大型医疗建筑设计

本文从医疗设施新的发展趋势入手,从工作团队架构、建筑形态演变、系统化建立、人性化空间考量以及面对突发事件之空间策略等几方面阐述了大型医疗建筑设计的原则及方法。     

Intelligent resource allocation in mobile blockchain for privacy and security transactions:a deep reinforcement learning based approach

In order to protect the privacy and data security of mobile devices during the transactions in the industrial Internet of Things (IIoT),we propose a mobile edge...     

Multimodal Transportation Flows in Energy Networks with an Application to Crude Oil Markets

Networks and Spatial Economics - Network models of energy markets have been beneficial for analyses and decision-making to tackle challenges related to the production, distribution and consumption...     

Spatial Potential Distribution around Trench Target during Plasma Immersion Ion Implantation

Plasma ion implantation, an alternative to conventional beam-line ion implantation, is a sheath-acceleration ionbombardment technique and the initial sheath is crucial to the process efficacy and surface properties. The initialspatial potential distributi     

Direct coupling of pulsed radio frequency and pulsed high power in novel pulsed power system for plasma immersion ion implantation

A novel power supply system that directly couples pulsed high voltage (HV) pulses and pulsed 13.56 MHz radio frequency (rf) has been developed for plasma processes. In this system, the sample holder is connected to both the rf generator and HV modulator. The coupling circuit in the hybrid system is composed of individual matching units, low pass filters, and voltage clamping units. This ensures the safe operation of the rf system even when the HV is on. The PSPICE software is utilized to optimize the design of circuits. The system can be operated in two modes. The pulsed rf discharge may serve as either the seed plasma source for glow discharge or high-density plasma source for plasma immersion ion implantation (PIII). The pulsed high-voltage glow discharge is induced when a rf pulse with a short duration or a larger time interval between the rf and HV pulses is used. Conventional PIII can also be achieved. Experiments conducted on the new system confirm steady and safe operation.     

Remote sensing, diagnosis and collaborative maintenance with Web-enabled virtual instruments and mini-servers

Optimised maintenance can reduce operating costs by demanding less resources and avoiding equipment breakdown, hence ensuring that daily manufacturing and production will not be interrupted. Web-based maintenance is one of the most efficient methods for optimising maintenance. The Web-based maintenance system that we have developed uses virtual instruments, to provide remote sensing, monitoring, and on-line fault diagnosis for equipment, together with a collaborative maintenance platform for international experts to interactively share their experiences in maintenance. Moreover, Web-based maintenance is suitable for multi-tasking and multi-user types of industrial work environments. In this paper, we summarise the methods used for Web-based remote sensing and monitoring, the design and implementation of Web-enabled virtual instruments, the architecture of the collaborative maintenance platform, and the design for the mini-servers. Each mini-server is equipped with a conventional mini-Web-server and a data acquisition (DAQ) server. With the help of Web-based maintenance, local companies can be transformed into global companies providing services to their customers anywhere and at anytime.     

Antibacterial properties of plasma-modified and triclosan or bronopol coated polyethylene

The antibacterial properties of medical polyethylene (PE) were enhanced by coating with triclosan or bronopol and plasma immersion ion implantation (PIII). O₂ plasma was first employed to produce a more hydrophilic surface on the PE, followed by argon or hydrogen plasma treatment to enhance the coating of triclosan or bronopol onto the surface. The modified surfaces were characterized by XPS, FTIR, SEM, and contact angle measurements. The antibacterial properties were evaluated utilizing the method of plate-counting of Staphylococcus aureus (Gram positive) and Escherichia coli (Gram negative). Our experimental results show that the plasma-modified PE with triclosan exhibits excellent antibacterial properties. Even after 6 weeks, the antibacterial effects against E. coli and S. aureus remain at high levels of 99.9 and 68.4%. The plasma-modified PE with bronopol has better antibacterial performances against E. coli and S. aureus in the beginning. Afterwards, the antibacterial effects degrade relatively rapidly. Our results reveal that non-reactive argon plasma was better than reactive hydrogen plasma in improving the antibacterial properties of PE. Bacterial adhesion on the modified samples was also investigated and the number of active adhered bacteria was observed to be always low.     

High voltage pulser with a fast fall-time for plasma immersion ion implantation

A novel high voltage (HV) modulator that offers a short fall time to minimize sputtering effects and allow more precise control of the incident ion fluence in plasma immersion ion implantation is described. The use of 36 insulated-gate bipolar transistors in the 30 kV hard-tube pulser reduces the HV fall time to 3.5 μs, compared to a fall time of 80 μs if a pull-down resister is used. The voltage balance is achieved by a voltage-balancing resistor, clamped capacitance, and the synchronization of drive signals. Compared to the traditional method employing a pull-down resister or an additional hard tube, our design consumes less power and is more economical and reliable.     

Improved hydrogen ionization rate in enhanced glow discharge plasma immersion ion implantation by enlarging the interaction path using an insulating tube

A small pointed hollow anode and large tabular cathode are used in enhanced glow discharge plasma immersion ion implantation (EGD-PIII). Electrons are repelled from the substrate by the electric field formed by the negative voltage pulses and concentrate in the vicinity of the anode to enhance the self-glow discharge process. To extend the application of EGD-PIII to plasma gases with low ionization rates, an insulating tube is used to increase the interaction path for electrons and neutrals in order to enhance the discharge near the anode. Results obtained from numerical simulation based on the particle-in-cell code, finite element method, and experiments show that this configuration enhances the ionization rate and subsequent ion implant fluence. The process is especially suitable for gases that have low ionization rates such as hydrogen and helium.     

Knowledge through participation: the triumphs and challenges of transferring Integrated Pest and Disease Management (IPDM) technology to cocoa farmers in Papua New Guinea

Income from cocoa is the main source of cash used to purchase food and services in many communities in the tropical lowlands of Papua New Guinea (PNG). Despite the availability of improved management technology, there has been poor transfer and uptake of these technologies among smallholder cocoa farmers, and potentially high bean yields and farmer incomes remain unrealised. A series of IPDM options that were shown to improve crop management and cocoa bean yield in research trials were demonstrated to farmers using an on-farm participatory approach that enabled farmers to evaluate the costs and benefits of each strategy before committing to adoption. The options were designed to provide several levels of entry to improved management, and ranged from no inputs (Option 1), manual inputs (Option 2: pruning, sanitation, weed management and regular complete pod harvesting), high level inputs (Option 3: pruning, sanitation, weed management, regular complete pod harvesting and fertiliser application), to intensive management (Option 4: pruning, sanitation, weed management, regular complete pod harvesting, and the application of fertiliser, fungicide and pesticide). Farmers from East New Britain, Madang and Bougainville, the three main cocoa growing provinces in PNG, participated in on-farm IPDM training and surveys to monitor changes in knowledge and management practice. Farmers opted in or out of the training as their commitments or level of interest changed, and new farmers joined in after observing changes in the cocoa blocks. Farmers were trained in epidemiology and crop management, were shown how to apply the IPDM inputs in their own cocoa blocks, and were given a simple training manual. Surveys conducted prior to, and 3 years after the training, showed an improvement in the farmers’ knowledge of cocoa management and a better understanding of cocoa pest and disease epidemiology. Three years after the training, pest and disease incidence in participating cocoa blocks had declined and cocoa yields had increased by an average of 30%. Trained farmers were encouraged to demonstrate improved management to neighbouring farmers, and the program has now been officially adopted as the national strategy to improve cocoa production in PNG. The participatory approach is an effective way of disseminating information and technology to farmers, however, it requires frequent follow-up visits by trained extension staff. We also discuss the significant challenges associated with conducting farmer surveys.