Synthesis and Characterization of SnO<SUB>2</SUB>Flower-Shaped by Hydrothermal Route for Formaldehyde Sensing Properties

In this work, we’ve made SnO2 flower formed with the aid of using easy test steps, and without cost, which is the hydrothermal approach and without a template. We have used a variety of techniques to characterize SnO2 flower-shaped by (SEM, TEM, XRD, BET and XPS) instruments. Confirmatory tests carried out have proven that the surface of the tetragonal structure of SnO2 has a rough surface which makes it excellent for its gas-sensing properties. The gas detection test of SnO2 flower-shaped proved that it possesses the selectivity of formaldehyde gas (about 30), the optimum operating temperature of the sensor is 220°C, and also the sensor has a high response time and recovery time is (5 s and 22 s) to 100 ppm, respectively. Particularly, the sensor has an obvious response value (2) when exposed to 5 ppm formaldehyde. As well, the mechanism of gas-sensing was also discussed.

Study on the Saccharification Process of Citrus Vinegar by Fruit-Grain Mixed Fermentation

This study aimed to enhance acid production rate and yield of citrus vinegar, and improve the quality of liquid fermented with fruit juice. [ Method] The saccharification process of citrus vinegar was investigated preliminarily with fruit-grain mixed fermentation method using liquor starters as saccharif- erous agents. [Result] The results indicated that the optimal glutinous rice saccharification conditions were as follows： fruit-grain ratio 3： 1, Aspergillus niger- Monascus purpureus ratio 3： 1, saccharifieafion temperature 60℃, and saccharification time 2.5 h. Under the optimized saccharification conditions, reducing sugar content in saceharified glutinous rice reached 146.43 mg/ml; after fermentation, alcohol content in fermentation broth was 6%, amino nitrogen content was 0.44 mg/ml, and acid yield was 3.1 g/L. [ Conclusion] Citrus vinegar brewed based on the optimized technological conditions exhibited better sensory and physico-chemical properties than that brewed with pure juice.

Modeling and identification for soft sensor systems based on the separation of multi-dynamic and static characteristics

Data-driven soft sensor is an effective solution to provide rapid and reliable estimations for key quality variables online. The secondary variables affect the primary variable in considerably different speed, and soft sensor systems exhibit multi-dynamic characteristics. Thus, the first contribution is improving the model in the previous study with multi-time-constant. The characteristics-separation-based model will be identified in substep way,and the stochastic Newton recursive(SNR) algorithm is adopted. Considering the dual-rate characteristics of soft sensor systems, the proposed model cannot be identified directly. Thus, two auxiliary models are first proposed to offer the intersample estimations at each update period, based on which the improved algorithm(DAM-SNR) is derived. These two auxiliary models function in switching mechanism which has been illustrated in detail. This algorithm serves for the identification of the proposed model together with the SNR algorithm, and the identification procedure is then presented. Finally, the laboratorial case confirms the effectiveness of the proposed soft sensor model and the algorithms.

Feasibility analysis and online adjustment of constraints in model predictive control integrated with soft sensor

Feasibility analysis of soft constraints for input and output variables is critical for model predictive control(MPC).When encountering the infeasible situation, some way should be found to adjust the constraints to guarantee that the optimal control law exists. For MPC integrated with soft sensor, considering the soft constraints for critical variables additionally makes it more complicated and difficult for feasibility analysis and constraint adjustment. Therefore, the main contributions are that a linear programming approach is proposed for feasibility analysis, and the corresponding constraint adjustment method and procedure are given as well. The feasibility analysis gives considerations to the manipulated, secondary and critical variables, and the increment of manipulated variables as well. The feasibility analysis and the constraint adjustment are conducted in the entire control process and guarantee the existence of optimal control. In final, a simulation case confirms the contributions in this paper.

Study on the Extraction Technology of Tannin from Mountain Walnut Shells

In this study, tannin was extracted from mountain walnut shells with organic solvent method. The extraction rate of tannin was affected by various fac- tors, including solvents, extraction temperature, extraction time, and solid-liquid ratios. L9 （4^3 ） orthogonal experimental design was employed. The content of tannin in the extraction solution was determined with zinc ion eomplexometrie titration method. According to the experimental methods, the optimal extraction condi- tions were as follows： extraction solvent water, extraction time 12 h, extraction temperature 50 ℃, solid-liquid ratio 1： 6.

Optimization on Extraction Conditions of Flavonoids from Edgeworthia chrysantha Lind1.

[Objectives]The extraction conditions of flavonoids from flowers of Edgeworthia chrysantha Lind1.were optimized.[Methods]With ethanol as an extraction agent,firstly by single-factor tests,the best levels of ethanol concentration,material-to-liquid ratio,extraction temperature and extraction time were determined.Then the optimal extraction conditions were determined through the quadratic orthogonal regression rotatable design.[Results]The optimal extraction conditions for flavonoids from E.chrysantha were∶material-to-liquid ratio 1∶15.4,extraction temperature 75℃,extraction time 120 min and ethanol concentration 75%,with which the highest yield of flavonoids was 6.02 mg/g.[Conclusions]This study provides a theoretical basis for the further development and utilization of E.chrysantha flowers.

Dynamic interaction analysis and pairing evaluation in control configuration design

This paper presents some new dynamic interaction analysis approaches for square or non-square systems and a pairing evaluation method. For square stable systems, an open-loop approach is proposed, which features the tradeoff between the contributions of response time constant and delay time to relative gain. For non-square stable systems, an extension from the proposed open-loop approach for square systems is presented and the corresponding pairing procedure is given. No interaction analysis approach is perfect for all systems, so any recommended pairing needs to be examined. An evaluation method is proposed in closed-loop with optimal controllers for each loop and whether the pairing is appropriate can be evaluated through testing if the equivalent relative gain is within defined scope. The advantages and effectiveness of proposed interaction analysis approaches and pairing evaluation method are highlighted via several examples of industrial processes.

Simultaneous acceleration of sulfur reduction and oxidation on bifunctional electrocatalytic electrodes for quasi-solid-state Zn–S batteries

The incomplete sulfur reduction and high ZnS re-oxidation energy barrier along with severe side reactions during the battery cycling compromise the practical application of Zn–S electrochemistry. Herein, a bifunctional electrocatalytic sulfur matrix that simultaneously accelerates the sulfur reduction and ZnS oxidation is proposed to realize a highly-efficient Zn–S cell. It is revealed that the N-heteroatom hotspots are more favorable for facilitating the conversion of S to ZnS while the CoO nanocrystal substantially lowers the ZnS activation energy barrier thereby suppressing the formation of disproportionation species(e.g.,SO_(4)^(2-)) and accumulation of inactive ZnS. Accordingly, the Co O anchored on the N-doped carbon-supported sulfur cathode delivers a high Zn^(2+)storage capacity of 1,172 m Ahg^(-1)and outstanding cycling stability with a capacity retention of 71.6% after500 cycles with a high average Coulombic efficiency of 97.8%. Simultaneously, the stable cycling of solid-state Zn–S pouch cells with an energy density of 585 Whkg^(-1)sulfuris also demonstrated. Moreover, the postmortem analysis reveals that the degradation of Zn–S cells is mainly attributed to the limited reversibility of Zn anodes rather than the ZnS decomposition and/or accumulation. The approach to the bidirectional catalysis manipulated the sulfur redox provides a new perspective to realize the theoretical potentials of Zn–S cells.

Twin crystal structured Al-10 wt.% Mg alloy over broad velocity conditions achieved by high thermal gradient directional solidification

Twin crystal structured Al-10 wt.% Mg alloys that were grown over a broad solidification velocity range were prepared and studied for the first time.The high thermal gradient(G)and growth velocity(V)of directional solidification resulted in the dominant solidification of twins:the twinned dendrite trunks at constant high Vs curved in the G direction with large angles in 7 mm diameter crucibles and invaded regular columnar grains because of a distinct kinetics growth advantage.Transitive deceleration experiments were designed to produce twin crystals that evolved with lower values of V(100,10,and 0.5μm/s)and had a structural coarsening trend.Twin cell growth in the absence of arms occurred at a growth velocity of 10μm/s.A coherency loss was observed at a growth velocity of 0.5μm/s with straight coherent twin boundaries turning into curved incoherent boundaries.Linear theoretical analyses were performed to understand the structural evolution of the twins.These results demonstrate the possibility of producing dense and controlled twin crystals in the Al-Mg system under most industrial production conditions;thus,this approach can be a new structural choice for designing Al-Mg-based alloys that have widespread commercial applications.

Cyclophilin A binds to AKT1 and facilitates the tumorigenicity of Epstein-Barr virus by mediating the activation of AKT/mTOR/NF-κB positive feedback loop

The AKT/mTOR and NF-κB signalings are crucial pathways activated in cancers including nasopharyngeal carcinoma(NPC), which is prevalent in southern China and closely related to Epstein-Barr virus(EBV) infection.How these master pathways are persistently activated in EBV-associated NPC remains to be investigated. Here we demonstrated that EBV-encoded latent membrane protein 1(LMP1) promoted cyclophilin A(CYPA) expression through the activation of NF-κB. The depletion of CYPA suppressed cell proliferation and facilitated apoptosis.CYPA was able to bind to AKT1, thus activating AKT/mTOR/NF-κB signaling cascade. Moreover, the use of mTOR inhibitor, rapamycin, subverted the activation of the positive feedback loop, NF-κB/CYPA/AKT/mTOR. It is reasonable that LMP1 expression derived from initial viral infection is enough to assure the constant potentiation of AKT/mTOR and NF-κB signalings. This may partly explain the fact that EBV serves as a tumor-promoting factor with minimal expression of the viral oncoprotein LMP1 in malignancies. Our findings provide new insight into the understanding of causative role of EBV in tumorigenicity during latent infection.