可控空气再循环技术的发展及应用前景

一部分清洗过井下采掘工作面的空气重新用来通风的可控空气再循环技术,近年来在国外发展迅速。本文指出了实际推广应用需要解决的四个主要问题。对我国矿山通风技术的现状分析认为,解决井下空气污染物的自动检测和建立科学的爆破制度等问题后,在我国矿山推广该项技术是可行的。

《转速可控型房间空气调节器能效“领跑者”制度实施细则》解读

我国首次实施能效"领跑者"制度,公众参与度和社会认识度亟待提高。本文在分析能效"领跑者"制度背景、转速可控型房间空气调节器市场情况及能效现状的基础上,对《转速可控型房间空气调节器能效"领跑者"制度实施细则》进行了解读,为相关方理解实施细则、实施能效"领跑者"提供了参考。

转速可控型房间空气调节器“领跑者”初评产品复检情况及难点

房间空气调节器的能效水平一直备受政府及社会各界人士的广泛关注。为落实国务院节能减排的战略方针,国家发展和改革委员会、工业和信息化部等部委出台了第一批能效"领跑者"实施细则,并采用"复检"的方式来校验产品的实际性能。本文以笔者所在公司负责的备选产品为例,介绍了本次复检测试的情况及测试过程中的难点。

转速可控型房间空气调节器能效标识备案实验室间比对试验结果分析与评价

为了保证转速可控型房间空气调节器能效标识备案实验室间比对试验时的准确性,制备符合均匀性和稳定性要求的标准样机,采用稳健统计技术对参与比对的实验室的全年能源消耗效率(APF)检测结果进行统计与分析。结果表明:在比对的43家实验室中,40家实验室结果为满意、3家为不满意,说明目前转速可控型房间空气调节器能效标识备案实验室的数据一致性较好。

QC83-80N矿用隔爆型可逆空气磁力起动器的真空化改造

文章对QC83- 80N矿用隔爆型空气磁力起动器的真空化改造特点进行了论述。改造后的开关采用JDB - 80N电子综合保护器对控制电机进行保护 ,可完成电动机的短路、过载、断相和漏电闭锁等保护功能。新设计的机械联锁机构与控制电路配合 ,不仅能从电气上而且能从机械上对正反向真空接触器进行闭锁 。

Removal of the airwave effect by main-part decomposition of the anomalous field of MCSEM data

The airwave effect greatly influences the observational data from controlledsource electromagnetic exploration in shallow seas, which obscures the abnormal effects generated by exploration targets and, hence, affects the accuracy of the late exploration data interpretation. In this study, we propose a method to separate the main part from the anomalous field of marine controlled-source electromagnetic method （MCSEM） data based on Stratton-Chu integral transforms to eliminate the airwave effect, which dominates observed electromagnetic （EM） response in shallow seawater. This method of separating the main part from the anomalous field is a type of finite impulse response filter based on a discrete data set. Theoretical analysis proved that the method is stable and able to effectively depress noise. A numerical test indicated that the method could successfully eliminate the airwave effect from the observed EM signals generated by an air water interface and a seawater layer. This technique is applicable for seawater models with either flat or rough seabeds.

Stiffness-damping matching method of an ECAS system based on LQG control

A novel method of matching stiffness and continuous variable damping of an ECAS(electronically controlled air suspension) based on LQG(linear quadratic Gaussian) control was proposed to simultaneously improve the road-friendliness and ride comfort of a two-axle school bus.Taking account of the suspension nonlinearities and target-height-dependent variation in suspension characteristics,a stiffness model of the ECAS mounted on the drive axle of the bus was developed based on thermodynamics and the key parameters were obtained through field tests.By determining the proper range of the target height for the ECAS of the fully-loaded bus based on the design requirements of vehicle body bounce frequency,the control algorithm of the target suspension height(i.e.,stiffness) was derived according to driving speed and road roughness.Taking account of the nonlinearities of a continuous variable semi-active damper,the damping force was obtained through the subtraction of the air spring force from the optimum integrated suspension force,which was calculated based on LQG control.Finally,a GA(genetic algorithm)-based matching method between stepped variable damping and stiffness was employed as a benchmark to evaluate the effectiveness of the LQG-based matching method.Simulation results indicate that compared with the GA-based matching method,both dynamic tire force and vehicle body vertical acceleration responses are markedly reduced around the vehicle body bounce frequency employing the LQG-based matching method,with peak values of the dynamic tire force PSD(power spectral density) decreased by 73.6%,60.8% and 71.9% in the three cases,and corresponding reduction are 71.3%,59.4% and 68.2% for the vehicle body vertical acceleration.A strong robustness to variation of driving speed and road roughness is also observed for the LQG-based matching method.

Super-resolution least-squares prestack Kirchhoff depth migration using the L_0-norm

Least-squares migration （LSM） is applied to image subsurface structures and lithology by minimizing the objective function of the observed seismic and reverse-time migration residual data of various underground reflectivity models. LSM reduces the migration artifacts, enhances the spatial resolution of the migrated images, and yields a more accurate subsurface reflectivity distribution than that of standard migration. The introduction of regularization constraints effectively improves the stability of the least-squares offset. The commonly used regularization terms are based on the L2-norm, which smooths the migration results, e.g., by smearing the reflectivities, while providing stability. However, in exploration geophysics, reflection structures based on velocity and density are generally observed to be discontinuous in depth, illustrating sparse reflectance. To obtain a sparse migration profile, we propose the super-resolution least-squares Kirchhoff prestack depth migration by solving the L0-norm-constrained optimization problem. Additionally, we introduce a two-stage iterative soft and hard thresholding algorithm to retrieve the super-resolution reflectivity distribution. Further, the proposed algorithm is applied to complex synthetic data. Furthermore, the sensitivity of the proposed algorithm to noise and the dominant frequency of the source wavelet was evaluated. Finally, we conclude that the proposed method improves the spatial resolution and achieves impulse-like reflectivity distribution and can be applied to structural interpretations and complex subsurface imaging.

Ultrasmall NiFe layered double hydroxide strongly coupled on atomically dispersed FeCo-NC nanoflowers as efficient bifunctional catalyst for rechargeable Zn-air battery

An atomically dispersed FeCo-NC material with the 3D flower-like morphology was used as a unique substrate for the controllable deposition of ultrasmall NiFe layered double hydroxide nanodots(termed as NiFe-NDs)to simultaneously promote the sluggish kinetics of oxygen reduction reaction(ORR)and oxygen evolution reaction(OER).The size-limiting growth of NiFe-NDs(~4.0 nm in diameter)was realized via the confinement of the 3D flower-like mesoporous structure and the rich N/O functionality of FeCo-NC.Benefiting from the distinctive structure with the simultaneously maximum exposure of both OER and ORR active sites,the NiFe-ND/FeCo-NC composite showed an ORR halfwave potential of 0.85 V and an OER potential of 1.66 V in0.1 mol L-1KOH at 10.0 mA cm-2.In-situ Raman analysis suggested the activity of OER was derived from the Ni sites on NiFe-ND/FeCo-NC.Moreover,the NiFe-ND/FeCo-NC-assembled Zn-air battery(ZAB)exhibited a very small discharge-charge voltage gap of 0.87 V at 20 mA cm-2and robust cycling stability.Furthermore,the NiFe-ND/FeCo-NC composite was also applicable for fabricating all-solid-state ZAB to power wearable electronics with superior cycling stability under deformation.Our work could enlighten a new applicable branch of atomically dispersed metal-nitrogen-carbon materials as unique substrates for fabricating multifunctional electrocatalysts.