细胞融合构建新型微藻及融合子的筛选和鉴定

利用细胞化学融合法,将生长迅速的兼养微藻和富含EPA和DHA的自养微藻进行融合。根据两种亲本藻的不同生长特性和脂肪酸组成差异,筛选出一种新型的微藻。利用随机扩增多态性技术（RAPD）,对融合子进行鉴定,确认融合子为一种新型的微藻。     

The application of a SRAM chip as a novel neutron detector

High-density, fast digital devices, like field programmable gate arrays (FPGAs), microcontrollers, and static random access memories (SRAMs), can be produced by nanotechnology. New technologies allow the design of fast and powerful devices; however, the decreasing dimensions create new problems. Even at ground level, cosmic ray particles arriving from outer space can affect digital devices and provoke single-event effects (SEEs) due to the smaller sensitive volume (SV). In general, for decreasing feature size of memory cells the expected critical charge decreases and the expected sensitivity to radiation increases.

High-density SRAM chips were used to design a fast response, highly sensitive neutron detector. We have conducted experiments with SRAMs at the DESY Research Centre in Hamburg, Germany. Memory contents (number of SEU) were recorded as a function of neutron expose time. The chips were exposed to a neutron field from an americium-beryllium neutron source (²⁴¹AmBe). The second experiment was accomplished in the 450?MeV electron Linac (Linac II) tunnel. Another batch of SRAMs was irradiated with ⁶⁰Co gamma rays to a dose of about 60?Gy, and no SEU was registered. This shows that gamma radiation has no substantial effect on the production of SEU in the SRAM. The proposed detector could be ideal for the detection of pulsed neutron radiation produced by high-energy electron linear accelerators and synchrotron facilities, which are currently in operation and planned for the near future.     

设计案例选辑

好的设计创意对传递产品的信息、塑造企业形象至关重要,也是整个品牌战略的一个重要部分.设计师们如何以具有想象力的创意去展示品牌,考验着他们的智慧与创造力.这里与读者分享一辑优秀的品牌和设计案例,希望能给大家一些启示.     

转子导程的参数选择

主要介绍转子导程的参数选择,并给出了实际设计时所碰到的挂轮选配问题的解决方案。     

书籍设计中的材质选择

概述了书籍设计材质的演变,与此同时运用丰富的实例,体现材质的选用对把握书籍设计的整体风格所起到的重要作用.从而使设计者更加意识到只有掌握了对书籍材质的正确选择,才能把看似单一的文字载体提升到艺术的高度,并赋予它丰富的内涵.才能让读者在欣赏文字作品的同时领略材质的美感,使文字作品在材质美的衬托下令其升华.     

新型冷冻保存剂在细胞低温冻存中的选择

低温冻存下细胞保存效果最好,但超低温保存必须借助于冷冻保护剂,不同的冷冻保护剂,其冷冻保护效果不同.抗冻蛋白将逐渐地取代传统的冷冻保存剂.其中抗冻蛋白来源的开拓、作用机理的探索和生产技术的提高将成为冷冻保存剂研究和发展的新方向.     

细胞阻抗谱检测芯片的设计及实验

通过一类细胞电阻抗谱微芯片的设计制作及相应观察和测试系统的搭建。提出了一种微量细胞样品活性的新型电学检测方法．一系列的HeLa细胞实验表明,通过细胞悬浮液微滴的电阻抗谱信息不仅能够分辨不同性质的细胞溶液,还能够间接地反映被测细胞当前的生理活性状态．根据电化学和生物系统的特点,建立了一个基于阻抗谱微芯片的等效电路模型,并能够较好地描述实验结果．作为生化传感器,细胞电阻抗谱芯片具有快速、易用等优点,能够广泛地应用于胞内电生理分析、药物筛选等领域．     

Improvement in a Hydrogen Maser by a New State Selection

The improvement in a hydrogen maser operation by a new state selection is described. The new state selection in which the Majorana transition is used is carefully designed about the beam optics and the reverse magnetic field in order to effectively eliminate the undesirable atoms for a maser oscillation. The efficiency of the state selection is improved to the extent of 90-percent elimination of undesirable atoms and high-performance operation is attained. In this operation, the magnetic inhomogeneity shift is reduced to about one tenth of that observed in the conventional state selection.     

Selection of Active Factors by Stepwise Regression in the Data Analysis of Supersaturated Design

Supersaturated design is a type of fractional factorial design in which the number of columns is greater than the number of rows. Several articles have considered methods for constructing supersaturated designs to assure a low level of nonorthogonality for all paired columns. Stepwise selection is recommended for the selection of active factors in data analysis for supersaturated design, under an assumption of the effect sparsity. This article considers selection errors of stepwise regression in the analysis of supersaturated designs. Specifically, type II error in the selection of stepwise regression is examined using simulation. Based on the results of simulation, some guidelines for data analysis of supersaturated design are discussed.     

用于生物舱细胞培养的小型恒温箱的研制

介绍新研制的一台拟用于卫星搭载、生物舱细胞培养、使用温度范围为-20～80℃的小型中温恒温箱,其外箱尺寸为40cm×40cm×40cm,控温精度为37±0.5℃。为实现小空间的高效率与高精度的恒温效果,采用半导体制冷器件为系统提供冷、热量。此外,还对半导体制冷器件的性能影响因素进行分析,并详述了其安装过程。     

部分负荷蓄冷空调系统设计选型探讨

以无锡某大型综合商场的冰蓄冷主机选型为例,针对带基载的冰蓄冷系统主机、蓄冰装置选型进行初步探讨,指出规范(JGJ158-2008《蓄冷空调工程技术规程》)在计算带基载的冰蓄冷主机时的不明确之处,以期为冰蓄冷系统的快速选型提供参考。     

燃料电池汽车余热驱动的吸附式制冷系统结构设计

为了有效利用燃料电池汽车的余热,本文建立了燃料电池汽车余热驱动的吸附式制冷系统.该吸附式制冷系统由三个主要的回路构成:吸附床加热冷却回路、吸附质循环回路以及热水循环回路.针对吸附式制冷系统的核心部件吸附床,在分析比较了各主要吸附床结构的前提下,最终确定采用单元吸附管组合结构,并进行了相应的设计计算.本文的研究结果对于低温热源驱动吸附式制冷的研究起到一定的指导作用.     

Stability analysis and robust design of polysilicon TFT load 4M SRAM cell by statistical method

Advances in high-density static RAM (SRAM) technology have been focused primarily on the application of p-channel polysilicon (poly-Si) thin film transistors (TFTs) as memory cell loads. The penalty, however, is that the electrical characteristics of poly-Si TFTs, such as on-current (I_on), off-current (I_off), subthreshold slope (s) and threshold voltage (V_th), have large variations, a problem which becomes much more serious as the device size is reduced. In this paper we model the relation between SRAM stability and variations in poly-Si TFT characteristics by a statistical method. From our model it is found that grain boundary traps play a more important role than any other parameter. The trap density should be uniform and this requirement becomes severe as the operating voltage is scaled down. It is, however, very difficult to control the grain boundary characteristics of poly-Si TFTs. We propose a robust design method as an indirect but cost-effective solution to parameter fluctuation, based on the Taguchi method of off-line quality control, and assure that the output performance is enhanced without varying the fabrication conditions. © 1998 John Wiley & Sons, Ltd.     

手机人性化设计中的心理元素

在数字化和网络化迅猛发展的今天，手机已经成为引领消费时尚的工业产品。随着手机普及率的提高和功能质量的同质化，消费者对手机的差异化要求越来越强烈，对手机设计的要求也越来越高，他们在选购手机时往往更加青睐于符合自己身份和性格特点的机型，而对于那些外观设计平庸或雷同的手机不屑一顾。面对日趋激烈的竞争市场和日益挑剔的消费者，以消费者为中心的人性化设计已成为时代的主题。生产者和设计师的主要精力集中在研究消费者的需求和消费动机上①。人性化设计是真正体现出对人的尊重和关心，其核心是以“人”为中心，     

工程设计中压力测量仪表的选择和应用

文章主要介绍了压力仪表类型比较、选型原则,并举例介绍。     

Transmitter-Receiver Path Selection for Cell Range Extension Using Multi-Hop D2D

Conventional approach of dealing with more users per coverage area in cellular networks implies densifying the amount of (Access Point) AP which will eventually result in a larger carbon footprint. In this paper, we propose a base station off-loading and cell range extension (CRE) scheme based on multi-hop device-to-device (MHD2D) path selection between transmitter and receiver node. The paper also provides derivations of upper and lower bounds for energy efficiency, capacity, and transmit power. The proposed path selection scheme is inspired by the foraging behavior of honey bees. We present the algorithm as a modified variant of the artificial bee colony algorithm (MVABC). The proposed optimization problem is modeled as a minimization problem where we optimize the Energy Efficiency (EE). The proposed path selection MVABC is compared with the Genetic Algorithm (GA) and also with classical artificial bee colony (ABC) through simulations and statistical analysis. The student’s t-test, p-value, and standard error of means (SEM) clearly show that MVABC based path selection out-performs the GA and classical ABC schemes. MVABC based approach is 66% more efficient when compared with classic ABC and about 62% efficient when compared with GA based scheme.     

Controlling Stem Cell Fate with Material Design

Advances in our understanding of stem cell interactions with their environment are leading to the development of new materials‐based approaches to control stem cell behavior toward cellular culture and tissue regeneration applications. Materials can provide cues based on chemistry, mechanics, structure, and molecule delivery that control stem cell fate decisions and matrix formation. These approaches are helping to advance clinical translation of a range of stem cell types through better expansion techniques and scaffolding for use in tissue engineering approaches for the regeneration of many tissues. With this in mind, this progress report covers basic concepts and recent advances in the use of materials for manipulating stem cells.