变频多联机空调系统设计

以广西钦州电厂二期扩建工程办公楼变频多联机空调系统设计为例,详细阐述变频多联机空调系统组成、设计方法、步骤以及设计过程中注意的问题。     

汽车进气系统开发探讨

介绍了汽车进气系统的功用及主要性能指标;结合进气系统开发实例探讨了进气系统容积的设定、管路形状及截面积的选择、内插管及谐振管等元件的应用等设计因素对进气系统性能所产生的影响。     

Enhanced discrimination of normal oocytes using optically induced pulling-up dielectrophoretic force

We present a method to discriminate normal oocytes in an optoelectrofluidic platform based on the optically induced positive dielectrophoresis (DEP) for in vitro fertilization. By combining the gravity with a pulling-up DEP force that is induced by dynamic image projected from a liquid crystal display, the discrimination performance could be enhanced due to the reduction in friction force acting on the oocytes that are relatively large and heavy cells being affected by the gravity field. The voltage condition of 10 V bias at 1 MHz was applied for moving normal oocytes. The increased difference of moving velocity between normal and starved abnormal oocytes allows us to discriminate the normal ones spontaneously under the moving image pattern. This approach can be useful to develop an automatic and interactive selection tool of fertilizable oocytes.     

On-chip three-dimensional tumor spheroid formation and pump-less perfusion culture using gravity-driven cell aggregation and balanced droplet dispensing

This paper presents a spheroid chip in which three-dimensional (3D) tumor spheroids are not only formed by gravity-driven cell aggregation but also cultured at the perfusion rates controlled by balanced droplet dispensing without fluidic pumps. The previous spheroid chips require additional off-chip processes of spheroid formation and extraction as well as bulky components of fluidic pumps. However, the present spheroid chip, where autonomous medium droplet dispensers are integrated on a well array, achieves the on-chip 3D tumor spheroid formation and perfusion culture using simple structure without bulky fluidic pumps. In the experimental study, we demonstrated that the spheroid chip successfully forms 3D tumor spheroids in the wide diameter range of 220 μm–3.2 mm (uniformity > 90%) using H358, H23, and A549 non-small cell lung cancer cells. At the pump-less perfusion culture (Q = 0.1–0.3 μl/min) of spheroids, the number of H358 cells in the spheroid increased up to 50% from the static culture (Q = 0 μl/min) and the viability of the cultured cells also increased about 10%. Therefore, we experimentally verified that the perfusion environment created by the spheroid chip offers a favourable condition to the spheroids with high increase rate and viability. The present chip achieves on-chip 3D tumor spheroid formation and pump-less perfusion culture with simple structure, thereby exhibiting potential for use in integrated in-vivo-like cell culture systems.     

An equation of state for a system with a single type of transformation

Based on theory of a previous paper, the writer has developed an equation of state for a system with a single type of transformation. This equation is of the form

$\text{h=A+Bv+Cp+Dpv?T(E+Fv+Gp+Hpv)}$

where h = ε + pv is the total heat, p the pressure, v the specific volume, T the temperature, and p, v, T are considered independent variables. A, B, C, etc., are constants for the system. The latent eat at constant (p, T) is given by

$\text{λp,T=(v}{}_2\text{?v}{}_1\text{)(}\text{?h}\text{?v}\text{)P,T= (v}{}_2\text{?v}{}_1\text{)[(B?TF)+p(D?TH)]}$

. These equations are checked with data on saturated and superheated ammonia, and the agreement is good to within a few tenths of a per cent. Also, checks with data on saturated and superheated steam show agreement within several per cent.     

基于单片机的输液系统的设计

针对医院在对病人静脉输液治疗监护这个任务繁重的问题,设计了一种采用单片机AT89C51为核心,以键盘、碰触开关及红外光电开关为输入系统,以液晶、声光报警电路及步进电机为输出系统的智能化输液控制及监控系统.     

西藏环境空气自动监测系统的建设构想

本文介绍了西藏环境空气质量监测系统建设与运行情况,指出该监测系统存在的不足,并对全区环境空气质量自动监测系统建设与运行提出构想。     

办公楼中央空调供暖系统改造

中央空调已成为现代办公楼宇中不可缺少的设备,同时也是办公楼中耗电量最大的设备。文章主要论述粤北地区某电厂对办公楼中央空调制热系统进行技术改造,利用锅炉疏水的余热加热供热介质,消除了不能制暖缺陷,同时实现了节能降耗的目的。     

中央空调通风系统清洗技术及措施

由于中央空调通风系统的污染及其不合理的使用,已经成为建筑物室内空气污染的主要来源之一。中央空调通风系统风管内结垢和微生物及由此产生的腐蚀故障,对系统的安全及低成本的运行影响极大,所以,必须定期进行清洗中央空调通风系统。     

空调风机组汽水加湿系统的开发与应用

卷烟生产工艺对温湿度的控制要求极其严格,从制丝、储丝到卷接包等生产过程均要求近似于恒温恒湿的生产环境,通常温度要求控制在20～28℃之间、相对湿度要求控制在55%～62%之间。相对稳定的温湿度能给卷烟生产、产品质量带来积极的影响,烟支的水份率、端部落丝量、含末率、整丝率、填充值无不与环境温湿度有关,而恰当的加湿方式对于实现温湿度精确控制和节能效益最大化的双重目标起着决定性作用。文章从实际出发,设计空调风机组汽水加湿系统并应用于实际生产,解决存在三大矛盾,较大幅度的降低运行能耗。     

国库集中支付制度在高校实施中的问题及完善措施

分析了国库集中支付制度在高校实施中与高校现行的经济运行、财务管理及会计核算体系产生的矛盾。表现为独立法人地位和预算资金的严格限制相矛盾、银校合作受到制约、支付方式与现行系统存在冲突。在强化预算管理、转变会计职能、推行政府采购、开通远程查报账系统和完善内外监控制度等几大方面提出了完善会计集中核算的对策建议。     

基于SSM分折的科研评价系统探讨

科技评价体系是一个复杂的,多目标评价体系。当今科技评价已逐渐从强调科研产出,转向同时关注资源的使用效率,注重科技创新能力的提升和对国民经济发展的贡献。如何建立一个客观、公正、健全、规范的,且具备可操作性的科学评价体系引起了政府和科技界的广泛关注。本文以SSM系统分析为基础,从3E出发探讨了评价指标体系的构建和评价系统的设计。基于系统分析基础上形成的指标体系,既考虑了直接的产出,又分析了内部运行机制,形成的指标体系相对更全面、完整,在此基础上针对具体评价内容选择适宜的评价方法,可定量或定性,软硬结合,具有透明性和延展性,同时易与决策管理部门交流。     

上海市2004年冬季城市大气气溶胶含Pb单颗粒物的来源查证

采用质子微探针技术，分析单个大气气溶胶颗粒物。将微束质子激发X射线分析(Micro-PIXE)同计算机模式识别技术结合，查证上海市2004年冬季城市大气气溶胶PM10中含Pb单颗粒物的来源。结果在上海大气气溶胶PM10中识别出七种铅污染排放源，它们分别是：汽车尾气，钢铁工业排尘，燃煤烟尘，土壤扬尘，柴油车尾气，助动车尾气和水泥尘。其中，钢铁工业排尘和燃煤排尘是禁止使用有铅汽油后上海市地区大气铅污染的最主要排放源。     

Pole-placement in discrete systems by using single and multirate sampling

This paper deals with closed-loop pole-placement in discrete, linear systems under single and multirate sampling. The technique is extendable to hybrid systems, i.e. those involving both continuous and discrete substates. The sampling rates for the state, input and output components are used as a controller design technique to achieve closed-loop pole-placement since the controller, which is also discrete or hybrid in the general case, can be periodically reparametrized, the main useful effect of which being the availability of multiple design gains whose number and value are under the designer's choice. The key design factor in the multirate sampling design is that once the closed-loop running sampling period (i.e. that defining the closed-loop dynamics and thus the controller reparametrization periodicity) has been chosen, one can use freedom in the choice of smaller sampling periods for the various plant input and output components as well as for those of the controller state. All these sampling periods are chosen as submultiples of the closed-loop running sampling period.     

基于磁致伸缩位移传感器的船闸闸门控制系统

连申线海安船闸位于南通海安县境内,海安船闸为双线船闸是江苏省干线航道网规划“两纵四横”中的第二纵,是沿海空间开发格局, “三极一带多节点”中的“一带”,纵贯长江三角洲东部,是连申线水上交通咽喉.该船闸控制为PLC控制系统,闸门运行采用磁致伸缩位移传感器开度控制.本文根据传感器的测量位移,推导了闸门开度方程.在控制程序的设计中,闸门的运行开度在监控屏幕上实时显示,并利用闸门开度反馈值作为闸门的无级变速与同步控制.这不仅有利于操作人员观察到船门运行状态,而且确保了闸门运行的平稳同步,还提高了闸门运行的安全性.     

基于SSM分折的科研评价系统探讨

科技评价体系是一个复杂的,多目标评价体系。当今科技评价已逐渐从强调科研产出,转向同时关注资源的使用效率,注重科技创新能力的提升和对国民经济发展的贡献。如何建立一个客观、公正、健全、规范的,且具备可操作性的科学评价体系引起了政府和科技界的广泛关注。本文以SSM系统分析为基础,从3E出发探讨了评价指标体系的构建和评价系统的设计。基于系统分析基础上形成的指标体系,既考虑了直接的产出,又分析了内部运行机制,形成的指标体系相对更全面、完整,在此基础上针对具体评价内容选择适宜的评价方法,可定量或定性,软硬结合,具有透明性和延展性,同时易与决策管理部门交流。