在新建、改扩建实验动物设施中的推广与应用。

基于DEFORM-3D的哈氏合金基带多道次轧制仿真研究

使用DEFORM-3D三维模拟软件对哈氏合金基带的粗轧过程进行多道次仿真,依托流变应力的计算,建立了材料物性模型和仿真模型,并利用前几道次的粗轧实验验证了模型的准确性。通过仿真实验探索了压下率、轧辊形状和摩擦因数对轧制流程的影响。结果表明,随着道次压下率的升高,平均轧制力升高,30%道次压下率的轧制流程带来基带应变不均匀性是表面裂纹产生的重要原因,成功预测了后续轧制实验中带材表面产生的裂纹,实际生产应尽量选用20%及以下的压下率;在该应用条件中,新设计的凹面轧辊流程能有效减小轧制力,降低设备要求,提高轧制安全性,实验中部分流程采用凹面轧辊有效地将侧面裂纹的出现延迟到了第8道次;好的润滑条件能减小摩擦,模拟结果表明摩擦因数越小,基带轧制的均匀性越好,但会增加工序的时间,也会提高材料进给的难度。研究结果优化了实际轧制流程,降低了基带轧制过程中的表面及边部裂纹等缺陷。

爆破荷载作用下减振孔减振隔振效应数值模拟研究

爆破产生的振动效应影响邻近建(构)筑物的安全。作为减振手段之一,减振孔可用于控制爆破振动影响。然而,目前减振孔布设方案多基于经验方法,并且减振效果评价标准主要集中在局部单排测点,无法全面表征减振孔后方区域内的减振效果与规律。基于枕头坝护坦爆破开挖工程,采用LS-DYNA软件中的数值分析方法,系统研究了减振孔排数、深度、爆心距和单排布孔数对有效减振区域面积、峰值减振率等减振效果的影响。首先,利用小尺寸爆破模型试验对LS-DYNA方法模拟爆破荷载作用下减振孔减振隔振效应的有效性进行了验证。随后,系统开展了不同减振孔参数对有效减振区域的影响规律研究。研究结果表明:减振效果最优的区域位于减振孔布设区后方垂直于爆源的位置;随着排数、深度、爆心距和单排布孔数的增大,有效减振区域面积增大;峰值减振率随排数增大而显著增大,随爆心距增大而减小,受到减振孔深度和爆破孔深度的共同影响。与单一测点减振率相比,有效减振区域面积可以体现减振效果的区域分布,并且不受测点选取位置影响。另外,基于不同减振孔参数对减振隔振效应的相关性分析表明,有效减振区域面积与减振孔深度相关性最明显,其次是减振孔排数和爆心距。峰值减振率与减振孔排数相关性最明显,集中减振率与减振孔排数和深度密切相关。研究结果对减振孔的布设和最大程度地利用减振效果保护邻近建(构)筑物具有参考意义。

吸风量对不同性质物料清粉效果的影响

以粗麦渣、粗麦心、细麦心3种物料作为原料,使用清粉机清粉,通过调节吸风量来研究吸风量对不同性质物料清粉效果的影响。结果表明:随着吸风量增加,粗麦渣物料筛出率先明显增加后明显减小,灰分降低率先显著增加后显著减小,清粉效率先显著增加后明显减小;粗麦心物料筛出率先明显增加后明显减小,灰分降低率先增加后降低,清粉效率先增加后减小,两种指标变化趋势并不显著;细麦心物料筛出率降低,灰分降低率增加,清粉效率先增加后减小,3项指标变化趋势均不显著。粗麦渣物料在吸风量2114~2509 m^(3)/h时、粗麦心物料在吸风量1978~2154 m^(3)/h时、细麦心在吸风量881~1041 m^(3)/h时有较好的清粉效果。3种物料分级效果从好到差依次为粗麦渣、粗麦心、细麦心。

稠油热采纳米降压增注体系的制备及性能

制备了一种稠油热采纳米降压增注体系,将其用于降低注汽压力及原油黏度,考察了纳米降压增注体系的性能。实验结果表明,纳米降压增注体系最优配方为:49.75%(w)纳米复配单体+49.75%(w)溶剂油+0.50%(w)酚基聚氧乙烯醚。在纳米降压增注体系用量为10%(w)时,350℃老化2 h后对稠油的降黏率为92.69%,具有较高的耐温性能,对沥青等大分子材料有较强的溶解性,当采用0.1 PV纳米降压增注体系为前置段塞时,纳米降压增注体系可降低注汽压力3.99 MPa,在多种温度及不同渗透率下降压增注性能优异。

石灰性[土娄]土夏玉米-冬小麦作物体系硫铵替代减磷增效研究

[目的]研究石灰性土壤上磷肥减施结合硫铵替代尿素措施的效果,为夏玉米-冬小麦体系合理施用磷肥和维持作物高产提供依据。[方法]在陕西关中设置3年田间定位试验,实施夏玉米-冬小麦轮作模式,共含有对照(CK,不施磷肥)、常规施磷(CP,年施磷量180 kg P_(2)O_(5)/hm^(2),撒施)、减施磷肥(RP,年施磷量134 kg P_(2)O_(5)/hm^(2),条施)、减磷结合硫铵替代尿素(RPSA,施磷量与RP相同,条施)4个处理。作物收获期采集植物和土壤样品,测定玉米和小麦产量、磷肥效率、pH及土壤磷水平。小麦拔节期测定根系形态、菌根侵染率等指标。[结果]与CK相比,施磷处理(CP,RP和RPSA)的玉米和小麦籽粒产量均显著提高,增幅分别为17.3%~24.8%和5.1%~19.0%;土壤有效磷(Olsen-P)和微生物量磷(MBP)显著提高;除RP外,施磷处理的土壤pH均显著降低。施磷处理间,2018-2019年度RP较CP产量显著降低14.6%,磷回收率和偏生产力显著提高。RPSA较RP土壤pH显著降低,有效磷、微生物量磷含量和根系形态及菌根侵染率均显著提高。土壤pH与土壤磷水平、小麦根系形态指标和产量均呈显著负相关。RDA结果表明:土壤pH是影响小麦菌根侵染率、根系形态和产量的最重要环境因子。[结论]磷肥减施结合硫铵替代尿素调控措施可以降低石灰性土壤pH,提高土壤有效磷和微生物量磷含量,促进小麦根系生长并提高菌根侵染率,是石灰性[土娄]土夏玉米-冬小麦体系有效的磷肥减施增效措施。

膜下滴灌减量施肥对甘蔗脱毒原种苗田间繁育效率和养分利用率的影响

本研究探讨不同膜下滴灌减量施肥模式对甘蔗脱毒原种苗生长、繁育效率及肥料利用率的影响,并分析最佳减量施肥模式,旨在为科学指导甘蔗脱毒原种苗田间繁育过程中滴灌施肥技术的应用提供理论依据。在所有对照和处理均配备膜下滴灌系统并进行水分管理的条件下,以空白对照(CK_(0))、常规施肥(CK_(1))为对照,设置1个膜下滴灌施肥处理T_(100)(施肥量同CK_(1))以及3个膜下滴灌减量施肥处理T_(80)、T_(70)和T_(60)(减量施肥20%、30%和40%),对甘蔗脱毒原种苗繁育过程中主要农艺性状、种茎产量、总芽数、繁育效率及养分利用率等指标进行比较分析。研究结果表明:在各项农艺指标中,2022、2023年T_(100)和T_(80)的平均分蘖率略低于CK_(1),但在成茎率、单株芽数、有效茎数方面较CK_(1)均有显著提升。在繁育总种芽数上,T_(100)和T_(80)最高,年平均分别达到(1480.87×10^(3))/hm^(2)和(1477.87×10^(3))/hm^(2),显著高于CK_(1)的(1302.50×10^(3))/hm^(2);T_(70)与CK_(1)间差异不显著;T_(60)最低仅为(1170.53×10^(3))/hm^(2)。在繁育效率方面,原种苗田间繁育倍数T_(100)和T_(80)最高,分别达到66.64倍和66.50倍;其次为T_(70)和CK_(1),繁育倍数为59.61倍和58.61倍;T_(60)繁育倍数最低,为52.67。在繁育收益方面,相较于CK_(0),T_(100)和T_(80)收益增幅最高,分别达到5.82和5.87万元/hm^(2);其次为T_(70),收益增幅为4.19万元/hm^(2),略高于CK_(1)(3.84万元/hm^(2));T_(60)最低,仅为2.51万元/hm^(2)。在肥料投入产出比方面,T_(80)最高,达到1∶21.89,明显高于T_(100)(1∶17.36);CK_(1)最低,为1∶11.45。在肥料利用率方面,所有施肥处理中,氮、磷、钾肥的利用率均为CK_(1)最低。而T_(80)最高,试验平均氮、磷、钾肥利用率分别达到51.57%、27.37%和67.45%,分别较CK_(1)提高了21.21、10.37和23.13个百分点。综上所述,在中等肥力红壤蔗区,采用T_(80)膜下滴灌减量施肥模式,可以同时获得较理想的甘蔗脱毒原种苗繁育效率和收益。

Experimental study on Cr(Ⅵ) reduction by Pseudomonas aeruginosa

Investigation on Cr(Ⅵ) reduction was conducted using Pseudomonas aeruginosa. The study demonstrated that the Cr(Ⅵ) can be effectively reduced to Cr(Ⅲ) by Pseudomonas aeruginosa. The effects of the factors affecting Cr(Ⅵ) reduction rate including carbon source type, pH, initial Cr(Ⅵ) concentration and amount of cells inoculum were thoroughly studied. Malate was found to yield maximum biotransformation, followed by succinate and glucose, with the reduction rate of 60.86%, 43.76% and 28.86% respectively. The optimum pH for Cr(Ⅵ) reduction was 7.0, with reduction efficiency of 61.71% being achieved. With the increase of initial Cr(Ⅵ) concentration, the rate of Cr(Ⅵ) reduction decreased. The reduction was inhibited strongly when the initial Cr(Ⅵ) concentration increased to 157 mg/L. As the amount of cells inoculum increased, the rate of Cr(Ⅵ) reduction also increased. The mechanism of Cr(Ⅵ) reduction and final products were also analysed. The results suggested that the soluble enzymes appear to be responsible for Cr(Ⅵ) reduction by Pseudomonas aeruginosa, and the reduced Cr(Ⅲ) was not precipitated in the form of Cr(OH) 3.

Drag reduction and shear resistance properties of ionomer and hydrogen bond systems based on lauryl methacrylate

Based on molecular dynamics simulation results, a lauryl methacrylate polymer with drag reduction and shear resistance properties was designed, and synthesized by emulsion polymerization using 2-vinyl pyridine and methyl methacrylate as the polar polymerization monomer. After ionization of lauryl methacrylate polymer, an ion-dipole interaction based drag reduction agent （DRA） was obtained. The existence of ion-dipole interaction was proven through characterization of the drag-reducing agent from its infrared （IR） spectrum. The pilot-scale reaction yield of the DRA under optimum conditions was investigated, and the drag reduction and shear resistance properties were measured. The results show that： l） The ion-dipole or hydrogen bonding interaction can form ladder-shaped chains, therefore the synthesized DRA has shear resistance properties; 2） The larger the molecular weight （MW） and more concentrated the distribution of MW, the better the drag reduction efficiency and the performance of the ionomer system was superior to that of the hydrogen bonding system; 3） With increasing shear frequency, the drag-reduction rates of both the DRAs decreased, and the drag reduction rate of the ionomer system decreased more slowly than of the corresponding hydrogen bonding system. From the point of view of drag reduction rate and shear resistance property, the ionomer system is more promising than the hydrogen bonding system

Recovery of iron and calcium aluminate slag from high-ferrous bauxite by high-temperature reduction and smelting process

A high-temperature reduction and smelting process was used to recover iron and calcium aluminate slag from high-ferrous bauxite. The effects of w（CaO）/w（SiO_2） ratio, anthracite ratio, and reduction temperature and time on the recovery and size of iron nuggets and on the Al_2O_3 grade of the calcium aluminate slag were investigated through thermodynamic calculations and experiments. The optimized process conditions were the bauxite/anthracite/slaked lime weight ratio of 100：16.17：59.37, reduction temperature of 1450°C and reduction time of 20 min. Under these conditions, high-quality iron nuggets and calcium aluminate slag were obtained. The largest size and the highest recovery rate of iron nuggets were 11.42 mm and 92.79wt%, respectively. The calcium aluminate slag mainly comprised Ca_2 SiO_4 and Ca_（12）Al_（14）O_（33）, with small amounts of Fe Al_2O_4, CaAl_2O_4, and Ca_2Al_2SiO_7.

CHARACTERISTICS OF THE OXYGEN REDUCTIONIN ATMOSPHERIC CORROSION

In this work on marine atmospheric corrosion the changes in oxygen reduction rate with decrease of electrolyte film thickness during drying was studied by Kelvin probe reference electrode technique andimpedance measurements based on previous results. For > 50μm electrolyte film thickness, the oxygen diffusion in liquid controlled the oxygen reduction process.As the cathodic limiting currents increased to about lmA/cm2 with evaporation, the rate of oxygen transportation at the gas/liquid boundary limited thecurrent increase. If the thickness decreased to less than 10μm, the very heterogeneous current distributioncaused a sharp decrease in the total cathodic current due to the effect of the electrolyte film’s increased solution resistance. The calculated result on the basis of the assumption showed good agreement with the experimental findings.

Chirp-rate调制的新型解调方法

提出了一种基于分段去斜率的Chirp-rate调制解调方法。根据CRM信号以不同调频斜率的Chirp信号作为调制信号的特点,接收端分为两级解调,第一级解调采用延时混频(去斜率)的方法,把不同调频斜率的Chirp信号转换为MFSK信号,第二级采用非相干方式对MFSK信号解调。最后分析了二进制CRM信号经过高斯信道的性能,在高信噪比情况下略好于基于分数阶傅里叶变换的CRM系统。

Application of Different Models for the Prediction of the Kinetics of Direct Reduction of Natural Iron Ores

Simulation of the direct reduction conditions was performed in a laboratory furnace. Lump samples from natural hematite iron ore were reduced by a gas mixture of H2 and CO (H2/CO =1.5) at temperatures of 700°C, 800°C and 900°C. The effect of reduction temperature on the reduction degree, reduction rate of samples and carbon deposition were investigated and discussed in this study. The thermo-gravimetric data obtained from the reduction experiments was run in a programme that calculates the solid conversion rate. Also, three models: 1) Grain Model (GM), 2) Volumetric Model (VM), and 3) the Random Pore Model (RPM), were used to estimate the reduction kinetics of natural iron ores. It was found that the RPM model result agreed best with the obtained experimental results. Furthermore, it gave better predictions of the natural iron oxide conversion and thereby the reduction kinetics.