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In order to achieve the target of low power consumption of the plant and quick start-up in the ignition phase of the peak-regulating natural gas turbine， the feasibility of canceling purge before ignition of natural gas turbine is studied considering of the actual working conditions of the unit and the existing industry standards of natural gas turbines. Through the analysis of geometric structures of the exhaust passage and the connecting part of heat recovery boiler， a layout strategy of natural gas monitoring system considering both sampling safety and data reliability is proposed. Take Ansaldo AE94.3A natural gas turbine in a power plant as an example， the purge process before ignition of natural gas turbine is analyzed， the elastic purging scheme based on concentration judgment for natural gas is proposed and process flows under abnormal working conditions， such as ignition failure， trip of natural gas turbine and human intervention are optimized. The analysis of the start-up curve of the unit before optimization shows that， the start-up time of the natural gas turbine can be reduced to a certain extent， the power consumption of the plant can be reduced， and the heating effect of the steam turbine can be improved after the optimization of the purge process.

Three forms of soluble phenolics, free phenolics (FP), esterified-bound phenolics (EP) and glycoside-bound phenolics (GP), were extracted from Sargassum pallidum, and their chemical composition was identified by ultra-high performance liquid chromatography-quadrupole-time of flight-tandem mass spectrometry (UPLC-QTOF-MS/MS). Their antioxidant and α-glucosidase inhibitory activities in vitro were evaluated. Results demonstrated that the soluble phenolics in S. pallidum mainly existed in a bound form, GP and EP fractions contained the highest contents of total phenolics (68.30 mg/g) and flavonoids (83.49 mg/g), respectively. A total of 22 compounds were identified in the three phenolic fractions, including three simple phenolics, four flavonoids and two phenolic acids. Biological activity tests indicated GP had the highest cellular antioxidant activity (CAA value = 18.18 μmol/g), 1,1-dipheny1-2-picrylhydrazyl (DPPH) radical scavenging activity (IC50 = 84.6 μg/mL) and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation scavenging activity (IC50 = 127.01 μg/mL), while EP had the strongest oxygen radical absorbance capacity (5 322.85 μmol/g) and α-glucosidase inhibitory activity with IC50 value of 27.09 μg/mL. The hypoglycemic activity of EP was significantly higher than that of acarbose. Inhibition kinetics analysis showed that the inhibition mode of α-glucosidase by the three phenolic fractions was a mixed type. In conclusion, bound phenolics from Sargassum pallidum have excellent antioxidant and α-glucosidase inhibitory activities, which will provide a scientific basis for the development of natural antioxidants and hypoglycemic foods.

This article reviews the molecular mechanism of iron metabolism covering iron absorption,transportation,utilization and storage with focus on the key proteins involved in iron metabolism and elaborate regulation factors. Based on these results of research it might be able to provide some new strategies to find potential biomarkers of iron metabolism to support early and correct diagnosis. What's more, a clear mechanism may also provide a breakthrough point for the targeted treatment of iron metabolism disorders in future.

Intentional islanding restoration of distribution systems with multi-generations is of great importance to ensure the power supply of critical loads under extreme conditions, which is beneficial to improve the reliability of distribution systems. There are transient voltage and frequency fluctuations in the process of intentional islanding restoration, when the loads and distributed generations are gradually connected to the grid. The safety and stability of the intentional islanding are affected by the fluctuations, and networking process may fail in serious cases. Hence, the rapid power response of the energy storage system is utilized to suppress voltage and frequency fluctuations. A fluctuation suppression model based on energy storage system control is established, where a voltage and current double-loop feed-forward disturbance compensation control system is designed. A vector control method for energy storage system with improved dual-loop control is proposed, which solves the problems of traditional V/f control voltage offset and excessive voltage fluctuation. MATLAB/Simulink is used to build simulation models in different control modes in accordance with the black-start principle. The simulation results show that the improved double-loop control based on the vector method has a stronger anti-interference ability and significantly improved the islanding black-start self-organizing networking process. Voltage and frequency fluctuations are reduced, and the dynamic response performance of the system is improved.

By critically reviewing 159 academic publications in English and Chinese from a range of academic platforms that focus on the study of left-behind children, we advance new theoretical turns in children's geography in future research of left-behind children: to explicate children's use of space in everyday life, to explore their subjectivities and agency, and to unpack the diversity of childhoods across spatial and social scales. We first review literature on left-behind children in the context of transnational/international migration: Scholars have written about how left-behind children participate in reconfiguring transnational family strategies and social ties with their parents across spaces; how they act out their roles in different periods of the migration process and in response to different social and cultural environments; and how they interact with multiple and multilevel social actors, factors and processes to form heterogeneous life strategies and meaning-making. We then conduct a thematic analysis of existing scholarship on left-behind children in the context of internal migration in China, revealing a dominant 'problem' frame due to the prevalent positivism and adult-centrism in the research paradigm and an emerging resiliency perspective. We identify three gaps in this literature: 1) scholars tend to build upon an abstract space of 'the rural' at the institutional level, leaving children's everyday spaces and their social practices in these spaces unexplored, including home, school campus, community centers and so on; 2) children's agency and subjectivity remain obscure, with scant empirical and theoretical discussions; and 3) the literature lacks methodological and epistemological diversity and could not bring children's experiences, voices, emotions and beliefs to the forefront of research. We conclude by outlining a new research agenda on rural left-behind children in the Chinese context. In terms of research themes, we advocate for more attention to three potential areas: 1) explicating the spatiality of left-behind children's daily life practices, especially the spatiality related to the mobility patterns of rural-urban migrants in China; 2) divulging children's experiences and subjectivities vis-à-vis their everyday practices, and 3) unpacking the complexity and heterogeneity of left-behind children's childhood experiences in different contexts. In terms of methodology, we encourage the creative uses of diverse research methods such as in-depths interviews, ethnography and Geographic Information System (GIS) that render left-behind children's voices, thoughts, feelings, cognition and actions more visible. This new research agenda could yield a richer and more balanced literature on the everyday lives and subjectivities of left-behind children, providing fresh perspectives for policy making and public debates.

BACKGROUND The direct discharge of Hg(Ⅱ) is harmful to the environment. At present, activated carbon is used to remove it, but the production of activated carbon through high-temperature pyrolysis and activation is very expensive. OBJECTIVES To investigate the adsorption difference and mechanism on low-concentration Hg(Ⅱ) for durian shell, coconut shell activated carbon and activated carbon fiber under different conditions. METHODS The remaining Hg(Ⅱ) in the adsorption solution was determined by atomic fluorescence spectrometry. The adsorb kinetic parameters of different adsorbents were determined by Lagergren pseudo-second-order kinetic model. RESULTS In the Lagergren pseudo-second-order kinetic model, the maximum adsorption capacity (QM) of the three materials was as follows: activated carbon fiber (5.61μg/g)>durian shell (1.68μg/g)>coconut shell activated carbon (0.96μg/g). The adsorption test and thermodynamic equation showed that the adsorption of Hg(Ⅱ) by the three materials was spontaneous (ΔG < 0). The adsorption of Hg(Ⅱ) by coconut shell activated carbon was mainly physical adsorption (ΔH>0), while the adsorption of durian shell was an endothermic process (ΔH < 0). Due to the increase of temperature, the adsorption rate and adsorption capacity were improved. CONCLUSIONS Durian shell from a wide range of sources can be used as an effective adsorbent to treat wastewater containing Hg(Ⅱ).

Carbon-based materials have large specific surface area, well-developed pores, and a large number of oxygencontaining functional groups on the surface, which have excellent mechanical properties. Introducing carbon-based materials into the hydrogel system can increase adsorption sites, improve mechanical properties, enrich network structure, realize complementary advantages, and overcome performance defects, which is the main idea for developing highperformance hydrogel adsorbents. In this paper, the structural characteristics of different types of carbon based composite hydrogels were summarized, and the mechanism of carbon based materials to enhance the performance of hydrogels was emphatically introduced. The preparation methods of composite hydrogels and their applications in the field of water purification were reviewed. The prospects, limitations and future research potential of carbon based composite hydrogels adsorbents were analyzed. [ABSTRACT FROM AUTHOR]

OBJECTIVES Due to the advantages of simple sample preparation, non-destructive determination, and rapid detection, the X-ray fluorescence spectrometry technique has become a robust method for determination of manganese in soil or sediment. Manganese in soil and sediment standard material has the maximum content of 2490mg/kg, thus the traditional X-ray fluorescence spectrometry (XRF) can easily suffer from the drawbacks of standard curve measurement range due to the limited manganese content in standard soil or sediment samples. OBJECTIVES To develop a good method for the determination of manganese in polluted soil or sediment. METHODS To address this major concern, manganese solutions were added to the commercially available soil standards in a quantitative manner to give a series of new soil standards with higher manganese content. The content of manganese can be determined by X-ray fluorescence spectrometry. RESULTS The establishment of a novel standard curve by taking advantage of these new soil standards could significantly promote the upper limit of manganese measurement from 2490mg/kg to 3780mg/kg. The analytical results of manganese were consistent with the reference value and a recovery of 97.8%-108.3%. The results of high-manganese samples were consistent with the values acquired by inductively coupled plasma-optical emission spectrometry, with the relative deviation less than 5.7% and the relative standard deviation lower than 0.4% (n=7). Conclusion Results show good accuracy and precision in the determination of high-manganese soils and sediments.

A new 2-GRR(FR)/GRR parallel drive bidirectional deflection platform is proposed. The movable platform is connected with the base through two branches which are crisscross and concentric in space，and the platform can deflect at large-angle area in both X and Y directions. Taking one of the branches as the research object，the local coordinate system of each component is established by D-H method，and the inverse kinematics analysis is performed. The analytical equation is obtained by using the bivariate inverse tangent function. Then the force and moment balance equations of each component are established according to the D'Alembert principle. The dynamics model of the platform is derived by New-Euler method，and the dynamic model is used to calculate the parallel drive bidirectional deflection platform. The graph of the driving torque required to achieve the specified motion under given external force and external torque is obtained.

To study the deformation and stress of ring-flexspline in harmonic gear under actual working conditions,an interference fit model is applied to solve the problem of assembling between the wave generator and flexspline with large deformation. Further more experiments are performed to test the validity of this method. Then the finite element numerical calculations of the whole harmonic gear are obtained under no-load and rated load on the base of the model. At last,the deformation and stress distributions law of flexspline in the no-load and load are analyzed by data processing. The results show that the stress distribution of the flexspline has its minor value along the neutral layer of flexspline ring,and the maximum stress is located on the tooth root which mainly is tangential. The deformation and stress increment of flexspline under rated load are0. 46% and 93. 6% respectively relative to the no-load. It also shows that the load has little effect on flexspline deformation,but a strong influence on its stress. The finite element analysis results which fit well with related literature calculations proved that the interference fit model is effective,so it can provide a more precise method to study harmonic gear drive in accordance with the actual working conditions.

For the reason that the position solution of a parallel mechanism is hard to be solved directly,the solution of positive position are parsed by the method of transformation to solve object location based on the solved inverse position solution in the 3- PRS parallel mechanism,and the velocity and acceleration of the passive joints are obtained by the D’Alembert principle,which can avoid the complexity of the direct derivation on the spatial mechanism. Through the analysis of an actual 3- PRS parallel mechanism instance,the results show that the method of objects transformation is simple and effective for solving the position positive solution of the parallel mechanism. At the same time,it is pointed out that the derived movements also exist besides the main three motions of 3- PRS parallel mechanism,this reveals that the derived kinematics must be taken into account in actual usage.

In this study, QTL mapping of grain size related traits and pyramided effect analysis of different sites were carried out to lay a foundation for marker-assisted breeding and fine mapping of grain size related genes. A total of 192 recombinant inbred lines derived from indica rice cultivars Modasui and Hanghui 315 were planted in three different seasons. A high-density genetic map was constructed based on whole-genome resequencing technology, and the QTLs for grain shape traits were mapped by complete interval mapping (ICIM) and verified by composite interval mapping (CIM). QTL mapping was carried out for grain length, grain width, length-width ratio, 1000-grain weight, cross-sectional area, and grain circumference. 50 and 81 QTLs were detected by ICIM and CIM, respectively, and 43 QTLs could be detected simultaneously. They were clustered on chromosome 2, 3, 5, 7, 8, and 9. Their highest phenotypic contribution rates were 15.74%, 54.07%, and 15.89%, respectively. These loci could be the candidate loci for subsequent gene function studies. According to the genotyping of bin markers, different progenies were divided into Hanghui 315 type and Modasui type in each QTL interval. Further data processing and analysis were performed to analyze the pyramided effect of QTLs. It was found that individuals with more pyramided synergistic alleles showed higher phenotypic values in different environments. The identified lines with multiple synergistic alleles can be used as donor parents in breeding practices. [ABSTRACT FROM AUTHOR]

Medication -- overuse headache (MOH) is a global public health problem involving medicine, economics and sociology. High frequency or chronic primary headache is a risk factor of MOH. The methods to prevent MOH are to strengthen the treatment and management of primary headache, to improve the understanding of MOH, and to avoid overuse of analgesics. This article reviews the diagnosis, clinical features, drug overuse and drug dependence, and treatment of MOH. [ABSTRACT FROM AUTHOR]

With the continuous improvement of material living standard, changes in working environment and living state have led to the development of the sub-health status and the aging of the population. Dietary supplements with multiple biological functions have become a hot topic for consumers and researchers. Carotenoids are not only natural pigments that play a key role in photosynthetic organisms, but also have various protective functions for human health. Therefore, they are often used as nutritional supplements in the food industry and pharmaceutical industry. However, the high sensitivity of carotenoids to processing conditions and environmental factors, as well as their strong hydrophobicity limit the bioavailability of carotenoids and their wide application in complex processed food environments; other nutrients such as lipid, cellulose, protein and mineral elements in food matrix also have great influence on the bioavailability of carotenoids. Related research has shown that emulsion, a special delivery system, can protect carotenoids from environmental factors and improve their bioavailability in the human body. From the perspective of multiple factors affecting the bioavailability of carotenoids, this review focused on the research progress and application status of carotenoids bioavailability regulated by emulsion delivery systems, and looked into the future development trend of these delivery systems. [ABSTRACT FROM AUTHOR]

In order to investigate the effects of fiber on the performance of 3D printing concrete (3DPC), the influence of fiber on the rheological properties, printing properties, mechanical properties, and pore structure of 3 DPC were studied by adding PVA fiber, PP fiber, and sisal fiber. The result of the rheological property test shows that the static yield stress of 3DPC increases linearly with the content of three kinds of fiber, but the influence of fiber on the rheological property of 3DPC is different. The results of printing performance test indicate that the addition of PVA fiber reduces the extrudability of 3DPC, but it significantly improves the size uniformity of extruded concrete. The test results of mechanical properties and pore structure point out that PP fiber significantly improves the compressive strength of 3DPC, sisal fiber has the most significant strengthening effect on the flexural strength of 3 DPC, and the increase of fiber content will reduce the apparent density of 3 DPC and increase the internal porosity, resulting in the reinforcement effect of high fiber content is weaker than that of low fiber content. [ABSTRACT FROM AUTHOR]

3D printing concrete technology, with the advantages of free formwork, high automation and intellectualization, has attracted more and more concerns, and achieved successful application in the field of construction engineering and other related fields. However, 3D printing technology puts forward higher requirements to the rheological performance of concrete, while the current standards or codes for concrete are no longer applicable to guide the mix design of 3D printing concrete. Meanwhile, due to the effect of the printing process, the hardened properties and reinforcement technology of 3D printing concrete are different from that of conventional concrete. Therefore, this paper reviews 3D printing concrete from four main aspects, i. e., rheological and printable performance, mix design, hardened properties, and reinforcement technology. Besides, for comprehensively presenting the development and application of 3D printing concrete, different types of engineering projects and special types of 3D printing concrete are introduced in this review. This review is expected to provide a reference for the further development and research of 3D printing concrete. [ABSTRACT FROM AUTHOR]

Objective To analyze the clinical features of patients with coronavirus disease 2019 (COVID-19) in Wuhan, and we provide reference for further prevention and control of the disease. Methods We collected the clinical data of patients with COVID-19 in Dongxihu Shelter Hospital of Wuhan from February 7 to March 6, 2020. The main symptoms, blood test results, lung CT results, and nucleic acid negative conversion were analyzed. Results A total of 654 patients were included, 175(26.76%) were mild, and 479(73.24%) were general. There were 344 males (52.60%), and 310 females (47.40%). The patients were with a mean age of (49.36± 10.30) years, and 97 patients (14.83%) with a history of hypertension, 51 patients (7.80%) had a history of diabetes. The main clinical symptoms were fever with 547(83.64%) patients, 186 cases (28.44%) had chills, 15 cases (2.29%) had shiver, 342(52.29%) had fatigue symptoms, 413(63.15%) had cough, 137(20.95%) had chest tightness, and 109(16.67%) had diarrhea during the course of the disease. Blood routine tests of 395 patients, the white blood cell count (WBC) was (4.12±1.46)x109/L. The total white blood cell count was normal in 378 cases(95.70%), increased in 7(1.77%), and decreased in 10(2.53%). The lymphocyte percentage was (23.10±10.02)%, lymphocyte (1.06±0.37)x109/L. The percentage and count of lymphocyte were low. All the 654 cases were examined by CT, 175 cases (26.76%) showed normal lung CT, 422 cases (64.52%) showed patchy or segmental ground-glass opacity, and 57 cases (8.72%) showed multilobar consolidation, ground-glass shadow coexisted with consolidation or streak shadow. The interval between positive nucleic acid test before admission and negative test after admission was as short as 5 days and as long as 24 days, the average was (12.35 ±3.73) days. Conclusion Fever, coughing, and fatigue are the main symptoms in patients with COVID-19. The typical lung CT findings can be used as the basis for clinical diagnosis and disease evaluation. Patients with mild and common type had better prognosis. [ABSTRACT FROM AUTHOR]

Objective To investigate the protective effect of berberine chloride on secondary damage (inflammation, oxidative damage and neuron loss) in bilateral thalami of traumatic brain injury (TBI) model mice. Methods Mice were randomly divided into 3 groups: control group (N = 6), TBI group (N = 6) and berberine group (N =6). TBI model was established by a free-falling hitting device. In control group, mice were not given free-falling hitting. Mice in berberine group were given a gavage of berberine chloride [50 mg/(kg⋅d)] for 21 d, while mice in TBI group were given the same dosage of normal saline for 21 d. Immunohistochemistry was used to count the number of neurons or gliocytes positive for inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), 8-hydroxy deoxyguanosine (8-OHdG) and neuronal nuclei (NeuN), the number of astrocytes positive for glial fibrillary acidic protein (GFAP) and the number of microglias positive for ionized calcium-binding adaptor molecule 1 (Iba1). Results The number of neurons or gliocytes positive for iNOS (P = 0.015), COX-2 (P = 0.022), 8-OHdG (P = 0.000) and NeuN (P = 0.000), the number of astrocytes positive for GFAP (P = 0.024) and microglias positive for Iba1 (P = 0.000) in TBI ipsilateral thalamus were significantly different among 3 groups. In TBI group, the number of neurons or gliocytes positive for iNOS (P = 0.005), COX-2 (P = 0.011) and 8-OHdG (P = 0.000), the number of astrocytes positive for GFAP (P = 0.011) and microglias positive for Iba1 (P = 0.000) were significantly higher than those in control group, while the number of neurons positive for NeuN (P = 0.000) was significantly lower than that in control group. In berberine group, the number of neurons or gliocytes positive for iNOS (P = 0.031), COX-2 (P = 0.024) and 8-OHdG (P = 0.008), the number of astrocytes positive for GFAP (P = 0.031) and microglias positive for Iba1 (P = 0.012) were significantly lower than those in TBI group, while the number of neurons positive for 8-OHdG (P = 0.014) and microglias positive for Iba1 (P = 0.024) were significantly higher than those in control group. The number of neurons positive for NeuN in berberine group was significantly higher than that in TBI group (P = 0.016), while lower than that in control group (P = 0.027). Additionally, number of neurons or gliocytes positive for COX-2 (P = 0.029) and 8-OHdG (P = 0.000) in TBI contralateral thalamus were significantly different among 3 groups. The number of neurons or gliocytes positive for COX-2 (P = 0.011) and 8-OHdG (P = 0.000) in TBI group was significantly higher than that in control group, while the number of neurons or gliocytes positive for COX-2 (P = 0.047) and 8-OHdG (P = 0.010) in berberine group was significantly lower than that in TBI group. The number of neurons positive for 8-OHdG in berberine group was significantly higher than that in control group (P = 0.004). Conclusions TBI could cause secondary damage of bilateral thalami, especially in ipsilateral thalamus, but only cause inflammation and oxidative damage in contralateral thalamus. Berberine chloride might exert neuroprotective effect on bilateral thalami after TBI by significantly suppressing inflammation and oxidative damage. [ABSTRACT FROM AUTHOR]

In cooperative communication systems, in order to overcome the low spectral efficiency problem of one-way relay network, the relay selection problem of two -way relay channel was investigated. The single relay selection strategy was proposed based on amplify forwarding and two-way relay selection strategy was proposed based on network coding. Moreover, bit error rate (BER) and diversity expressions were derived, and the performance of two ways was compared by the simulation. The results indicated that two strategies can achieve full diversity in multi-relay wireless networks. In the high SNR region, the bit error rate of TWRS-NC is half of TWRS-AF, and the gain of TWRS-NC is two times of the TWRS-AF; when bit error rate is fixed at 10-4, the double maximum standard is better than MIN-W selection criteria 1 dB. [ABSTRACT FROM AUTHOR]

[ Objective ]This study was aimed to provide references for the production, structural adjustment and industrial layout of Sichuan advantage agricultural products. [ Method ]Using the comparative advantage index method, the scale and efficiency of Sichuan major agricultural products during 2009-2011 were analyzed and internal and external comparative advantages were discussed. Finally, the status, trends and competitive advantage of major agricultural products in Sichuan were researched. [ Result ]The dominant agricultural products of Sichuan were rapeseed, potato, tea, tobacco and rice. According to trend characteristics, potato, tobacco and rice showed upward trends, while rapeseed and tea exhibited downward trends during 2009-2011. The upward trends of the index of scale advantages of major agricultural products in Sichuan were tobacco and rice, while rapeseed and tea showed a downward trend, and the scale advantages index for potato were basically unchanged. The upward trends of the efficiency advantage index major agricultural products in Sichuan were potato and rice, while rapeseed, tobacco and tea showed a downward trend. [ Suggestion ]The planting techniques and technological level of rapeseed, potato, tea, tobacco and rice should be improved to enhance its overall efficiency. Meanwhile, with the development of competitive agricultural actual adjustment range, importance should be attached to developing competitive agricultural products and comprehensively planning the new layout of an area for major agricultural products in order to strengthen the market competitiveness of Sichuan agricultural products at home and abroad. [ABSTRACT FROM AUTHOR]

Function partitioning of maintenance equipment is studied based on the fact that failure rates are different in different usage conditions. With the consideration of the types, usage occasion and volume of maintenance equipment, an assigning model from maintenance device to maintenance equipment is built for the failure rate in main occasion of maintenance equipment. The maintenance devices can be initially assigned to maintenance equipment by its main usage occasion without consideration of volume limitation, and the assigning correction of maintenance devices is conducted based on the difference between occasion failure rates with the consideration of volume limitation. An assigning algorithm of two maintenance equipment is proposed, and an example is given, which proved the model and solution algorithm are scientific. [ABSTRACT FROM AUTHOR]

Objective:To explore the effects of two criteria of hCG administration on the clinical outcomes of IVF/ICSI -ET. These criteria were individually based on the follicle diameter and the follicle symmetry. Methods: It's a prospective randomized study in our hospital reproductive center. IVF/ICSI-ET patients were randomly divided into two groups from Jan 2013 to Mar 2013. The criterion of hCG administration in Group A was based on the follicle diameter, while Group B on the follicle symmetry. Clinical and laboratory outcomes were then compared. Results: The average days of Gn, serum levels of progesterone and estradiol on the hCG day, the average number of matured eggs, and the rate of matured oocytes of group B were significantly higher than those of group A(P<0.05). There was not significant difference in the numbers of frozen embryos and good quality embryos between the two groups. However, the clinical pregnancy rate of group B was significantly lower than that of group A (42.19% vs. 54.22%, χ²=4.18, P=0.04), and the incidence of OHSS in group B significantly higher than that of group A(10.77% vs. 5.86%, χ²=4.07,P=0.04). Conclusions: The criterion based on the uniform size of follicular is not superior to the traditional criterion focused on the dominant follicle size in the efficacy and safety of IVF/ICSI-ET treatment. [ABSTRACT FROM AUTHOR]

A novel composite polypropylene-acrylate sorbent PP-g-(AA+BMA) is prepared by grafting acrylic acid (AA) and butyl methacrylate (BMA) on the polypropylene (PP) fiber substrate using two -step electron beam irradiation method. First, AA was grafted onto PP substrate by electron beam. Then, the pretreated PP was soaked in BMA solution and the loaded monomer was grafted on the PP substrate by electron beam induced. Fourier transform infrared spectra (FT-IR) and scanning electron microscopy (SEM) were employed to characterize the morphological changes and chemical composition of PP substrate. In addition, the factors influenced the grafting degree were discussed, such as the irradiation time, concentration of monomer. The results indicated that the filtration efficiency of PP fiber was improved significantly after graft modification, when the grafting degree was 17.24%, the maximum sorption capacity for DMP reached 18.17 g/g and 20.25 g/g for DEP, respectively. [ABSTRACT FROM AUTHOR]

Based on the related literatures from Web of Science database retrieval about seed industry security between 1982 to 2013, this paper carried out bibliometric analysis on research trend, country, research direction, organization, author, journals and the highly cited papers. The results showed that there were about 64 countries or regions, 544 research institutes were engaged in this research, and 83 related research areas, 967 authors, 945 journals, and 1 837 papers was published. The highest frequency for one cited paper was 497. The United State lead the world in seed industry security study. There was still a bigger gap between China and US in this area. Although the number of researchers engaged in this area is large, there were few authors who were active and high productive. Most of the authors working at colleges and universities, mainly engaged in theoretical study. Here we would suggest keeping track and increasing investment for scientific research in this area. This study aimsed at analyzing objectively the seed security situation at home and abroad, grasping timely its development frontier and new trends, providing reference for researchers and decision makers, and promoting studies on seed industry security and development. [ABSTRACT FROM AUTHOR]

Aim at the problem for how to analyze the propensity to spread of shortage of supplies in emergency logistics decision support system, this paper proposed a new model to study the propensity to spread of shortage of supplies for emergency logistics network. This paper, by the mechanism of viral spreading and introducing the parameter of time "t", it constructed SI-SIRS ( susceptible infective and susceptible infective recover susceptible) model to analyze the scale-free network which included 61 nodes. Case analysis shows that SIRS effectively depicts the spread behavior of shortage of supplies in emergency logistics network. Propensities to spread of shortage of supplies are effected by node self-spread ability, network topology, individual nodes differences and responding mechanism of emergency logistics. [ABSTRACT FROM AUTHOR]

This paper analyzed relationship between train's lateral vibration and track irregularity input by wavelet transform and the cross-correlation function. Track irregularity input leaded to train lateral vibration, it analyzed the relationship between them to reduce the lateral vibration and predict of vibration changes. Firstly, it established train lateral vehicle model by Simulink, and then simulated lateral, rolling and yawing vibration signal. Secondly, it analyzed relationship between three kinds of vibration above and horizontal irregularity input as well as alignment irregularity input by wavelet transform and the cross-correlation function. Simulation results show that cross-correlation function value between horizontal irregularity and lateral, yawing vibration is bigger than that between alignment irregularity and lateral, yawing vibration, and cross-correlation function value between alignment irregularity and rolling vibration is bigger than that between horizontal irregularity and rolling vibration. It is affirmed that horizontal irregularity is the important factor causing train lateral and yawing vibration, and alignment irregularity is the important factor causing train rolling vibration at the same time. [ABSTRACT FROM AUTHOR]

The present authors take use of the four large-scale survey data obtained from the Chinese Household Income Project (CHIP) among workers, to examine the trends in the economic returns to education in urban China between 1988 and 2007. The results indicate that the rates of the returns to education had experienced a sharp rise during 1988 to 2002, while increases in returns to schooling were in a gradual steady process in the later reform era. Consistent with the earlier studies per se, net returns to schooling for men and women were significantly different, and the gender differences declined with the economic reform. However, those differences in returns to schooling between occupations, ownerships, and regions did not decrease but were undulating with economic growth in the reform period. Thus, in order to reduce the differences between regions, ownerships, and occupations of income gap, more attention should be paid to the human capital in resource allocation for incentives, investment be increased in less-developed regions in education to improve the quality of the labor force in underdeveloped areas, and the competitiveness of regional workforce be enhanced. Also the reform of the state-owned enterprises should be attended to, restrictions on market access to monopoly industries be relazed, and the labor market institutional barriers to increase efficiency of resource allocation be reduced. More importantly, the liberalization and institutional construction of free market should be improved in the less-developed regions, where it is an indispensable institutional condition to attract high-quality human resources. [ABSTRACT FROM AUTHOR]

To increase bandwidth in multi-hop wireless networks, this paper introduced the helper node to assist other links to transmit packets. It introduced a new concept cooperative routing which contained a routing path and corresponding helper nodes for each link. Based on this, the paper proposed a distributed cooperative routing algorithm and verified it on the real testbed. The results show the distributed algorithm can significantly improve the network performance. [ABSTRACT FROM AUTHOR]

Surface soil samples were monthly collected from six land use types (abandoned greenhouse field, forest land, sloped farmland, table land, flat vegetable land and greenhouse field) in Dianchi watershed of Yunnan to determine the soil pH and the contents of soil organic matter (OM), total nitrogen (TN), and total phosphorus (TP), aimed to understand the effects of different land use types on the spatiotemporal distribution of the soil nutrients. The soil pH, SOM, TN and TP, contents, and soil C/ N differed significantly with soil land use types. The soil pH was in the order of abandoned greenhouse field > flat vegetable land > greenhouse field > table land > sloped farmland > forest land; the OM content was in the sequence of abandoned greenhouse field > flat vegetable land > greenhouse field > sloped farmland > forest land > table land; the TN content was in the order of greenhouse field > flat vegetable land > abandoned greenhouse field > sloped farmland > table land > forest land; the TP content was in the order of flat vegetable field > greenhouse field > abandoned greenhouse field > sloped farmland > table land > forest land; and the C/ N ratio was in the sequence of forest land > sloped farmland > flat vegetable plot > table land > abandonedgreenhouse field > greenhouse field. The OM, TN and TP contents were affected by fertilization, irrigation, field cultivation and season. All the test parameters had the highest values in rainy season, which could be related to the local top-dressing habits. There were significant positive correlations among the TN, TP and OM under all the land use types. In greenhouse field and abandoned greenhouse field, due to the severe human disturbances, the soil pH and OM, TN and TP contents were obviously higher than those in forestland and table land. [ABSTRACT FROM AUTHOR]

The new concept of rank preference dominating correlation coefficient is proposed in this paper, based on the new concept, we introduced the rank preference optimal ordering method in the multi-attribute decision making. The new method can get the obvious differences among alternatives by overcoming the lack of the optimal ordering method, moreover, the new method can be achieved by editing computer programs, which makes it to play an important role in practical problems. [ABSTRACT FROM AUTHOR]

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