TiAl alloys were produced by investment casting method combined with induction skull melting (ISM) technique. In situ scanning electron microscopy (SEM) was utilized to study the fracture characteristics and crack...TiAl alloys were produced by investment casting method combined with induction skull melting (ISM) technique. In situ scanning electron microscopy (SEM) was utilized to study the fracture characteristics and crack propagation of a notched investment cast TiAl specimens in tension under incremental loading conditions. The whole process of crack initiation, propagation and failure during tensile deformation was observed and characterized. The results show that the fracture mechanism was sensitive to not only the microcracks near the notched area but also lamellar orientation to loading axis. The high tensile stress leads to the new microcracks nucleate along lamellar interfaces of grains with favorable orientation when local stress intensity reaches the toughness threshold of the material. Thus, both plasticity and high tensile stress are required to cause notched TiAl failure.展开更多
The selective laser melting(SLM)processed aluminum alloys have already aroused researchers’attention in aerospace,rail transport and petrochemical engineering due to the comprehensive advantages of low density,good c...The selective laser melting(SLM)processed aluminum alloys have already aroused researchers’attention in aerospace,rail transport and petrochemical engineering due to the comprehensive advantages of low density,good corrosion resistance and high mechanical performance.In this paper,an Al-14.1Mg-0.47Si-0.31Sc-0.17Zr alloy was fabricated via SLM.The characteristics of single track at different process parameters,and the influence of hatch spacing on densification,microstructural features and tensile properties of block specimens were systematically studied.The hatch spacing has an influence on the overlap ratio of single track,and further affects the internal forming quality of printed specimen.At a laser power of 160 W and scanning speed of 400 mm/s,the densification of block specimen increased first and then decreased with the increase of hatch spacing.The nearly full dense specimen(98.7%)with a tensile strength of 452 MPa was fabricated at a hatch spacing of 80μm.Typical characteristics of dimple and cleavage on the tensile fracture of the AlMgSiScZr alloy showed the mixed fracture of ductility and brittleness.展开更多
AIM:To summarize clinical,endoscopic,radiologic and pathologic features of special diaphragm-like strictures found in small bowel,with no patient use of nonsteroidal anti-inflammatory drugs(NSAIDs).METHODS:From Januar...AIM:To summarize clinical,endoscopic,radiologic and pathologic features of special diaphragm-like strictures found in small bowel,with no patient use of nonsteroidal anti-inflammatory drugs(NSAIDs).METHODS:From January 2000 to fecember 2009,5 cases(2 men and 3 women,with a mean age of 41.6 years) were diagnosed as having diaphragm-like strictures of small bowel on imaging,,operation and pathology.All the patients denied the use of NSAIDs.The clinical,endoscopic,radiologic and pathologic findings in these 5 patients were retrospectively reviewedfrom the hospital database.Images of capsule endoscopy(CE) and small bowel follow-through(SBFT) obtained in 3 and 3 patients,respectively,and images of double-balloon enteroscopy and computed tomography enterography(CTE) obtained in all 5 patients were available for review.RESULTS:All patients presented with long-term(2-16 years) symptoms of gastrointestinal bleeding and varying degrees of anemia.There was only one stricture in ?our cases and three lesions in one case,and all the lesions were located in the middle or distal segment of ileum.Circumferential stricture was shown in the small bowel in three cases in the CE image,but the capsule was retained in the small bowel of 2 patients.Routine abdomen computed tomography scan showed no other abnormal results except gallstones in one patient.The lesions were shown as circumferential strictures accompanied by dilated small bowel loops in the small bowel on the images of CTE(in all 5 cases),SBFT(in 2 cases) and double-balloon enteroscopy(in all cases).On microscopy,a chronic inflammatory infiltrate and circumferential diaphragm were found in all lesions.CONCLUSION:fiaphragm-like strictures of small bowel might be a special consequence of unclear damaging insults to the intestine,having similar clinical,endoscopic,radiologic and pathologic features.展开更多
Folic acid conjugated chitosan was prepared by cross-linking reaction with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride(EDC), and then used as a template to prepare folic acid-chitosan(FA-CS) conjugate...Folic acid conjugated chitosan was prepared by cross-linking reaction with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride(EDC), and then used as a template to prepare folic acid-chitosan(FA-CS) conjugated nanoparticles and load mitoxantrone nanoparticles(FA-CSNP/MTX). Drug dissolution testing, CCK-8 method, and confocal microscopy were used to detect their controlled-release capability in different situations and the specific uptake by HONE1 cells. The experimental results show that the nanoparticles have uniform size distribution of 48-58 nm. The highest encapsulation rate of the particles on mitoxantrone hydrochloride(MTX) is(77.5±1.9)%, and the drug loading efficiency is(18.4±0.4)%. The sustained release effect, cell growth inhibition activity and targeting effect of the FA-CS/MTX nanoparticles are good in artificial gastric fluid and intestinal fluid. It is demonstrated that the FA-CSNP system is a potentially useful system for the targeted delivery of anticancer drug MTX.展开更多
A theoretical basis for the optimization of carbon dioxide injection parameters and the development of the drainage system can be provided by identifying the permeability change characteristic of coal and rock after i...A theoretical basis for the optimization of carbon dioxide injection parameters and the development of the drainage system can be provided by identifying the permeability change characteristic of coal and rock after injection of carbon dioxide into the coal seam. Sihe, Yuwu, and Changcun mines were used as research sites. Scanning electron microscopy and permeability instruments were used to measure coal properties such as permeability and surface structure of the coal samples at different pH values of carbon dioxide solution and over different timescales. The results show that the reaction between minerals in coal and carbonate solution exhibit positive and negative aspects of permeability-the dissolution reaction between carbonate minerals in coal and acid solution improves the conductivity of coal whilst, on the other hand, the clay minerals in the coal (mainly including montmorillonite, illite and kaolinite) exhibit expansion as a result of ion exchange with the H~ in acid solution, which has a negative effect on the per- meability of the coal. The permeability of coal samples increased at first and then decreased with immer- sion time, and when the soaking time is 2-3 months the permeability of the coal reached a maximum. In general, for coals with permeabilities less than 0.2 mD or greater than 2 roD, the effect on the permeabil- ity is low: when the permeability of the coal is in the range 0.2-2 mD, the effect on the permeability is highest. Research into permeability change characteristics can provide a theoretical basis for carbon diox- ide injection under different reservoir permeability conditions and subsequent drainage.展开更多
Anthracite in Jincheng is a highly metamorphic coal and its system of fissures and pores is differentfrom that of low and medium ranked coal.In order to discover their characteristics,69 samples were collected from 18...Anthracite in Jincheng is a highly metamorphic coal and its system of fissures and pores is differentfrom that of low and medium ranked coal.In order to discover their characteristics,69 samples were collected from 18 CBM wells in Zhengzhuang in Jincheng and their fissures and pores were observed by a Scanning Electron Microscope(SEM).To the naked eyes and by SEM,the pores in the Jincheng anthracite are seen to have abundant mold pores with isolated,shallow and poor connectivity(diameters between 1~50 μm) and few plant tissue pores,gas pores,and solution pores.Most of the fissures are filled with clay minerals or closed;while open fissures are not often visible in the Jincheng coal(aperture between 3~10 μm).These characteristics are determined by the high rank and high vitrinite content of the coal.The existence of too many mold pores and filled fissures does not allow the migration of methane,hence hydraulic fracture stimulation will be required and is an effective method of adding and connecting fissures to enhance CBM production.展开更多
Stearic acid (67.83℃) and myristic acid (52.32℃) have high melting temperatures that can limit their use as phase change material (PCM) in low temperature solar heating applications such as solar space and greenhous...Stearic acid (67.83℃) and myristic acid (52.32℃) have high melting temperatures that can limit their use as phase change material (PCM) in low temperature solar heating applications such as solar space and greenhouse heating in regard to climatic requirements. However, their melting temperatures can be adjusted to a suitable value by preparing a eutectic mixture of the myristic acid (MA) and the stearic acid (SA). In the present study, the thermal analysis based on differential scanning calorimetry (DSC) technique shows that the mixture of myristic acid (MA) and stearic acid (SA) in the respective composition (by mass) of 64% and 36% forms a eutectic mixture having melting temperature of 44.13℃ and the latent heat of fusion of 182.4J·g-1. The thermal energy storage characteristics of the MA-SA eutectic mixture filled in the annulus of two concentric pipes were also experimentally established. The heat recovery rate and heat charging/discharging fractions were determined with respect to the change in the mass flow rate and the inlet temperature of heat transfer fluid. Based on the results obtained by DSC analysis and by the heat charg- ing/discharging processes of the PCM, it can be concluded that the MA-SA eutectic mixture is a potential material for low temperature thermal energy storage applications in terms of its thermo-physical and thermal characteristics.展开更多
Using optical microscope and scanning electron microscopy (SEM), revealed the content of pyrite and the microscopic or sub-microscopic occurrence features of pyrite in coal of Huainan. The samples of this study are ...Using optical microscope and scanning electron microscopy (SEM), revealed the content of pyrite and the microscopic or sub-microscopic occurrence features of pyrite in coal of Huainan. The samples of this study are from four different mines in Huainan coal field. The results show that, in general, the coal of Huainan is low sulfur coal, but the con- tent of pyrite in Guqiao mine is relatively higher. The occurrence types of pyrite in coal mainly include: strawberry ball pyrites, massive pyrites, tuberculoid pyrite and pyrite filling in cracks or joints. After analysis based on three indicating facies parameters IAA, IS and/R, the reason for the higher level of pyrite component is that the deoxidization of swamp wa- ter is stronger, salinity is greater and the hydrodynamic is bad. The strawberry ball pyrites found in Guqiao mostly formed in the syngenesis stage. The spherical raspberry pyrites symbiotic with clay minerals was formed due to the reaction of H2S with Fe in the grid of silicate crystal.展开更多
Abdominal cocoon,the idiopathic form of sclerosing encapsulating peritonitis,is a rare condition of unknown etiology that results in an intestinal obstruction due to total or partial encapsulation of the small bowel b...Abdominal cocoon,the idiopathic form of sclerosing encapsulating peritonitis,is a rare condition of unknown etiology that results in an intestinal obstruction due to total or partial encapsulation of the small bowel by a f ibrocollagenous membrane.Preoperative diagnosis requires a high index of clinical suspicion.The early clinical features are nonspecif ic,are often not recognized and it is diff icult to make a def inite pre-operative diagnosis.Clinical suspicion may be generated by the recurrent episodes of small intestinal obstruction combined with relevant imaging f indings and lack of other plausible etiologies.The radiological diagnosis of abdominal cocoon may now be conf idently made on computed tomography scan.Surgery is important in the management of this disease.Careful dissection and excision of the thick sac with the release of the small intestine leads to complete recovery in the vast majority of cases.展开更多
Grout plays an important role in the transmission and maintenance of anchoring force,and in the protection of anchorage materials against corrosion.Thus,the hardening characteristics of grout directly affect the ancho...Grout plays an important role in the transmission and maintenance of anchoring force,and in the protection of anchorage materials against corrosion.Thus,the hardening characteristics of grout directly affect the anchoring effectivity and long-term reliability.We have excavated a prestressed anchorage which has been in service for 20 years,and have tested the grout which has worked for that long period under complicated geological conditions through strength tests and have analyzed its mineral composition using scanning electron microscopy(SEM) and X-ray diffraction(XRD).The results show that the mineral composition of the 12.5 m segment differs from other segments,and corresponds with poor coagulation characteristics of the 12.5 m segment grout.Analysis shows that unhydrated tricalcium silicate may be the reason for the localized poor coagulation.展开更多
Theaim of the present work wasto analyze moisture flow and moisture content data for high-temperature drying by usingan advanced image- processing algorithm.Since wood starts to shrink below the fibre saturation point...Theaim of the present work wasto analyze moisture flow and moisture content data for high-temperature drying by usingan advanced image- processing algorithm.Since wood starts to shrink below the fibre saturation point during drying, the size and shape of wood will change. The dry wood image was thoroughly transformed to the shape of the wet wood image prior to calculating the dry weight moisture content. The use of the image- processing algorithm for the dry weight moisture content on density data from the CT-scanning during drying in a controlled high-temperature environment showed that this method is a powerful tool for analyzing the moisture flow inside the wood piece. Furthermore, the new CT-scanner together with the climate chamber gave unique results, as it has not been possible to study high-temperature drying with this method before.展开更多
Objective: The aim of our study was to explore the eikonic characteristic of skeletal metastasis of primary pul- monary carcinoma. Methods: Whole-body bone scans with 99Tcm methylene diphosphonate were performed in ...Objective: The aim of our study was to explore the eikonic characteristic of skeletal metastasis of primary pul- monary carcinoma. Methods: Whole-body bone scans with 99Tcm methylene diphosphonate were performed in 258 patients with pathologically proven pulmonary carcinoma. The rate of skeletal metastasis, distribution of the metastatic lesions and their characteristics were analyzed. Results: Among the total 258 patients, 142 cases developed skeletal metastasis. The overall rate of skeletal metastasis was 55.0%. The metastases located in axial skeleton were 49.6%, appendicular skeleton 36.0%, trunk bones of the axial skeleton 48.4%, and appendicular girdle skeleton 31.4%. Ribs, thoracic vertebrae, ilium and lumbar vertebrae had a higher rate of skeletal metastasis, which were 38.4%, 24.0%, 21.7%, 20.2%, respectively. 1252 le- sions were detected including 406 at the left side of the body, 387 lesions at the middle position and 459 at the right side of the body. There was no significant difference in terms of number of lesions between left side and right side (X2 = 3.3, P = 0.072). 1224 skeletal metastatic foci (97.8%) were presented as strong radioactive, 26 (2.1%) as mixed lesions, and 2 (0.2%) as low radioactive. According to the shape of lesions, there were 810 punctate lesions (71.5%), 159 (14.0%) lump form, 108 (9.5%) strip form and 56 (4.9%) lamellar form. The accumulative skeletal metastasis rate was 28.7% for the patients with one to three lesions. The metastasis rate decreased gradually as the number of metastatic lesions increased. Conclusion: Skeletal metastasis is very common in patients with pulmonary carcinoma. Most skeletal metastases are characterized by strong radio- active and earlier punctate form; they often occur in the trunk bones of axial skeleton or appendicular girdles. The distribution of earlier metastases has not obvious regularity, and advanced skeletal metastases are widely and randomly distributed in the body, which are characterized by often concurrently multiple and polymorphous lesions.展开更多
The aim of this study was to observe the morphological changes of muscle in the process of rigor mortis. The quadriceps of 40 rats at various postmortem intervals were observed under the...The aim of this study was to observe the morphological changes of muscle in the process of rigor mortis. The quadriceps of 40 rats at various postmortem intervals were observed under the scanning electron microscope(SEM) and the light microscope by phosphotungstic acid haematoxylin(PTAH) stain. The results showed that the striations of muscle were blurred within 4 h, but they became apparent from 6 h to 24 h after death. The authors suggest that this phenomenon be associated with the increased resistance of muscle against the postmortal changes. The observations by scanning electron microscopy and light microscopy have revealed that the muscles do contract in the process of rigor mortis because the distance between two Z lines shortens and the I band narrows, compared with those in anaesthetised animals. The basic biochemical process for the formation of rigor mortis is the same as that of muscle contraction except that the former happens postmortem and the latter antemortem.展开更多
Hydration products and morphology characteristics of C3A (tricalcium aluminate)-CaCO3-H2O system were studied by means of XRD, DSC, FTIR spectrum analysis and SEM. The results indicate that, the new phases, i.e., C3...Hydration products and morphology characteristics of C3A (tricalcium aluminate)-CaCO3-H2O system were studied by means of XRD, DSC, FTIR spectrum analysis and SEM. The results indicate that, the new phases, i.e., C3A·0.5CaCO3·0.5Ca(OH)2·11.5H2O and C3A·CaCO3·11H2O are found in this system due to the activity of CaC03; the formation of C4AH13 and C2AH8 is prohibited and the generation of C3AH6 is delayed in the early hydration process. C3A·0.5CaCO3·0.5Ca(OH)2.11.5HEO is not stable and will be totally transferred within 24 h; C3A·CaCO3.11H2O exists stably once formation, and its flake-like crystalline phases in the early hydration transform to long rod shape, and to finally fine-needle at 28 d.展开更多
To reduce greenhouse gas emissions from fossil fuel fired power plants,a range of new combustion technologies are being developed or refined,including oxy-fuel combustion,co-firing biomass with coal and fluidized bed ...To reduce greenhouse gas emissions from fossil fuel fired power plants,a range of new combustion technologies are being developed or refined,including oxy-fuel combustion,co-firing biomass with coal and fluidized bed combustion.Flame characteristics under such combustion conditions are expected to be different from those in normal air fired combustion processes.Quantified flame characteristics such as temperature distribution,oscillation frequency,and ignition volume play an important part in the optimized design and operation of the environmentally friendly power generation systems.However,it is challenging to obtain such flame characteristics particularly through a three-dimensional and non-intrusive means.Various tomography methods have been proposed to visualize and characterize flames,including passive optical tomography,laser based tomography,and electrical tomography.This paper identifies the challenges in flame tomography and reviews existing techniques for the quantitative characterization of flames.Future trends in flame tomography for industrial applications are discussed.展开更多
Oxygen-free copper and pre-metalized graphite were brazed using CuNiSnP braze alloy by high frequency induction heating method. Interracial microstructures and reaction phases were analyzed by scanning electron micros...Oxygen-free copper and pre-metalized graphite were brazed using CuNiSnP braze alloy by high frequency induction heating method. Interracial microstructures and reaction phases were analyzed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The strength and resistance of the joints were tested. It is found that when the brazing parameters are optimized, the structures of the joints are graphite/(Cu,Ni)/Ni(s.s)+NixPy/Cu3P+Cu(s.s) (including Sn)+eutectic structures (Cu3P+Ni3P+Cu(s.s)/Cu (s.s)/Cu). When the temperature increases to 750℃ or the holding time prolongs to 300 s, the eutectie structures disappear and the amount of Cu3P increases. The maximum shear strength of the joints is 5.2 MPa, which fracture at the interface of graphite and metallization. The resistance of the joints is no more than 5 mΩ.展开更多
Adamantiades-Behcet's disease (ABD) is a chronic,relapsing,systemic vasculitis of unknown etiology.It is more prevalent in populations along the ancient Silk Road from Eastern Asia to the Mediterranean Basin,and m...Adamantiades-Behcet's disease (ABD) is a chronic,relapsing,systemic vasculitis of unknown etiology.It is more prevalent in populations along the ancient Silk Road from Eastern Asia to the Mediterranean Basin,and most frequently affects young adults between the second and fourth decades of life.ABD-complicated gastroenteropathy is a significant cause of morbidity and mortality,with abdominal pain as the most common symptom.The ileocecal region is affected predominantly,with ulcerations that may lead to penetration and/or perforation,whereas other parts of the gastrointestinal system including the esophagus and stomach can also be affected.Endoscopy is useful to locate the site and extent of the lesions,and tissue biopsy is often warranted to examine the histopathology that is often suggestive of underlying vasculitis of small veins/venules or,alternatively in some cases,nonspecific inflammation.Bowel wall thickening is the most common finding on computed tomography scan.Treatment is largely empirical since well-controlled studies are difficult to conduct due to the heterogeneity of the disease,and the unpredictable course with exacerbation and remission.Corticosteroids with or without other immunosuppressive drugs,such as cyclophosphamide,azathioprine,sulfasalazine,tumor necrosis factor α antagonist or thalidomide should be applied before surgery,except in emergency.展开更多
Core and cast sections observation and description,and logging,scanning electron microscope and core lab analysis data etc. were applied to the present research of the characteristics and mechanism of low permeability...Core and cast sections observation and description,and logging,scanning electron microscope and core lab analysis data etc. were applied to the present research of the characteristics and mechanism of low permeability beach-bar sandstone reservoir of Es4 in Dongying sag. The results indicated the reservoir has the characteristics of middle-low pores,low-permeability,low compositional and structural maturity,and thin throat. The low-permeability is mainly due to sedimentation (fine particles and argillaceous inter beds) and diagenesis (compaction,cementation,and dissolution). The cementation reduced the physical property of the reservoir mainly by carbonate cementation,quartz autogeny and enragement,and autogeny clay. Clay minerals usually jam the pores by filling holes,close-fitting the wall of hole,bridging,wrapping grains,and separate attaching the pores and so on. The dissolution is insufficient so as not to improve the porosity and permeability of the reservoir obviously. So it is also an important factor of forming low-permeability reservoir.展开更多
AIM: To share our experience of the management and outcomes of patients with pneumatosis cystoides in- testinalis (PCI). METHODS: The charts of seven patients who under- went surgery for PCI between 2001 and 2009 ...AIM: To share our experience of the management and outcomes of patients with pneumatosis cystoides in- testinalis (PCI). METHODS: The charts of seven patients who under- went surgery for PCI between 2001 and 2009 were re- viewed retrospectively. Clinical features, diagnoses and surgical interventions of patients with PCI are discussed. RESULTS: Seven patients with PCI (3 males, 4 fe- males; mean age, 50 ~ 16.1 years; range, 29-74 years) were analyzed. In three of the patients, abdominal pain was the only complaint, whereas additional vomiting and/or constipation occurred in four. Leukocytosis was detected in four patients, whereas it was within normal limits in three. Subdiaphragmatic free air was observed radiologically in four patients but not in three. Six of the patients underwent an applied lapa- rotomy, whereas one underwent an applied explorative laparoscopy. PCI localized to the small intestine only was detected in four patients, whereas it was localized to the small intestine and the colon in three. Three patients underwent a partial small intestine resection and four did not after PCI was diagnosed. Five patients were diagnosed with secondary PCI and two with pri- mary PCI when the surgical findings and medical his- tory were assessed together. Gastric atony developed in one case only, as a complication during a postopera- tive follow-up of 5-14 d. CONCLUSION: Although rare, PCl should be consid- ered in the differential diagnosis of acute abdomen. Diagnostic laparoscopy and preoperative radiological tests, including computed tomography, play an impor- tant role in confirming the diagnosis.展开更多
基金Project(51001040)supported by the National Natural Science Foundation of ChinaProject(200802130014)supported by Specialized Research Fund for the Doctoral Program of Higher Education,China+1 种基金Project(HIT.NSRIF.2010116)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(HITQNJS 2009022)supported by Development Program for Outstanding Young Teachers in Harbin Institute of Technology
文摘TiAl alloys were produced by investment casting method combined with induction skull melting (ISM) technique. In situ scanning electron microscopy (SEM) was utilized to study the fracture characteristics and crack propagation of a notched investment cast TiAl specimens in tension under incremental loading conditions. The whole process of crack initiation, propagation and failure during tensile deformation was observed and characterized. The results show that the fracture mechanism was sensitive to not only the microcracks near the notched area but also lamellar orientation to loading axis. The high tensile stress leads to the new microcracks nucleate along lamellar interfaces of grains with favorable orientation when local stress intensity reaches the toughness threshold of the material. Thus, both plasticity and high tensile stress are required to cause notched TiAl failure.
基金Project(51775481)supported by the National Natural Science Foundation of ChinaProject(E2019203418)supported by the Natural Science Foundation of Hebei Province,China。
文摘The selective laser melting(SLM)processed aluminum alloys have already aroused researchers’attention in aerospace,rail transport and petrochemical engineering due to the comprehensive advantages of low density,good corrosion resistance and high mechanical performance.In this paper,an Al-14.1Mg-0.47Si-0.31Sc-0.17Zr alloy was fabricated via SLM.The characteristics of single track at different process parameters,and the influence of hatch spacing on densification,microstructural features and tensile properties of block specimens were systematically studied.The hatch spacing has an influence on the overlap ratio of single track,and further affects the internal forming quality of printed specimen.At a laser power of 160 W and scanning speed of 400 mm/s,the densification of block specimen increased first and then decreased with the increase of hatch spacing.The nearly full dense specimen(98.7%)with a tensile strength of 452 MPa was fabricated at a hatch spacing of 80μm.Typical characteristics of dimple and cleavage on the tensile fracture of the AlMgSiScZr alloy showed the mixed fracture of ductility and brittleness.
基金Supported by Shanghai Leading Academic Discipline Project,No. S30203Key project in biological medicine of Shang-hai Science and Technology Commission,No. 10411953200
文摘AIM:To summarize clinical,endoscopic,radiologic and pathologic features of special diaphragm-like strictures found in small bowel,with no patient use of nonsteroidal anti-inflammatory drugs(NSAIDs).METHODS:From January 2000 to fecember 2009,5 cases(2 men and 3 women,with a mean age of 41.6 years) were diagnosed as having diaphragm-like strictures of small bowel on imaging,,operation and pathology.All the patients denied the use of NSAIDs.The clinical,endoscopic,radiologic and pathologic findings in these 5 patients were retrospectively reviewedfrom the hospital database.Images of capsule endoscopy(CE) and small bowel follow-through(SBFT) obtained in 3 and 3 patients,respectively,and images of double-balloon enteroscopy and computed tomography enterography(CTE) obtained in all 5 patients were available for review.RESULTS:All patients presented with long-term(2-16 years) symptoms of gastrointestinal bleeding and varying degrees of anemia.There was only one stricture in ?our cases and three lesions in one case,and all the lesions were located in the middle or distal segment of ileum.Circumferential stricture was shown in the small bowel in three cases in the CE image,but the capsule was retained in the small bowel of 2 patients.Routine abdomen computed tomography scan showed no other abnormal results except gallstones in one patient.The lesions were shown as circumferential strictures accompanied by dilated small bowel loops in the small bowel on the images of CTE(in all 5 cases),SBFT(in 2 cases) and double-balloon enteroscopy(in all cases).On microscopy,a chronic inflammatory infiltrate and circumferential diaphragm were found in all lesions.CONCLUSION:fiaphragm-like strictures of small bowel might be a special consequence of unclear damaging insults to the intestine,having similar clinical,endoscopic,radiologic and pathologic features.
基金Projects(31201074,81371013) supported by the National Natural Science Foundation of ChinaProject(2011105102016) supported by the Key Program of Medical Health of Dongguan City,Guangdong Province,ChinaProject(2011108102026) supported by Dongguan Universities Program,China
文摘Folic acid conjugated chitosan was prepared by cross-linking reaction with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride(EDC), and then used as a template to prepare folic acid-chitosan(FA-CS) conjugated nanoparticles and load mitoxantrone nanoparticles(FA-CSNP/MTX). Drug dissolution testing, CCK-8 method, and confocal microscopy were used to detect their controlled-release capability in different situations and the specific uptake by HONE1 cells. The experimental results show that the nanoparticles have uniform size distribution of 48-58 nm. The highest encapsulation rate of the particles on mitoxantrone hydrochloride(MTX) is(77.5±1.9)%, and the drug loading efficiency is(18.4±0.4)%. The sustained release effect, cell growth inhibition activity and targeting effect of the FA-CS/MTX nanoparticles are good in artificial gastric fluid and intestinal fluid. It is demonstrated that the FA-CSNP system is a potentially useful system for the targeted delivery of anticancer drug MTX.
基金the Major Projects of National Science and Technology Project‘‘Development of Coal-Bed Gas Dynamic Evaluation Model and Software System’’support under contract number 2011ZX05034-005 and 2011ZX05042-003Henan Polytechnic University Outstanding Youth Fund under contract number J2013-03
文摘A theoretical basis for the optimization of carbon dioxide injection parameters and the development of the drainage system can be provided by identifying the permeability change characteristic of coal and rock after injection of carbon dioxide into the coal seam. Sihe, Yuwu, and Changcun mines were used as research sites. Scanning electron microscopy and permeability instruments were used to measure coal properties such as permeability and surface structure of the coal samples at different pH values of carbon dioxide solution and over different timescales. The results show that the reaction between minerals in coal and carbonate solution exhibit positive and negative aspects of permeability-the dissolution reaction between carbonate minerals in coal and acid solution improves the conductivity of coal whilst, on the other hand, the clay minerals in the coal (mainly including montmorillonite, illite and kaolinite) exhibit expansion as a result of ion exchange with the H~ in acid solution, which has a negative effect on the per- meability of the coal. The permeability of coal samples increased at first and then decreased with immer- sion time, and when the soaking time is 2-3 months the permeability of the coal reached a maximum. In general, for coals with permeabilities less than 0.2 mD or greater than 2 roD, the effect on the permeabil- ity is low: when the permeability of the coal is in the range 0.2-2 mD, the effect on the permeability is highest. Research into permeability change characteristics can provide a theoretical basis for carbon diox- ide injection under different reservoir permeability conditions and subsequent drainage.
基金supported by the National Basic Research Program of China (No.2006CB202200)
文摘Anthracite in Jincheng is a highly metamorphic coal and its system of fissures and pores is differentfrom that of low and medium ranked coal.In order to discover their characteristics,69 samples were collected from 18 CBM wells in Zhengzhuang in Jincheng and their fissures and pores were observed by a Scanning Electron Microscope(SEM).To the naked eyes and by SEM,the pores in the Jincheng anthracite are seen to have abundant mold pores with isolated,shallow and poor connectivity(diameters between 1~50 μm) and few plant tissue pores,gas pores,and solution pores.Most of the fissures are filled with clay minerals or closed;while open fissures are not often visible in the Jincheng coal(aperture between 3~10 μm).These characteristics are determined by the high rank and high vitrinite content of the coal.The existence of too many mold pores and filled fissures does not allow the migration of methane,hence hydraulic fracture stimulation will be required and is an effective method of adding and connecting fissures to enhance CBM production.
基金Supported by the Research Fund of Gaziosmanpasa University (No.2003/42).
文摘Stearic acid (67.83℃) and myristic acid (52.32℃) have high melting temperatures that can limit their use as phase change material (PCM) in low temperature solar heating applications such as solar space and greenhouse heating in regard to climatic requirements. However, their melting temperatures can be adjusted to a suitable value by preparing a eutectic mixture of the myristic acid (MA) and the stearic acid (SA). In the present study, the thermal analysis based on differential scanning calorimetry (DSC) technique shows that the mixture of myristic acid (MA) and stearic acid (SA) in the respective composition (by mass) of 64% and 36% forms a eutectic mixture having melting temperature of 44.13℃ and the latent heat of fusion of 182.4J·g-1. The thermal energy storage characteristics of the MA-SA eutectic mixture filled in the annulus of two concentric pipes were also experimentally established. The heat recovery rate and heat charging/discharging fractions were determined with respect to the change in the mass flow rate and the inlet temperature of heat transfer fluid. Based on the results obtained by DSC analysis and by the heat charg- ing/discharging processes of the PCM, it can be concluded that the MA-SA eutectic mixture is a potential material for low temperature thermal energy storage applications in terms of its thermo-physical and thermal characteristics.
基金Supported by the National Natural Science Foundation of China(40772092,40972106)
文摘Using optical microscope and scanning electron microscopy (SEM), revealed the content of pyrite and the microscopic or sub-microscopic occurrence features of pyrite in coal of Huainan. The samples of this study are from four different mines in Huainan coal field. The results show that, in general, the coal of Huainan is low sulfur coal, but the con- tent of pyrite in Guqiao mine is relatively higher. The occurrence types of pyrite in coal mainly include: strawberry ball pyrites, massive pyrites, tuberculoid pyrite and pyrite filling in cracks or joints. After analysis based on three indicating facies parameters IAA, IS and/R, the reason for the higher level of pyrite component is that the deoxidization of swamp wa- ter is stronger, salinity is greater and the hydrodynamic is bad. The strawberry ball pyrites found in Guqiao mostly formed in the syngenesis stage. The spherical raspberry pyrites symbiotic with clay minerals was formed due to the reaction of H2S with Fe in the grid of silicate crystal.
文摘Abdominal cocoon,the idiopathic form of sclerosing encapsulating peritonitis,is a rare condition of unknown etiology that results in an intestinal obstruction due to total or partial encapsulation of the small bowel by a f ibrocollagenous membrane.Preoperative diagnosis requires a high index of clinical suspicion.The early clinical features are nonspecif ic,are often not recognized and it is diff icult to make a def inite pre-operative diagnosis.Clinical suspicion may be generated by the recurrent episodes of small intestinal obstruction combined with relevant imaging f indings and lack of other plausible etiologies.The radiological diagnosis of abdominal cocoon may now be conf idently made on computed tomography scan.Surgery is important in the management of this disease.Careful dissection and excision of the thick sac with the release of the small intestine leads to complete recovery in the vast majority of cases.
基金supported by National Key Technology R&D Program during the 11th Five-Year Plan Perio(Grant NO. 2008BAB29B01)State Key Program of National Natural Science of China(Grant NO. 41130745)Research foundation of the State Key Laboratory of Geohazard Prevention & Geoenvironment Protection (Grant NO.SKLGP2010Z008)
文摘Grout plays an important role in the transmission and maintenance of anchoring force,and in the protection of anchorage materials against corrosion.Thus,the hardening characteristics of grout directly affect the anchoring effectivity and long-term reliability.We have excavated a prestressed anchorage which has been in service for 20 years,and have tested the grout which has worked for that long period under complicated geological conditions through strength tests and have analyzed its mineral composition using scanning electron microscopy(SEM) and X-ray diffraction(XRD).The results show that the mineral composition of the 12.5 m segment differs from other segments,and corresponds with poor coagulation characteristics of the 12.5 m segment grout.Analysis shows that unhydrated tricalcium silicate may be the reason for the localized poor coagulation.
文摘Theaim of the present work wasto analyze moisture flow and moisture content data for high-temperature drying by usingan advanced image- processing algorithm.Since wood starts to shrink below the fibre saturation point during drying, the size and shape of wood will change. The dry wood image was thoroughly transformed to the shape of the wet wood image prior to calculating the dry weight moisture content. The use of the image- processing algorithm for the dry weight moisture content on density data from the CT-scanning during drying in a controlled high-temperature environment showed that this method is a powerful tool for analyzing the moisture flow inside the wood piece. Furthermore, the new CT-scanner together with the climate chamber gave unique results, as it has not been possible to study high-temperature drying with this method before.
文摘Objective: The aim of our study was to explore the eikonic characteristic of skeletal metastasis of primary pul- monary carcinoma. Methods: Whole-body bone scans with 99Tcm methylene diphosphonate were performed in 258 patients with pathologically proven pulmonary carcinoma. The rate of skeletal metastasis, distribution of the metastatic lesions and their characteristics were analyzed. Results: Among the total 258 patients, 142 cases developed skeletal metastasis. The overall rate of skeletal metastasis was 55.0%. The metastases located in axial skeleton were 49.6%, appendicular skeleton 36.0%, trunk bones of the axial skeleton 48.4%, and appendicular girdle skeleton 31.4%. Ribs, thoracic vertebrae, ilium and lumbar vertebrae had a higher rate of skeletal metastasis, which were 38.4%, 24.0%, 21.7%, 20.2%, respectively. 1252 le- sions were detected including 406 at the left side of the body, 387 lesions at the middle position and 459 at the right side of the body. There was no significant difference in terms of number of lesions between left side and right side (X2 = 3.3, P = 0.072). 1224 skeletal metastatic foci (97.8%) were presented as strong radioactive, 26 (2.1%) as mixed lesions, and 2 (0.2%) as low radioactive. According to the shape of lesions, there were 810 punctate lesions (71.5%), 159 (14.0%) lump form, 108 (9.5%) strip form and 56 (4.9%) lamellar form. The accumulative skeletal metastasis rate was 28.7% for the patients with one to three lesions. The metastasis rate decreased gradually as the number of metastatic lesions increased. Conclusion: Skeletal metastasis is very common in patients with pulmonary carcinoma. Most skeletal metastases are characterized by strong radio- active and earlier punctate form; they often occur in the trunk bones of axial skeleton or appendicular girdles. The distribution of earlier metastases has not obvious regularity, and advanced skeletal metastases are widely and randomly distributed in the body, which are characterized by often concurrently multiple and polymorphous lesions.
文摘The aim of this study was to observe the morphological changes of muscle in the process of rigor mortis. The quadriceps of 40 rats at various postmortem intervals were observed under the scanning electron microscope(SEM) and the light microscope by phosphotungstic acid haematoxylin(PTAH) stain. The results showed that the striations of muscle were blurred within 4 h, but they became apparent from 6 h to 24 h after death. The authors suggest that this phenomenon be associated with the increased resistance of muscle against the postmortal changes. The observations by scanning electron microscopy and light microscopy have revealed that the muscles do contract in the process of rigor mortis because the distance between two Z lines shortens and the I band narrows, compared with those in anaesthetised animals. The basic biochemical process for the formation of rigor mortis is the same as that of muscle contraction except that the former happens postmortem and the latter antemortem.
基金Project(50678177) supported by by the National Natural Science Foundation of China
文摘Hydration products and morphology characteristics of C3A (tricalcium aluminate)-CaCO3-H2O system were studied by means of XRD, DSC, FTIR spectrum analysis and SEM. The results indicate that, the new phases, i.e., C3A·0.5CaCO3·0.5Ca(OH)2·11.5H2O and C3A·CaCO3·11H2O are found in this system due to the activity of CaC03; the formation of C4AH13 and C2AH8 is prohibited and the generation of C3AH6 is delayed in the early hydration process. C3A·0.5CaCO3·0.5Ca(OH)2.11.5HEO is not stable and will be totally transferred within 24 h; C3A·CaCO3.11H2O exists stably once formation, and its flake-like crystalline phases in the early hydration transform to long rod shape, and to finally fine-needle at 28 d.
基金Supported by the National Natural Science Foundation of China(50736002,61072005)the 1000-Talent-Plan,Changjiang Scholars and Innovative Team Development Plan(IRT0952)partly by Research Councils United Kingdom's Energy Programme(EP/G063214/1)
文摘To reduce greenhouse gas emissions from fossil fuel fired power plants,a range of new combustion technologies are being developed or refined,including oxy-fuel combustion,co-firing biomass with coal and fluidized bed combustion.Flame characteristics under such combustion conditions are expected to be different from those in normal air fired combustion processes.Quantified flame characteristics such as temperature distribution,oscillation frequency,and ignition volume play an important part in the optimized design and operation of the environmentally friendly power generation systems.However,it is challenging to obtain such flame characteristics particularly through a three-dimensional and non-intrusive means.Various tomography methods have been proposed to visualize and characterize flames,including passive optical tomography,laser based tomography,and electrical tomography.This paper identifies the challenges in flame tomography and reviews existing techniques for the quantitative characterization of flames.Future trends in flame tomography for industrial applications are discussed.
基金Project(50705022) supported by the National Natural Science Foundation of ChinaProject supported by the Program for New Century Excellent Talents in University
文摘Oxygen-free copper and pre-metalized graphite were brazed using CuNiSnP braze alloy by high frequency induction heating method. Interracial microstructures and reaction phases were analyzed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The strength and resistance of the joints were tested. It is found that when the brazing parameters are optimized, the structures of the joints are graphite/(Cu,Ni)/Ni(s.s)+NixPy/Cu3P+Cu(s.s) (including Sn)+eutectic structures (Cu3P+Ni3P+Cu(s.s)/Cu (s.s)/Cu). When the temperature increases to 750℃ or the holding time prolongs to 300 s, the eutectie structures disappear and the amount of Cu3P increases. The maximum shear strength of the joints is 5.2 MPa, which fracture at the interface of graphite and metallization. The resistance of the joints is no more than 5 mΩ.
文摘Adamantiades-Behcet's disease (ABD) is a chronic,relapsing,systemic vasculitis of unknown etiology.It is more prevalent in populations along the ancient Silk Road from Eastern Asia to the Mediterranean Basin,and most frequently affects young adults between the second and fourth decades of life.ABD-complicated gastroenteropathy is a significant cause of morbidity and mortality,with abdominal pain as the most common symptom.The ileocecal region is affected predominantly,with ulcerations that may lead to penetration and/or perforation,whereas other parts of the gastrointestinal system including the esophagus and stomach can also be affected.Endoscopy is useful to locate the site and extent of the lesions,and tissue biopsy is often warranted to examine the histopathology that is often suggestive of underlying vasculitis of small veins/venules or,alternatively in some cases,nonspecific inflammation.Bowel wall thickening is the most common finding on computed tomography scan.Treatment is largely empirical since well-controlled studies are difficult to conduct due to the heterogeneity of the disease,and the unpredictable course with exacerbation and remission.Corticosteroids with or without other immunosuppressive drugs,such as cyclophosphamide,azathioprine,sulfasalazine,tumor necrosis factor α antagonist or thalidomide should be applied before surgery,except in emergency.
基金Project P06012 supported by the Key Research Project of SINOPEC
文摘Core and cast sections observation and description,and logging,scanning electron microscope and core lab analysis data etc. were applied to the present research of the characteristics and mechanism of low permeability beach-bar sandstone reservoir of Es4 in Dongying sag. The results indicated the reservoir has the characteristics of middle-low pores,low-permeability,low compositional and structural maturity,and thin throat. The low-permeability is mainly due to sedimentation (fine particles and argillaceous inter beds) and diagenesis (compaction,cementation,and dissolution). The cementation reduced the physical property of the reservoir mainly by carbonate cementation,quartz autogeny and enragement,and autogeny clay. Clay minerals usually jam the pores by filling holes,close-fitting the wall of hole,bridging,wrapping grains,and separate attaching the pores and so on. The dissolution is insufficient so as not to improve the porosity and permeability of the reservoir obviously. So it is also an important factor of forming low-permeability reservoir.
文摘AIM: To share our experience of the management and outcomes of patients with pneumatosis cystoides in- testinalis (PCI). METHODS: The charts of seven patients who under- went surgery for PCI between 2001 and 2009 were re- viewed retrospectively. Clinical features, diagnoses and surgical interventions of patients with PCI are discussed. RESULTS: Seven patients with PCI (3 males, 4 fe- males; mean age, 50 ~ 16.1 years; range, 29-74 years) were analyzed. In three of the patients, abdominal pain was the only complaint, whereas additional vomiting and/or constipation occurred in four. Leukocytosis was detected in four patients, whereas it was within normal limits in three. Subdiaphragmatic free air was observed radiologically in four patients but not in three. Six of the patients underwent an applied lapa- rotomy, whereas one underwent an applied explorative laparoscopy. PCI localized to the small intestine only was detected in four patients, whereas it was localized to the small intestine and the colon in three. Three patients underwent a partial small intestine resection and four did not after PCI was diagnosed. Five patients were diagnosed with secondary PCI and two with pri- mary PCI when the surgical findings and medical his- tory were assessed together. Gastric atony developed in one case only, as a complication during a postopera- tive follow-up of 5-14 d. CONCLUSION: Although rare, PCl should be consid- ered in the differential diagnosis of acute abdomen. Diagnostic laparoscopy and preoperative radiological tests, including computed tomography, play an impor- tant role in confirming the diagnosis.