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China’s sour gas reservoir is very rich in reserves, taking the largest whole offshore natural gas field in China-Puguang gas field as an example, its hydrogen sulfide content reaches 14.1%. The use of renewable energy, such as solar energy through photocatalytic technology, can decompose hydrogen sulfide into hydrogen and monomeric sulfur, thus realizing the conversion and resourceization of hydrogen sulfide gas, which has important research value. In this study, a concentration sample database of a hydrogen sulfide leakage scenario in a chemical park is constructed by Fluent software simulation, and then a leakage concentration prediction model is constructed based on the data samples to predict the hydrogen sulfide leakage diffusion concentration in real-time. Several machine learning algorithms, such as neural networks, support vector machines, and deep confidence networks, are implemented and compared to find the model algorithm with the best prediction performance. The prediction performance of the support vector machine model optimized by the sparrow search algorithm is found to be the best. The prediction model ensures the accuracy of the prediction results while greatly reducing the computational time cost, and the accuracy meets the requirements of practical engineering applications.

The complete genome sequence of passiflora virus Y (PaVY) from passion fruit growing in Guangdong province, China, was determined. The entire positive single-strand RNA genome comprises 9681 nucleotides (nt) excluding the poly(A) tail and encodes a polyprotein of 3084 amino acids flanked by 5' and 3' untranslated regions of 169 and 257 nt, respectively. In sequence comparisons and phylogenetic analysis, PaVY appears to represent a new species in the bean common mosaic virus subgroup of the genus Potyvirus. This is the first report of the complete genome sequence of PaVY and the first report of this virus in China.

Maize growth in Northeast China is suffering from climate change (seasonal drought, cold springs) and low nutrient use efficiency caused by one-time fertilization. Drip fertigation is widely used in vegetable and fruit plant production, yet an efficient, practicable and cost-effective drip fertigation system is lacking for maize production. A two-year field experiment was conducted to evaluate the potential of different drip fertigation methods for increasing maize yield, and water and nutrient use efficiency in sandy and clay soil. Five irrigation methods were applied in each soil: conventional (rain-fed, CK), drip irrigation (DI), surface drip fertigation (SDF), fertigation plus plastic film mulching (SDFP), and subsurface fertigation (SSDF). Compared with rain-fed method (CK), water optimization by DI increased grain yield by (28% in sandy soil and 12% in clay soil), partial fertilizer productivity (PFP) and nitrogen (N), phosphorus (P) and potassium (K) uptake, without effect on water productivity (WP) in both soils. The optimization of both water and nutrient management by SDF increased grain yield by (41% in sandy soil and 17% in clay soil), PFP and NPK uptake, at greater extent than DI. Furthermore, SDF also increased the water productivity in both soils. Compared with DI, SDF increased post-silking N in both soil, and K accumulation in sandy soil. There was no significant difference in yield and PFP between SDF, SSDF and SDFP methods in both soils. In sandy soil, the net profit of DI, SDF, SSDF and SDFP was 13%, 28%, 31% and 10% higher than that of CK, respectively. In clay soil, However, No obvious advantage in net income was found in either DI or fertigation treatments. SDF and SSDF are recommended to increase maize yield, water and nutrient use efficiency, as well as economic benefit synchronously in sandy soil.

The complete genome sequence of passiflora virus Y (PaVY) from passion fruit growing in Guangdong province, China, was determined. The entire positive single-strand RNA genome comprises 9681 nucleotides (nt) excluding the poly(A) tail and encodes a polyprotein of 3084 amino acids flanked by 5' and 3' untranslated regions of 169 and 257 nt, respectively. In sequence comparisons and phylogenetic analysis, PaVY appears to represent a new species in the bean common mosaic virus subgroup of the genus Potyvirus. This is the first report of the complete genome sequence of PaVY and the first report of this virus in China.

Road traffic accident prediction is an important topic in traffic research. Taking China's traffic safety status as the research object, according to the non-linear characteristics of China's road traffic accidents, using principal component analysis to reduce the dimensionality of road traffic accident statistics data in China, comparing the two methods of SVR and BP neural network Comparison shows that the estimation accuracy of SVR is better than that of BP neural network, and its prediction accuracy meets the requirements of road traffic accident prediction.

This paper aims to investigate the adaptation of maize root system architecture (RSA) in response to increasing planting densities. A three-year field study was conducted with three planting densities (40,000, 70,000, and 90,000 plants per ha, which are abbreviated as D40000, D70000 and D90000, respectively). The dynamic change of root morphological traits and the 3-dimensional RSA were quantified. The grain yield per ha increased with increasing plant density from D40000 to D70000, and then decreased at D90000. Compared to D70000, high planting density of D90000 did not changed the total root biomass per ha but increased shoot biomass per ha by 4 to 8% in two of the three experimental years. Grain yield per plant and plant NPK concentration decreased with increasing planting density. Total accumulation of P and K per ha also decreased at D90000 compared to D70000. Root to shoot ratio was reduced at high planting density beginning 50 days after emergence. Compared to the control (D70000), total root length (TRL) per plant was reduced by 18 to 30% at D90000 and increased by 43 to 56% at D40000, root biomass per plant was reduced by 23 to 34% at D90000 and increased by 66 to 75% at D40000. High plant density reduced the number of nodal roots, lateral root density (LRD) and the average lateral root (LR) length, but with less effect on the length of axial roots. The RSA is characteristic of “intra-row contraction and inter-row extension”. Vertically, root growth in top soil layer (0- to 36- cm) was enhanced under supra-optimal plant density, but had a negligible effect in deep soil layers (36- to 60- cm). To adapt to the limited photosynthesis capacity in the roots under high planting density, maize plants tend to reduce nodal root number and inhibit lateral root growth. They maintain nodal root length to explore a larger soil space, and adjust root growth in the intra-row and inter-row direction to avoid root-to-root competition.

A target in crop production is to simultaneously increase grain yield (GY) and grain nitrogen concentration (GNC). In maize, nitrogen (N) and genotype are two major factors affecting GY and GNC. Both N remobilization from vegetative tissues and post-silking N uptake contribute to grain N, but their relative contributions are genotype specific, and are affected by the N application rate. It is unclear whether the responses of GY and GNC to N application differ between genotypes with different post-silking N uptake and vegetative N remobilization characteristics. We investigated the effect of N application rate on post-silking N uptake, vegetative N remobilization, GY, and GNC of two high-yielding maize hybrids, ZD958 and XY335, which have contrasting N remobilization characteristics. We tested five N application rates (0, 60, 120, 180, 240 kg N ha−1) in a 4-year field study (from 2010 to 2013). There was a significant year × N × genotype interaction in the amount of vegetative N remobilization and N remobilization efficiency (NRE), and residual stalk N concentration at maturity. Compared with the low-NRE cultivar ZD958, XY335 showed the same GY but higher GNC because it had higher vegetative N remobilization, NRE but lower residual stalk N concentration under the favorable weather condition in 2010. The response of GNC to increasing N levels was the same between XY335 and ZD958 and was not affected by year conditions. The N level required to obtain the highest GY was the same in the two hybrids (156 ± 13 kg ha−1and 159 ± 19 kg ha−1), but that required to obtain the highest GNC was greater in XY335 (216 ± 30 kg ha−1) than in ZD958 (195 ± 23 kg ha−1). From these results, we conclude that precise N fertilizer management as well as the selection of high-yielding hybrids with high NRE can increase GNC without negatively affecting GY or leading to surplus N storage in vegetative organs.

The current-limiting mode of inverters raises the problem of severely restricted fault currents and brings challenges to overcurrent protection. This paper provides an overview of the concept for inverter dominated distribution systems and then discusses its characteristics with respect to overcurrent protection comparing to traditional networks. Based on the overcurrent protection scheme, it is considered to adjust the current-limiting value of inverters according to the power of motors and system operating modes to achieve coordination between the limited fault currents and overcurrent protection. Simulations are conducted and the results prove the effectiveness of the scheme.

The no-load closing of transformer in the medium-voltage ship power system will cause a large inrush current and threaten the security of the system. This paper aims to provide reference for the pre-magnetization technology of the transformer in medium-voltage ship. Firstly, the basic principles of the inrush current and the series small-capacity transformer based pre-magnetization technology for the transformers are analyzed. Based on the analysis, the typical medium-voltage engineering ship and power generation ship are taken as examples to perform the simulation of the series small-capacity transformer based pre-magnetization scheme, and the result shows that the pre-magnetization technology can suppress the inrush current effectively. Besides, the factors of the switch closing time and the number of generators operating in parallel are considered in the research and their effects of on the inrush current as well as the transient voltage drop are analyzed. Finally, the influence of the pre-magnetization scheme on the differential protection is studied and the operation suggestions are given.

Pain perception can be altered by activity in the periaqueductal gray (PAG). The PAG can decrease the incoming nociceptive signals at the level of the spinal dorsal horn, but it is not clear whether the PAG can also affect the sensory thalamus, ventral posterolateral and ventral posteromedial thalamic nuclei, to modulate pain. However, the PAG and the thalamus have direct connections with each other; so we postulated that the PAG may also modulate pain by inhibiting the sensory nuclei in the thalamus, and that these may also reciprocally influence the PAG. Here, by analyzing the local field potentials recorded from the sensory thalamus and the PAG in chronic pain patients with deep brain stimulation electrodes, we show that PAG stimulation inhibited the sensory thalamus with decreasing thalamic delta, theta, alpha and beta power, and sensory thalamus stimulation excited the PAG with increasing PAG delta and theta power. We demonstrate that the PAG and the sensory thalamus interact reciprocally at short latency, which may be related to pain modulation. © 2013 Springer-Verlag Berlin Heidelberg.

This study describes a reliable protocol for callus induction and rapid mass propagation of the ecologically important plant, Zygophyllum xanthoxylon (Bunge) Maxim. The optimum callus induction medium was Murashige and Skoog (MS) supplemented with 4.4 μM 6-benzylaminopurine (BAP) and 2.7 μM α-naphthalene–acetic acid (NAA), on which the callus induction frequencies from different seedling explants were all 100%. However, seedling-derived callus did not form regenerated shoots. In order to achieve shoot multiplication, shoots were developed from cultured plumules, at an average of 3.1 shoots per explant, and the regenerated shoot tips were further multiplied by subculture. The best shoot multiplication from shoot tips was achieved on MS supplemented with 5.4 μM NAA and 22.2 μM BAP after 40 d of culture. Seventy-three percent of regenerated shoots formed roots when cultured on MS supplemented with 8.6 μM IAA after 4 wk of culture. The plants that acclimatized successfully in sand flourished the following year, with normal morphology and growth characteristics.

Precision nitrogen (N) management (PNM) is a promising strategy to improve N use efficiency and protect the environment while maintaining or increasing crop yield. In-season non-destructive diagnosis of crop N status is crucial for the success of this strategy. The objectives of this study were to (i) evaluate how well the GreenSeeker active canopy sensor can non-destructively estimate N status indicators of spring maize (Zea mays L.) in Northeast China and (ii) evaluate different N status diagnostic approaches based on N nutrition index (NNI) estimated via GreenSeeker sensor measurements. Two N rate field experiments involving 6 N rates (0, 60, 120,180, 240, and 300 kg N ha−1) were conducted in 2014 in Lishu County, Jilin Province in Northeast China. The results indicated that across sites and growth stages, GreenSeeker-based vegetation indices explained 89%–90% and 80%–86% of maize aboveground biomass and plant N uptake variability, respectively. The performance of GreenSeeker for estimating N status indicators from crop growth stage V7 to V10 was better than early growth stages (V5 and V6). The normalized difference vegetation index (NDVI) became saturated when aboveground biomass reached about 3.1 t ha−1 or plant N uptake reached about 75 kg ha−1; whereas no obvious saturation effect was found with ratio vegetation index (RVI). Across growth stages, about 50% of variability in maize N concentration was explained, but the standard error of estimate (SEa) was not acceptable. The NNI values were significantly correlated with GreenSeeker-based vegetation indices, with R2 being 0.64–0.80 at a specific growth stage. It is concluded that the GreenSeeker sensor has good potential for in-season non-destructive diagnosis of spring maize N status at V7–V8, but more studies are needed to further evaluate and improve its performance for practical applications.

The trip speed of traditional step mode distance protection with inverse time characteristics is quite slow when a short circuit fault occurs at the end of the protected line. To deal with this problem, a novel measured impedance convergence based inverse time distance protection is proposed in this paper. In this method, the convergence of measured impedance can dynamically reflect the level and attenuation degree of post-fault transient noise, and the method can adaptively decide the data window length of protective algorithm according to the result of real-time measured impedance convergence. More specifically, the faster the measured impedance convergence is, the shorter data window length of protective algorithm and the faster trip speed will be. Furthermore, a comprehensive adaptive variable data window distance protection scheme is established by using aforementioned two methods synthetically, which can overcome flaws of single method and efficiently improve trip speed of zone 1 of distance protection. Finally, the feasibility and effectiveness of the proposed scheme is proved with the simulation results. Ill. 8, bibl. 10, tabl. 4 (in English; abstracts in English and Lithuanian). DOI: http://dx.doi.org/10.5755/j01.eee.123.7.2365

As two form of differential protection applied dominantly, phasor value based differential protection is easily influenced by current transformer saturation, and sampled value based differential protection must improve the performance response to slight internal faults. In this paper, multi different protection which combines phasor value based differential protection with sampled value based differential protection is proposed. In such scheme, the shortcoming of each differential theory is overcome and the merits are compensatory each other. The result of EMTP/ATP digital simulation indicates that the proposed scheme advances greatly the performances of differential protection for transmission line such as reliability, sensitiveness, trip speed and immunity to current transformer saturation. Especially the algorithm and logic of the proposed scheme are easily and experientially, so it can be suit for project application well.

For the purpose of the monitor system in digital protection, the embedded real-time operating system (RTOS) and the embedded GUI (graphical user interface) is introduced to design the monitor system. Combining the necessity and the application value of the operation system, the choice of embedded Linux and Qt/Embedded is completely viable for the monitor system in digital protection for generator-transformer sets. The design with embedded Linux and embedded GUI enriches system information, increases developing efficiency and improve the generality.

To ensure distance relay can measure the impedance and trip the fault phase selectively during power swing, it is necessary to study fault classification during power swing. The conventional sequence current and phase-to-phase impedance relay based fault classification scheme has been analyzed to mal-operate in some cases during power swing. In order to overcome the disadvantage, single-phase-to-ground impedance relay and phase-to-phase impedance relay and sequence voltage criterion based improved fault classification scheme is proposed in this paper. The results of ATP digital simulation and dynamic simulation tests indicate that proposed scheme has advantage with origin scheme particularly in fault classification under the condition of power swing.

It is very difficult to get a good image of sub-basalt reflections using a conventional seismic exploration method, because of the poor S/N ratio of the seismic data and the existence of strong multiples between the high-velocity layers in sub-basalt. In this paper, we solve the problem using the wide-angle seismic exploration method with the assistance of the forward modeling. In the course of identifying and then applying the wide angle seismic reflections, the impact of high-velocity layers on the seismic wave field in the different geological environment has been discussed based on forward modeling. The final seismic imaging section of sub-basalt has been obtained by the deliberate analysis and careful processing.

In his De pictura‚ Leon Battista Alberti used the tale of Narcissus, who was turned into a flower‚ to present painting as the flower of arts: “What is painting but the act of embracing by means of art the surface of the pool?” Indeed, the view through the surface of the pool, or through the (looking) glass‚ gives evidence of a theory of knowledge entailed by artificial perspective which mathematics and the philosophy of nature were not ready to accommodate. Narcissus’ metamorphosis calls attention not only to the critical function of a see-through plane for visual knowledge‚ but also to the magic of shadows. Narcissus did not fall in love with his own specular-image, but with a shadow that he believed to be of someone else. If the seduction of the other is the first step towards the recognition of the self, the magnetism of the shadow is the first step on the road to knowledge. Yet, the shadow was a challenge for painters. Taking a picture of reality, each painting is a ‘still life’, where shadow is essentially a changeable form. Leonardo was aware of the problem, which also arose in depicting the continuous transformation of nature. While artificial perspective will lead mathematicians to conceive of a visual geometry, which extends Euclid’s, a reverse perspective, namely a “doctrine of shadows,” will lead Leibniz to address Leonardo's demand for a geometry “which is done with motion.” In this article we will discuss how the dialogue between art and science, starting in the Renaissance, transformed our view of geometry and our understanding of natural processes. We will also try to rethink such an important contemporary issue like quantum interference effects.