The three-electrode field-distortion gas switch (TFGS) is one of the typical gas switches used for Marx generators. In order to reduce the jitter of the TFGS further, it is an effective method to add an UV(ultraviolet) pre-ionization structure in the switch. In this paper, an experimental circuit which can change pre-ionization parameters independently is proposed. The effects of pre-ionization injection time, pre-ionization current amplitude, and pre-ionization duration time on the breakdown delay and jitter of trigger gap and overvoltage gap of TFGS are studied experimentally. The results show that there is an injection time threshold of pre-ionization in the trigger gap. When the injection time is less than the threshold, the jitter of trigger gap is low and it is basically not affected by pre-ionization current amplitude and duration time. As for the over-voltage gap, when the pre-ionization injection time is earlier than the breakdown time of trigger gap, the jitter decreases with the increase of pre-ionization current amplitude, and it is not affected by the pre-ionization duration time. When the pre-ionization injection time is later than the breakdown time of trigger gap, the jitter is high and it is not affected by the pre-ionization current amplitude and duration time. On the basis, the optimal pre-ionization parameters for reducing switch jitter are obtained.

Compared to the traditional three-electrode field-distortion gas switch(TFGS), the UV pre-ionization three-electrode field-distortion gas switch can generate multiple discharge channels during the discharge process, which is beneficial for reducing the switch inductance and electrode erosion. In this paper, a novel compact UV pre-ionization TFGS is proposed. The effects of pre-ionization injection time, pre-ionization current amplitude, and pre-ionization duration time on the discharge channel number of trigger gap and overvoltage gap of the UV pre-ionization TFGS are studied experimentally. The results show that with the decrease of pre-ionization injection time, the increase of pre-ionization duration time, and the increase of pre-ionization current amplitude, the number of discharge channel in trigger gap increases, and the larger of the working coefficient, the greater of the increase amplitude. As for the over-voltage gap, the number of discharge channel increases with the increase of working coefficient, but is basically not affected by preionization current amplitude and duration time. In addition, the effect of pre-ionization parameters on reducing switch inductance and electrode erosion are also calculated or estimated.

This study aimed to construct a vector lentivirus carrying the Smo gene and transfect pancreatic cancer cells positive for CD24CD44 surface antibody and detect the infectivity. A lentivirus carrying a specific Smo fragment was designed and synthesized, and its functionality was tested. An overexpression group, inhibitory group, and negative control group were used for subsequent experimental research and comparison. A virus was successfully designed and produced. The best viral load was the 1X106 TU virus, where the cell growth and fluorescence effect of culture wells with polybrene dilution were the best. These are the transfection conditions and transfection param-eters for subsequent experiments. This plasmid was detected with a flag antibody by Western blot. The result was that it had a large specific 250kD band, and the membrane protein was overexpressed successfully. The expression results of Smo in five groups of cells after virus transfection detected by RT-PCR: blank group were 1.0038±0.0344, CON238 negative group: 1.0276±0.2944d, CON077 negative group: 0.8793±0.0402; LV-SMO15570-2 overexpres-sion group: 2.7479±0.8308, and LV-SMO-RNAi37304-1 inhibition group: 0.2386±0.0481. There were differences among the overexpression group and inhibition group with the other three groups. Homogeneity of variance: Bartlett F = 4.3530, P = 0.0016 < 0.05, heterogeneous. K-W test: cc2 = 10.9905* P = 0.0267, and there was a statisti-cally significant difference. The designed virus achieved the goal requirements. An sRNA fragment was designed for the key gene Smo of the Hh signaling pathway, and a vector lentivirus carrying this fragment was successfully constructed. The expression of Smo was analyzed after transfecting SW1990CD24CD44 positive cells, suggesting that the function of the RNA fragment designed for the key gene Smo in this experiment was successful.

"We have not unlocked the three pounds of matter sitting in between our ears," said Barack Obama. The brain is the most complex human organ, with energy efficiency far beyond that of any existing equivalent computing technology. Great efforts are being invested globally into deciphering its functioning. If successful, the resulting knowledge may forever change medical, consumer, and communications semiconductor industry sectors.

Business Intelligence (BI) has been viewed as sets of powerful tools and approaches to improving business executive decision-making, business operations, and increasing the value of the enterprise. This literature review presents the development of business Intelligence in recent years. Architecture, technologies, performance evaluation and applications four aspects are discussed to illustrate the BI used technology and the future trend. It presents how to improve the BI efficiency and what method is adopted for enterprise to solve the problems which they encounter.

Experiments of the return current post installed X-pinches were carried out on the 1-MA "QiangGuang-1" facility with the purpose of understanding X-pinch characteristics under this setup and establishing X-pinch backlighting diagnostics for the wire-array Z-pinches. Different wire-array loads along with the two-wire 30 mu m Mo X-pinch backlighter were tested. The X-pinches emit the X-ray radiation with the burst time variation of +/- 4 ns and the bright spot size of similar to 30 mu m. X-ray backlighting shadowgraphy images of the over-mass and radiation-suppressed Z-pinch wire array were obtained.

Active solder is a novel lead-free solder with the addition of titanium and/or rare earth elements. Because rare-earth metals have a stronger affinity for oxygen than most metals and tend to reduce metal oxides via formation of rare-earth oxides, compared with conventional lead-free solder, active solders have many advantages, such as bonding and soldering without flux and without pre-plating, which can greatly reduce soldering steps and cost, and it was used in packaging and assembling for electronic devices, such as materials bonding between semiconductor/metal/ceramics. But for the applications of active solder, detailed information about its microstructures and mechanical properties is absent, which is very crucial for the process mechanics based reliability analysis and prediction. In this work, the characteristics of strain rate of active solder alloy (Sn-3.5%Ag-3%Ti-Ce) were investigated and tensile tests were achieved by six-axis micro-tester under the different strain rate conditions. The microstructures of active solder alloy were investigated by SEM and the distribution of elements were analyzed by energy-dispersive x-ray (EDX). Compared with the conventional lead-free solder Sn96.5Ag3Cu0.5, active solder alloy showed a bit worse mechanical properties which should be improved so as to increase the mechanical reliability for applications in electronic packaging.

A bi-directional neural interface (NI) system was designed and prototyped by incorporating a novel neural recording and processing subsystem into a commercial neural stimulator architecture. The NI system prototype leverages the system infrastructure from an existing neurostimulator to ensure reliable operation in a chronic implantation environment. In addition to providing predicate therapy capabilities, the device adds key elements to facilitate chronic research, such as four channels of electrocortigram/local field potential amplification and spectral analysis, a three-axis accelerometer, algorithm processing, event-based data logging, and wireless telemetry for data uploads and algorithm/configuration updates. The custom-integrated micropower sensor and interface circuits facilitate extended operation in a power-limited device. The prototype underwent significant verification testing to ensure reliability, and meets the requirements for a class CF instrument per IEC-60601 protocols. The ability of the device system to process and aid in classifying brain states was preclinically validated using an in vivo non-human primate model for brain control of a computer cursor (i.e. brain-machine interface or BMI). The primate BMI model was chosen for its ability to quantitatively measure signal decoding performance from brain activity that is similar in both amplitude and spectral content to other biomarkers used to detect disease states (e.g. Parkinson's disease). A key goal of this research prototype is to help broaden the clinical scope and acceptance of NI techniques, particularly real-time brain state detection. These techniques have the potential to be generalized beyond motor prosthesis, and are being explored for unmet needs in other neurological conditions such as movement disorders, stroke and epilepsy.

This paper reports the micro-power telemetry unit that can sense pressure, humidity, and bio-potentials, for the study of micro-package techniques for implantable biomedical micro-systems used in research, diagnosis and therapy. The micro-package study is aimed to develop and demonstrate the micro-package technology for micro-implants to have an implant life of 0.2 to 2.0 years. The telemetry device consumes <; 1.0 μA at 3 volts, with a volume <; 0.2 cm3 including lithium rechargeable battery, and has RF links to charge Li battery and to receive external on-off commands. The device output pulse width changes with a capacitive pressure sensor; and the pulse period changes with an external resistor as the humidity sensor or the bio-potential signals in series with the resistor. The first model of telemetry units, packaged with silicon and epoxy only, lasted more than 70 days in 40°C saline solution. The RF recharging and on-off control circuits was tested, and the lifetime of second generation telemetry unit are being evaluated.

The surfaces of optoelectronic materials such as silicon, GaAs, nitrides and oxides are known to be very difficult to bond with low melting point solders (<;300°C). Small portion of active elements (3.1~4.1wt% Ti and 0.2% Ce) added into conventional SnAg solder could improve its solderability with inorganic material surfaces. In this work, some bonding experiments using active solder containing active elements were carried out. Bonding and mechanical behaviors of active solder were compared with SnAg solder preform and PbSn solder paste. The bonded joints were studied using SEM and the distribution of elements using energy-dispersive x-ray (EDX) analysis. Tensile test results revealed that, silicon could be directly bonded with copper, Kovar and silicon without metallization and the bonding strength of silicon bonding was 3.67 MPa. The successful bonding was attributed to the migration of active element to the solder-silicon interface for chemical reaction and the creation of an interfacial layer that contained active element oxide. Such oxide-bondable solders could be useful for 3D packaging and optoelectronic integration.

The X-ray emission, especially the K-shell emission, from a neon gas-puff Z-pinch powered by the Qiang Guang-I accelerator. about 1.5 MA in amplitude and 100 ns in rise time, were calculated based on the two-level model and measured with X-ray diodes and an eight-frame X-ray pinhole camera. The simulation results showed that the K-shell yield is highly sensitive to the peak current. The experimental results confirmed that the matching of the Z-pinch load (mass and initial radius) to the current is crucial for getting a higher X-ray yield. Being determined by the imploding time, the pinch current plays a more important role than the current amplitude in K-shell emission. It seems that the preferable imploding time is about 110 ns. The K-shell radiation power with double shells, as a whole, is higher than that using single neon shell. While an implosion of a light (32 mu g/cm) and small (20 mm in diameter) neon shell evolves with rather twist and asymmetries, a heavier (41 mu g/cm) and bigger (25 mm in diameter) neon shell implodes more symmetrically. The double neon shells, 30 mm and 30 mu g/cm for the outer shell, and 15-mm and 10 mu g/cm for the inner shell, create almost "perfect" implosions evidenced by the early-time plasma shells with little perturbation and late stagnated pinch liners with a good axial uniformity. It was found that the "Zippering" effect leads to an earlier K-shell emission in the cathode region than that in the anode region, which extends the pulse width of K-shell emission.

An implantable bi-directional brain-machine interface (BMI) prototype is presented. With sensing, algorithm, wireless telemetry, and stimulation therapy capabilities, the system is designed for chronic studies exploring closed-loop and diagnostic opportunities for neuroprosthetics. In particular, we hope to enable fundamental chronic research into the physiology of neurological disorders, define key electrical biomarkers related to disease, and apply this learning to patient-specific algorithms for therapeutic stimulation and diagnostics. The ultimate goal is to provide practical neuroprosthetics with adaptive therapy for improved efficiency and efficacy.

Experiments on Z-pinch has been carried out based on a 2 MA pulsed power facility. Gas puff and wire array liners were tested at current 1.4 ~ 2.1 MA with rise time 80 ~ 100 ns. For Krypton specific mass of 23 and 47 μg/cm, soft X-ray yield of 55 and 62 kJ, radiation power of 1.9 and 1.7 TW have been obtained, with imploding time of 90 and 118 ns corresponding to current of 1.4 and 1.5 MA and rise time of 80 and 96 ns. For tungsten specific mass of 182 μg/cm, array diameter 12 mm, wire diameter 5 μm, wire number 48 and wire space 0.8 mm, soft X-ray yield of 32 kJ and radiation power of 1.3 TW were obtained with imploding time of 140 ns corresponding to current 1.6 MA and rise time of ~100 ns. Double nested neon puff liner was tested with keV level X-ray radiation power observed to be greater than that achieved using single liners. 5 filtered XRDs were used to measure X-ray waveform and energy spectrum. A nanosecond, two energy region, 4-framing (for each energy region) soft X-ray imaging camera with 1.8 ns temporal resolution and 1.2 ns timing error was developed to monitor the temporal and spatial evolution of the Z-pinch liner. A nanosecond 4-framing ultraviolet camera was employed to observe the liner's motion during implosion. Total soft X-ray energy was measured by a nickel foil bolometer. Leading (precursor) plasma in the case of tungsten wire array and zip effect in the case of gas puff were observed during implosion. Regarding theoretical approach, driving current waveform will obviously influence initial liner parameter scaling, and maximum imploding kinetic energy per unit liner length can be 0.9 times the square of driving current amplitude multiplying by the natural algorithm of the ratio of initial liner diameter to the final.

Introduction: Onplants can be used as temporary anchorage devices for orthodontic tooth movement and orthopedic protraction of the maxilla. The device requires 3 to 4 months of osseointegration and can be removed after the orthodontic treatment. The purpose of this study was to investigate the degree of osseointegration and the biomechanical properties of onplants during various healing periods in an animal model.Methods: Sixteen rabbits were used in the study, and 3 onplants were placed on the calvaria of each rabbit ( n = 48). The rabbits were divided into 4 healing-period groups with 12 onplants in each group: 2, 4, 8, and 12 weeks. At the end of the healing periods, the animals were killed, and bone blocks, each containing an onplant, were prepared for either histologic examination or biomechanical characterization. Results: The histologic and histomorphometric results showed significant increases in bone formation or bone contact ratio at the bone-onplant interface in the 8-week and 12-week groups when compared with the 2-week and 4-week groups (P <.05). Under a light microscope, smaller and fewer osteoblasts-a sign of maturity of the osteoblast were observed in the 8-week and 12-week groups when compared with the 4-week group. However, evaluation of the biomechanical properties of the onplants showed that the shear force increased with the length of healing period (7.56 +/- 2.92, 75.30 +/- 9.64, 155.56 +/- 12.15, and 305.71 +/- 12.74 N for the 4 healing periods, respectively), and significant differences were found between the 8-week and the 12-week healing periods (P <.05).Conclusions: These results suggest that osseointegration occurred mainly after the 4-week healing period. The shear force of onplants increased with healing time, suggesting that shear force is not necessarily determined by the area of newly formed bone, but to a certain degree depends also on the density of the newly formed bone. The notion of loading onplants for orthodontic tooth movement as early as possible needs further clinical study for verification.

A new single crystal silicon carbide (SiC) MEMS fabrication process is developed using a proton-implantation smart-cut technique. A 6H-SiC layer with 1.3 mu m thickness has been achieved over an oxidized silicon substrate using the proposed technique. TENT analyses of the silicon carbide thin film reveal single crystal characteristics, which is attractive for potential integration of MEMS devices with high-temperature microelectronics in the same structural layer for harsh environment applications. Implant-induced defect density in the silicon carbide can be substantially reduced to a negligible level through high-temperature annealing. Prototype single crystal 6H-SiC MEMS devices, such as strain sensors, have been successfully fabricated as demonstration vehicles for future harsh-environment micro-system implementation.