油罐冒罐事故的原因分析及预防

通过事故实例分析，阐述油罐冒罐事故的原因，并针对原因提出要加强操作人员的责任心教育，完善各项规章制度，不断提高操作人员素质，严格遵守岗位操作规程，及时消除设备缺陷、完善罐区硬件设施和罐区实行现代科学管理等项措施。     

激光光子复合治疗酒渣鼻

目的:探讨强脉冲光结合激光治疗酒渣鼻毛细血管扩张的疗效.方法:自2008年9月至2011年10月,采用540、420 nm强脉冲光及长脉冲1 064 nm Nd:YAG激光对50例伴有/不伴有丘疹、脓疱的毛细血管扩张型酒渣鼻患者进行治疗.根据患者面部的皮肤类型及毛细血管扩张程度,选择适当的治疗参数,其中540nm强脉冲光能量密度13～16J/cm2;长脉冲1 064 nm Nd:YAG激光能量60～100 mJ,治疗1～6次,平均2.93次,每次治疗间隔1个月.以420 nm强脉冲光治疗炎性丘疹,能量密度7～12J/cm2.结果:治疗后随访3～6个月,治愈率24.00％,总有效率92.00％.无不良反应发生.结论:采用540、420 nm强脉冲光结合长脉冲1 064 nm Nd:YAG激光复合治疗伴有/不伴有丘疹、脓疱的酒渣鼻毛细血管扩张其疗效确切,效果满意.     

A novel speech-processing strategy incorporating tonal information for cochlear implants

Good performance in cochlear implant users depends in large part on the ability of a speech processor to effectively decompose speech signals into multiple channels of narrow-band electrical pulses for stimulation of the auditory nerve. Speech processors that extract only envelopes of the narrow-band signals (e.g., the continuous interleaved sampling (CIS) processor) may not provide sufficient information to encode the tonal cues in languages such as Chinese. To improve the performance in cochlear implant users who speak tonal language, we proposed and developed a novel speech-processing strategy, which extracted both the envelopes of the narrow-band signals and the fundamental frequency (F0) of the speech signal, and used them to modulate both the amplitude and the frequency of the electrical pulses delivered to stimulation electrodes. We developed an algorithm to extract the fundatmental frequency and identified the general patterns of pitch variations of four typical tones in Chinese speech. The effectiveness of the extraction algorithm was verified with an artificial neural network that recognized the tonal patterns from the extracted F0 information. We then compared the novel strategy with the envelope-extraction CIS strategy in human subjects with normal hearing. The novel strategy produced significant improvement in perception of Chinese tones, phrases, and sentences. This novel processor with dynamic modulation of both frequency and amplitude is encouraging for the design of a cochlear implant device for sensorineurally deaf patients who speak tonal languages.     

推进剂初始温度影响液体火箭发动机燃烧稳定性的数值模型

对自然推进剂（ＭＭＨ／ＮＴＯ）初始温度对火箭发动机燃烧稳定性的影响进行了研究,从推进剂初始温度对蒸发速率的影响规律出发,发展了初始温度大小影响蒸发速率的物理模型。燃烧流动过程应用圆柱坐标系下的两相湍流化学反应Ｎａｖｉｅｒ－Ｓｔｏｋｅｓ方程来描述,控制方程是用限体积法在任意曲线坐标系下进行离散,计算采用ＴＭＭ方法生成的正交网格。完善了一种压力隐式算子分裂算法,使之应用到燃烧过程和不稳定燃烧中,提高了计算的精度和稳定性;以蒸发作为燃烧速率控制过程,由ＭＭＨ的分解蒸发速率来控制。用蒸发和分解的时滞来分析燃烧不稳定性。应用ＣＦＤ技术发展了评定燃烧稳定性的脉冲枪模型,之后对推进剂初始温度对燃烧稳定性的影响进行了数值研究,得到其对振荡的敏感分析,并给出燃烧稳定性的极限图,说明了该物理模型和算法的可靠性。     

Hybrid Born iterative method in low-frequency inverse scatteringproblem

With its fast convergence, the distorted Born iterative method (DBIM) has been widely used in low-frequencg inverse scattering analysis, however its inherent drawback, sensitive-to-noise disturbance, may greatly limit its practical applications. In this paper, the numerical analysis is made to compare the DBIM and the Born iterative method (BIM). Then a hybrid BIM is presented. In this method, the DBIM is employed to speed the solution convergence in the initial several iterations and the BIM is used to improve the solution stability in the later iterations. The switch condition is also given. The simulation results show that the method is valid for the inverse scattering solution     

用于非均匀介质重建的选代算法收敛性的研究

研究轴对称二维非均匀介质重建迭代算法的收敛性问题。首先借助于玻恩近似将非线性积分方程线性化，然后，利用玻恩迭代法和变形玻恩迭代法，由散射场数据对轴对称二维非均匀介质进行重建。通过几个例子研究了影响迭代算法收敛性的几种因素，如送代算法本身、积分离散化后的网格划分、正则化方法中的正则化参数选取等。     

Implementation of 2-D pseudo-rotated digital filters using a forward lattice structure

The 1-D FDLS shows the localized feedback property and is suitable for modular and concurrent implementation. It is known that the 1-D FDLS shows interesting properties with respect to finite word-length effects. In this paper, a new result is given for the estimation of the lower and upper bound of the variance of the roundoff noise. It is presented how the FDLS can be incorporated to implement 2-D pseudo-rotated digital filters. The 1-D roundoff noise analysis is extended to the 2-D case. It is indicated how 2-D filter banks can be derived from the FDLS.     

Novel and efficient realizations of FIR digital filters

An FIR filter can usually be realized in the direct form or in cascade form. The Chebyshev-type structures, known for the 2-D FIR filter implementation, are generalized to the realization of arbitrary 1-D causal FIR filters. The new realizations show several attractive properties and can be implemented using modular pipelineable processor arrays     

Synthesis of Imidazole‐Based AIEgens with Wide Color Tunability and Exploration of their Biological Applications

Research on aggregation‐induced emission (AIE) has become increasingly popular recently and various AIE luminogens (AIEgens) have been developed based on tetraphenylethene, hexaphenylsilole, distyrylanthracene, tetraphenylpyrazine, etc. However, facile tuning of the AIEgen emissions in a wide range remains challenging. Herein, a novel series of AIEgens is reported, based on imidazole‐cored molecular rotors, with facile synthesis and emission colors covering the whole visible spectrum. Moreover, these imidazole derivatives exhibit biological functions unique among the AIEgens, including mitochondria‐specific imaging and antifungal activity. Benefiting from the easy preparation and the tunable emission, the imidazole derivatives are expected to not only diversify the family of AIEgens but also enrich their biological applications.