Particle Residence Time in Column Flotation Based on Cyclonic Separation

The cyclonic static micro-bubble column flotation (FCSMC) is an effective separation device for fine particle treatment. The high mineralization rate and short flotation time of this equipment can be attributed to its unique cyclonic force field. It also has been observed that the presence of a cyclonic force field leads to a lower bottom separation size limit and a reduction of unselective entrainment. The collection zone of the column is considered to consist of two parts,a column separation zone and a cyclonic zone. Total recovery of the collection zone was developed. For our study,we analyzed the particle movement in the cyclonic zone. Particle residence time equations for the cyclonic zone were de-rived by force analysis. Results obtained in this study provide a theoretical foundation for the design and scale-up of the FCSMC.

Binaural Speech Separation Algorithm Based on Long and Short Time Memory Networks

Speaker separation in complex acoustic environment is one of challenging tasks in speech separation.In practice,speakers are very often unmoving or moving slowly in normal communication.In this case,the spatial features among the consecutive speech frames become highly correlated such that it is helpful for speaker separation by providing additional spatial information.To fully exploit this information,we design a separation system on Recurrent Neural Network(RNN)with long short-term memory(LSTM)which effectively learns the temporal dynamics of spatial features.In detail,a LSTM-based speaker separation algorithm is proposed to extract the spatial features in each time-frequency(TF)unit and form the corresponding feature vector.Then,we treat speaker separation as a supervised learning problem,where a modified ideal ratio mask(IRM)is defined as the training function during LSTM learning.Simulations show that the proposed system achieves attractive separation performance in noisy and reverberant environments.Specifically,during the untrained acoustic test with limited priors,e.g.,unmatched signal to noise ratio(SNR)and reverberation,the proposed LSTM based algorithm can still outperforms the existing DNN based method in the measures of PESQ and STOI.It indicates our method is more robust in untrained conditions.

Underdetermined DOA estimation and blind separation of non-disjoint sources in time-frequency domain based on sparse representation method

This paper deals with the blind separation of nonstation-ary sources and direction-of-arrival （DOA） estimation in the under-determined case, when there are more sources than sensors. We assume the sources to be time-frequency （TF） disjoint to a certain extent. In particular, the number of sources presented at any TF neighborhood is strictly less than that of sensors. We can identify the real number of active sources and achieve separation in any TF neighborhood by the sparse representation method. Compared with the subspace-based algorithm under the same sparseness assumption, which suffers from the extra noise effect since it can-not estimate the true number of active sources, the proposed algorithm can estimate the number of active sources and their cor-responding TF values in any TF neighborhood simultaneously. An-other contribution of this paper is a new estimation procedure for the DOA of sources in the underdetermined case, which combines the TF sparseness of sources and the clustering technique. Sim-ulation results demonstrate the validity and high performance of the proposed algorithm in both blind source separation （BSS） and DOA estimation.

USING TWO-DIMENSIONAL TIME RESOLVED LIGHT SCATTERING TO STUDY THE CURE REACTION INDUCED PHASE SEPARATION PROCESS OF EPOXY-AMINE-POLYETHERSULFONE BLEND WITH SECONDARY PHASE SEPARATION

The generalized two-dimensional correlation analysis based on time-resolved light scattering patterns （2D TRLS） has been employed to study the phase separation process of an epoxy-amine-polyethersulfone blend in which the secondary phase separation takes place. The results of the 2D TRLS provided more detailed information that was not readily observed in the 1D TRLS patterns. （i） During the first process of phase separation, the sequential order of coarsening in size of the domains among the larger and smaller ones has been reversed between the diffusion regime and the hydrodynamic regime. （ii） The change of the larger domains in size, due to the hydrodynamic flow in the late stage of the first phase separation process, keeps on taking place earlier than that of the new domains appeared in the secondary phase separation process. （iii） During the secondary phase separation process the size growth of the smaller domains takes place earlier than that of the larger ones, probably due to the assumption that the coarsening mode could decrease the interface tension more quickly.

单生过程separationcutoff的基于特征值的判别准则

对于时间逆具有随机单调性的以{0,1,…,mn}({mn}为关于n单调增的自然数列)为状态空间且从0出发的单生过程族,利用其负转移速率矩阵第一非零特征值的正性及最快强平稳时的任意阶矩,可以由转移速率矩阵的特征值表示这些性质,得到该族马氏过程separation cutoff存在的一个基于特征值的判别准则,验证了Peres的乘积条件对于此类单生过程成立.

TDOA estimation of dual-satellites interference localization based on blind separation

The time difference of arrival(TDOA)estimation plays a crucial role in the accurate localization of the satellite interference source.In the dual-satellites interference source localization system,the target signal from the adjacent satellite is likely to be interfered by the normal communication signal with the same frequency.Therefore,the signal to noise ratio(SNR)of the target signal would become too low,and the TDOA estimation through cross-correlation processing would be unreliable or even unattainable.This paper proposes a technique based on blind separation to solve the co-channel interference problem,where separation of the mixed signal can be carried out by the particle filter(PF)algorithm.The experimental results show that the proposed method could achieve more accurate TDOA estimation.The measured data obtained by using the software radio platform at 915 MHz and 2 GHz respectively verify the effectiveness of the proposed method.

Solid- liquid phase separation and resource recycling study for waste rolling oily sludge

On the basis of the characteristics of a highly emulsified solid-liquid phase （fine particles, sticky consistency,black color, and low reuse ratio）, waste rolling oily sludge has been a focal problem in the steel industry. In this article, a solid-liquid phase separation and resource recycling process was described, with pilot test results showing that flocculation-sedimentation is an effective pretreatment, and that the filtration-coagulationvacuum distillation process is simple and feasible with a 53.5% recovery rate for regenerated oil that is qualified for return to the roiling production line. Then,solid phase oil-sludge was extracted by solvents with a 77% metal resource recovery rate and a wide utilization range. Finally, according to the experimental results, a set of feasibility plans for a 50 t/a waste rolling oily sludge solid-liquid separation and resource recycle project was designed, with the expectation of 50% regenerated oil yield, 70% solid metal resource recovery, and a 2. 5-year investment payback period.

Comparative study on efficacy of three sperm-separation techniques

Aim: To evaluate the comparative effectiveness of real-time sperm separation technique (Wang's tube method) andother two conventional methods in isolating high-quality sperm preparation, and to compare the spouse pregnancy ratein intrauterine insemination (IUI) with sperm preparations isolated by these methods. Methods: The effectivenessof the real-time sperm separation technique, the conventional swim-up and the Percoll discontinuous density gradientmethods in isolating sperm preparations from 60 infertile patients (20 with apparently normal semen and 40, abnormalsemen contaminated with microorganisms and other impurities) was evaluated and compared. The microorganisms to beremoved included bacteria, vires, Chlamydia trachomaticum, Ureaplsama urealyticum, etc. The spouse pregnancyrates in IUI with sperm preparations isolated by these three techniques from 80 oligoasthenoteratospermic patients werealso compared. Results: The quality (including the percentages of normal form, normal-chromatin and motilesperm, and the grade of motility) of sperm obtained by the real-time sperm separation technique was much higher ( P< 0.01) as compared with those by the other two methods. The Wang's tube method was also more effective in remov-ing microorganisms and other impurities. The method provided a higher IUI pregnancy rate than the other two spermseparation techniques ( P < 0.05). Conclusion: The real-time sperm separation technique is the most effectivemethod so far available in isolating high-quality sperm samples to be used in assisted reproduction.

A Lagrangian criterion of unsteady flow separation for two-dimensional periodic flows

The present paper proposes a Lagrangian criterion of unsteady flow separation for two-dimensional periodic flows based on the principle of weighted averaging zero skin-friction given by Haller （HALLER, G. Exact theory of unsteady separation for two-dimensional flows. Journal of Fluid Mechanics, 512, 257-311 （2004））. By analyzing the distribution of the finite-time Lyapunov exponent （FTLE） along the no-slip wall, it can be found that the periodic separation takes place at the point of the zero FTLE. This new criterion is verified with an analytical solution of the separation bubble and a numerical simulation of lid-driven cavity flows.

The Calculation of Collision Risk on Air-Routes Based on Variable Nominal Separation

In this paper,a new method to calculate collision risk of air-routes,based on variable nominal separation,is proposed. The collision risk model of air-routes,based on the time variable and initial time interval variable,is given. Because the distance and the collision probability vary with time when the nominal relative speed between aircraft is not zero for a fixed initial time interval,the distance,the variable nominal separation,and the collision probability at any time can be expressed as functions of time and initial time interval. By the probabilistic theory,a model for calculating collision risk is acquired based on initial time interval distribution,flow rates,and the proportion of aircraft type. From the results of calculations,the collision risk can be characterized by the model when the nominal separation changes with time. As well the roles of parameters can be shown more readily.

Multi-dimensional blind separation method for STBC systems

Intercepted signal blind separation is a research topic with high importance for both military and civilian communication systems. A blind separation method for space-time block code （STBC） systems is proposed by using the ordinary independent component analysis （ICA）. This method cannot work when specific complex modulations are employed since the assumption of mutual independence cannot be satisfied. The analysis shows that source signals, which are group-wise independent and use multi-dimensional ICA （MICA） instead of ordinary ICA, can be applied in this case. Utilizing the block-diagonal structure of the cumulant matrices, the JADE algorithm is generalized to the multidimensional case to separate the received data into mutually independent groups. Compared with ordinary ICA algorithms, the proposed method does not introduce additional ambiguities. Simulations show that the proposed method overcomes the drawback and achieves a better performance without utilizing coding information than channel estimation based algorithms.

Indistinguishability of orthogonal time-separated bell states

This paper proves that it is impossible to identify orthogonally time-separated Bell states. If two qubits of a Bell state interact with the measurement apparatus at different time, any attempt to identify this state will disturb it.

Speech Signal Recovery Based on Source Separation and Noise Suppression

In this paper, a speech signal recovery algorithm is presented for a personalized voice command automatic recognition system in vehicle and restaurant environments. This novel algorithm is able to separate a mixed speech source from multiple speakers, detect presence/absence of speakers by tracking the higher magnitude portion of speech power spectrum and adaptively suppress noises. An automatic speech recognition (ASR) process to deal with the multi-speaker task is designed and implemented. Evaluation tests have been carried out by using the speech da- tabase NOIZEUS and the experimental results show that the proposed algorithm achieves impressive performance improvements.

A time-optimal aircraft-following model based on Pontryagin's minimum principle

A time-optimal aircraft-following model is introduced to address air traffic flow interference by velocity reduction. The objective function is set up as minimizing the recovery time during which the separation minima are not infringed and the separation of the air traffic flow returns to the initial separation at the terminal time. Pontryagin＇s minimum principle is used to solve the optimum aircraft-following velocity control law. An analytical minimum safe following separation is also provided under the time-optimal control law. The simulation results show that the precision first-order tracking accuracy is achieved without losing the separation.

Numerical Solutions of Finite Well in Two Dimensions Using the Finite Difference Time Domain Method

The higher excited states for two dimensional finite rectangular well potential are calculated numerically,by solving the Schrödinger equation using the finite difference time domain method.Although,this method is suitable to calculate the ground state of the quantum systems,it has been improved to calculate the higher excited states directly.The improvement is based on modifying the iterative process involved in this method to include two procedures.The first is known as cooling steps and the second is known as a heating step.By determining the required length of the cooling iteration steps using suitable excitation energy estimate,and repeating these two procedures using suitable initial guess function for sufficient times.This modified iteration will lead automatically to the desired excited state.In the two dimensional finite rectangular well potential problem both of the suitable excitation energy and the suitable initial guess wave function are calculated analytically using the separation of variables technique.

Restoration of Time-Spatial Scales in Global Temperature Data

The objective of this paper is to utilize images of spatial and temporal fluctuations of temperature over the Earth to study the global climate variation. We illustrated that monthly temperature observations from weather stations could be decomposed as components with different time scales based on their spectral distribution. Kolmogorov-Zurbenko (KZ) filters were applied to smooth and interpolate gridded temperature data to construct global maps for long-term (≥ 6 years) trends and El Nino-like (2 to 5 years) movements over the time period of 1893 to 2008. Annual temperature seasonality, latitude and altitude effects have been carefully accounted for to capture meaningful spatiotemporal patterns of climate variability. The result revealed striking facts about global temperature anomalies for specific regions. Correlation analysis and the movie of thermal maps for El Nino-like component clearly supported the existence of such climate fluctuations in time and space.

基于机器学习算法和ARIMA模型的旱地春小麦产量预测

为探究机器学习算法与时间序列结合预测春小麦产量的可行性,使用HP滤波算法,将1971-2021年甘肃省定西市安定区和2014-2021年定西市渭源县的产量数据分离为气象产量和趋势产量,利用研究区的气象数据,分别基于随机森林(random forest,RF)、循环神经网络(recurrent neural network,RNN)、支持向量机(support vector machine,SVM)、反向传播神经网络(back propagation neural network,BPNN)和长短期记忆网络(long short-term memory,LSTM)5种机器学习算法实现春小麦气象产量的预测对比;构建了ARIMA时间序列模型,探究旱地春小麦趋势产量的最佳预测模型。结果表明,旱地春小麦产量中气象产量占比大,趋势产量占比小,且气象产量的变化趋势基本与总产量一致。LSTM模型对研究区内气象产量的模拟效果最佳。通过参数率定,获得最优的趋势产量预测模型为ARIMA(4,1,2)模型,其残差基本为白噪声,符合正态分布。利用LSTM和ARIMA(4,1,2)模型组合,对2014-2021年渭源县的春小麦产量进行预测,并与研究区的实际产量数据比较,预测结果与实际值接近,模型精度较高,其R^(2)为0.96,MAPE为1.22%,MAE为32.12 kg·hm^(-2),RMSE为35.32 kg·hm^(-2)。在本研究条件下,LSTM和ARIMA(4,1,2)组合模型具有良好的预测精度,可实现旱地春小麦产量的预测。

时间控制模式在血液分离机运行管理中的价值研究

目的:构建血流分离机时间控制管理模型,探讨其在血液分离机运行管理中的应用价值。方法:分析成分血采集血液分离时间延迟原因,采用数据挖掘算法分析其影响因素与时间控制水平的关联性,在时间评估预测等多维度构建血液分离时间控制管理模型,制定时间控制管理对策。选取2019-2022年上海市徐汇区中心医院的600名献血者和采血期间临床在用的17台血液分离机,根据管理模式不同,将其分为对照组(300名献血者,14台血液分离机)和观察组(300名献血者,15台血液分离机,含对照组12台和新增加的3台),对照组血液分离机采用质量控制模式,观察组采用时间控制模式,对比两组成分血采集过程中的问题数、延迟比例、满意人数和参与采集成分血工作的相关医务人员考核成绩。结果:观察组成分血采集过程中发生设备、医用耗材、医务人员及献血者相关问题的献血者人数分别为11名(占3.7%)、17名(占5.7%)、7名(占2.3%)和18名(占6.0%),均少于对照组,其差异有统计学意义(x^(2)=7.192、6.822、8.153、11.405,P<0.05);观察组成分血采集过程中血液分离机运行正常、明显延迟和显著延迟的献血者人数分别为236名(占78.7%)、46名(占15.3%)和18名(占6.0%),运行正常人数占比高于对照组,明显延迟和显著延迟占比低于对照组,其差异有统计学意义(x^(2)=17.821、7.131、8.549,P<0.05);观察组献血者满意人数为284名(占94.7%),高于对照组,其差异有统计学意义(x^(2)=30.171,P<0.05);参与观察组献血者成分血采集工作的医务人员考核成绩为(91.14±4.86)分,高于对照组,其差异有统计学意义(t=4.587,P<0.05)。结论:时间控制模式能够控制血液分离机运行问题发生概率,缩短血液分离机运行延迟时间,改善献血者献血体验和采血服务质量,提高医务人员业务水平。

基于时间间隔标准的尾流安全评估分析方法

科学地优化飞机间尾流间隔是提升机场吞吐量的重要举措,确保安全是尾流间隔实施的首要前提。首先,基于大涡模拟试验数据,对经典的两阶段消散模型(Wake Two-Stage Decay Model,D2P)模型进行改进,创建顶风对尾涡环量衰减的影响模型。然后,针对基于时间间隔(Time-Based Separation,TBS)未考虑顶风会影响尾涡移动和尾涡环量衰减,通过转化为飞机地速和构建改进D2P模型深刻分析两因素对尾涡遭遇严重度的影响。最后,计算实施TBS时不同风速不同机型组合对应的最小尾流间隔,并综合分析对应间隔的尾涡遭遇严重度。结果表明:虽然TBS未考虑顶风对尾涡移动和环量衰减的影响,但可以确保前后机安全性;在顶风8 m/s应用TBS方案时,各机型组合的尾涡遭遇严重度约为静风时的30%。TBS安全地缩减了顶风时的尾流间隔。

基于统计指标的曲线桥支座脱空病害识别方法

为快速评估曲线连续梁桥支座健康状态,提出了基于时程统计指标的桥梁支座脱空病害识别方法。首先,提取行车激励下桥面测点加速度信号的20个时程统计指标,通过概率统计的方式,得出各统计指标的置信区间;其次,根据各时程统计指标对支座脱空的敏感程度不同,采用熵值法确定各统计指标的权重分配值;最后,根据各测点异常指标数计算损伤指数,综合判断测点附近支座是否出现脱空病害。为验证方法的有效性,以某3×25 m曲线连续梁桥为工程背景,建立车桥耦合动力学模型进行分析验证。结果表明:该方法可以准确识别脱空支座所在位置,并且可以有效识别较小的损伤;相比于中间支座脱空,时程统计指标对端支座脱空更为敏感。