A novel suspension-floating-circulating fluidized combustion technology for coal slurry

A novel suspension-floating-circulating fluidized combustion technology is proposed for burning coal slurry fuel in traditional circulating ftuidized bed boilers （CFBB）. This technology can solve some existing problems in large- capacity CFBB burning coal slurry. The principles of the suspension-floating-circulating fluidized combustion technology were introduced in detail in this paper. A 130 t/h CFBB was retrofitted based on the technology, and the retrofitted system mainly includes a long-distance transport sub-system, a bed-material conveying sub-system with a wind-seal device invented by the authors, a superheater thermoregulation device using a novel temperature regulator, a return loop flu- idization facility, and a pneumatic ash conveying sub-system with sealed pump. The achieved performance of the retro- fitted CFBB shows that the thermal efficiency is 89.83 %, the combustion efficiency is 96.24 %, and the blending proportion of slurry is 94 %.

Characteristics of dynamic strain and strength of frozen silt under long-term dynamic loading

The dynamic swain and strength of frozen silt under long-term dynamic loading are studied based on creep tests. Three groups of tests are performed (Groups I, II, and III). The initial deviator stresses of Groups I and II are same and the dynamic stress ampli- tude of Group II is twice as that of Group I. The minimum value of dynamic stress in Group IlI is near zero and its dynamic stress amplitude is larger than those of Groups I and II. In tests of all three groups there are similar change trends of accttmulative sWain, but with different values. The accumulative swain curves consist of three stages, namely, the initial stage, the steady stage, and the gradual flow stage. In the tests of Groups I and II, during the initial stage with vibration times less than 50 loops the strain ampli- tude decreased with the increase of vibration times and then basically remained constant, fluctuating in a very small range. For the tests of Group III, during the initial and steady stages the sWain amplitude decreased with the increase of vibration times, and then increased rapidly in the gradual flow stage. The dynamic strength of frozen silt decreases and trends to terminal dynamic strength as the vibration times of loading increase.

Status and prospects of frozen soil studies using CT technology

This paper introduces the characteristics of Computed Tomography （CT） technology and reviews its history, current situation, representative achievements, and use of using CT technology on frozen soil study, including auxiliary equipment specially de- signed for frozen soil studies. CT numbers are used to analyze frozen soil internal structure change, defining and exploring dam- age evolution, and use of CT images on observing soil mesostructure. Finally, this paper presents existing problems confronted by using CT in frozen soil studies, possible solutions and challenges, among which, we introduce high quality CT image processing for frozen soils, and relations between CT number change and each component change on frozen soil samples within the region of interest. It is shown that present CT technology is one of the most ideal and effective technology to study frozen soil mesostructure using non-desmactive testing. CT technology will play a key role in the study and development in the field of frozen soil by means of auxiliary equipment and the digital imaging processing.

A model test system with a dynamic load device for geotechnical engineering in cold regions

A model test system with a dynamic load device for geotechnical engineering in cold regions is presented. This system consists of a model test tank, a refrigeration device and temperature controller, a dynamic load device, together with sensors and data loggers for detecting stress, deformation, and temperature changes. The system can accommodate soil blocks up to 3 m in length, 2.5 m in width, and 1 m in height. The lowest temperature provided by the refrigeration device is -20 ℃. The maximum load provided by the dynamic load device is 100 kN and the vibration fi＇equency of the dynamic load can range from 0.1 to 10 Hz. A number of waveforms, such as sine waves, rectangular waves, triangle waves, and other user-defined waves can be generated by the dynamic load device controller.

Expression of MMP-1 in the Scar Tissue of Skin and Oral Mucosa

[Objectives] To investigate expression of MMP-1 in the scar tissue of skin and oral mucosa,and to explore if there is the significance of MMP-1 in the scar of skin and oral mucosa.[Methods]All samples were collected from surgical postoperative soft tissue from Department of Oral and Maxillofacial Surgery and Plastic Surgery in the Affiliated Qingdao Hiser Medical Center of Qingdao University Medical College,including 22 samples of dermal scar tissue,20 samples of normal skin tissue,and 13 samples of oral mucosal scar tissue,and 20 samples of normal oral mucosal tissue. HE staining was used to observe the morphology and collagen arrangement of fibroblasts in the scar tissue,the expression of MMP-1 in different tissue was observed by immunohistchemical staining. [Results] The positive expression rates of MMP-1 in skin scar tissue,oral mucousal scar tissue,normal skin tissue and normal mucosal tissue were 27. 27%,69. 23%,5. 00%,10. 00%. Comparison of positive expression of MMP-1 in skin scar tissue and oral mucosal scar tissue: the positive expression rate of MMP-1 in oral mucosal scar tissue was higher than that of MMP-1 in skin scar tissue,and the statistically significant difference was found between them( P < 0. 05).Comparison of positive expression of MMP-1 in skin scar tissue and normal skin tissue: the positive expression in skin scar tissue was higher than that in normal skin,and the statistically significant difference was found between them( P < 0. 05). Comparison of positive expression of MMP-1 in oral mucosal scar tissue and normal oral mucosal tissue: the positive expression rate of MMP-1 in oral mucosal scar tissue was higher than that in normal mucosal tissue,and the statistically significant difference was found between them( P < 0. 05). Comparison of positive expression of MMP-1 in normal oral mucosal tissue and normal skin tissue: the positive expression rate of MMP-1 in oral mucosal scar tissue was higher than that in normal mucosal tissue,and there was no statistically significant difference between them( P > 0. 05). [Conclusions] The positive expression of MMP-1 was different from that in the scar tissue of the oral mucosa,indicating that MMP-1 might be related to the severity of scar formation in different tissues.

Chlorogenic acid ameliorates chronic stress-induced prefrontal cortex injury through activating the 5-HT/BDNF signaling pathway in rats

The chlorogenic acid(CGA)has a strong neuroprotective ability and cognitive improvement.The purpose of this study was to investigate the effect and mechanism of CGA on chronic restraint stress(CRS)-induced prefrontal cortex(PFC)injury and depression-like behavior.Rats were restrained for 6 h each day to create a CRS paradigm that lasted for 21 days.One hour prior to constraint,CGA(50 mg/kg,100 mg/kg and 150 mg/kg)was intragastrically delivered.The results showed that CGA could reduce serum corticosterone(CORT)levels in rats and 100 mg/kg CGA could prevent CRS-induced depression-like behaviors.Histopathological revealed that 100 mg/kg CGA ameliorated CRS-induced PFC microstructural.Furthermore,5-HT content was also increased.Therefore,100 mg/kg of CGA will be used to further probe the molecular mechanism of regulating 5-HT.Observations using transmission electron microscopy demonstrated that CGA reduced CRS-induced PFC synaptic damage.CGA promotes cAMP-CREB-BDNF signaling pathway and inhibits indoleamine 2,3-dioxygenase(IDO)and serotonin transporter(SRET).Cellular thermal shift assays(CETSA)and molecular docking studies have shown that IDO,SERT and CGA docking have priority potential targets.Together,a protective effect of CGA is seen in rats with CRS-induced PFC by regulating the expression of IDO and SERT and then affecting the effect of 5-HT on the cAMP-CREB-BDNF signaling pathway.