Industrial utilization of arsenic-containing gold dressing tailings as pellet prepared by straight grate process

The utilization of arsenic-containing gold dressing tailings is an urgent issue faced by gold production companies worldwide.The thermodynamic analysis results indicate that ferrous arsenate(FeAsO_(4)),pyrite(FeS_(2))and sodium cyanide(NaCN)in the arsenic-containing gold metallurgical tailings can be effectively removed using straight grate process,and the removal of pyrite and sodium cyanide is basically completed during the preheating stage,while the removal of ferrous arsenate requires the roasting stage.The pellets undergo a transformation from magnetite to hematite during the preheating process,and are solidified through micro-crystalline bonding and high-temperature recrystallization of hematite(Fe_(2)O_(3))during the roasting process.Ultimately,pellets with removal rates of 80.77% for arsenic,88.78% for sulfur,and 99.88% for cyanide are obtained,as well as the iron content is 61.1% and the compressive strength is 3071 N,meeting the requirements for blast furnace burden.This study provides an industrially feasible method for treating arsenic-containing gold smelting tailings,benefiting gold production enterprises.

Micro-analysis of high-temperature oxidation-resistance of a new kind of heat-resistant grid plate in grate-kiln

To further improve the oxidation-resistance of materials and reduce the cost of grid plates in grate-kiln, a new kind of heat-resistant grid plate was developed. The microstructure of this grid plate with a life more than 18 months was studied by XRD, SEM and EDS techniques. The results show that high hardness, high intensity and good impact property make the new kind of heat-resistant grid plate and its oxide film have a higher resistance to deformation and abrasion at 900-1000℃ Besides, small grain size is beneficial to form a complete protective oxide film. The oxide film composed of SiO2 layer, Cr2O3 layer and Fe2O3 layer is rather thin and bonds closely with the backing. The forming of the chemical stable nickel-rich layer increases the density of Cr2O3 layer.

“文件全文简便索求”——Grateful Med的一种文件特别索求形式

美国国立医学图书馆建立的MEDLARS系统是当前世界最大的医学文献计算机检索系统,共包括30多个联机数据库,如 MEDLINE、TOXILINE、AIDSLINE 等已为我国用户熟知,而其中又以 MEDLINE 为最大,使用率最高。1986年美国国立医学图书馆推出 Grateful Med 检索软件(目前使用到第五版),使用户方便地检索 MELARS 数据库文献题录,但欲得到原文仍需求助于图书馆。最近在 Grateful Med 基础上发展了“文件全文简便索求”形式—Loansome Doc,使检索二次文献与索求文献全文一气呵成,目前正在部分地区网络试行,计划在 Grateful Med 第六版实现。这一功能的实现是文献情报工作的又一重大进展,对实现更大范围的文献资源共享具有极为重要的意义。为此美国国会特别拨款3300万美元支持计划实施,五年内将全面提供利用。现将 Loansome Doc 介绍摘译如下。

Efficient thermal analysis method for large scale compound semiconductor integrated circuits based on heterojunction bipolar transistor

In this paper, an efficient thermal analysis method is presented for large scale compound semiconductor integrated circuits based on a heterojunction bipolar transistor with considering the change of thermal conductivity with temperature.The influence caused by the thermal conductivity can be equivalent to the increment of the local temperature surrounding the individual device. The junction temperature for each device can be efficiently calculated by the combination of the semianalytic temperature distribution function and the iteration of local temperature with high accuracy, providing a temperature distribution for a full chip. Applying this method to the InP frequency divider chip and the GaAs analog to digital converter chip, the computational results well agree with the results from the simulator COMSOL and the infrared thermal imager respectively. The proposed method can also be applied to thermal analysis in various kinds of semiconductor integrated circuits.

Experimental Study on the Armor Grate Plate of Sloping Breakwater Under the Action of Irregular Waves

The irregular wave experiment on the stability of the Grate Plate was carried out in the light of the wind wave spectrum recently advanced by Prof. Wen Shengchang. The stability formulas of GP under the action of irregular waves were procured. Comparisons between the formulas obtained and those of GP under regular waves advanced by the first author in 1993 showed a coincident result.

MEDLARS微机检索软件——GRATEFUL MED

GRATEFUL MED是以用户友好方式检索美国国立医学图书馆(NLM)MEDLARS数据库的微机软件包。它旨在方便用户,具有简化常常使用户感到困惑的通讯联系和检索操作命令的作用,即使用户不了解MEDLARS系统的检索语言,也能很容易地获取所需文献。这一软件自1986年2月问世以来已经销售了16000多份拷贝。 GRATEFUL MED可以在IBM PC机或兼容微机(4.0版本,1988年12月发行),以及苹果公司的Macintosh系列微型机(1.0版本,1989年9月发行)上运行。

The Results of Research to Determine the Parameters of HardeningWorking Area of the Gin and Linter Grates

The article provides substantiation of the choice of the quenching parametersfor the working zone of gin and linter grates and the quenchingparameters.The results of bench and industrial tests of the grate with ahardened working zone are also given.

CFD Analysis of Flow in a Grated Inlet

Effectively managing floods in urban regions requires effectively designed and well-maintained runoff collection system. The absence of such a system and intense rainfall event will have the potential to disrupt the urban life and cause significant economic loss to properties. Grated inlets, which are a key component in urban drainage network, are used to capture the runoff. In this work, a three dimensional CFD model was developed based on open-source CFD tool, OpenFOAM&#174, to model flow over a grated inlet. An incompressible, transient, multiphase flow, Volume of Fluid (VOF) simulation was performed to predict the water flow rate through the grate inlet. The predicted flow rates are compared with the HEC-22 monograph values. The close agreement between the results shows the potential of using CFD modeling approach to test the reliability of existing drainage inlets for different flow scenarios.

Learn to Be Grateful

How long has it been since you had the feeling of being moved? Do you feel grateful when you taste the delicious dinner your mother

Large Spacing Array with Offset Phase Center Elements for Highly Integrated Applications

A scanning and uniform array architecture with large spacing,low complexity and high scalability is presented for high integration massive array applications.It is constructed by offset phase center elements arranged in a uniform and regular way,but its spacing can be larger than that of traditional arrays.An ideal model of the offset phase center element is established and its far-field distribution is derived.To suppress grating lobes,the phase center of any element is designed to be movable without changing its physical position.Using genetic algorithm(GA),a new constraint condition limiting the number of phase center changes is proposed to solve the objective function of the minimum values of grating lobes(GLs)and side lobes(SLs).It is shown that the optimal results can be achieved by two changes of phase centers.A multimode circular patch is developed and designed,and characteristics of the offset phase center are analyzed and verified.A prototype array of 12×12 offset phase center elements is implemented based on multi-mode circular patches.Full wave simulation results of radiation patterns show that the level of grating lobes is suppressed at least 7dB with 1.12λ spacing,while the scanning angle is 20°.

Topology optimization of on-chip integrated laser-driven particle accelerator

Particle accelerators are indispensable tools in both science and industry.However,the size and cost of conventional RF accelerators limits the utility and scope of this technology.Recent research has shown that a dielectric laser accelerator(DLA)made of dielectric structures and driven at optical frequencies can generate particle beams with energies ranging from MeV to GeV at the tabletop level.To design DLA structures with a high acceleration gradient,we demonstrate topology optimization,which is a method used to optimize the material distribution in a specific area based on given load conditions,constraints,and performance indicators.To demonstrate the effectiveness of this approach,we propose two schemes and design several acceleration structures based on them.The optimization results demonstrate that the proposed method can be applied to structure optimization for on-chip integrated laser accelerators,producing manufacturable structures with significantly improved performance compared with previous size or shape optimization methods.These results provide new physical approaches to explore ultrafast dynamics in matter,with important implications for future laser particle accelerators based on photonic chips.

Chalcogenide As₂S₃Sidewall Bragg Gratings Integrated on LiNbO₃Substrate

This paper introduces the design and applications of integrated As2S3 sidewall Bragg gratings on LiNbO3 substrate. The grating reflectance and bandwidth are analyzed with coupled-mode theory. Coupling coefficients are computed by taking overlap integration. Numerical results for uniform gratings, phase-shifted gratings and grating cavities as well as electro-optic tunable gratings are presented. These integrated As2S3 sidewall gratings on LiNbO3 substrate provide an approach to the design of a wide range of integrated optical devices including switches, laser cavities, modulators, sensors and tunable filters.

Multiwavelength Actively Mode-locked Fiber Laser with a Double-ring Configuration and Integrated Cascaded Sampled Fiber Bragg Gratings

A modified multiwavelength actively mode-locked fiber ring laser is proposed and experimentally demonstrated. In this kind of laser, stable multiwavelengths lasing is achieved by integrating cascaded sampled fiber Bragg gratings(SFBGs) into the laser cavity. To implement actively mode-locking technique, a double-ring cavity configuration is used to assure that the cavity lengths for all wavelengths lasing are identical. Thus, simultaneous mode locking of all wavelengths has been successfully achieved by using the same mode-locking signal.

Ultralow cross talk arrayed waveguide grating integrated with tunable microring filter array

The silicon-based arrayed waveguide grating(AWG)is widely used due to its compact footprint and its compatibility with the mature CMOS process.However,except for AWGs with ridged waveguides of a few micrometers of cross section,any small process error will cause a large phase deviation in other AWGs,resulting in an increasing cross talk.In this paper,an ultralow cross talk AWG via a tunable microring resonator(MRR)filter is demonstrated on the SOI platform.The measured insertion loss and minimum adjacent cross talk of the designed AWG are approximately 3.2 and-45.1 d B,respectively.Compared with conventional AWG,its cross talk is greatly reduced.

The Martin moving grate technology

The thermal treatment of waste using grate-based systems has gained global acceptance as the preferred method for sustainable management of residual waste.This is because the energy content of the waste is utilized and quality products and residues are produced.Modern Waste-to-Energy(WtE)plants are extremely complex.Sound knowledge of“fuel”waste and its effects on the design and operation of WtE plants is crucial for the successful planning and operation of these plants.To respond to new challenges and/or priorities,developing and implementing innovative technologies is necessary.With long-term global partnerships and innovative grate and combustion technologies,Martin guarantees that in future,residual waste will be treated following ecological and economic constraints and in compliance with international legal requirements.

Integrated contra‑directionally coupled chirped Bragg grating waveguide with a linear group delay spectrum

Due to the advantages of low propagation loss,wide operation bandwidth,continuous delay tuning,fast tuning speed,and compact footprints,chirped Bragg grating waveguide has great application potential in wideband phased array beamforming systems.However,the disadvantage of large group delay error hinders their practical applications.The nonlinear group delay spectrum is one of the main factors causing large group delay errors.To solve this problem,waveguides with nonlinear gradient widths are adopted in this study to compensate for the nonlinear efect of the grating apodization on the mode efective index.As a result,a linear group delay spectrum is obtained in the experiment,and the group delay error is halved.

基于CNN-LSTM混合神经网络的高速铁路地震响应预测

为了更好地挖掘高速铁路在地震时的响应信息,提高光纤光栅监测的效率及预测精度,该文针对地震响应数据的时序性及非线性的特点,提出卷积神经网络(CNN)和长短期记忆(LSTM)网络的混合神经网络模型预测方法.通过在高速铁路简支梁桥上布设准分布式光纤光栅采集地震时轨道板、钢轨、底座板、箱梁的响应数据,在每根光纤上布置7个光栅,利用两边光栅的响应数据预测中间点的光栅响应,将采集位置、历史数据及地震波形等信息作为特征图输入.利用CNN提取特征,再将提前提取出来的特征数据以时序方式作为LSTM网络的输入数据,最后LSTM网络进行地震应变响应预测.实验结果表明,LSTM网络在3层时效果最好,CNN-LSTM方法具有较高的预测精度,根均平方误差(R_(RMSE))、平均绝对误差(R_(MAE))、决定系数(R^(2))分别达到了0.3753、0.2968、0.9371.

区段煤柱变形光纤光栅监测应用研究

针对近距离煤层下伏工作面过上覆遗留煤柱时,发生动静载叠加诱发强矿压显现,导致区段煤柱发生变形失稳造成人员伤亡和设备破坏。为探索基于光纤光栅实时监测区段煤柱变形发育特征,分析进、出遗留煤柱阶段矿压显现机理,将FBG、光栅应力计的光测方法相结合,结合现场实测的区段煤柱变形应力应变水平参量变化规律,研究煤柱应变空间分布规律及回采过程中工作面前方煤柱内部应变时域响应特征,验证光测方法在煤体应变水平观测的可行性。结果表明:工作面回采经过上覆遗留煤柱期间,区段煤柱顶板受集中应力影响,上部岩层块体破断并发生回转导致煤柱载荷增加,随着工作面推进覆岩断裂进一步向上传递,关键层断裂回转发生导致工作面来压,最终导致区段煤柱变形失稳。根据现场光栅应变增量幅度判断煤柱内局部变形的剧烈程度,在集中应力作用下,区段煤柱变形时发生最大应变为650×10^(-6),上覆岩层集中应力造成煤柱应变水平峰值位置为煤柱宽度11.5 m,沿煤柱宽度方向应变表现出先增加后减小然后趋于稳定的趋势,内部应变随采动过程中影响范围在5 m左右。综合研究工作面回采经过上覆遗留煤柱时应变对区段煤柱发生变形失稳的特点和规律,以及应变水平变化和煤柱物理力学性质,得到煤柱破坏的前兆特征,在外力作用下达到变形峰值前对煤柱提前进行卸压和防护的安全处理。