大功率液压系统油温自动控制装置

介绍了一种用于大型液压泵站的油温控制方法，该方法可对4个温度点进行自动控制。     

地源热泵在顺德地区应用的可行性分析

根据顺德地区自然气候环境、土壤温度状况,对多种不同的热泵系统的节能、技术性和经济性参数进行了比较和分析,证明地源热泵具有节能、环保的优点,在顺德地区具有广阔的发展前景.     

滚珠轴承两级复合叶轮高速泵的研制

阐述了两级复合叶轮高速泵的结构设计特点和水力设计方法。理论上采用以效率为目标函数的优化水力设计方法，并采用复合叶轮和双密封结构，经水力试验和现场运行表明，该泵具有很理想的性能和密封可靠性。     

电液比例变量泵的测试

主要介绍了双边联合控制的电液比例变量泵的工作原理，设计了基于单片机的测试系统，并利用此测试系统对电液比例变量泵的静态特性进行了潮试和计算机仿真。     

空调器热泵制热量的提高

本对房间空调器热泵实际使用状态与额定状态的差异进行了分析，提出了增强热泵制热效果的方案。     

Excel的VBA在密封罩设计中的应用

详细论述了VB(Visual Basic)程序设计语言与Excel软件相结合成功解决磁力泵中关键零部件密封罩的繁杂设计案例。它将EXCEL的输入、输出窗口处理工作表和单元格的各种功能与VBA语言的绘图和操作控件的能力进行了强——强结合。使类似石油、化工行业上所用的高压薄壁容器的设计程序自动化、操控表格化，整个设计过程连续、准确、直观、迅速、可靠。     

PWM功能在试验设备中的应用

通过材料试验设备的两个典型实例,即热变形维卡软化点测定仪中加热速率的控制及节水灌溉试验设备中水泵压力的控制,对AVR单片机PWM功能的应用做了探讨.     

土壤源热泵在扬州某五星级酒店中的设计探讨

文章针对节能减排的当前形势,通过对在扬州某建筑中的土壤源热泵经济性及节能性进行的分析,提出了地源热泵使用的可行性。     

Influence of induced ciprofloxacin resistance on efflux pump activity of Klebsiella pneumoniae

Objective

The efflux pump (EP) is one of the major mechanisms of antibiotic resistance in Klebsiella pneumoniae. However, there are few reports on the effect of the abuse of antibiotic use on the activity of EPs. To determine whether the use of low efficacy antibiotics has any effect on the activity of EPs and induces drug resistance in K. pneumoniae, we investigated the effect of ciprofloxacin on the activity of EPs in K. pneumoniae strains.

Methods

Sixteen susceptible K. pneumoniae strains were isolated from patients and their minimum inhibitory concentrations (MICs) of ciprofloxacin were measured in the absence and presence of the pump inhibitor carbonyl cyanide m-chlorophenyl hydrazone (CCCP). The strains were then induced with a gradient of ciprofloxacin until the MICs of the strains showed no further increase, to obtain induced resistant strains. The EP activities of the strains before and after induction were compared using EP inhibition and ethidium bromide (EtBr) accumulation assays.

Results

The MIC values of the strains were 16–256 times higher after induction than before induction. In the presence of CCCP, the MIC values of 50% of the induced strains were 2–4-fold lower than that in the absence of this inhibitor. The EtBr accumulation assay showed that the fluorescence of EtBr in the induced cells was lower than that in the cells before induction.

Conclusions

EPs are widespread in susceptible and drug-resistant K. pneumoniae strains. Induction with ciprofloxacin may increase the activity of EPs in K. pneumoniae. The EtBr accumulation assay is more sensitive than the EP inhibition assay in evaluating the activity of EPs in K. pneumoniae.     

变频冷冻水泵运行效率测试与分析

在不同运行条件下对某变频冷冻水泵的性能参数进行了测试，获得了不同转速下该变频冷冻水泵机组的总效率(全效率)、变频器效率、电机和水泵的综合效率、变频冷冻水泵的水力效率比和容积效率比，总结得出了该变频冷冻水泵各效率随转速变化的规律。同时指出，在计算采用压差控制的变频冷冻水泵的能耗时，不应将变频冷冻水泵的总效率当作常数，不同运行控制方式对变频冷冻水泵效率有着不同的影响。