地下水除铁锰滤柱反冲洗废水结团絮凝处理的中试研究

以西安某地下水除铁除锰石英砂滤柱反冲洗废水为处理对象，利用结团絮凝工艺进行了中试研究，得出了混凝剂PAC、助凝剂PAM、水流上升速度Uw和强制搅拌转速”对结团絮凝工艺的影响规律。在上升流速为34cm／min时，通过优化得出适宜的搅拌转速n为4～8r／min，PAC投量为20mg／L左右，PAM投量为1.0～1．25mg／L。适当增加投药量，最大上升流速可达42．5cm／min。在上述运行条件下，可使出水浊度小于10NTU，Fe小于1．6mg／L，Mn小于0．5mg／L，畋）【）M11小于2．0mg／L；排泥含水率为90％～97％，污泥比阻值为（O．1～O．2）×10^9 s^2／g。

老年人房室结折反性心动过速的射频消融治疗

采用常规方法对 3 1例 6 0岁以上的房室结折反性心动过速 ( AVNRT)患者进行射频消融治疗。 1例术中发生房颤而终止手术 ,2例房室结双径路改变失败 ,2例患者出现一过性 0房室传导阻滞 ,慢道消融前后房室结快道前传有效不应期明显改变 ( 3 4 1± 82 ms,3 2 9± 6 4 ms,P>0 .0 5)。结果表明 ,房室结慢道射频消融是治疗老年人 AVNRT安全、有效的方法。

浅议会计软件的反记账和反结账功能

一、反记账和反结账功能的定义 记账和结账是会计核算程序中的重要步骤,记账是根据审核无误后的记账凭证和相关原始凭证登记有关账簿,结账则是在期末根据会计核算的要求结算出各个账户的本期发生额和期末余额。不论是实行会计电算化还是在手工记账中都需要进行上述操作。

突变反型异质结及其双极晶体管的研制

文章对突变反型异质结的能带图、接触电势差和势垒区宽度进行了讨论和研究。同时,介绍了基于分子束外延(MBE)法生长的SiGe/Si结构的异质结双极晶体管(HBT)制造工艺,并给出了测试结果。

Microenvironment and electronic state modulation of Pd nanoparticles within MOFs for enhancing low-temperature activity towards DCPD hydrogenation

Precise control of the local environment and electronic state of the guest is an important method of controlling catalytic activity and reaction pathways.In this paper,guest Pd NPs were introduced into a series of host UiO-67 MOFs with different functional ligands and metal nodes,the microenvironment and local electronic structure of Pd is modulated by introducing bipyridine groups and changing metal nodes(Ce6O6 or Zr6O6).The bipyridine groups not only promoted the dispersion Pd NPs,but also facilitated electron transfer between Pd and UiO-67 MOFs through the formation of Pd-N bridges.Compared with Zr6 clusters,the tunability and orbital hybridisation of the 4f electronic structure in the Ce6 clusters modulate the electronic structure of Pd through the construction of the Ce-O-Pd interfaces.The optimal catalyst Pd/UiO-67(Ce)-bpy presented excellent low-temperature activity towards dicyclopentadiene hydrogenation with a conversion of>99%and a selectivity of>99%(50℃,10 bar).The results show that the synergy of Ce-O-Pd and Pd-N promotes the formation of active Pdδ+,which not only enhances the adsorption of H2 and electron-rich C=C bonds,but also contributes to the reduction of proton migration distance and improves proton utilization efficiency.These results provide valuable insights for investigating the regulatory role of the host MOFs,the nature of host-guest interactions,and their correlation with catalytic performance.

坚持多管齐下确保结算资金的正常运行

维护支付清算系统的正常运行,确保结算渠道的畅通是人民银行的一项重要职责。人行曲阳县支行把维护结算纪律、严格结算制度、加强结算管理作为维护公平竞争、加速资金周转、促进经济持续、健康发展的大事来抓,坚持疏导与服务并重,管理与处罚结合,确保了结算渠道的畅通。一年来,全辖结算业务量达92.8万笔,日均2580笔,没有发生过压票压汇、随意退票退汇、拖延付款和无理拒付等问题,从而保证了结算资金的正常运行。

A dendritic Cu/Cu_(2)O structure with high curvature enables rapid and efficient reduction of carbon dioxide to C2 in an H-cell

Electrocatalytic reduction of CO_(2)(CO_(2)RR)to multicarbon products is an efficient approach for ad-dressing the energy crisis and achieving carbon neutrality.In H-cells,achieving high-current C_(2)products is challenging because of the inefficient mass transfer of the catalyst and the presence of the hydrogen evolution reaction(HER).In this study,dendritic Cu/Cu_(2)O with abundant Cu^(0)/Cu^(+)interfaces and numerous dendritic curves was synthesized in a CO_(2)atmosphere,resulting in the high selectivity and current density of the C_(2)products.Dendritic Cu/Cu_(2)O achieved a C_(2)Faradaic efficiency of 69.8%and a C_(2)partial current density of 129.5 mA cm^(-2)in an H-cell.Finite element simulations showed that a dendritic structure with a high curvature generates a strong electric field,leading to a localized CO_(2)concentration.Additionally,DRT analysis showed that a dendritic struc-ture with a high curvature actively adsorbed the surrounding high concentration of CO_(2),enhancing the mass transfer rate and achieving a high current density.During the experiment,the impact of the electronic structure on the performance of the catalyst was investigated by varying the atomic ratio of Cu^(0)/Cu^(+)on the catalyst surface,which resulted in improved ethylene selectivity.Under the optimal atomic ratio of Cu^(0)/Cu^(+),the charge transfer resistance was minimized,and the desorption rate of the intermediates was low,favoring C_(2)generation.Density functional theory calculations indicated that the Cu^(0)/Cu^(+)interfaces exhibited a lower Gibbs free energy for the rate-determining step,enhancing C_(2)H4 formation.The Cu/Cu_(2)O catalyst also exhibited a low Cu d-band center,which enhanced the adsorption stability of*CO on the surface and facilitated C_(2)formation.This observa-tion explained the higher yield of C_(2)products at the Cu^(0)/Cu^(+)interface than that of H_(2)under rapid mass transfer.The results of the net present value model showed that the H-cell holds promising industrial prospects,contingent upon it being a catalyst with both high selectivity and high current density.This approach of integrating the structure and composition provides new insights for ad-vancing the CO_(2)RR towards high-current C_(2)products.

Evolution Mechanism of Calcium Carbonate in Solution

Calcium carbonate was synthesized in a CaCl2/NaCO3 mixed solution by using ethylenediaminetetraacetic acid （EDTA） as an additive. The thermodynamics and kinetics analyses indicate that although the driving force of amorphous calcium carbonate （ACC） precipitation is always less than that of calcite and vaterite precipitation, the nucleation rate of ACC is greater than that of calcite and vaterite at the initial stage of the precipitation reaction. With the increasing incubation time, vaterite and calcite particles nucleate heterogeneously by using the as-formed particles as active sites. Scanning electron microscopy images indicate that the transformation mechanism of ACC and vaterite to calcite is the dissolution-recrystallisation reaction. The presence of EDTA not only improves the stabilities of ACC and vaterite, but also leads to forming enlongated, connected rhombohedral calcite crystals after incubation 7 days in solutions. The ACC and vaterite are stabler in air than in solutions at room temperature, although the dissolution-recrystallisation reaction occurs on the surface.

Antiphase boundary-like structure in α′′ martensite of TC21 titanium alloy

The morphology and formation mechanism of the substructure of martensite in TC21 alloy was investigated by XRD and TEM. The results showed that the martensitic transformation from β to α＂ occurs upon quenching after solution treatment between 960-1000 ℃. The antiphase boundary （APB）-like structure was observed clearly in the α＂ martensite plates. The APB-like contrasts exist along the （001） and （020） planes of α＂ martensite. This APB-like structure of α＂ martensite was identified as a kind of stacking fault with an APB-like morphology induced by martensitic transformation and not by order/disorder transition. During martensitic transformation, martensitic domains nucleate and grow, eventually encounter each other, resulting in the formation of the APBdike contrast.

Influence of sodium silicate on manganese electrodeposition in sulfate solution

The influences of sodium silicate on manganese electrodeposition in sulfate solution were investigated. Manganese electrodeposition experiments indicate that a certain amount of sodium silicate can improve cathode current efficiency and initial pH 7.0?8.0 is the optimized pH for high cathode current efficiency. The analyses of scanning electron microscopy (SEM) and X-ray diffraction (XRD) indicate the compact morphology and nanocrystalline structure of electrodeposits. X-ray photoelectron spectrometry (XPS) analysis shows that the elements of Mn, Si and O exist in the deposit. The solution chemistry calculations of sulfate electrolyte and sodium silicate solution indicate that species of Mn2+, MnSO4, Mn(SO4)2?2 , Mn2+, MnSiO3, Mn(NH3)2+, SiO32?and HSiO3? are the main active species during the process of manganese electrodeposition. The reaction trend between Mn2+ and Si-containing ions is confirmed by the thermodynamic analysis. In addition, polarization curve tests confirm that sodium silicate can increase the overpotential of hydrogen evolution reaction, and then indirectly improve the cathode current efficiency.

2D numerical study on the effect of conductor between the transmitter and survey area in CSEM exploration

In CSEM exploration, the receivers are generally located about three to five times the skin depth from the transmitter. In this paper, we study the effect of a conductor between the transmitter and the survey area on the target conductor response using forward modeling and inversion. The 2D forward finite element calculations show that the conductor mainly affects the response at middle and low frequencies. The lower the resistivity and the larger the conductor, the larger the effect and the effect increases with decreasing frequency. The inversion results indicate that the calculated position of the target body can move towards the source, leading to an incorrect interpretation without considering the conductor. In order to reduce the effect of a conductor between the source and the survey area, CSEM acquisition should be conducted in three dimensions using multiple sources and 3D inversion should be used during interpretation.

Microstructure and shear strength of reactive brazing joints of TiAl/Ni-based alloy

Reactive brazing of TiAl-based intermetallics and Ni-based alloy with Ti foil as interlayer was investigated. The interfacial microstructure and shear strength of the joints were studied. According to the experimental observations, the molten interlayer reacts vigorously with base metals, forming several continuous reaction layers. The typical interfacial microstructure of the joint can be expressed as GH99/（Ni,Cr）ss（γ）/TiNi（β2）＋TiNi2Al（τ4）＋Ti2Ni（δ）/δ＋Ti3Al（α2）＋Al3NiTi2（τ3）/α2＋τ3/TiAl. The maximum shear strength is 258 MPa for the specimen brazed at 1000°C for 10 min. Higher brazing temperature or longer brazing time causes coarsening of the phases in the brazing seam and formation of brittle intermetallic layer, which greatly depresses the shear strength of the joints.

The 3D magnetic structure beneath the continental margin of the northeastern South China Sea

Understanding the continental margin of the Northeastern South China Sea is critical to the study of deep structures, tectonic evolution, and dynamics of the region. One set of important data for this endeavor is the total-field magnetic data. Given the challenges associated with the magnetic data at low latitudes and with remanent magnetism in this area, we combine the equivalent-source technique and magnetic amplitude inversion to recover 3D subsurface magnetic structures. The inversion results show that this area is characterized by a north-south block division and east-west zonation. Magnetic regions strike in EW, NE and NW direction and are consistent with major tectonic trends in the region. The highly magnetic zone recovered from inversion in the continental margin differs visibly from that of the magnetically quiet zones to the south. The magnetic anomaly zone strikes in NE direction, covering an area of about 500 km × 60 km, and extending downward to a depth of 25 km or more. In combination with other geophysical data, we suggest that this strongly magnetic zone was produced by deep underplating of magma associated with plate subduction in Mesozoic period. The magnetically quiet zone in the south is an EW trending unit underlain by broad and gentle magnetic layers of lower crust. Its magnetic structure bears a clear resemblance to oceanic crust, assumed to be related to the presence of ancient oceanic crust there.

The Analysis Method of Time Reversal for Defect Diagnosis of Concealed Structure

In this paper, a new method of time reversal for defect diagnosis of concealed structure has been proposed based on the detecting technique of structure acoustic wave and the theory of time reversal. The time reversal recurrence formula for detecting the acoustic wave speed constitution of concealed structures with bilevel asynchronous test has been established. The wave speed constitution can be reconstructed in 2 D graticule form by means of this method. The result of model test shows the method is valid.

关于日语接续助词——“のに”“くせに”““非汉字符号”のを”

日语表示逆态接续的助词中,“のに”、“くせに”“ちのを”这三个助词,用法及意义颇有近似之处。按一般说法,它们表示逆态接续,含有不满、责难情绪,可以互换等等,似乎比较容易掌握。实际上,对于学生来说,常常为它们的用法,意义相近而感到困惑,掌握不好,用不恰当。

Coupled effect of cement hydration and temperature on rheological properties of fresh cemented tailings backfill slurry

The fluidity of fresh cemented tailings backfill（CTB） slurry depends on its rheological properties. Hence, it is crucial to understand the rheology of fresh CTB slurry, which is related to the cement hydration progress and temperature evolution within CTB mixtures. For this reason, a numerical model was developed to predict the evolution of the rheological properties of fresh CTB slurry under the coupled effect of cement hydration and temperature. Experiments were conducted to investigate the rheological behaviours of the fresh CTB slurry. By comparing the simulated results with the experimental ones, the availability of this developed model was validated. Thereafter, the model was used to demonstrate the coupled effect of cement hydration and temperature on the evolution of fresh CTB slurry＇s rheological properties, under various conditions（initial CTB temperature, cement to tailings ratio, and water to cement ratio）. The obtained results are helpful to better understanding the rheology of CTB slurry.

Simulation of a Silicon LED in Standard CMOS Technology

A reverse bias silicon p-n junction based on light emitting diode is designed in standard 0.6μm industrial CMOS technology.The mechanism of the light emitting of this device is discussed.The device is simulated by the commercial software.I-V characteristic under forward or reverse bias is simulated utilizing the commercial software.The results between simulation and experiment data are compared.The results show that it is a promising device and may find applications in light linking.

Global Attractor of a Reaction-diffusion System with Hamiltonian Structure

In this paper, we consider a reaction diffusion system with Hamitonian structure, we first prove the existence of an invariant region for system and the continuity of the semigroup, then establish the absorbing sets and global attractor.