脉管制冷机直流机理研究和抑制方法探讨

双向进气脉管制冷机中存在的直流流动不仅增加了冷端换热器的负载 ,降低了脉管制冷机的性能 ,而且还是引起脉管制冷机制冷温度不稳定的一个重要原因。文中从流体网络理论出发 ,分析了直流产生的机理 ,对目前各种抑制方法进行了探讨 ,指出了进一步研究的方向。     

高功率多脉冲调制器研究

 研制了能产生多脉冲的高功率脉冲调制器，该调制器由初级储能系统、带绕式变压器、水介质Blumlein线和场发射二极管组成。在场发射二极管上获得3个峰值功率大于20 GW，半高脉宽约60 ns，脉冲间隔约15 ms，电压约400 kV的高功率电脉冲。理论计算、模拟计算与实验结果基本一致。分析表明主开关恢复时间是影响调制器输出脉冲时间间隔的主要因素。     

伪随机编码超宽带短脉冲的探测能力研究

 为进行弱信号检测，研究在脉冲雷达中获得大信号时间宽度与信号带宽积的方法，利用伪随机编码方法调制超宽带短脉冲，可以在保持子脉冲信号带宽的情况下，以低功率发射长脉冲串类噪声信号，而提高信号的能量，提高探测距离。通过仿真实验得出，利用伪随机编码技术可以使超宽带信号具有更强的探测能力，可以在回波信号功率水平远远小于噪声水平（如信噪比5%）的情况下实现对探测目标的高保真成像。     

Evaluation of Multiple Corona Reactor Modes and the Application in Odor Removal

Effects of multiple corona reactor modes on pulse characteristics, energy transfer efficiency, and odor (H₂S and NH₃) removal were investigated experimentally by the wire-plate corona reactor(s). The removal efficiency of H₂S was only 91% and the energy consumption was 16.1 Wh m⁻³ by the single mode with a gas-flow rate of 23 m³ h⁻¹ and an initial concentration of 200 mg m⁻³. At the same experimental conditions, almost 100% removal efficiency was achieved and the energy consumption was only 12.8 and 14.9 Wh m⁻³ by the series and parallel modes. In the case of 50 mg m⁻³ NH₃ removal at the same gas-flow rate, the removal efficiencies with the single mode, the series and parallel modes were 64, 92 and 70%, respectively. The energy requirement did not increase at the same residence time under the experimental conditions of the single mode with a gas-flow rate of 11.5 m³ h⁻¹ and the series or parallel mode with a gas-flow rate of 23.0 m³ h⁻¹. The experimental results indicate that the series and parallel modes are effective in saving energy consumption, improving removal ability and efficiency, especially for the series mode.     

激光与材料参数对瞬态SBS 诱导的激光超声破坏效果的影响

 通过数值求解一维瞬态受激布里渊散射（SBS）声光耦合波方程，从理论上分析了泵浦激光参数及光学材料参数对SBS过程发生阈值的影响。以SBS过程中建立起来的应力场抗拉（压）强度和散射场的反射率为判据，分析了激光脉宽及作用区域长度对激光超声破坏材料效果的影响，探讨了短脉冲激光（约ns）引起的激光超声对材料的破坏机理；讨论了通过参数配置有效遏制SBS过程激光超声对光学材料的破坏问题。     

一个新的IEC61000-4-2标准ESD电流解析表达式

 分析了两个ESD标准电流波形表达式，并提出一个新的基于脉冲函数来描述ESD标准电流的解析表达式，该表达式符合最新的标准IEC61000-4-2，在零时刻的电流及其微分部为0，且波形与实际测量波形基本吻合。     

Active long pulse shaping technique of pulsed CO2 laser using multi-pulse discharge control

We describe the pulse forming of pulsed CO₂ laser using multi-pulse superposition technique. Various pulse shapes, high duty cycle pulse forming network (PFN) are constructed by time sequence. This study shows a technology that makes it possible to make various long pulse shapes by activating SCRs of three PFN modules consecutively at a desirable delay time with the aid of a PIC one-chip microprocessor. The power supply for this experiment consists of three PFN modules. Each PFN module uses a capacitor, a pulse forming inductor, a SCR, a high voltage pulse transformer, and a bridge rectifier on each transformer secondary. The PFN modules operate at low voltage by driving the primary of HV pulse transformer. The secondary of the transformer has a full-wave rectifier, which passes the pulse energy to the load in a continuous sequence.We investigated various long pulse shapes as different trigger time intervals of SCRs among three PFN modules. As a result, we could obtain laser beam with various pulse shapes and durations from about 250 to 1000 μs.     

Quantitative Biodetection of Anticancer Drug Rituxan with DNA Biosensor Modified PAMAM Dendrimer/Reduced Graphene Oxide Nanocomposite

PAMAM dendrimer/reduced graphene oxide nanocomposite modified pencil graphite electrode (PAMAM/RGO/PGE) was used to fabricate an electrochemical DNA biosensor for determination of Rituxan (RTX) at low concentrations, for the first time. The fabricated biosensor was characterized with FE‐SEM, EIS, and CV techniques. The ds‐DNA/PAMAM/RGO/PGE was used as a working electrode to study the interaction between the RTX and salmon sperm ds‐DNA by DPV technique. Because of the interaction between the drug and DNA leads to a decrease in the guanine oxidation peak current, it was used as an indicator for the determination of the RTX. Under the optimized experimental conditions, a wide linear relationship between RTX concentration and guanine signal was obtained within the range of 7.0 to 60.0 μmol L⁻¹ and 60.0 to 300.0 μmol L⁻¹ with a low detection limit (0.56 μmol L⁻¹). To clarify the interaction mechanism between the RTX and the ds‐DNA, DPV and UV‐Vis measurements were used. The reproducibility, stability, and performance of the constructed biosensor was examined by quantitative measuring RTX in pharmaceutical and human serum samples with good precision (RSD; 2.0–6.0 %) and acceptable recoveries (100.04–101.95 %).     

Selective Determination of Verapamil in Pharmaceutics and Urine Using a Boron‐doped Diamond Electrode Coupled to Flow Injection Analysis with Multiple‐pulse Amperometric Detection

This work presents a simple and low‐cost method for fast and selective determination of Verapamil (VP) in tablets and human urine samples using a boron‐doped diamond working electrode (BDD) coupled to a flow injection analysis system with multiple pulse amperometric detection (FIA‐MPA). The electrochemical behaviour of VP in 0.1 mol L⁻¹ sulfuric acid showed three merged oxidation peaks at around +1.4 V and upon reverse scan, one reduction peak at 0.0 V (vs. Ag/AgCl). The MPA detection was performed applying a sequence of three potential pulses on BDD electrode: (1) at +1.6 V for VP oxidation, (2) at +0.2 V for reduction of the oxidized product and (3) at +0.1 V for cleaning of the working electrode surface. The FIA system was optimized with injection volume of 150 μL and flow rate of 3.5 mL min⁻¹. The method showed a linear range from 0.8 to 40.0 μmol L⁻¹ (R>0.99) with a low limit of detection of 0.16 μmol L⁻¹, good repeatability (RSD<2.2 %; n=10) and sample throughput (45 h⁻¹). Selective determination of VP in urine was performed at+0.2 V due to absence of interference from ascorbic and uric acids in this potential. The addition‐recovery tests in both samples were close to 100 % and the results were similar to an official method.     

Quantum control spectroscopy of vibrational modes: Comparison of control scenarios for ground and excited states in β-carotene

Quantum control spectroscopy (QCS) is used as a tool to study, address selectively and enhance vibrational wavepacket motion in large solvated molecules. By contrasting the application of Fourier-limited and phase-modulated excitation on different electronic states, the interplay between the controllability of vibrational coherence and electronic resonance is revealed. We contrast control on electronic ground and excited state by introducing an additional pump beam prior to a DFWM-sequence (Pump-DFWM). Via phase modulation of this initial pump pulse, coherent control is extended to structural evolution on the vibrationally hot ground state (hot-S₀) and lowest lying excited state (S₁) of β-carotene. In an open loop setup, the control scenarios for these different electronic states are compared in their effectiveness and mechanism.