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There is a large amount of unstructured data in the current corn cross-border supply chain system and it has the characteristics of multi-source heterogeneous. Traditional risk early warning methods have defects such as over-reliance on manual decision-making and low accuracy of early warning. In order to solve the above problems, this paper proposed a system risk early warning method of corn cross-border supply chain based on deep belief network and multi-class fuzzy support vector machine. Firstly, based on the principle of embedding coding and normalization, a large number of unstructured data in the corn cross-border supply chain system were preprocessed and converted into structured data for subsequent calculation. Then, based on the deep belief network, the high-latitude features of the data were extracted, and the change trend and correlation of risk indicators in the corn cross-border supply chain system were adaptively mined. Finally, the extracted high-dimensional features were input into the multi-class fuzzy support vector machine model for training to realize the risk classification early warning of corn cross-border supply chain. The accuracy of the algorithm proposed in this paper can reach 94.88% under the condition of similar running time. It is 52.17% higher than that of the worst algorithm, and the comprehensive performance was superior to other algorithms which can provide theoretical support for the application of system risk regulation of corn cross-border supply chain.

Background Community-based clinical teaching is of vital importance in the training of medical undergraduates, but high level of effectiveness of teaching is difficult to be guaranteed at present. So it is essential to establish a scientific and effective system for assessing the effectiveness of community-based clinical teaching for medical undergraduates. Objective To develop an effectiveness assessment system of community-based clinical teaching for medical undergraduates, providing support for assessing the effectiveness of community-based clinical teaching in these undergraduates. Methods The item pool for the system used for assessing the effectiveness of community-based clinical teaching in medical undergraduates was developed on the basis of reviewing relevant literature and assessment tools, and was drawn up by group discussions. Then the items were improved according to two rounds of Delphi consultation with a purposive sample of 32 relevant experts from June 2019 to April 2020, and used to develop the Effectiveness Assessment System of Community-based Clinical Teaching for Medical Undergraduates (EASCCTMU) . The Analytic Hierarchy Process was used to calculate the weight of each indicator. Results The response rate was 100.0% for both rounds of consultation. The authoritative coefficients for the first and second rounds of consultation were 0.87 and 0.88, respectively. The Kendall's coefficient of concordance for the first and second rounds of consultation were 0.65 and 0.61, respectively (P

To study the response of coastal wetlands to climate change, assess the impacts of climate change on the coastal wetlands and formulate feasible and practical mitigation strategies are the important prerequisite for securing coastal ecosystems. In this paper, the possible impacts of sea level rise caused by climate change on the coastal wetlands in the Yangtze Estuary were analyzed by the Source-Pathway-Receptor-Consequence (SPRC) model and IPCC definition on the vulnerability. An indicator system for vulnerability assessment was established, in which sea-level rise rate, subsidence rate, habitat elevation, inundation threshold of habitat and sedimentation rate were selected as the key indicators. A quantitatively spatial assessment method based on the GIS platform was established by quantifying each indicator, calculating the vulnerability index and grading the vulnerability index for the assessment of coastal wetlands in the Yangtze Estuary under the scenarios of sea-level rise. The vulnerability assessments on the coastal wetlands in the Yangtze Estuary in 2030 and 2050 were performed under two sea-level rise scenarios (the present sea-level rise trend over recent 30 years and IPCC A1F1 scenario). The results showed that with the projection in 2030 under the present trend of sea-level rise (0. 26 cm∙a-1), 6. 6% and 0. 1% of the coastal wetlands were in the low and moderate vulnerabilities, respectively; and in 2050, 9. 8% and 0. 2% of the coastal wetlands were in low and moderate vulnerabilities, respectively. With the projection in 2030 under the A1F1 scenario (0. 59 cm∙a-1), 9. 0% and 0. 1% of the coastal wetlands were in the low and moderate vulnerabilities, respectively; and in 2050, 9. 5%, 1. 0% and 0. 3% of the coastal wetlands were in the low, moderate and high vulnerabilities, respectively. [ABSTRACT FROM AUTHOR]

The high productivity of saltmarsh vegetation in coastal wetlands plays an important role on the formation of soil carbon pool. This paper studied the biomass difference, the spatiotemporal dynamics and vertical distribution of soil carbon storage in three dominant saltmarsh plant communities, i. e. , Phragmites australis, Spartina alterniflora and Scirpus mariqueter in the Chongming Dongtan wetland, in the Yangtze Estuary. The results indicated that the gross biomass in the three saltmarsh plant communities was in the order of S. alterniflora (5750. 7 g · m-2 ) > P. australis (4655. 1 g · m-2) > S. mariqueter (812. 7 g · m-2). The aboveground biomass was the highest in summer and autumn, and the underground biomass was the highest in winter. The soil carbon storage (0-50 cm) was the lowest in spring, gradually increased, and was the highest in winter. The annual increment of soil carbon storage decreased from the high tidal zone to the low tidal zone, and was in the order of P. australis community (711. 8 g · m-2 ) > S. alterniflora community (646. 2 g · m-2)> S. mariqueter community (185. 3 g · m-2 ) > bare mudflat (65. 6 g · m-2). The highest value was in the 25-30 cm, 10-15 cm, 30-35 cm and 30-40 cm soil layers for bare mudflat and the S. mariqueter, S. alterniflora and P. australis communities, respectively. There was a significant linear relationship between the soil carbon storage and the underground biomass in the different saltmarsh communities. [ABSTRACT FROM AUTHOR]

To investigate the effects of alternate partial root-zone drip irrigation (ADI) on the morphological characteristics and root hydraulic conductivity of apple seedlings, three irrigation modes, i. e. , fixed partial root -zone drip irrigation (FDI, fixed watering on one side of the seedling root zone), controlled alternate partial root -zone drip irrigation (ADI, alternate watering on both sides of the seedling root zone), and conventional drip irrigation (CDI, watering cling to the seedling base), and three irrigation quotas, i. e. , each irrigation amount of FDI and ADI was 10, 20 and 30 mm, and that of CDI was 20, 30 and 40 mm, respectively, were designed. In treatment ADI, the soil moisture content on the both sides of the root zone appeared a repeated alternation of dry and wet process; while in treatment CDI, the soil moisture content had less difference. At the same irrigation quotas, the soil moisture content at the watering sides had no significant difference under the three drip irrigation modes. At irrigation quota 30 mm, the root-shoot ratio, healthy index of seedings, and root hydraulic conductivity in treatment ADI increased by 31. 6% and 47. 1%, 34. 2% and 53. 6%, and 9. 0% and 11. 0%, respectively, as compared with those in treatments CDI and FDI. The root dry mass and leaf area had a positive linear correlation with root hydraulic conductivity. It was suggested that controlled alternate partial root-zone drip irrigation had obvious compensatory effects on the root hydraulic conductivity of apple seedlings, improved the soil water use by the roots, benefited the equilibrated dry matter allocation in seedling organs, and markedly enhanced the root -shoot ratio and healthy index of the seedlings. [ABSTRACT FROM AUTHOR]

For synthesizing the textile coating agent with high waterproof and moisture permeable performance, water-borne polyurethanes modified by silicone (WSPU) were prepared by polyaddition reaction using poly (tetramethylene oxide)glycol, polyethylene glycol, and α, ω aminopropyl polysiloxane as mixing soft segments, dimethylolpropionic acid as hydrophilic chain extender, 1,4-butanediol as hard segment regulator and isophorone diisocyanate. The chemical composition of WSPU was characterized by infrared spectroscopy and nuclear magnetic resonance spectroscopy. The microstructure of WSPU films were investigated by differential scanning calorimetry, transmission electron microscopy and positron annihilation lifetime spectroscopy. Mechanical properties of WSPU films were investigated by static tensile test. Results show that modified polyurethane(WSPU) membranes have significant micro-phase separation structure and large hole free volume that result in the increase of moisture permeability, maximum of which could reach 2 130.1 g ⋅ (m² ⋅ d)-1 This research has the value of industrial promotion. [ABSTRACT FROM AUTHOR]

The GAP/PEG/TMP/IPDI energetic binder film was synthesized by using PEG and GAP as raw materials, trimethylolpropane as crosslinking agent,and isophorone diisocyanate as curing agent. The binder film was characterized by FTIR, DSC and XRD. Because of the introduction of PEG, the tensile strength of GAP/PEG binder film was raised to 3. 11 MPa and the breaking elongation was 475%. With the increasing degree of crosslinking of the binder film, the vitrified temperature of soft segment in the binder film decreased after an initial increase. The DSC and XRD results show that the GAP/PEG binder film is an amorphous polymer and the initial decomposition temperature of copolymer was 183 °C. [ABSTRACT FROM AUTHOR]

PURPOSE: To establish an animal model for maxillary incisors intrusion with mini-implant as the anchorage and study the effect on the surface morphology of cementum after the force had been given. METHODS: 9 dogs were selected and randomly divided into 5 groups, group I was the control group(1 dog) with no force given; groups II, III, IV, V were experimental groups (2 dogs each). Mini-implants were inserted into the labial alveolar bone between the roots of second and third maxillary incisors on both sides, 100 gram force was imposed on the first and the second incisors on both sides. The animals were sacrificed at the end of 1,2,4,12 weeks (activation for 4 weeks, then retention for 8 weeks after force removal) respectively after activation. Scanning electron microscopy was used to examine the surface of the cementum. RESULTS: In group II, the surfaces of root tip had a little scratch, which was small, confined. In group III, near the apical 1/3 of root, lacunas were fused, but no dentin exposed. In group IV, at the junction of the apical 1/3 and the middle 1/3 of the root, lacunas went deep into the dentin, which were wide and serious. In group V, the surfaces of lacunas were low ,smooth and even. CONCLUSIONS: As the intrusion goes on, the area of absorption expands from the root tip to neck. Root resorption increases with the duration of the applied force prolonged and repair of the cementum occurs at the resorbed area after force removal. Supported by Natural Science Foundation of Gansu Province (Grant No.0710RJZA029) and Medical Foundation of Lanzhou University (Grant No.LZUYX200705). [ABSTRACT FROM AUTHOR]

The flame structures, combustion surface temperature, quenched surface appearances, quenched surface relict elements and quenched surface relict compounds of A1/AP/HTPB propellant (P-A0), A1/hydrogen storage alloy/AP/HTPB propellant (P-A10) and hydrogen storage alloy/AP/HT- PB propellant(P-A17) were researched by using single frame photography, W-Re micro-thermal couple, scanning electron microscope (SEM), energy dispersive spectrum (EDS) and X-ray diffraction (XRD) methods. The results show that the combustion surface of P-A10 and P-A17 exhibits a stronger injection phenomena compared to P-A0 ; their surface temperatures are increased by 5.92 °C and 7.45 °C, respectively, and their condensed phase reaction areas are increased by 13. 13% and 47.30% separately in the presence of hydrogen storage alloy; The quenched surface of P-A17 is neat relatively, and the swell surface of alloy group is mostly oxidized; The amount of carbon left behind on quenched surfaces of P-A10 and P-A17 is lowed by 15.81% and 27.61% separately, which proves that combustion efficiency of AP/ HTPB propellant organic components on the burning surface could be promoted by hydrogen storage alloy; The amount of A1 on quenched surface changes from high to low and when the amount of A12 O3 on a quenched surface changes from low to high by the order of P-A0, P-A10 and P-A17, which proves that combustion efficiency of hydrogen storage alloy is higher than A1. Combustion properties of AP/HTPB propellant could be improved when using hydrogen storage alloy as combustion agent in place of A1. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the influence of removable thermoplastic appliances and fixed appliances on periodontal status., Methods: Cochrane library, PubMed, EMBASE, CBM, CNKI, VIP, Wanfang Database were searched from the date of inception to 2017.10.16，to find clinical trials about removable thermoplastic appliances and fixed appliances on periodontal status. The quality of the included studies was assessed by two reviewers independently, and meta analysis was performed using RevMan5.3., Results: Totally 11 studies including 543 patients were identified. The results of meta analysis showed there were significant difference in PLI and SPD at 3 months and PLI and GI at 6 months between removable thermoplastic appliances and fixed appliances, and no significant difference was observed in GI at 3 months and SPD at 6 months between the two groups., Conclusions: In the early orthodontic treatment, removable thermoplastic appliances has better effect than the fixed appliance on periodontal health.

There is a lack of observation data on greenhouse gas (GHG) and ammonia emissions from sewage sludge composting, though the emissions can result in environmental issue and nitrogen loss. In this study, GHG and ammonia emissions were monitored under different operating parameters during sludge composting with continuous aerated turning pile at full scale. Results illustrated that the reduction of amendment addition could result in low organic matter transformation (1.38% and 8.85% for the test group and the control group, respectively). Though low C/N ratio might slightly increase the ammonia emission (8.68% higher than the control group), it was helpful to reduce both GHG emission (1.70 g x kg(-1)) DC for the test group and 2.85 g x kg(-1) DC for the control group, respectively) and total nitrogen loss (16.1% and 21.8% for the test and control groups, respectively). Through applying an aertion strategy in which the airflow rate was lower in the beginning and higher in the end of sludge composting, a higher GHG emission and a lower ammonia emission were observed in the test group, e. g., 55.1% higher of GHG emission than the control, and 66.86 g x m(-2) and 72.04 g x m(-2) of ammonia emission in the test and the control, respectively. And a good conversation of total nitrogen thus occurred in the test as a result of such aeration strategy, with only 51.34% of TN loss as compared to the control.

Greenhouse gas (GHG) emission from vegetable land is of great concern recently because agriculture land is one of the major sources contributing to global GHG emission. In this study, an experiment of Lactuca sativa L. land applied with different animal manure composts was carried out in a greenhouse vegetable land located in the surburb of Beijing to monitor the emission of GHG (CH4 and N2O) and ammonia in situ, and to analyze the affecting factors of GHG and ammonia emission. Results showed that the emission factors (EFs) of CH4 from Treatment NRM, RM and CF were 0.2%, 0.027% and 0.004%, respectively,the EFs of N2O from these three treatments were 0.18%, 0.63% and 0.74%, respectively, and the EFs of ammonia were 2.00%, 3.98% and 2.53%, respectively. CH4 emission flux was significantly affected by soil temperature and humidity, while N2O emission flux was related to soil temperature, surface temperature and humidity. The emission fluxes of CH4, N2O and NH3 were significantly affected by soil moisture, but there was little relation between CH4, N2O and NH3 emissions and the ambient temperature in the greenhouse.

To study the response of coastal wetlands to climate change, assess the impacts of climate change on the coastal wetlands and formulate feasible and practical mitigation strategies are the important prerequisite for securing coastal ecosystems. In this paper, the possible impacts of sea level rise caused by climate change on the coastal wetlands in the Yangtze Estuary were analyzed by the Source-Pathway-Receptor-Consequence (SPRC) model and IPCC definition on the vulnerability. An indicator system for vulnerability assessment was established, in which sea-level rise rate, subsidence rate, habitat elevation, inundation threshold of habitat and sedimentation rate were selected as the key indicators. A quantitatively spatial assessment method based on the GIS platform was established by quantifying each indicator, calculating the vulnerability index and grading the vulnerability index for the assessment of coastal wetlands in the Yangtze Estuary under the scenarios of sea-level rise. The vulnerability assessments on the coastal wetlands in the Yangtze Estuary in 2030 and 2050 were performed under two sea-level rise scenarios (the present sea-level rise trend over recent 30 years and IPCC A1F1 scenario). The results showed that with the projection in 2030 under the present trend of sea-level rise (0.26 cm x a(-1)), 6.6% and 0.1% of the coastal wetlands were in the low and moderate vulnerabilities, respectively; and in 2050, 9.8% and 0.2% of the coastal wetlands were in low and moderate vulnerabilities, respectively. With the projection in 2030 under the A1F1 scenario (0.59 cm x a(-1)), 9.0% and 0.1% of the coastal wetlands were in the low and moderate vulnerabilities, respectively; and in 2050, 9.5%, 1.0% and 0.3% of the coastal wetlands were in the low, moderate and high vulnerabilities, respectively.

Abstract: The high productivity of saltmarsh vegetation in coastal wetlands plays an important role on the formation of soil carbon pool. This paper studied the biomass difference, the spatiotemporal dynamics and vertical distribution of soil carbon storage in three dominant saltmarsh plant communities, i. e., Phragmites australis, Spartina alterniflora and Scirpus mariqueter in the Chongming Dongtan wetland, in the Yangtze Estuary. The results indicated that the gross biomass in the three saltmarsh plant communities was in the order of S. alterniflora (5750.7 g x m(-2)) > P. australis (4655.1 g x m(-2)) > S. mariqueter (812.7 g x m(-2)). The aboveground biomass was the highest in summer and autumn, and the underground biomass was the highest in winter. The soil carbon storage (0-50 cm) was the lowest in spring, gradually increased, and was the highest in winter. The annual increment of soil carbon storage decreased from the high tidal zone to the low tidal zone, and was in the order of P. australis community (711. 8 g x m(-2)) > S. alterniflora community (646.2 g x m(-2)) > S. mariqueter community (185.3 g x m(-2)) > bare mudflat (65.6 g x m(-2)). The highest value was in the 25-30 cm, 10-15 cm, 30-35 cm and 30-40 cm soil layers for bare mudflat and the S. mariqueter, S. alterniflora and P. australis communities, respectively. There was a significant linear relationship between the soil carbon storage and the underground biomass in the different saltmarsh communities.

There is a great uncertainty of greenhouse gas (GHG) reduction and nitrogen conservation from the full process of sludge composting and land application of compost in China due to the lack of emission data of GHG such as N2O and CH4 and ammonia (NH3). The purpose of this study is to get emission characteristics of GHGs and NH3 from the full process with on-site observation. Results showed that the total GHG emission factor from full process of the turning windrow (TW) system (eCO2/dry sludge, 196.21 kg x t(-1)) was 1.61 times higher of that from the ATP system. Among the full process, N2O was mostly from the land application of compost, whereas CH4 mainly resulted from the sludge composting. In the sludge composting of ATP, the GHG emission equivalence of the ATP (eCO2/dry sludge, 12.47 kg x t(-1) was much lower than that of the TW (eCO2/dry sludge, 86.84 kg x t(-1)). The total NH3 emission factor of the TW (NH3/dry sludge, 6.86 kg x t(-1)) was slightly higher than that of the ATP (NH3/dry sludge, 6.63 kg x t(-1)). NH3 was the major contributor of nitrogen loss in the full process. During the composting, the nitrogen loss as NH3 from both TW and ATP was nearly the same as 30% of TN loss from raw materials, and the N and C loss caused by N2O and CH4 were negligible. These results clearly showed that the ATP was a kind of environmentally friendly composting technology.

Objective: To evaluate the accuracy of cone-bean CT (CBCT) on the measurement of the tooth length., Methods: One hundred and sixty single root premolars extracted for orthodontic purposes were selected. The tooth length was measured with vernier caliper. The premolars were divided into 10 groups randomly, 16 premolars in each group.In each group, the teeth were lined in molar area, premolar area, canine area and anterior tooth area in maxilla and mandible. Then CBCT was taken, and the tooth length was measured using the software supplied by the manufacturer in coronal and sagittal plane. Accuracy was compared between vernier caliper measurement and CBCT measurement., Results: The tooth length measured by CBCT was smaller than that measured with the vernier caliper. Significant differences were found in six areas, except the maxillary and mandibular premolar areas. With the increase of mesial-distal inclination or buccolingual torque angle, the difference between tooth length measured by CBCT and that measured with vernier caliper increased. The correlation between buccolingual torque angle (∠X1) and the coronal view of CBCT radiology tooth length (Spearmen index was 7.00, P < 0.001), and the correlation between mesial-distal inclination and the coronal view of CBCT radiology tooth length (Spearmen index was 0.624, P < 0.001) were found., Conclusions: The tooth length measured by CBCT was smaller than that measured with vernier caliper.

To investigate the effects of alternate partial root-zone drip irrigation (ADI) on the morphological characteristics and root hydraulic conductivity of apple seedlings, three irrigation modes, i.e., fixed partial root-zone drip irrigation (FDI, fixed watering on one side of the seedling root zone), controlled alternate partial root-zone drip irrigation (ADI, alternate watering on both sides of the seedling root zone), and conventional drip irrigation (CDI, watering cling to the seedling base), and three irrigation quotas, i. e., each irrigation amount of FDI and ADI was 10, 20 and 30 mm, and that of CDI was 20, 30 and 40 mm, respectively, were designed. In treatment ADI, the soil moisture content on the both sides of the root zone appeared a repeated alternation of dry and wet process; while in treatment CDI, the soil moisture content had less difference. At the same irrigation quotas, the soil moisture content at the watering sides had no significant difference under the three drip irrigation modes. At irrigation quota 30 mm, the root-shoot ratio, healthy index of seedlings, and root hydraulic conductivity in treatment ADI increased by 31.6% and 47.1%, 34.2% and 53.6%, and 9.0% and 11.0%, respectively, as compared with those in treatments CDI and FDI. The root dry mass and leaf area had a positive linear correlation with root hydraulic conductivity. It was suggested that controlled alternate partial root-zone drip irrigation had obvious compensatory effects on the root hydraulic conductivity of apple seedlings, improved the soil water use by the roots, benefited the equilibrated dry matter allocation in seedling organs, and markedly enhanced the root-shoot ratio and healthy index of the seedlings.

Purpose: To establish an animal model for maxillary incisors intrusion with mini-implant as the anchorage and study the effect on the surface morphology of cementum after the force had been given., Methods: 9 dogs were selected and randomly divided into 5 groups, group I was the control group(1 dog) with no force given; groups II,III,IV,V were experimental groups (2 dogs each). Mini-implants were inserted into the labial alveolar bone between the roots of second and third maxillary incisors on both sides, 100 gram force was imposed on the first and the second incisors on both sides.The animals were sacrificed at the end of 1, 2, 4,12 weeks (activation for 4 weeks,then retention for 8 weeks after force removal) respectively after activation.Scanning electron microscopy was used to examine the surface of the cementum., Results: In group II, the surfaces of root tip had a little scratch, which was small,confined. In group III, near the apical 1/3 of root, lacunas were fused, but no dentin exposed. In group IV, at the junction of the apical 1/3 and the middle 1/3 of the root, lacunas went deep into the dentin,which were wide and serious. In group V, the surfaces of lacunas were low ,smooth and even., Conclusions: As the intrusion goes on, the area of absorption expands from the root tip to neck. Root resorption increases with the duration of the applied force prolonged and repair of the cementum occurs at the resorbed area after force removal.