The Research of Information Filtering Technology Based on Bayesian Network

AbstractInformation filtering research is currently a hot topic. The screening and filter information is for information according to the predetermined standard classification. The paper gives a use of Bayesian network method for information on the objective of classification, thereby, make the information filtering accuracy obtained improve greatly

Ammonia Volatilization from Urea-Application Influenced Germination and Early Seedling Growth of Dry Direct-Seeded Rice

Poor seed germination and early seedling growth associated with urea-induced soil ammonia volatilization are major constraints in the adoption of dry direct-seeded rice. To directly examine soil ammonia volatilization and its damage to seed germination and early seedling growth of dry direct-seeded rice when urea is applied at seeding, two Petri-dish incubation experiments and a field experiment were conducted. Ammonia volatilization due to urea application significantly reduced seed germination and early seedling growth of dry direct-seedling rice. NBPT significantly reduced ammonia volatilization following urea application. The application of ammonium sulfate, instead of urea at seeding, may mitigate poor crop establishment of dry direct-seeded rice. Root growth of dry direct-seeded rice was more seriously inhibited by soil ammonia volatilization than that of shoot. Results suggest that roots are more sensitive to soil ammonia toxicity than shoots in dry direct-seeded rice system when N is applied as urea at seeding

Varietal responses of root characteristics to low nitrogen application explain the differing nitrogen uptake and grain yield in two rice varieties

Rice root characteristics are tightly associated with high-efficient nitrogen uptake. To understand the relationship of root plastic responses with nitrogen uptake when reducing nitrogen application for green rice production, a hydroponic experiment and a soil pot experiment were conducted under high (HN) and low (LN) nitrogen applications, using two rice (Oryza sativa L.) varieties, NK57 and YD6, three nitrogen absorption traits (total nitrogen accumulation, net NH4+ influx on root surface, nitrogen uptake via apoplasmic pathway) and root characteristics were investigated. In comparison with HN, LN significantly reduced nitrogen absorption and grain yield in both varieties. Concomitantly, there was a decrease in total root length, root surface area, root number, root volume, and root cortical area under LN, while single root length, root aerenchyma area, and root lignin content increased. The expression of OsAMT1;1 and OsAMT1;2 down-regulated in both varieties. The findings revealed that YD6 had smaller reduction degree for the three nitrogen absorption traits and grain yield, accompanied by smaller reduction degree in total root length, root surface area, root cortical area, and expression of the two genes under LN. These root characteristics were significantly and positively correlated with the three nitrogen absorption traits and grain yield, especially under LN. These results indicate that a large root system, lower reduction degree in several root characters, and high expression of OsAMT genes in YD6 explains its high nitrogen accumulation and grain yield under reduced nitrogen application. The study may provide rationale for developing varieties with low nitrogen fertilizer requirements for enabling green rice production

Lead Induced Ototoxicity and Neurotoxicity in Adult Guinea Pig

Lead exposure causes or aggravates hearing damage to human or animal, but the detailed effects of lead exposure on auditory system including injury sites of the cochlea in mammal remain controversy. To investigate the effect of chronic lead exposure on auditory system, 40 adult guinea pigs with normal hearing were randomly divided into five groups. They were fed 2 mmol/L lead acetate in drinking water for 0, 15, 30, 60, and 90 days (n = 8), respectively. Lead concentrations in blood, cochlea, and brainstem were measured. Auditory function was measured by auditory brainstem response (ABR) and distortion product otoacoustic emission (DPOAE). The morphology of cochlea and brainstem was observed, and expression of autophagy-related protein in brainstem was also assessed. The blood lead concentration reached a high level at the 15th day and kept stable, but the lead level in brainstem and cochlear tissue increased obviously at the 60th day and 90th day of lead exposure, respectively. There was no significant difference in the morphology of hair cells and stria vascularis (SV) among these five groups, but the number of spiral ganglion neuron (SGN) gradually decreased after 60 days. The differences of ABR thresholds and DPOAE amplitudes were not statistically significant among each group, but I wave latency, III latency, and I-III wave interval of ABR were delayed with the prolonging of time of lead exposure. The expressions of autophagy-related protein ATG5, ATG6, and LC3B in brainstem were increased after 30 days. These results suggest that the key target of lead toxicity was the auditory nerve conduction pathway including SGNs and brainstem, rather than cochlear hair cells and SV. Autophagy may play a very important role in lead toxicity to auditory nervous system

Measurement of Impedance-Frequency Property of Traction Network Using Cascaded H-Bridge Converters: Device Design and On-Site Test

To investigate the harmonic resonance in electric railways, determination of the traction network impedance using a utility instrument is an important and challenging task. This article presents a novel industrial test device which can directly measure the impedance of the actual traction network which is the power source of the railway. The structure arrangement and the parameter design are accomplished to meet the requirements for high-voltage level and strong anti-electromagnetic interference capability. Following this, frequency-dependent impedance measurement is implemented through the injection of controlled harmonic currents using the cascaded H-bridge converters. Furthermore, the power flow analysis is carried out to demonstrate that this device does not need any additional power source and can generate harmonic power. In a new-built railway, this device has been adopted to conduct the on-site test of the traction network impedance. Then, the multi-conductor simulation model is established for the purpose of mutual verification between the field test result and simulation result. Furthermore, the on-site test results can be applied to determine the resonance frequency before a nenw-built line is put into use so that any harmonic resonance can be avoided by taking effective measures in advance

Influence of the Catenary Distributed Parameters on the Resonance Frequencies of Electric Railways Based on Quantitative Calculation and Field Tests

High-order harmonic resonance is a key issue in the traction power supply systems (TPSS) of electric railways for safe operation. The effective evaluation of the resonance frequency is critical for taking measures to suppress harmonic resonance. In this paper, the influence of the distributed parameters of traction networks on resonance frequencies based on accurate calculation is proposed. The quantitative assessments of the distributed impedance and admittance are investigated. Furthermore, the theoretical calculation is directly verified using field tests at a high voltage level equal to 25 kV. The results show that the resonance frequencies of the TPSS are mainly affected by the distributed parameters, including the self-admittance and self-impedance of the contact wires, and the self-admittance of the positive feeders. In addition, the admittance connected in parallel has a greater effect than the series-connected impedance. The calculation method is also adapted to TPSS connected to renewable energy