高灵敏度太赫兹探测模块低温杜瓦设计及力热特性研究

高灵敏度太赫兹探测模块(High Sensitivity Terahertz Detection Module,HSTDM)是中国空间站巡天望远镜的科学载荷之一,主要开展太赫兹天文观测任务.该模块的核心是工作在10 K温区的氮化铌超导隧道结(Superconductor-Insulator-Superconductor,SIS)混频器,其低温制冷条件由满足空间应用的两级脉冲管制冷机提供.能最大限度减小制冷机热负载的低温杜瓦是实现这一空间10 K温区制冷环境的关键部件,且需要适应火箭发射力学振动环境.主要介绍了这一专用低温杜瓦的结构设计、力学特性仿真分析与试验测试以及热特性仿真分析.低温杜瓦的基频为189.36 Hz,力学分析结果表明内部支撑结构最大应力小于材料的屈服应力,振动试验结果表明低温杜瓦结构能够适应力学环境.低温杜瓦内部结构对制冷机一级冷端的漏热量为1800 mW,对二级冷端的漏热量为20.6 mW,均小于制冷机的制冷量,热分析结果表明低温杜瓦支撑结构的热设计满足隔热要求.力热特性研究结果表明该低温杜瓦设计能够满足太赫兹探测模块的空间应用需求.

Preparation of YBa_2Cu_3O_(7-δ) superconducting thick film on Ni-W tapes via electrophoretic deposition

The preparation of La0.4Sr0.6TiO3 （LSTO） buffer layer and YBa2Cu3O7-δ（YBCO） superconducting thick film by a low cost technology was studied. The crystal orientation of LSTO and YBCO films was detected by X-ray diffraction, the conductivity of LSTO film and superconductivity of YBCO coating were investigated by standard four-probe method. Excellent in-plane alignment, smooth and dense LSTO buffer layer was successfully prepared on textured Ni-W taps by metal organic deposition （MOD）. YBCO thick film was fabricated by electrophoretic deposition （EPD）. The effects of applied voltage and deposition time on the YBCO coatings properties were studied. The results show that the critical current density of the YBCO coating deposited under 138 V for 35 min was about 600 A/cm2 （0 T, 77 K）.

Central venous port placement in advanced breast cancer patients:comparison of the anatomic- landmark and ultrasound-guided techniques

Objective： The aim of this study was to compare the anatomic-landmark and ultrasound-guided techniques in the placement of an internal jugular vein port in patients with advanced breast cancer. Methods： Between March 2010 and October 2010, 60 patients with advanced breast cancer underwent central venous port placement for the delivery of chemotherapy, preferably through the internal jugular vein. Patients were randomly assigned to either the anatomic-landmark or the ultrasound-guided group. Failure on first attempt, number of attempts until successful catheterization, time to successful placement, the accordance of the two placement approaches, and the demographics of each patient were recorded. Results： The consistency of the direction of two lines drawn using the anatomic-landmark and ultrasound-guided techniques or of the diameter of the internal jugular vein as determined by the two approaches was 85% （51/60）. The rate of successful place- ment at first attempt was higher in the ultrasound group than in the anatomic-landmark group （P 〈 0.05）. A greater number of attempts and longer time to successful port placement were needed in the latter （P 〈 0.05）. Conclusion： The findings of this study indicate that, in the placement of an internal jugular vein port, the ultrasound （US）-guJded technique has several advantages over the anatomic-landmark technique.

Forced-flow gas cooled current leads for SCQ magnets in BEPCⅡ

Current leads are used to connect the superconducting magnets in cryogenic temperature to the power station in room temperature. It is the main source of heat leak into the eryostat of magnets on static operation. This paper presents the optimized methods of the leads for BEPC Ⅱ , and the effects of different cross section ar- ea on the heat leak, temperature profile as well as the voltage drop of the leads. The multi-tube structure is adopted and improved for the leads. The results of numerical simulation using CFD software package Fluent6. 0 for the muhi-tube-structure leads are presented, which can be used to improve the design of the leads.

A Study on Ship Deperming Coil System Using High Temperature Superconducting Cable Technology

Naval ship deperming is effective to reduce the potential damage from sea mines some of which sense magnetic field of the ship, and thus, is an important treatment of naval ships in the recent world. Large electric current is required to impose the magnetic field on the ship hull, which in turn means that the deperming coil needs to be wound on ship hull when the coil is composed of conventional conductive materials, such as copper. We considered a few HTS （high temperature superconducting） coil systems to deperm naval ships because we expect the shorter deperming time and lower manual workload for ship deperming operation, compared conventional conductor coil systems. We have in the past presented a solution using a fiat two-coil system arranged on seabed with tightly bound HTS conductor by analytical calculation of magnetic field on the conductor. By considering present and already developed technologies, a conductor with cylindrically wound on the core arranged as fiat multi-turn coils on seabed was designed using analytical methods.

Development of the Highly Homogeneous Magnetic Field for Simulative Gyrotron by HTS

The low temperature superconducting magnet system, with the highly homogeneous magnetic field, has been applied extensively, and has had important effects on many domains. With the development of the cryogenic and superconducting techniques, it is possible that high temperature superconducting magnet with highly homogeneous magnetic field is manufactured by high temperature superconductor（HTS）. Therefore, a simulative gyrotron applied into war, with highly homogeneous magnetic field, is designed and manufactured by high temperature superconducting material.

Intravascular Access in Chelonia mydas and Dermochelys coriacea Using the Seldinger Technique U Itrasou nd-Guided

Strand-ed turtles need fluid parenterally. The jugular access is best for the maintenance and patency of the catheter. The Seldinger technique guided by ultrasound seems to be the safest for catheter insertion. Five juveniles Chelonia mydas with fibropapillomatosis and an adult male leatherback turtle （Dermochelys coriacea） with altered buoyancy were sent to Santos Municipal Aquarium for rehabilitation. Turtles underwent catheterization of the jugular vein using the Seldinger technique with central venous polyurethane catheter monolumen 14 G to Dermochelys and 18 G for Chelonia, guided by ultrasound with 10 MHz transducer catheters were sutured to the skin and animals were subjected to fluid. In all turtles, the catheters were patency and were well established. There were no granulomatous reactions or related infections. The Dermochelys improved clinically after fluid resuscitation, and the catheter was removed one week after. In one Chelonia excision was 21% of its weight in tumors, and the animals received colloid catheter by enabling the mitigation of bleeding due to removal. The use of ultrasonography has enabled monitoring of all access as the patency of the catheter and fluid diffusivity.

Analysis on the Application of Electrical New Technology of in Electromechanical Integration

The electrical new technology is a new frontier science.This kind of technology, with the development and progress of society, makes the continuous development and innovation.It is the future development trend of electrical engineering system,which plays a very important role in technological innovation.The principle and theoretical support for the development of electrical new technology includes Bio- electro magnetics, plasma physics, electromagnetic fluid mechanics and gas discharge physics etc.In addition, under the application of permanent magnetic materials and other new materials, the electrical new technology and obtained further development also promote the development and application of electronic power supply, strong magnetic field technology, solar photovoltaic power generation, and superconducting power technology.This paper mainly analyzes the application of electrical new technology in electromechanical integration.

Implementing two optimal economical quantum cloning with superconducting quantum interference devices in a cavity

We propose a unified scheme to implement the optimal 1→ 3economical phase-covariant quantum cloning and optimal 1→3 economical real state cloning with superconducting quantum interference devices (SQUIDs) in a cavity.During this process,no transfer of quantum information between the SQUIDs and cavity is required.The cavity field is only virtually excited.The scheme is insensitive to cavity decay.Therefore,the scheme can be experimentally realized in the range of current cavity QED techniques.

Application of superconductive gravity technique on the constraints of core-mantle coupling parameters

The parameters, i.e. the Period and the Quality factor, of the Earth's free core nutation (FCN) are closely related to the dissipative coupling between the core and the mantle. Based on the FCN parameters obtained from the actual observations and theoretical simulation, significantly constrained in this study were several key parameters near the core-mantle boundary (CMB), related to the core and mantle coupling, including viscosity at the top of liquid core, conductivity at the bottom of the mantle, and dynamic ellipticity of the CMB. In order to choose high quality observations from global stations of the superconducting gravimeters (SG) on the Global Geodynamics Project (GGP) network, we adopted two criteria, the standard deviations of harmonic analysis on tidal observations and the quality of the FCN parameters calculated with the observations from single station. After the mean ocean tidal effects of the recent ocean tidal models were removed, the FCN parameters were retrieved by stacking the tidal gravity observations from the GGP network. The results were in a good agreement with those in the recent research by using the SG and/or the VLBI observations. Combined with an FCN theoretical model deduced by angular momentum method, the viscous and electromagnetic coupling parameters near the CMB were evaluated. Numerical results indicated that the viscosity at the top of the liquid core was in the range from 6.6×102 to 2.6×103 Pa·s, which was in good agreement with those obtained from the Earth's nutation, the FCN and variations in the length of day (LOD). The conductivity at the bottom of the mantle should be as large as 2.6×106-1.0×107 S m-1 to match the FCN quality factors from the actual observations. The dissipative coupling had a little influence of 1-2 sidereal days for the FCN period.

Inspection of reinforced concrete interface delamination using ultrasonic guided wave non-destructive test technique

An ultrasonic-guided wave(UGW) is a very promising tool in the field of structural health monitoring and non-destructive test.Numerical analysis was used to simulate the propagation in the rebar and explore the characteristics of UGW in the steel rebar waveguide.Two-dimensional fast Fourier transform was used to process the numerical results and to evaluate the damage.Subsequently,different UGW test influence factors were investigated.The results clearly showed that both the group velocity and the amplitude of longitudinal modes were not very sensitive to stress and temperature variations.However,the received UGW signal energy decreased with the increasing concrete strength.Finally,the interface condition between the concrete and the rebar was investigated.Time-domain and frequency-domain analyses were used to process the received signals.Different interface delamination lengths of the UGW energy attenuation were analyzed and a relationship was obtained.This study successfully proved that UGW is an effective tool in the non-destructive test of reinforced concrete interface delamination.

Superconducting Energy Storage Flywheel——An Attractive Technology for Energy Storage

Flywheel energy storage(FES) can have energy fed in the rotational mass of a flywheel,store it as kinetic energy,and release out upon demand.The superconducting energy storage flywheel comprising of magnetic and superconducting bearings is fit for energy storage on account of its high efficiency,long cycle life,wide operating temperature range and so on.According to the high temperature superconducting(HTS) cooling mode,there are zero field cooling(ZFC) bearings and field cooling(FC) bearings.In practice,the superconducting bearings are formed by field-cooled superconductors and permanent magnets(PMs) generally.With respect to the forces between a permanent magnet and a superconductor,there are axial(thrust) bearings and radial(journal) bearings.Accordingly,there are two main types of high-temperature superconducting energy storage flywheels,and if a system comprising both the thrust bearing and the radial bearing will have the characteristics of both types of bearings.Magnetic force,magnetic stiffness and damping are these three main parameters to describe the levitation characteristics.Arrangement and shape of superconductors,thickness of superconductor,superconducting flux creep and critical current density of the superconductor affect the magnetic levitation force of these superconducting bearings.The key factors of FES technology,such as flywheel material,geometry,length and its support system were described,which directly influence the amount of energy storage and flywheel specific energy.All these results presented in this paper indicate that the superconducting energy storage flywheel is an ideal form of energy storage and an attractive technology for energy storage.

肝癌局部消融治疗规范的专家共识

局部消融治疗是在影像技术的引导下对肿瘤靶向定位,用物理或化学的方法杀死肿瘤细胞;影像引导技术包括超声、CT和MRI;治疗途径有经皮、经腹腔镜手术和经开腹手术三种.局部消融治疗的特点：一是直接作用于肿瘤,具有高效快速的优势;二是治疗范围局限于肿瘤及其周围组织,对机体影响小,可以反复应用.局部消融治疗在过去20年左右发展迅速,已经成为继手术切除、介入治疗后的第三大肝癌治疗手段,而且由于其疗效确切,特别是在小肝癌的治疗方面,射频消融治疗的疗效与手术切除相近,因此,被认为是小肝癌的根治性治疗手段之一.