真空低温环境下超大面源黑体现场校准技术

红外辐射面源黑体应用于特定红外特性目标的模拟,各种红外探测、制导系统的外场测试。随着空间应用的红外成像器的口径的增大,红外辐射面源的口径也相应增大,为了保证超大辐射面黑体的性能指标满足要求,必须对其在真空低温条件下进行性能校准。但目前国内还没有相应计量标准,无法保证测试结果的准确可靠。设计了一种真空低温环境下超大面源黑体现场校准装置,实现对超大面源黑体的发射率、辐射温度、温场均匀性、温度稳定性等性能参数的校准,并取得了较好的试验结果,实现了真空低温环境下超大面源黑体的参数校准。     

激光在肿瘤方面的应用

恶性肿痛不但常见，且为人类主要死亡原因之一，目前有效的治愈办法不多，是当今医学研究重要课题之一。激光器自1960年发明以后，首先应用干眼科，也较早地运用于肿瘤的治疗。自七十年代初开始有人研究光敏药物合并激光诊治恶性肿瘤，八十年代已正式列为临床研究，尤其近二三年发展很快。从世界形势看，使用激光的医生尚属少数，远不能说已经推广。其实想采用激光并不难，只要相信它，有了设备，试用后就不愿扔下了。     

应用OBI系统分析胸部肿瘤调强放疗的摆位误差

目的：应用机载影像系统（on boardinmger,OBl）分析胸部肿瘤调强放射治疗时分次间的摆位误差,并依此计算CTV外扩PTV边界的大小。方法：应用Varian-21EX医用直线加速器治疗47例胸部肿瘤。每周治疗前获取锥形束断层扫描（cone beam computed tomography,CBCT）图像,将CBCT图像和计划CT图像及其靶中心匹配,计算平移和旋转误差。结果：平移误差左右（x）方向为（-0．3194±3．6943）mm,头脚（y）方向为（0．4851±6．2636）mm,前后（z）方向为（0．4144±5．2818）mm;旋转误差冠状面（c）为（0．2080±1．4925）°,矢状面（s）为（0．0922±1．2976）°结沦：对于胸部肿瘤调强放疗（IMRT）,临床靶体积（CTV）到计划靶体积（PTV）的外放边界在左右方向宜为7mm,头脚方向宦为11mm,前后方向宜为10mm。考虑到旋转误差,与靶区比较长时靶区两端外放要更大一些.     

Obliquity factor for radiation from solid-state laser

The radiated field consists of forward radiation at an angle ? and backward radiation at ? ? ? reflected from the dielectric-air interface into an additional component of field at angle ?. The total radiation contains a factor that simplifies into an expression recently obtained by more sophisticated methods, and which is here interpreted as the Huygens obliquity factor for the arrangement. A small correction to the expression is also obtained.     

A cryogenic focal plane array for 85-115 GHz using MMICpreamplifiers

A new focal plane array for 85-115 GHz is described in this paper. This array has 16 pixels, and uses InP monolithic-microwave integrated-circuit preamplifiers with 40-dB gain, followed by a wide-band subharmonic mixer to convert to a 5-20-GHz intermediate-frequency band. A low-loss isolator is used to achieve an excellent input match. Square corrugated feed horns are used for efficient filling of the focal plane. Critical components are operated at a temperature of 20 K. Noise temperature varies from 50 to 130 K, including all pixels across the full band     

Prospects for using platinum coordination compounds possessing antitumor activity

The review presents a complete analysis of studies on experimental and clinical application of platinum complexes with special reference to cis-dichlorodiamminoplatinum, both separately and in combination with other chemotherapeutic preparations. Platinum complexes show their highest antiblastic activity in treatment of ovarian, testicular, lung tumours and those located in the head and neck regions as well as of the bladder cancer and tumours of the other localizations resistant to the action of alkylating agents and other preparations. The clinical material is systematized so that it is possible on the basis of the analysis performed to choose an optimum regime for treating different tumours by platinum complexes.     

空间飞行器冷屏防霜结构

空间飞行器冷屏是一种包裹在高速飞行器外的基于相变制冷的装置,可以降低高速飞行器在太空飞行时的红外辐射特性。冷屏在发射前需要进行低温制冷剂加注。如果没有保护装置,在地面加注时会引起冷屏表面严重结霜,恶化冷屏表面红外辐射特性。设计了一种由保温层和氮气保护层组成的防霜结构。氮气保护层利用氮气在低温下不易凝结的特性,保护冷屏外壳使不结霜;保温层利用保温材料的热阻特性,使保温层外壁温度在当地露点温度以上,从而防止空气中水蒸气在保温层外壁凝结。建立了氮气保护气填充速度随时间变化的关系式。实验表明,冷屏表面和保温层外壳均实现了零结霜,取得了很好的防霜效果。     

红外遥感用低温制冷器的进展

低温制冷器与红外探测器配套,是军事现代化、高新技术等急需发展的关键产品。国内研制技术也已接近国际先进水平,基本掌握了小型化、低振动、长寿命、细方形漆包线制作、间隙密封、消除电磁干扰等相关关键技术。本文列出了已研制过的直线电机谐振压缩机的主要技术性能。希望主管、用户、研制、生产各方通力合作,应用－改进－再应用－再改进,实现我国低温制冷器的产业化。     

Prospects of using rare-earth hexaborides in thermoelectric single-photon detectors

The results of the numerical simulation of heat propagation processes occurring after the absorption of single photons with energies of 1 eV–1 keV in a three-layer sensor of a thermoelectric detector are analyzed. Different configurations of the sensor with a tungsten absorber, a thermoelectric layer of cerium hexaboride, and a tungsten heat sink are considered. It is shown that sensors for detecting photons of a specific spectral range with the required energy resolution and counting rate can be developed by varying the geometric sizes of the sensor layers. It is concluded that a three-layer sensor has a number of advantages in comparison with a single-layer sensor and has characteristics allowing consideration of the thermoelectric detector as a realistic alternative to superconducting single-photon detectors.     

红外遥感低温制冷器的进展

与红外探测器配套的低温制冷器是军用急需发展的高新技术产品,国内研制已接近国际先进水平,基本掌握了小型化、低振动、长寿命、细方形漆包线制作,间隙密封、消除电磁干扰等关键技术,介绍了研制的直线电机谐振压缩机的主要技术性能。希望主管、用户、研制、生产各方通力合作,在应用和改进过程中,实现我国低温制冷器的产业化。     

Methods for creating hyperthermia in tumors by using electromagnetic fields

Evidence on the methods for creation of hyperthermia in treatment of human tumours using superhigh-frequency external, intracavitary, and implanted irradiators are generalized. Inductive, capacitive and interstitial methods of heating are described. Advantages and shortcomings, depths of heating and heat-production structures are presented for each method. The known devices for regional hyperthermia are considered.     

Undulator design for synchrotron radiation sources using simulatedannealing

Simulated annealing provides an algorithm for arranging measured wiggler field errors to minimize a “cost function” characterizing errors in electron trajectories and other aspects of magnetic field quality. Rocketdyne has most recently demonstrated the efficacy of this approach in the design and fabrication of a pure permanent magnet prototype small-gap undulator for BNL. The cost functions developed for this purpose are derived and the results presented     

Prospects for visible and VUV free electron lasers using dielectric resonance

Operation near spectral resonance lines of helium and of the alkali metals is capable of yielding high gain in an FEL at visible and VUV wavelengths. When the wavelength is on the order of 1 percent off resonance, absorption and saturation effects are relatively unimportant.     

未来无线终端的展望

对目前市场上各种手持通信终端进行了介绍,分析了其存在的问题,对未来无线终端设计的思路及所需解决的问题进行了讨论。     

An approximation of the radiation integral for distorted reflectorantennas using surface-error decomposition

The physical optics/aperture integration (PO/AI) formulation is often used to analyze the radiation patterns of reflector antennas. In this study, the PO/AI radiation integrals for distorted reflector antennas are addressed. The surface error of the antennas is approximated by a series of surface expansion functions. The radiation integral is decomposed into a series of radiation-type integrals, each of which corresponds to one of the surface expansion functions. Each of these radiation-type integrals is then weighted by amplitude coefficients. The advantage of performing the decomposition is that each of the radiation-type integrals can be computed and the pattern data stored. The computation of the pattern for a distorted reflector antenna with a changing error profile is performed by recalling the pattern data for each perturbation term and weighting it with the amplitude coefficient. This facilitates rapid evaluation of the radiation integral in cases where the error profile is changing (for example, time-varying errors). The superposition of integrals presented in this paper was shown to be valid for surface-error profiles up to 0.1 λ rms amplitude     

Optimization of LDD devices for cryogenic operation

The optimization of lightly doped drain (LDD) devices to maximize hot-carrier device lifetime at cryogenic temperature is studied. The hot-carrier-induced device degradation behavior and mechanisms of the various LDD and conventional devices are investigated. Carefully designed LDD devices can have better device reliability at low temperature compared to the conventional devices. However, the device lifetime is very short at low temperature for all the devices, and the difference in device lifetime between LDD and control devices is not appreciably large. The degradation behavior of both LDD and non-LDD devices at 77 K does not follow the simple behavior modeled by substrate current. For a given device, the maximum degradation is not observed at the bias condition for maximum substrate current. The optimum LDD design depends on the specific stressing bias conditions at 77 K     

RADIATION FROM THE CRYOGENIC CALIBRATION LOAD FOR MICROWAVE RADIOMETERS

A styrofoam layer is introduced to the cryogenic calibration load for microwave radiometers in order to keep the antenna at ambient temperature while calibrating. Obviously the insulation layer has nonuniform temperature profile. A novel approach based on the transmission-line theory is presented to calculate the emission from the load. According to the sample calculation through this new approach, the contribution of the insulation layer to the load radiation can not be neglected.     

Phototherapy of tumors using photosensitizing agents

The experimental and clinical data on a new method of cancer treatment--photodestruction of tumours treated with the photosensitizing preparations--are reviewed. Particular emphasis is given to porphyrin compounds. The problems are considered dealing with accumulation of these compounds in cells and tissues, with the mechanism of photoalteration of sensitized tumours, with testing of the method on transplanted and spontaneous animal tumours as well as with the data on the phototherapy of human tumours with a hematoporphyrin-derivative used as a photosensitizer. The prospects for the method development are evaluated.     

Molecular-genetic aspects of drug therapy of malignant tumors

State and prospects of the drug cancer therapy are examined in the light of achievements of modern molecular oncology. Special attention is paid to the molecular genetic analysis of the appearance of individual and multiple cellular drug resistance in connection with amplification of definite genes as well as oncogenes. The idea about the possible role of oncogene activation as a universal cell reaction in response to an injury of environmental factors is advanced. It concerns both oncogenesis and induction of cancer cell drug resistance.     

集成电路新技术展望

介绍了集成电路技术的发了近美国国家半导体技术发展蓝图讨论了集成电路技术发展近况和趋势。着重讨论了在集成电路生产中采用的新材料和新技术。