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Ethylene-acrylate rubber (AEM)/polyvinylidene fluoride (PVDF) thermoplastic vulcanizate (TPV) was prepared by dynamic vulcanization, and the effects of rotor shear rate during dynamic vulcanization on the microphase structure and properties of TPV were investigated. The results showed that the higher the shear rate of the rotor during the dynamic vulcanization process, the more likely the phase inversion of AEM and PVDF occured, and the microscopic phase structure was more refined, forming a TPV with a “sea-island” structure. With the increase of shear rate of rotor, the tensile strength and elongation at break of TPV increased first and then decreased. When the share rate was 75 r/min, AEM/PVDF TPV had better mechanical properties, the tensile strength reached 14.84 MPa, and the elongation at break was 246%. TPV had better hot oil and hot air resistance.

Mobile edge computing (MEC) supports terminal devices to offload tasks or applications to edge cloud server for processing. Edge cloud server will consume local resources when processing external tasks, so it is particularly important to build a resource pricing mechanism that charges terminal devices to reward edge cloud. The existing pricing mechanism relies on the static pricing of intermediaries, and high cost and late processing of terminal tasks make it difficult to realize the effective utilization of edge cloud computing resources. Aiming at the above problems, this paper proposes an edge cloud resource pricing mechanism based on Stackelberg game. Firstly, in view of the local task shelving problem of terminal devices due to insufficient funds during resource pricing, an auxiliary mechanism including loans and incentives is proposed to realize the timely processing of terminal devices tasks. Secondly, four price-oriented factors that affect resource pricing are proposed, and two pricing schemes, consistency and elasticity, are formulated to improve the accuracy and efficiency of pricing and prepare for dynamic pricing. Then, in order to make the dynamic pricing between terminal devices and edge cloud directly, a resource pricing mechanism model based on Stackelberg game is built, and the resource demand and pricing problem is transformed into the problem of maximum revenue of edge cloud and minimum payment cost of terminal devices. Finally, through improved reinforcement learning SARSA (state action reward state action) algorithm, the optimal strategy of resource demand and pricing is obtained. Experiments show that the pricing mechanism proposed in this paper is more than 12% better than other pricing algorithms in terms of edge cloud revenue maximization, and the edge cloud revenue under the elasticity pricing scheme is 24% better than that of the consistency pricing scheme.

The cause of action represents the nature of the legal relationships involved in the case.A scientific and rational choice of the cause of action will facilitate the correct application of laws and enable the courts to perform classification management of cases.Cause of action prediction aims to endow computers with the ability to automatically predict the cause category based on the textual case description.Due to the small number of the samples of low-frequency categories and the difficulty of learning effective features,previous methods usually filters out the samples of low-frequency category in data preprocessing.However,in the problem of predicting the cause of action,the key challenge is how to make an accurate prediction for the cases of low-frequency cause categories.To solve this problem,in this paper,we propose a novel hierarchical learning method based on unbalanced samples for predicting cause of action.Firstly,all causes are divided into the first-level and second-level causes according to their inherent hierarchical structure.Then,the tailed ones in second-level causes can be merged into a new first-level category with sufficient samples,and the hierarchical learning is applied to realize the prediction of cause of action.Finally,we refine the loss function to alleviate the problem of data imbalance.Experimental results show that the proposed method is significantly superior over the baseline methods,leading to an improvement of 4.81% in terms of accuracy.Also,we verify the benefits of introducing the hierarchical learning as well as refining the loss function for unbalanced data.

Effect of curing characteristics matching of blending polyurethane rubber(MPU) and nitrile rubber(NBR) on properties of MPU/NBR blends was investigated. The results showed that the MPU phase was heat treated at 130 ℃ before the blending process to shorten the vulcanization induction period and made the curing characteristics similar to NBR. The interphase segregation of MPU and NBR could be effectively reduced, and the degree of vulcanization could be increased. The physical and mechanical properties of MPU/NBR blends were improved. When the heat treatment time was 8 min, the tensile strength of MPU/NBR blend increased by 37%, and the heat-resistant oil aging property was significantly improved.

Objective: To make up for the lack of research on the extraction technology, fatty acid composition, and physical and chemical properties of Canavalia gladiata oil in China, and provide technical support for the development and utilization of Canavalia gladiata oil. Methods: The process parameters of extracting Canavalia gladiata oil with n-hexane were optimized. Gas chromatography-mass spectrometry （GC-MS） was used to analyze and determine the type and content of fatty acids in Canavalia gladiata oil. Results: The best extraction conditions for the Canavalia gladiata oil were as follows: the ratio of liquid-to-material was 25∶1 （mL/g）, the temperature for extracting was 70 ℃, the time for extracting was 2 h. Under these extraction conditions, the extraction rate of the Canavalia gladiata oil was 3.12%. 9 kinds of fatty acids were analyzed and determined by GC-MS method, of which 3 kinds of fatty acids were mainly palmitic acid, oleic acid and linoleic acid, which accounted for about 85.29% of the total fatty acids, and unsaturated fatty acids were 89.12%. The content of saturated fatty acid was 10.88%, the content of monounsaturated fatty acid was 72.53%, the content of diunsaturated fatty acid was 12.76%, and the content of triunsaturated fatty acid was 3.83%. Conclusion: Canavalia gladiata oil was dominated by unsaturated fatty acids, oleic acid content was the highest, The types of fatty acids were similar to soybean oil, but the ratio was different, and the physical and chemical properties were similar to common peanut oil and soybean oil.

A series of silver-modified phosphotungstic acid catalysts AgxH3-xPW12O40 (x=1, 2, 3) were synthesized by incorporating silver nitrate into phosphotungstic acid. The structure, stability and acidity of the catalysts synthesized were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermal gravimetric analysis-derivative thermogravimetric analysis (TGA-DTG) and 31P-TMPO magic-angle spinning nuclear magnetic resonance (31P-TMPO MAS-NMR) spectroscopy. The effects of various reaction parameters, such as methanol/oil molar ratio, amount of catalyst, reaction time, and reaction temperature on the catalytic transesterification of soybean oil and methanol with Ag2HPW12O40 were investigated. The results demonstrated that Ag2HPW12O40 had the best catalytic activity, superior biodiesel yield and excellent durability. The high catalytic activity of the catalyst was attributed to Brønsted-Lewis acid synergy. With 6 wt.% Ag2HPW12O40 catalyst, the yield of biodiesel reached 96.4% with a methanol/soybean oil molar ratio of 32/1, a reaction temperature of 150℃ and a reaction time of 20 h.

To decipher the role of jasmonate in chemical elicitor L-glutamate induced resistance to pathogens, tomatoes were treated with 0.1 mg/mL L-glutamate and/or 0.1 mmol/L methyl jasmonate. After inoculating with Alternaria alternata spore suspension, disease incidence of fruit was observed. The effect of L-glutamate on jasmonate biosynthesis and signaling pathways were analyzed by reverse transcription quantitative real-time polymerase chain reaction at the transcriptional level. The results showed that the disease incidence decreased by 35% in L-glutamate treatment compared with the control, while there was no significant difference between L-glutamate and the control in methyl jasmonate group. Concurrently, allene oxide synthase, allene oxide cyclase, coronatine insensitive 1, transcription factor MYC2 and protease inhibitor PI-II were down-regulated by L -glutamate, accompanied by higher expression level of the negative regulator JAZ1. Collectively, the inhibition of JA pathway might be involved in L-glutamate induced resistance to Alternaria alternata in tomato fruit. These findings provided a better understanding for L-glutamate mediated resistance, leading to more sufficient theoretical basis for its commercial application. [ABSTRACT FROM AUTHOR]

A design of direct digital frequency synthesizer(DDFS) is proposed in this paper.Piecewise polynomial approximation algorithm is used to replace the look-up table,which leads to a phase to cosine amplitude mapper.The polynomial expression chosen by minimum-mead square error is used to achieve the maximum spurious free dynamic range(SFDR)，about 94.98 dBc. A DDFS of 14 bit input phase to amplitude mapper is developed in FPGA and an optimized digital system is designed to implement the method.It is shown that digitized amplitude error is smaller than 2.6×10-4 and promising result of 93 dBc SFDR,which is much closer to theoretical upper bound .This study also provide a new method about scaling signal source for next generation induction magnetometer.

The groundwater temperature is an important indicator of groundwater dynamic change. Therefore, comprehensively monitoring groundwater temperature, understanding its temporal and spatial distribution characteristics, and studying its change rule can not only reflect the hydrogeological characteristics of groundwater system, but also provide a basis for its identification and division. With an elevation of 3,500 m--2,400 m, the Heilongtan groundwater system of Lijiang, Yunnan Province is a typical mountain and basin landform with wide distribution of soluble rocks, strong development of karst, and combination of faults and folds. Its hydrogeological environment is complex, challenging the delimitation of spring area and groundwater system. Because the study area is located in the plateau mountainous area, and the temperature field of karst groundwater can also reflect the variation of groundwater temperature at different elevations in the mountain and canyon areas on the plateau, this study has a great referential significance for the research of groundwater in other similar areas. Based on previous research results as well as a large number of monitoring data on groundwater temperature obtained in the study area from June to November, 2018, the spatial-temporal variation characteristics of groundwater temperature in the spring area and the variation characteristics of borehole water temperature were compared and analyzed, and the indicative significance of these two types of variation characteristics were discussed. Meanwhile, the feasibility of system division of the Heilongtan spring area was verified. The results show that there is a good spatial correlation between the elevation of groundwater level and temperature, and the groundwater temperature in the recharge area at high altitude is low. From the recharge area to the discharge area, the water temperature experiences a gradual upward trend. The water temperature in the discharge area can also indicate the circulation of groundwater runoff. The lower the water temperature in the discharge area is, the smoother groundwater becomes. In terms of time, as groundwater receives a large amount of rainfall recharge during the flood season, the circulation of groundwater flow increases, which may result in a short storage time of water and the phenomenon that the groundwater temperature in the discharge area is closer to that in the recharge area and that the overall water temperature decreases. At the end of the flood season, as rainfall decreases, the circulation of groundwater flow weakens, and the underground water temperature in the discharge area rises in different degrees. In a certain depth below the surface, the groundwater temperature does not completely conform to the theoretical law that the temperature rises gradually with the increase of depth, On the contrary, the groundwater temperature will remain unchanged or decrease gradually with the increase of depth, the reasons of which can be summarized as follows. (1) The temperature of surface water formed by precipitation is higher than that of groundwater, and the groundwater will be heated during infiltration and recharge. (2) When a deep karst pipeline is developed, the groundwater will "wash" away the heat from the deep, and the groundwater temperature will decrease with the increase of depth. (3) If the vertical movement of groundwater is intense, with large up-and-down disturbances and good temperature exchange conditions, the temperature value will become relatively stable in this active zone. This phenomenon is found in all monitoring points in the discharge area, especially in the period of smooth groundwater flow. (4) Under the influence of solar radiation energy, the surface temperature shows diurnal and seasonal variations. The diurnal variation affects 1--2 m below the surface, and the seasonal variation affects 30 m below the surface. This study shows that there are similarities and differences in the groundwater temperature in the study area, and the groundwater temperature is a good indication for the delimitation of groundwater system. This study also verifies the rationality of the existing delimitation system in the study area. [ABSTRACT FROM AUTHOR]

A new relative influence weight function was proposed in combination with the existing linear threshold model.Combining with the information itself sensitivity and the threshold characteristic of the node itself,a threshold model(URLT model) was proposed,which can measure the information communication ability.By simulating the spread of different networks,different sensitivity information and different node thresholds,and comparing the final propagation situation,the experimental results show that the final influence range is consistent with the real spread situation.Therefore,the model has some reference value for the discovery and suppression of the law of information dissemination.

Background and objective The aim of this study is to investigate the clinical characteristics of patients with primary bronchopulmonary carcinoma complicated with chronic obstructive pulmonary disease (COPD), and to optimize the early diagnoses in the coexistence of COPD and primary bronchopulmonary carcinoma. Methods The clinical data of 118 patients with COPD complicated with primary bronchopulmonary carcinoma were analyzed retrospectively, including age, sex, smoking history, smoking index, clinical symptoms and signs, pathological type, staging, metastasis site and lung function index. 120 patients with simple COPD were selected as control. Results The smoking rate (55.1%) and smoking index ≥400 branch /year (90.8%) of the patients with COPD complicated with primary bronchopulmonary carcinoma were higher than the simple COPD group (20.8%, 48.0%). The difference between the two groups was statistically significant (P0.05), while the incidence of hemoptysis, weight loss, chest pain, hoarseness, pleural effusion and atelectasis were significantly higher than those in simple COPD group (P0.05), but the diffusing capacity of carbon monoxide (DLCO) of COPD patients complicated with primary bronchopulmonary carcinoma was lower than that of simple COPD patients (P

Since more and more third-party Android applications integrate backup services, the security issues of mobile backup modules are critical. By studying how widely these backup services were being used in the Android applications, the differences of code security about four mainstream Android backup SDK were investigated. After analyzing and comparing the usages, protocols and API functions of these SDK. Based on the above findings and three reported security issues of mobile backup services, the countermeasures for third-party application developers were suggested to securely call the SDK of mobile backup services.

Functional gait disorder (FGD) is a common subtype of functional movement disorder (FMD), mainly characterized by instability, lameness and Parkinson's gait. The clinical manifestations of FGD are the same as those of other types of gait disorder, with the possibility of misdiagnosis. However, there are significant differences in the treatment principles between them, so clear diagnosis and accurate treatment are crucial to improve patients' symptoms and prognosis. This paper aims to systematically review the epidemiological characteristics, clinical manifestations, auxiliary examination, diagnosis and differential diagnosis, treatment and prognosis of FGD, in order to improve the understanding of clinicians. [ABSTRACT FROM AUTHOR]

A plenty of XML documents exist in petroleum engineering field, but traditional XML integration solution can’t provide semantic query, which leads to low data use efficiency. In light of WeXML(oil&gas well XML data) semantic integration and query requirement, this paper proposes a semantic integration method based on extraction rules and ontology mapping. The method firstly defines a series of extraction rules with which elements and properties of WeXML Schema are mapped to classes and properties in WeOWL ontology, respectively; secondly, an algorithm is used to transform WeXML documents into WeOWL instances. Because WeOWL provides limited semantics, ontology mappings between two ontologies are then built to explain class and property of global ontology with terms of WeOWL, and semantic query based on global domain concepts model is provided. By constructing a WeXML data semantic integration prototype system, the proposed transformational rule, the transfer algorithm and the mapping rule are tested.

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As a green natural biopolymer, chitosan-based polymeric surfactants have attracted more and more attention because of their excellent properties. The common methods for preparation of macromolecular surfactants modified by chitosan were summarized, including alkylation, quaternization, carboxymethylation and acylation. The modification conditions and the properties of products were summarized. The applications and potential applications of chitosan-modified polymeric surfactants in the fields of food, medicine and cosmetics were introduced. The rules in the preparation of chitosan-modified polymeric surfactants were summarized and the development direction was prospected. [ABSTRACT FROM AUTHOR]

The geochemical behavior of elements in earth surface is closely related to natural environment, and the change of element distribution in soil records the environmental characteristics during its formation. Focusing on the typical black soil sections in Baiquan area, the paper studies the distribution rule of major and trace elements and its implied environmental information, and discusses the weathering degree of the soil sections and climatic evolution characteristics during the formation of section. The results show that except SiO2 and Na2O, the content of major elements in the soil sections is generally higher than that in Northeast Plain. The average chemical index of alteration (CIA) is 58, with high Saf value, belonging to weak weathering. The trace elements essential for plant growth, such as N, P, S, Mn, B, I, Ge, Se and Mo, accumulate under warm climatic condition, with high content in surface and illuvial layers, and low in eluvial layer and parent material layer; while under cold and dry conditions, they accumulate on the surface. The strong correlation between metal trace elements and Fe indicates that its vertical component is controlled not only by climatic conditions, but also by major elements. The migration rule of major elements reveals the soil in humus layer is of high maturity, mainly formed in a warm and humid climate. The illuvial layer may be at the removal stage of Na and Ca, with soil formed in a relatively cold and dry climate. [ABSTRACT FROM AUTHOR]

Using nitric acid and tartaric acid to dissolve the sample, the contents of copper, iron, nickel, cadmium, arsenic, antimony and bismuth in high bismuth lead were determined by inductively coupled plasma atomic emission spectrometry. Determination range ωCu (0.10%-5.00%), ωFe (0.001%-0.10%), ωNi (0.001%-0.10%), ωCd (0.001%-0.050%), ωAs (0.50%-7.00%), ωSb (0.50%-5.00%), ωBi (1.00%-7.00%). The recovery of each element is 91.5%-115%. The method is accurate and simple. It is suitable for the simultaneous determination of copper, iron, nickel, cadmium, arsenic, antimony and bismuth in high bismuth lead. [ABSTRACT FROM AUTHOR]

The approach to UQPSK carrier synchronization is widely used in digital satellite communication and UAV transmission of ground and tracking system. But it is hard to realize the related recovery modes for only analog signals or complex loop. So a modified approach to UQPSK carrier synchronization was presented based on decision feedback phase locked loop (PLL) with the constellation characteristics of UQPSK signal. The approach was arranged to be implemented quickly for phase compensation and fast phase capture with fast convergence speed under the condition of low signal-to'noise ratio. The simulation and analysis results of UQPSK carrier synchronization system show that the BER of the approach to UQPSK carrier synchronization is similar to the theoretical BER, and there is the high reliability in system. [ABSTRACT FROM AUTHOR]

[Objectives] SSR (Simple Sequence Repeat) markers are a very useful method for species identification, molecular linkage mapping, and genetic diversity studies. In order to develop molecular markers for Anoplophora chinensis, SSR markers were identified based on transcriptome sequence. This study provides a basis for studies of genetic diversity and the integrated control of A. chinensis. [Methods] The software MISA was used to explore all microsatellite loci in the transcriptome database of A. chinensis. Primers were designed using the software Primer Premier 3.0, and screened using PCR amplification and electrophoresis. [Results] A total of 2 360 SSRs were identified through software analysis; a frequency of 25.31%. These had 1758 sequences, accounting for 18.85% of the total number of sequences. Most repeat types were mononucleotide motifs (79.03%) followed by trinucleotide motifs (12.54%). The dominant repeat type was A/T (99.30%). The proportion of SSR length to 10-11 bp was highest (56.10%), the maximum number of repeats was 10 and the number of SSR loci was 1188 (50.34%). These results indicate the feasibility of using polymorphism analysis to develop SSR markers for A. chinensis.A total of 60 primer pairs were randomly selected and verified by PCR amplification, 53 of which were able to amplify the expected products; a primer availability rate as high as 88% which could be used in future studies. [Conclusion] The information analysis of SSR loci and the design and validation of primers will be helpful for gene mining, and for research on population genetic structure, genetic diversity, evolutionary relationships and the integrated control of A. chinensis. [ABSTRACT FROM AUTHOR]

Acetone is an important ketone product in hemicellulose pyrolysis, whereas, its formation mechanism is still unclear. In this paper, xylose, a typical hemicellulose monosaccharide, was selected as a model compound. Density functional theory (DFT) was employed for calculating the possible pathways of acetone generation in xylose pyrolysis. The influence of temperature on the competitiveness of possible pathways was also discussed. The results showed that 3-carbonyl butyraldehyde, a four-carbon-intermediate, was an important intermediate for the formation of acetone during the pyrolysis of xylose. The decomposition pathways of 3-ketopentose were the most favorable for acetone formation from the C1-C2-C3 and C3-C4-C5 segments of xylose. The decomposition of D-xylose can also easily results in the formation of C3-C4-C5 acetone. With the temperature increase, the proportion of C2-C3-C4 acetone increased correspondingly. [ABSTRACT FROM AUTHOR]

The sample was decomposed by hydrochloric acid, nitric acid, hydrofluoric acid and perchloric acid, and at pH = 6-9, Fe, Al, Cr, Ti, Ag, Hg, Bi, Ni, Co, Pb, Zn, Cu, Cd and Mn were separated by hexamethylenetetramine-copper reagent. Calcium and magnesium were determined by EDTA complexometric titration in ammonia solution of pH = 10 and ammonium chloride buffer solution of ammonia chlorideasacid chromium blue K-naphthol green Bas indicator; orcalcium was determined by EDTA complexometric titration in potassium hydroxide solution with calcium reagent as indicator. The content of magnesium or calcium (< 5%) with low content can be accurately determined by ICP-AES when the sample is high in calcium and low in magnesium or high in magnesium and low in calcium. Calcium and magnesium in three standard samples were determined by this method. The results were in agreement with the certified values. The relative standard deviation was between 0.69% and 1.3% (n = 7), and the recovery was between 99% and 102%. This method is practical and has been successfully applied to the determination of calcium and magnesium in various ores. [ABSTRACT FROM AUTHOR]

Traditional network routing cannot reach Shannon capacity limit of the "maximum flow-minimum cut" theory in multicast network, but network coding is a very good solution to these problems, it can increase the throughput also balance network load, and improve bandwidth utilization ratio. But malicious attacks in network can introduce error packets, it will bring packets of "error propagation" problem under the linear network coding and waste a large number of resources. Therefore, how to improve the security of communication network while optimizing network transmission performance is an urgent problem to be solved. In this paper, the homomorphism of the classic linear block code in linear network coding was proposed for the case of binary field and its extensions for network error-control, in order to resolve the problem of pollution attacks in multicast network. And the safety performance and transmission performance were analyzed. Experimental results demonstrate that homomorphic error-control codes for linear network coding can detect and correct error packets timely based on not destroy packet encoding rules. It can get good performance in error control, improve network performance and save the cost of network consumption. [ABSTRACT FROM AUTHOR]

The vegetative filter strips can effectively intercept erosion of water and sediment on the slope, with huge potential to prevent and control soil erosion and agricultural non-point source pollution. A series of muddy water scouring experiments under different inflow conditions in the indoor soil trays were conducted to investigate the effects of vegetative filter strip (VFS) on intercepting nitrogen (N) and phosphorus (P) under different inflow conditions and its internal hydrological responses. The results showed that the VFS could effectively intercept N and P in the runoff. When the inflow was 200, 400, 600 L µ h-1, the intercepting rates were 74.9%, 62.0%, 58.3% for N and 85.0%, 75.6%, 72.0% for P, respectively. The best intercepting effect occurred at the lower inflow rates. Different inflow N and P concentrations had no significant effect on N and P interception efficiency. Under different inflow conditions, the intercepting rates of N and P by VFS increased with the increases of Froude value with a significant linear positive correlation. However, there were linear negative correlations between the intercepting rate and resistance coefficient, shear stress and stream power. The relationship between the N and P intercepting rates and shear stress was the best among others, and the N and P intercepting rates could be well predicted by a formula containing shear stress. [ABSTRACT FROM AUTHOR]

The sample was decomposed with sodium carbonate-potassium carbonate-boric acid, leached with hydrochloric acid,and the content of aluminum in fly ash was determined by inductively coupled plasma atomic emission spectrometry. Measuring range of Al is 5.00% to 25.00%. After the standard recovery experiment, the recovery rate of aluminum element is 99 6%-106% (n = 3). The method is accurate and simple,and is suitable for the determination of aluminum in fly ash. [ABSTRACT FROM AUTHOR]

Modal Energy Analysis (MODENA) is a new method which is proposed to solve the structural-acoustic coupling analyses. An algorithm that integrates finite element method (FEM) and MODENA is proposed to carry out the structural-acoustic coupling analyses of complex dynamic systems. Firstly, the accuracy and efficiency of the algorithm is proved by a regular rectangular plate coupled with a parallelepiped cavity. Then the proposed algorithm is applied to a stiffened plane-cavity coupling system. Results show that the FEM-MODENA can carry out the structural-acoustic analyses with sufficient accuracy compared with the FEM-FEM results. Meanwhile, the algorithm can still provide a good approximation about the energy response of structure and acoustic domain when the modes in specific frequency range are taken into account. [ABSTRACT FROM AUTHOR]

In order to solve the instability of free rigid rocket and elastic rocket attitude control systems, taking the pitch channel as an example, the attitude angle and attitude angular velocity deviation feedbacks are added to the PD controller for the free rigid rocket, and a structure filter is added to the controller for the elastic rocket. The simulation results show that pitch channel steady-state errors of free rigid rocket and elastic rocket attitude control systems are 0.05%,-0.30% separately. So the instability of free rigid rocket and elastic rocket attitude control systems is controlled effectively. [ABSTRACT FROM AUTHOR]

A method was introduced for finding all proportional integral derivation (PID) controllers that satisfy a robust performance constraint for a given transfer function of magnetic bearing with time-delay by using the frequency response. The H-infinity index of additive weight uncertainty on the basis of robustness stability condition of closed loop system was first got by small gain theorem. Then, Based on the boundary crossing theorem, the parameter boundaries with the expected decay ratio index of PID controller were derived. The system can be stabilized and robustly meet the performance requirements by choosing PID controllers parameter in the stability region. The proposed method avoids the complexity of stability regions of PID parameters, and the closed-loop system has strong robustness for magnetic bearing with time-delay system. The simulation and experiment results demonstrate the validity of this method. [ABSTRACT FROM AUTHOR]

Taking soils in a long-term experimental field over 29 years with different land uses types, including arable land, bare land, grassland and larch forest land as test materials, the distribution and storage of soil organic carbon (SOC) in the profile (0-200 cm) in typical black soil (Mollisol) region of China were investigated. The results showed that the most significant differences in SOC content occurred in the 0-10 cm surface soil layer among all soils with the order of grassland>arable land>larch forest land>bare land. SOC contents at 10-120 cm depth were lower in arable land as compared with the other land use types. Compared with arable land, grassland could improve SOC content obviously. SOC content down to a depth of 60 cm in grassland was significantly higher than that in arable land. The content of SOC at 0-10 cm in bare land was significantly lower than that in arable land. Although there were no significant differences in SOC content at 0-20 cm depth between larch forestland and arable land, the SOC contents at 20-140 cm depth were generally higher in larch forestland than that in arable land. In general, SOC content showed a significantly negative relationship with soil pH, bulk density, silt and clay content and an even stronger significantly positive relationship with soil total N content and sand content. The SOC storage in arable land at 0 - 200 cm depth was significantly lower than that in the other three land use types, which was 13.6%, 11.4% and 10.9% lower than in grassland, bare land and larch forest land, respectively. Therefore, the arable land of black soil has a great potential for sequestering C in soil and improving environmental quality. [ABSTRACT FROM AUTHOR]

Gastric cancer is the most common malignant neoplasm of digestive system. Our country is a high-risk area of gastric cancer and its morbidity and mortality are higher than the world average. Most patients have entered the advanced stage when they were diagnosed with gastric cancer. So most of them need to radiotherapy and chemotherapy after surgery. As the research moves along, gastric cancer patients can get drug targeted therapy through the molecular detection of tumor specimens to realize the personalized treatment. RNA interference (RNAi) technology is widely used for gene function study, and get the rapid development in the study of mammals. siRNA plays a central role in RNAi, which possesses specific inhibits a mRNA, to adjust the different protein abnormal expressions in tumors occur. The study of siRNA will provide a broader space for gastric cancer gene therapy. [ABSTRACT FROM AUTHOR]

To better understand the aroma characteristics of Hongda tobacco variety in Qujing of Yunnan Province, this study took flue-cured tobacco in C3F level as material, and measured the contents of chlorogenic acid, rutin and scopoletin of 636 flue-cured tobacco varieties with HPLC method. This stud)' also analyzed and compared the polyphenolic contents of different varieties, producing areas, altitudes, terrains and soil types. The results indicated that: (l)The averaged polyphenol content of Hongda flue-cured tobacco was 37.65 mg/g, among which the contents of chlorogenic acid, rutin and scopoletin were 23.97 mg/g, 13.58 mg/g and 0.09 mg/g, respectively. (2) The chlorogenic acid and polyphenol contents of Hongda variety were significantly higher than those in other varieties. (3) The polyphenol content in flue-cured tobacco planted in different natural environment exhibited significant or extreme significant differences. Among different producing areas, the polyphenol content in Huize was the highest, and that in Luliang was the lowest. Among different altitudes, the contents of chlorogenic acid, rutin, scopolet, and total polyphenol in varieties planted at low altitude were significantly higher than those planted at medium or high altitude. Among different tarrains, the contents of chlorogenic acid and total polyphenol of flue-cured tobacco planted near the river channel were significantly higher than that planted at other terrains, and that of flue-cured tobacco planted at purple soil were extreme significantly higher than that planted at other agrotypes. (4)The result from analysis of grey correlation indicated that polyphenol content could mainly influence the index of sensory smoking quality, such as ash color, impact and fullness and thickness. [ABSTRACT FROM AUTHOR]

At the device driver moment, short time strategy has been used to confirm processing devices for procedures, in order to avoid the conflict caused by two devices select the same short processing time that will delay the completion time for the procedures, the conflict mediation algorithm of the integrated flexible scheduling based on the device driver has been proposed. The proposed algorithm selects the second shortest processing procedure from schedulable procedures set as the pre-scheduling procedure for the two conflict devices, by comparing the pre-scheduling results for the possible combining schemes, selects the combining scheme which finish as early as possible. When the free device has multiple schedulable shortest processing procedures, the algorithm uses the dynamic essential short path strategy to confirm the schedulable procedures. Analysis and examples have shown that the proposed algorithm can reduce the total processing time of the integrated flexible scheduling with device/procedure select confliction. [ABSTRACT FROM AUTHOR]

Aiming at the problems of that cavitation of hydraulic valve will cause the noise, performance degradation and even lead to hydraulic valve failure, cavitation phenomenon appearing in the flow field between the flapper and nozzle of an electrohydraulic servo valve was studied, and the 3D flow field model was established by Pro/E software. Its grid was divided and boundary conditions were set by Gambit software prior to implementing the simulation. The mathematical models of the flow field were established, which combined standard turbulence model and gas-liquid mixture. The flow field distribution and cavitation characteristics in the different nozzle inlet velocity were analyzed by FLUENT software with finite element simulation method. Images of cavitation phenomenon in the flow field were observed and recorded through high-speed video cameras. The results indicate that at flow conditions with lower Reynolds numbers, cavitation begins to form at the nozzle outer wall and the flapper leading edge. Further increasing of Reynolds numbers, attached cavity on the flapper curved surface grows up gradually and with the jet flow velocity increasing, cloud-like cavitation is observed. Some numerical calculated results at different flow conditions are verified by the experimental data, which show the cavitation model in the flow field between the flapper and nozzle of an electrohydraulic servo valve and the numerical calculation method are reasonable. [ABSTRACT FROM AUTHOR]