The retarding effect of protein retarder on phosphorus building gypsum(PBG)and desulfurization building gypsum(DBG)was investigated,and the results show that protein retarder for DBG can effectively prolong the settin...The retarding effect of protein retarder on phosphorus building gypsum(PBG)and desulfurization building gypsum(DBG)was investigated,and the results show that protein retarder for DBG can effectively prolong the setting time and displays a better retarding effect,but for PBG shows a poor retarding effect.Furthermore,the deterioration reason of the retarding effect of protein retarder on PBG was investigated by measuring the pH value and the retarder concentration of the liquid phase from vacuum filtration of PBG slurry at different hydration time,and the measure to improve the retarding effect of protein retarding on PBG was suggested.The pH value of PBG slurry(<5.0)is lower than that of DBG slurry(7.8-8.5).After hydration for 5 min,the concentration of retarder in liquid phase of DBG slurry gradually decreases,but in liquid phase of PBG slurry continually increases,which results in the worse retarding effect of protein retarder on PBG.The liquid phase pH value of PBG slurry can be adjusted higher by sodium silicate,which is beneficial to improvement in the retarding effect of the retarder.By adding 1.0%of sodium silicate,the initial setting time of PBG was efficiently prolonged from 17 to 210 min,but little effect on the absolute dry flexural strength was observed.展开更多
Commercial sterility does not guarantee the sustained stability of ultrahigh temperature(UHT)milk over 6 months shelf life.We explore the microbiota presented in normal(SZ)and quality deteriorated UHT milk(QY and WY)p...Commercial sterility does not guarantee the sustained stability of ultrahigh temperature(UHT)milk over 6 months shelf life.We explore the microbiota presented in normal(SZ)and quality deteriorated UHT milk(QY and WY)products from the same brand.Based on high-throughput sequencing research results,11 phyla and 54 genera were identified as dominant microbiota.Pseudomonas,Streptococcus,and Acinetobacter as core functional microbiota significantly influenced the UHT milk quality properties.Moreover,principal component analysis(PCA)and multivariate analyses were used to examine the quality characteristics,including 11 physicochemical parameters,10 fatty acids,and 2 enzyme activities,in normal and quality deteriorated UHT milk.We found that the abundance of Pseudomonas increased in quality deteriorated milk(WY)and showed a significant positive correlation with heat-resistant protease content.Acinetobacter in quality deteriorated milk(QY)also considerably contributed to the content of heat-resistant lipase,which resulted in spoilage deterioration of UHT milk.展开更多
Objective:To explore the risk factors for the progression of renal function deterioration in patients with diabetic nephropathy(DN).Methods:The clinical data and biochemical indexes of 100 diabetic patients admitted t...Objective:To explore the risk factors for the progression of renal function deterioration in patients with diabetic nephropathy(DN).Methods:The clinical data and biochemical indexes of 100 diabetic patients admitted to our hospital from October 2021 to October 2022 were retrospectively analyzed.The patients were divided into a DN group,which consisted of 55 cases,and a nondiabetic nephropathy group(NDN),which consisted of 45 cases.The urinary microalbumin to creatinine ratio,the clinical data(gender,age,duration of the disease,and BMI),and the biochemical indexes(triglycerides[TG],low-density lipoprotein cholesterol[LDL-C],high-density lipoprotein cholesterol[HDL-C],total cholesterol[TC],glycated hemoglobin A1c[HbA1c],systolic blood pressure[SBP],diastolic blood pressure[DBP])of the two groups were compared.Subsequently,the risk factors related to the progression of renal function deterioration in DN were analyzed through multifactorial logistic regression analysis.Results:No statistically significant difference was observed in the comparison of gender,age,BMI,LDL-C,and DBP between the two groups(P>0.05).The DN group demonstrated a longer disease duration and higher SBP,TC,HDL-C,HbA1c,and TG compared to the NDN group(P<0.05).Through multifactorial logistic regression analysis,it was found that the duration of the disease,the TC,the HDL-C,the HbA1c,the TG,and the SBP were independent risk factors of the deterioration of renal function in DN patients.Conclusion:Other than conventional indicators,TC,HDL-C,HbA1c,TG,and SBP are also crucial indicators in determining the progression of renal function deterioration in DN patients.展开更多
The Sound and the Fury is William Faulkner's greatest work; four narrators tell the story of the deterioration of the Compson family from different perspective, exploring the cause of deterioration indirectly. The...The Sound and the Fury is William Faulkner's greatest work; four narrators tell the story of the deterioration of the Compson family from different perspective, exploring the cause of deterioration indirectly. The novel centers on Caddy's moral decay from different perspective. The thesis analyzes the processing fall of the Compson family through the analysis of three characters, Caddy, Quentin, and Jason. Caddy's deterioration is closely related to her loss of virginity, and her impending wedding causes Quentin to commit suicide who loves her deeply and possessively. However, Jason is heartless who he does not care his family. His tragedy lies in the decay of human nature. The thesis gives the general cause of the downfall of the family and readers will have a general concept of the family's deterioration.展开更多
The English language has been deteriorating because of the modern e-mail and chat room language abbreviations,in corporation of different dialects depending on culture,and the inappropriate use of words as well as inc...The English language has been deteriorating because of the modern e-mail and chat room language abbreviations,in corporation of different dialects depending on culture,and the inappropriate use of words as well as incorrect spelling.If we want to keep English language from deterioration,we should take advantage of the advances in technology and to learn about other cultures dialects,but we should keep the proper written and spoken English in mind.展开更多
Different from oil and gas production,hydrate reservoirs are shallow and unconsolidated,whose mechanical properties deteriorate with hydrate decomposition.Therefore,the formations will undergo significant subsidence d...Different from oil and gas production,hydrate reservoirs are shallow and unconsolidated,whose mechanical properties deteriorate with hydrate decomposition.Therefore,the formations will undergo significant subsidence during depressurization,which will destroy the original force state of the production well.However,existing research on the stability of oil and gas production wells assumes the formation to be stable,and lacks consideration of the force exerted on the hydrate production well by formation subsidence caused by hydrate decomposition during production.To fill this gap,this paper proposes an analytical method for the dynamic evolution of the stability of hydrate production well considering the effects of hydrate decomposition.Based on the mechanical model of the production well,the basis for stability analysis has been proposed.A multi-field coupling model of the force state of the production well considering the effect of hydrate decomposition and formation subsidence is established,and a solver is developed.The analytical approach is verified by its good agreement with the results from the numerical method.A case study found that the decomposition of hydrate will increase the pulling-down force and reduce the supporting force,which is the main reason for the stability deterioration.The higher the initial hydrate saturation,the larger the reservoir thickness,and the lower the production pressure,the worse the stability or even instability.This work can provide a theoretical reference for the stability maintaining of the production well.展开更多
Salt weathering leads to destruction of many valuable cultural heritage monuments and porous building material. The present study aims at providing more laboratory evidence for evaluating the effects of salt precipita...Salt weathering leads to destruction of many valuable cultural heritage monuments and porous building material. The present study aims at providing more laboratory evidence for evaluating the effects of salt precipitation on the deterioration process. In view of this, the remoulded soil specimens were mixed with three kinds of salts(i.e., NaCl, Na_2SO_4 and their mixture) with different salt concentrations, and the specimens were kept in environment cabinet for undergoing different wet-dry cycles. After each cycle, the ultrasound velocity measurements were employed to monitor the deterioration process. For the specimens that have suffered three wet-dry cycles, the mechanical properties(i.e. shear strength and compression strength) were determined to evaluate the degree of deterioration. Furthermore, considering the realistic conservation environment of earthen sites, mechanical stability of these specimens against sediment-carrying wind erosion was conducted in a wind tunnel. These experiments results indicate that the overall average velocities of the specimens after the third cycle are significantly lower than those subjected to only one cycle. Ultrasound velocity, mechanical strength and wind erosion rate decrease when salt content increases. However, the internal friction angle increases firstly, and then decreases with the increase in salt content added to the specimens. Na_2SO_4 contributes most of the surface deterioration, while NaCl plays little role in the deterioration. The damage potential of the salt mixture is less obvious and largely dependent on the crystallisation location.展开更多
To relieve the increasing traffic load, many early built highways need to be widened or reconstructed. The rapid performance detection to existing subgrades is important to their reasonable evaluation and maximized ut...To relieve the increasing traffic load, many early built highways need to be widened or reconstructed. The rapid performance detection to existing subgrades is important to their reasonable evaluation and maximized utilization. Based on five kinds of soils taken from an existing highway in southern China, three commonly detecting methods were used to determine their moisture contents, compaction degrees and resilient moduli. The results showed that the measured moisture contents were greater than the design value, and the compaction degrees decreased sharply compared to the original ones. The moisture and heat exchange produced a decrease in the resilient modulus of plate loading test(PLT) from the standard 60 MPa down to 40 MPa. Afterwards, the portable falling weight deflectometer(PFWD) and dynamic cone penetrometer(DCP) were used to evaluate the subgrade performances. The measured PFWD moduli and the DCP penetration rates were correlated with the resilient moduli of PLT, deflections of the Beckman beam test, compaction degrees and moisture contents. The correlation analysis indicates that both of two methods are suitable in rapid detecting subgrade performances, but PFWD method is more recommended for it has higher accuracy and efficiency.展开更多
Excessive rainfall provides a favorable condition for field mold infection of plants, which triggers field mold(FM) stress. If FM stress occurs during the late maturation stage of soybean seed, it negatively affects s...Excessive rainfall provides a favorable condition for field mold infection of plants, which triggers field mold(FM) stress. If FM stress occurs during the late maturation stage of soybean seed, it negatively affects seed yield and quality. To investigate the responses of soybean seed against FM stress and identify the underlying biochemical pathways involved, a greenhouse was equipped with an artificial rain producing system to allow the induction of mold growth on soybean seed. The induced quality changes and stress responses were revealed on the levels of both transcriptome and metabolome. The results showed that soybean seeds produced under FM stress conditions had an abnormal and inferior appearance, and also contained less storage reserves, such as protein and polysaccharide. Transcriptional analysis demonstrated that genes involved in amino acid metabolism, glycolysis, tricarboxylic acid, β-oxidation of fatty acids, and isoflavone biosynthesis were induced by FM stress. These results were supported by a multiple metabolic analysis which exhibited increases in the concentrations of a variety of amino acids, sugars, organic acids, and isoflavones, as well as reductions of several fatty acids. Reprogramming of these metabolic pathways mobilized and consumed stored protein, sugar and fatty acid reserves in the soybean seed in order to meet the energy and substrate demand on the defense system, but led to deterioration of seed quality. In general, FM stress induced catabolism of storage reserves and diminished the quality of soybean seed in the field. This study provides a more profound insight into seed deterioration caused by FM stress.展开更多
Under the periodic rise and fall of the water level in the Three Gorges Reservoir in China,the rock mass in the ebb and flow zone of the slope is always in a state of a dry-wet cycle.In order to explore the influence ...Under the periodic rise and fall of the water level in the Three Gorges Reservoir in China,the rock mass in the ebb and flow zone of the slope is always in a state of a dry-wet cycle.In order to explore the influence of dry-wet cycle on mechanical properties of jointed sandstone,the triaxial and uniaxial compression tests of dry-wet cycle of jointed sandstone were carried out.For the experiment,four groups of samples with different numbers of joints were set up,and the jointed rock samples were subjected to 20 dry-wet cycles.Using both the triaxial compression test and the Mohr-Coulomb(M-C)rock fracture criterion,the strength envelope of the sandstone samples was fitted,and their strength degradation was further analyzed and studied.The results show that:(1)The peak intensity and elastic modulus of the sandstone samples decrease with increased number of dry-wet cycles.(2)The total deterioration of mechanical properties of intact rock samples is bigger than that of jointed sandstone samples as the number of dry-wet cycles increases.(3)With the increase of confining pressure,the peak intensity of intact sandstone samples increases much more than that of jointed sandstone samples,which indicates that joints and their numbers have obvious influence.(4)Joints and their numbers play an important role in guiding the damage effects of sandstone samples,which weaken the damage caused by dry-wet cycles.Therefore,the envelope of the M-C strength criterion of intact sandstone samples moves more than that of jointed sandstone samples.展开更多
The shear strength deterioration of bedding planes between different rock types induced by cyclic loading is vital to reasonably evaluate the stability of soft and hard interbedded bedding rock slopes under earthquake...The shear strength deterioration of bedding planes between different rock types induced by cyclic loading is vital to reasonably evaluate the stability of soft and hard interbedded bedding rock slopes under earthquake;however,rare work has been devoted to this subject due to lack of attention.In this study,experimental investigations on shear strength weakening of discontinuities with different joint wall material(DDJM)under cyclic loading were conducted by taking the interface between siltstone and mudstone in the Shaba slope of Yunnan Province,China as research objects.A total of 99 pairs of similar material samples of DDJM(81 pairs)and discontinuities with identical joint wall material(DIJM)(18 pairs)were fabricated by inserting plates,engraved with typical surface morphology obtained by performing three-dimensional laser scanning on natural DDJMs sampled from field,into mold boxes.Cyclic shear tests were conducted on these samples to study their shear strength changes with the cyclic number considering the effects of normal stress,joint surface morphology,shear displacement amplitude and shear rate.The results indicate that the shear stress vs.shear displacement curves under each shear cycle and the peak shear strength vs.cyclic number curves of the studied DDJMs are between those of DIJMs with siltstone and mudstone,while closer to those of DIJMs with mudstone.The peak shear strengths of DDJMs exhibit an initial rapid decline followed by a gradual decrease with the cyclic number and the decrease rate varies from 6%to 55.9%for samples with varied surface morphology under different testing conditions.The normal stress,joint surface morphology,shear displacement amplitude and shear rate collectively influence the shear strength deterioration of DDJM under cyclic shear loading,with the degree of influence being greater for larger normal stress,rougher surface morphology,larger shear displacement amplitude and faster shear rate.展开更多
Seed deterioration is an irresistible physiological phenomenon. The aim to study seed deterioration is to see if seed deterioration can be retarded artificially and the higher seed vigor of fine varieties be maintaine...Seed deterioration is an irresistible physiological phenomenon. The aim to study seed deterioration is to see if seed deterioration can be retarded artificially and the higher seed vigor of fine varieties be maintained. The change of seed deterioration occurs in almost every system, and affects many kinds of enzyme and almost all organcllc, as a result, the seed loses its vigor. The reason of seed deterioration and the lost of seed vigor are mainly studied and discussed in this paper. According to the external and internal two kinds of theory advanced by E. H. Roberts, Much deep discussions are made from the view of biochemistry.展开更多
In the present paper, we have investigated the tribological properties and microstructure of the used gear oil theoretically and experimentally. The deterioration process of the in-service gear lubricant oils was also...In the present paper, we have investigated the tribological properties and microstructure of the used gear oil theoretically and experimentally. The deterioration process of the in-service gear lubricant oils was also discussed. The viscosity and microstructure of oils running different mileages were analyzed by viscometer and Fourier Transform Infrared Spectroscopy (FTIR), respectively. In addition, the friction and wear behaviors of the friction pair of the GCr15 steel ball and disc were investigated using a ball on disc tribometer under different mileages’ gear oils lubrication conditions. These techniques give reproducible and reliable data with which to evaluate the severity of deterioration process of oils. The objective of this work is to understand the deterioration process of gear oil and analyze the influence of deterioration on the performance and microstructure of lubricant oils used in gear box. Possible explanations of deterioration process as well as its influence on friction and wear behaviors are also discussed. The results reveals the tribological properties of used oils depended on strongly the microstructure and its deterioration process of oil.展开更多
Our research focused on the analy sis of concrete deterioration mechan ism under the coup ling effects of flexural load,cy clic wetting and dry ing, and sulfate. The relative dy namic modulus of elasticity of a corrod...Our research focused on the analy sis of concrete deterioration mechan ism under the coup ling effects of flexural load,cy clic wetting and dry ing, and sulfate. The relative dy namic modulus of elasticity of a corroded concrete samp le was tested, and scannin g electron microscop e was used to observe the microstructure of concrete under the coup ling effects of flexural load,cy clic wetting and dry ing, and sulf ate. Results manif ested that flexur al load and cy clic wetting and dry ing durin g the concrete service chan ged the corrosion p rocess of the sulfate mediu m in con crete and enh anced the deterioration of con crete p erforman ce.Furthermore, the influencin g p atterns of strength grade of concr ete, mass concentration of sulfate solution, and mineral admixtures on the degree of concrete deterioration were identified.展开更多
The heritage buildings at the west bank of Luxor were affected by expansive Esna shale differentially from site to others. The role of expansive Esna shale was evaluated by using X-ray diffraction spectra (particle si...The heritage buildings at the west bank of Luxor were affected by expansive Esna shale differentially from site to others. The role of expansive Esna shale was evaluated by using X-ray diffraction spectra (particle size, strain), X-ray fluorescence, basic soil properties test, swelling test, soil classification, and unconfined compression test. Three different samples were examined to determine the expansive role in the deterioration of heritage sites. The expansive is high, according to: (a) Soil classification based on plasticity index, (b) Classification chart based on the liquid limit and plastic index, (c) Classification chart based on clay content and activity, (d) Soil classification, and (e) Swelling pressure which determines the safety factor. In addition, expansive classification assesses that Esna shale Formation is one of environmental hazards characterized by damage role near Nile flood and irrigation area and characterized by deterioration role in heritage sites far from Nile flood and irrigation area. This paper refers to evaluation as a main process of integrated conservation approach.展开更多
By studying the phenomena of limestone built from the White Monastery in Sohag Governorate damage where this study discusses the results of the analyzes and the study’s petrographic limestone, we can study and discus...By studying the phenomena of limestone built from the White Monastery in Sohag Governorate damage where this study discusses the results of the analyzes and the study’s petrographic limestone, we can study and discuss what has been done to analyze X-ray diffraction and X-ray flourecence, and by scanning electron microscope in order to determine the cause of the damage and to study the properties of limestone to choose the most appropriate treatment methods especially the internal structure affected by the environmental conditions surrounding the private and increasing ground water levels along with the use of the most appropriate ways to buffer water to conserve the limestone of the environmental factors that damage it.展开更多
The Roman Period temple of Isis at Shenhur was built and enhanced amid the rule of Augustus (30 BCE-14 CE) through that of Trajan (98-117 CE). It was built of two sorts of local limestone and decorated with reliefs. E...The Roman Period temple of Isis at Shenhur was built and enhanced amid the rule of Augustus (30 BCE-14 CE) through that of Trajan (98-117 CE). It was built of two sorts of local limestone and decorated with reliefs. Examination of conservation state uncovered that it was collapsed and only partly preserved and it disposed of some still buried rooms. The temple is exposed to different deteriorations processes created by internal and external stresses because of the mineral composition of the building materials, atmosphere variables, salts crystallization and groundwater. In this study, the deterioration problems of the wall reliefs were examined for the aim of its conservation. For this purpose, the chemical, physical and structural characterization were performed by means of X-Ray Diffraction (XRD) and observation of thin section by transmitted light optical microscopy (LOM), polarized microscope, Scanning Electron Microscope (SEM) attached with EDX and thermogravimetric (DTA & TGA). Additionally, microbiological study and chemical analyses of ground water were carried out. Results demonstrated that the deterioration of Shenhur was because of the forceful activity of the environment agents and soluble salts such as chlorides and sulphates. These results and information allowed that the identification of the types of salts and deterioration features might be used in the future for conservation purposes.展开更多
Aswan is famous for Granite rock art reliefs. Seti I granite rock art relief is one of the most important of them. This granite rock art relief suffers from weakness, fragility, fragmentation and peeling because of ma...Aswan is famous for Granite rock art reliefs. Seti I granite rock art relief is one of the most important of them. This granite rock art relief suffers from weakness, fragility, fragmentation and peeling because of many deterioration factors, especially environmental deterioration impacts, such as desert climate with high temperature, residential areas with cafes and shops, and air pollution from exhausts and Kima factory. They can cause chemical weathering. Scientific investigations and analyzes were conducted on this rock art relief such as USB microscope, Polarized (PM) investigation, scanning electron microscope investigation with X-ray energy dispersal unit (EDX) and X-ray diffraction (XRD) analysis to determine the nature and the degree of deterioration, as well as the chemical and mineral composition of the rock and its natural, chemical and mechanical properties. A treatment suggestion to this granite rock art relief has been done.展开更多
El-Amir Muhammad’s minaret in Akhmim, Sohag, Egypt, is constructed of limestone and has been exposed to many factors of damage as a result of the high levels of ground water. Limestone is strongly affected by ground ...El-Amir Muhammad’s minaret in Akhmim, Sohag, Egypt, is constructed of limestone and has been exposed to many factors of damage as a result of the high levels of ground water. Limestone is strongly affected by ground water, especially when being impure. The current work discusses the results of analytical techniques including chemical testing to determine the types of soluble salts through optical microscopy, electronic scanning electron microscope with an X-ray energy dispersion system (ESEM) to study and determine the causes of rapid degradation. Microbial weathering phenomena toward limestone were also studied. Different bacteria and fungi were isolated from outdoors and indoors of air and limestone of the building of which Bacillus cereus OK447647, B. subtilis OK447648, Serratia marcescens OK447650, Pseudomonasoryzihabitans OK447649, Aspergillus flavus, A. niger, Penicillium chrysogenum and Cladosporium cladosporoids were the most representative. B. cereus OK447647 and B. subtilis OK447648 have shown ability for calcium carbonate dissolving. The minimal inhibitory concentrations (MICs) of sodium azide were investigated against the growth of microbial isolates. Sodium azide at 100 ppm was found to be the best treatment for bacterial isolates although it had no significant effect against fungi.展开更多
文摘The retarding effect of protein retarder on phosphorus building gypsum(PBG)and desulfurization building gypsum(DBG)was investigated,and the results show that protein retarder for DBG can effectively prolong the setting time and displays a better retarding effect,but for PBG shows a poor retarding effect.Furthermore,the deterioration reason of the retarding effect of protein retarder on PBG was investigated by measuring the pH value and the retarder concentration of the liquid phase from vacuum filtration of PBG slurry at different hydration time,and the measure to improve the retarding effect of protein retarding on PBG was suggested.The pH value of PBG slurry(<5.0)is lower than that of DBG slurry(7.8-8.5).After hydration for 5 min,the concentration of retarder in liquid phase of DBG slurry gradually decreases,but in liquid phase of PBG slurry continually increases,which results in the worse retarding effect of protein retarder on PBG.The liquid phase pH value of PBG slurry can be adjusted higher by sodium silicate,which is beneficial to improvement in the retarding effect of the retarder.By adding 1.0%of sodium silicate,the initial setting time of PBG was efficiently prolonged from 17 to 210 min,but little effect on the absolute dry flexural strength was observed.
基金supported by the National Natural Science Foundation of China(32172279,31871831)Shenyang Science and Technology Innovation Platform Project(21-103-0-14,21-104-0-28)Shenyang City Youth Science and Technology Innovation Leading Talent Project(RC200495).
文摘Commercial sterility does not guarantee the sustained stability of ultrahigh temperature(UHT)milk over 6 months shelf life.We explore the microbiota presented in normal(SZ)and quality deteriorated UHT milk(QY and WY)products from the same brand.Based on high-throughput sequencing research results,11 phyla and 54 genera were identified as dominant microbiota.Pseudomonas,Streptococcus,and Acinetobacter as core functional microbiota significantly influenced the UHT milk quality properties.Moreover,principal component analysis(PCA)and multivariate analyses were used to examine the quality characteristics,including 11 physicochemical parameters,10 fatty acids,and 2 enzyme activities,in normal and quality deteriorated UHT milk.We found that the abundance of Pseudomonas increased in quality deteriorated milk(WY)and showed a significant positive correlation with heat-resistant protease content.Acinetobacter in quality deteriorated milk(QY)also considerably contributed to the content of heat-resistant lipase,which resulted in spoilage deterioration of UHT milk.
文摘Objective:To explore the risk factors for the progression of renal function deterioration in patients with diabetic nephropathy(DN).Methods:The clinical data and biochemical indexes of 100 diabetic patients admitted to our hospital from October 2021 to October 2022 were retrospectively analyzed.The patients were divided into a DN group,which consisted of 55 cases,and a nondiabetic nephropathy group(NDN),which consisted of 45 cases.The urinary microalbumin to creatinine ratio,the clinical data(gender,age,duration of the disease,and BMI),and the biochemical indexes(triglycerides[TG],low-density lipoprotein cholesterol[LDL-C],high-density lipoprotein cholesterol[HDL-C],total cholesterol[TC],glycated hemoglobin A1c[HbA1c],systolic blood pressure[SBP],diastolic blood pressure[DBP])of the two groups were compared.Subsequently,the risk factors related to the progression of renal function deterioration in DN were analyzed through multifactorial logistic regression analysis.Results:No statistically significant difference was observed in the comparison of gender,age,BMI,LDL-C,and DBP between the two groups(P>0.05).The DN group demonstrated a longer disease duration and higher SBP,TC,HDL-C,HbA1c,and TG compared to the NDN group(P<0.05).Through multifactorial logistic regression analysis,it was found that the duration of the disease,the TC,the HDL-C,the HbA1c,the TG,and the SBP were independent risk factors of the deterioration of renal function in DN patients.Conclusion:Other than conventional indicators,TC,HDL-C,HbA1c,TG,and SBP are also crucial indicators in determining the progression of renal function deterioration in DN patients.
文摘The Sound and the Fury is William Faulkner's greatest work; four narrators tell the story of the deterioration of the Compson family from different perspective, exploring the cause of deterioration indirectly. The novel centers on Caddy's moral decay from different perspective. The thesis analyzes the processing fall of the Compson family through the analysis of three characters, Caddy, Quentin, and Jason. Caddy's deterioration is closely related to her loss of virginity, and her impending wedding causes Quentin to commit suicide who loves her deeply and possessively. However, Jason is heartless who he does not care his family. His tragedy lies in the decay of human nature. The thesis gives the general cause of the downfall of the family and readers will have a general concept of the family's deterioration.
文摘The English language has been deteriorating because of the modern e-mail and chat room language abbreviations,in corporation of different dialects depending on culture,and the inappropriate use of words as well as incorrect spelling.If we want to keep English language from deterioration,we should take advantage of the advances in technology and to learn about other cultures dialects,but we should keep the proper written and spoken English in mind.
基金financially supported by the National Natural Science Foundation of China(Grant No.51890914)。
文摘Different from oil and gas production,hydrate reservoirs are shallow and unconsolidated,whose mechanical properties deteriorate with hydrate decomposition.Therefore,the formations will undergo significant subsidence during depressurization,which will destroy the original force state of the production well.However,existing research on the stability of oil and gas production wells assumes the formation to be stable,and lacks consideration of the force exerted on the hydrate production well by formation subsidence caused by hydrate decomposition during production.To fill this gap,this paper proposes an analytical method for the dynamic evolution of the stability of hydrate production well considering the effects of hydrate decomposition.Based on the mechanical model of the production well,the basis for stability analysis has been proposed.A multi-field coupling model of the force state of the production well considering the effect of hydrate decomposition and formation subsidence is established,and a solver is developed.The analytical approach is verified by its good agreement with the results from the numerical method.A case study found that the decomposition of hydrate will increase the pulling-down force and reduce the supporting force,which is the main reason for the stability deterioration.The higher the initial hydrate saturation,the larger the reservoir thickness,and the lower the production pressure,the worse the stability or even instability.This work can provide a theoretical reference for the stability maintaining of the production well.
基金Projects(2010BAK67B16,2013BAK08B11,2014BAK16B02)supported by the National Science and Technology Support Program of China during the 12th Five-year Plan Period
文摘Salt weathering leads to destruction of many valuable cultural heritage monuments and porous building material. The present study aims at providing more laboratory evidence for evaluating the effects of salt precipitation on the deterioration process. In view of this, the remoulded soil specimens were mixed with three kinds of salts(i.e., NaCl, Na_2SO_4 and their mixture) with different salt concentrations, and the specimens were kept in environment cabinet for undergoing different wet-dry cycles. After each cycle, the ultrasound velocity measurements were employed to monitor the deterioration process. For the specimens that have suffered three wet-dry cycles, the mechanical properties(i.e. shear strength and compression strength) were determined to evaluate the degree of deterioration. Furthermore, considering the realistic conservation environment of earthen sites, mechanical stability of these specimens against sediment-carrying wind erosion was conducted in a wind tunnel. These experiments results indicate that the overall average velocities of the specimens after the third cycle are significantly lower than those subjected to only one cycle. Ultrasound velocity, mechanical strength and wind erosion rate decrease when salt content increases. However, the internal friction angle increases firstly, and then decreases with the increase in salt content added to the specimens. Na_2SO_4 contributes most of the surface deterioration, while NaCl plays little role in the deterioration. The damage potential of the salt mixture is less obvious and largely dependent on the crystallisation location.
基金Project(2017YFC0805307) supported by the National Key Research and Development Program of ChinaProjects(51878078, 51927814, 51911530215) supported by the National Natural Science Foundation of China+4 种基金Project(2018-025) supported by the Training Program for High-level Technical Personnel in Transportation Industry, ChinaProject (2018JJ1026) supported by the Excellent Youth Foundation of Natural Science Foundation of Hunan Province, ChinaProject(17A008) supported by the Key Project of Education Department of Hunan Province, ChinaProjects(kfj150103, kfj170104) supported by the Open Research Fund of State Engineering Laboratory of Highway Maintenance Technology, Changsha University of Science & Technology, ChinaProject(CX20190644) supported by the Postgraduate Scientific Research Innovation Project of Hunan Province, China。
文摘To relieve the increasing traffic load, many early built highways need to be widened or reconstructed. The rapid performance detection to existing subgrades is important to their reasonable evaluation and maximized utilization. Based on five kinds of soils taken from an existing highway in southern China, three commonly detecting methods were used to determine their moisture contents, compaction degrees and resilient moduli. The results showed that the measured moisture contents were greater than the design value, and the compaction degrees decreased sharply compared to the original ones. The moisture and heat exchange produced a decrease in the resilient modulus of plate loading test(PLT) from the standard 60 MPa down to 40 MPa. Afterwards, the portable falling weight deflectometer(PFWD) and dynamic cone penetrometer(DCP) were used to evaluate the subgrade performances. The measured PFWD moduli and the DCP penetration rates were correlated with the resilient moduli of PLT, deflections of the Beckman beam test, compaction degrees and moisture contents. The correlation analysis indicates that both of two methods are suitable in rapid detecting subgrade performances, but PFWD method is more recommended for it has higher accuracy and efficiency.
基金supported by the National Natural Science Foundation of China(31971853)the National Key Research and Development Program of China(2016YFD0300209)the Science Fund for Distinguished Young Scholars of Sichuan,China(20JCQN0155)。
文摘Excessive rainfall provides a favorable condition for field mold infection of plants, which triggers field mold(FM) stress. If FM stress occurs during the late maturation stage of soybean seed, it negatively affects seed yield and quality. To investigate the responses of soybean seed against FM stress and identify the underlying biochemical pathways involved, a greenhouse was equipped with an artificial rain producing system to allow the induction of mold growth on soybean seed. The induced quality changes and stress responses were revealed on the levels of both transcriptome and metabolome. The results showed that soybean seeds produced under FM stress conditions had an abnormal and inferior appearance, and also contained less storage reserves, such as protein and polysaccharide. Transcriptional analysis demonstrated that genes involved in amino acid metabolism, glycolysis, tricarboxylic acid, β-oxidation of fatty acids, and isoflavone biosynthesis were induced by FM stress. These results were supported by a multiple metabolic analysis which exhibited increases in the concentrations of a variety of amino acids, sugars, organic acids, and isoflavones, as well as reductions of several fatty acids. Reprogramming of these metabolic pathways mobilized and consumed stored protein, sugar and fatty acid reserves in the soybean seed in order to meet the energy and substrate demand on the defense system, but led to deterioration of seed quality. In general, FM stress induced catabolism of storage reserves and diminished the quality of soybean seed in the field. This study provides a more profound insight into seed deterioration caused by FM stress.
基金financially supported by the National Natural Science Foundation of China(No.5197806)Graduate Research and Innovation Foundation of Chongqing,China(No.CYS21027)。
文摘Under the periodic rise and fall of the water level in the Three Gorges Reservoir in China,the rock mass in the ebb and flow zone of the slope is always in a state of a dry-wet cycle.In order to explore the influence of dry-wet cycle on mechanical properties of jointed sandstone,the triaxial and uniaxial compression tests of dry-wet cycle of jointed sandstone were carried out.For the experiment,four groups of samples with different numbers of joints were set up,and the jointed rock samples were subjected to 20 dry-wet cycles.Using both the triaxial compression test and the Mohr-Coulomb(M-C)rock fracture criterion,the strength envelope of the sandstone samples was fitted,and their strength degradation was further analyzed and studied.The results show that:(1)The peak intensity and elastic modulus of the sandstone samples decrease with increased number of dry-wet cycles.(2)The total deterioration of mechanical properties of intact rock samples is bigger than that of jointed sandstone samples as the number of dry-wet cycles increases.(3)With the increase of confining pressure,the peak intensity of intact sandstone samples increases much more than that of jointed sandstone samples,which indicates that joints and their numbers have obvious influence.(4)Joints and their numbers play an important role in guiding the damage effects of sandstone samples,which weaken the damage caused by dry-wet cycles.Therefore,the envelope of the M-C strength criterion of intact sandstone samples moves more than that of jointed sandstone samples.
基金supported by the National Natural Science Foundation of China(Grant Nos.42377182,52079133 and 41931295).
文摘The shear strength deterioration of bedding planes between different rock types induced by cyclic loading is vital to reasonably evaluate the stability of soft and hard interbedded bedding rock slopes under earthquake;however,rare work has been devoted to this subject due to lack of attention.In this study,experimental investigations on shear strength weakening of discontinuities with different joint wall material(DDJM)under cyclic loading were conducted by taking the interface between siltstone and mudstone in the Shaba slope of Yunnan Province,China as research objects.A total of 99 pairs of similar material samples of DDJM(81 pairs)and discontinuities with identical joint wall material(DIJM)(18 pairs)were fabricated by inserting plates,engraved with typical surface morphology obtained by performing three-dimensional laser scanning on natural DDJMs sampled from field,into mold boxes.Cyclic shear tests were conducted on these samples to study their shear strength changes with the cyclic number considering the effects of normal stress,joint surface morphology,shear displacement amplitude and shear rate.The results indicate that the shear stress vs.shear displacement curves under each shear cycle and the peak shear strength vs.cyclic number curves of the studied DDJMs are between those of DIJMs with siltstone and mudstone,while closer to those of DIJMs with mudstone.The peak shear strengths of DDJMs exhibit an initial rapid decline followed by a gradual decrease with the cyclic number and the decrease rate varies from 6%to 55.9%for samples with varied surface morphology under different testing conditions.The normal stress,joint surface morphology,shear displacement amplitude and shear rate collectively influence the shear strength deterioration of DDJM under cyclic shear loading,with the degree of influence being greater for larger normal stress,rougher surface morphology,larger shear displacement amplitude and faster shear rate.
基金Supported by the State Key Program of National Natural Science of China(70931001), the Science Fund for Creative Research Group of National Natural Science Foundation of China (60821063), National Science and Technology Support Plan of China (2006BAH02A09), the Science Fund for Youth Scholars of Ministry of Education of China (200801451053), and the Research Committee and the Department of Industrial and Systems Engineering of Hong Kong Polytechnic University Research Grants (G-U323)
文摘Seed deterioration is an irresistible physiological phenomenon. The aim to study seed deterioration is to see if seed deterioration can be retarded artificially and the higher seed vigor of fine varieties be maintained. The change of seed deterioration occurs in almost every system, and affects many kinds of enzyme and almost all organcllc, as a result, the seed loses its vigor. The reason of seed deterioration and the lost of seed vigor are mainly studied and discussed in this paper. According to the external and internal two kinds of theory advanced by E. H. Roberts, Much deep discussions are made from the view of biochemistry.
文摘In the present paper, we have investigated the tribological properties and microstructure of the used gear oil theoretically and experimentally. The deterioration process of the in-service gear lubricant oils was also discussed. The viscosity and microstructure of oils running different mileages were analyzed by viscometer and Fourier Transform Infrared Spectroscopy (FTIR), respectively. In addition, the friction and wear behaviors of the friction pair of the GCr15 steel ball and disc were investigated using a ball on disc tribometer under different mileages’ gear oils lubrication conditions. These techniques give reproducible and reliable data with which to evaluate the severity of deterioration process of oils. The objective of this work is to understand the deterioration process of gear oil and analyze the influence of deterioration on the performance and microstructure of lubricant oils used in gear box. Possible explanations of deterioration process as well as its influence on friction and wear behaviors are also discussed. The results reveals the tribological properties of used oils depended on strongly the microstructure and its deterioration process of oil.
基金Funded by Fujian Education Department(Nos.JA11329 and JA12412)Quanzhou(Fujian)Techno logy Research and Development Program(Nos.2013Z158,2013Z47,and 2010G7)
文摘Our research focused on the analy sis of concrete deterioration mechan ism under the coup ling effects of flexural load,cy clic wetting and dry ing, and sulfate. The relative dy namic modulus of elasticity of a corroded concrete samp le was tested, and scannin g electron microscop e was used to observe the microstructure of concrete under the coup ling effects of flexural load,cy clic wetting and dry ing, and sulf ate. Results manif ested that flexur al load and cy clic wetting and dry ing durin g the concrete service chan ged the corrosion p rocess of the sulfate mediu m in con crete and enh anced the deterioration of con crete p erforman ce.Furthermore, the influencin g p atterns of strength grade of concr ete, mass concentration of sulfate solution, and mineral admixtures on the degree of concrete deterioration were identified.
文摘The heritage buildings at the west bank of Luxor were affected by expansive Esna shale differentially from site to others. The role of expansive Esna shale was evaluated by using X-ray diffraction spectra (particle size, strain), X-ray fluorescence, basic soil properties test, swelling test, soil classification, and unconfined compression test. Three different samples were examined to determine the expansive role in the deterioration of heritage sites. The expansive is high, according to: (a) Soil classification based on plasticity index, (b) Classification chart based on the liquid limit and plastic index, (c) Classification chart based on clay content and activity, (d) Soil classification, and (e) Swelling pressure which determines the safety factor. In addition, expansive classification assesses that Esna shale Formation is one of environmental hazards characterized by damage role near Nile flood and irrigation area and characterized by deterioration role in heritage sites far from Nile flood and irrigation area. This paper refers to evaluation as a main process of integrated conservation approach.
文摘By studying the phenomena of limestone built from the White Monastery in Sohag Governorate damage where this study discusses the results of the analyzes and the study’s petrographic limestone, we can study and discuss what has been done to analyze X-ray diffraction and X-ray flourecence, and by scanning electron microscope in order to determine the cause of the damage and to study the properties of limestone to choose the most appropriate treatment methods especially the internal structure affected by the environmental conditions surrounding the private and increasing ground water levels along with the use of the most appropriate ways to buffer water to conserve the limestone of the environmental factors that damage it.
文摘The Roman Period temple of Isis at Shenhur was built and enhanced amid the rule of Augustus (30 BCE-14 CE) through that of Trajan (98-117 CE). It was built of two sorts of local limestone and decorated with reliefs. Examination of conservation state uncovered that it was collapsed and only partly preserved and it disposed of some still buried rooms. The temple is exposed to different deteriorations processes created by internal and external stresses because of the mineral composition of the building materials, atmosphere variables, salts crystallization and groundwater. In this study, the deterioration problems of the wall reliefs were examined for the aim of its conservation. For this purpose, the chemical, physical and structural characterization were performed by means of X-Ray Diffraction (XRD) and observation of thin section by transmitted light optical microscopy (LOM), polarized microscope, Scanning Electron Microscope (SEM) attached with EDX and thermogravimetric (DTA & TGA). Additionally, microbiological study and chemical analyses of ground water were carried out. Results demonstrated that the deterioration of Shenhur was because of the forceful activity of the environment agents and soluble salts such as chlorides and sulphates. These results and information allowed that the identification of the types of salts and deterioration features might be used in the future for conservation purposes.
文摘Aswan is famous for Granite rock art reliefs. Seti I granite rock art relief is one of the most important of them. This granite rock art relief suffers from weakness, fragility, fragmentation and peeling because of many deterioration factors, especially environmental deterioration impacts, such as desert climate with high temperature, residential areas with cafes and shops, and air pollution from exhausts and Kima factory. They can cause chemical weathering. Scientific investigations and analyzes were conducted on this rock art relief such as USB microscope, Polarized (PM) investigation, scanning electron microscope investigation with X-ray energy dispersal unit (EDX) and X-ray diffraction (XRD) analysis to determine the nature and the degree of deterioration, as well as the chemical and mineral composition of the rock and its natural, chemical and mechanical properties. A treatment suggestion to this granite rock art relief has been done.
文摘El-Amir Muhammad’s minaret in Akhmim, Sohag, Egypt, is constructed of limestone and has been exposed to many factors of damage as a result of the high levels of ground water. Limestone is strongly affected by ground water, especially when being impure. The current work discusses the results of analytical techniques including chemical testing to determine the types of soluble salts through optical microscopy, electronic scanning electron microscope with an X-ray energy dispersion system (ESEM) to study and determine the causes of rapid degradation. Microbial weathering phenomena toward limestone were also studied. Different bacteria and fungi were isolated from outdoors and indoors of air and limestone of the building of which Bacillus cereus OK447647, B. subtilis OK447648, Serratia marcescens OK447650, Pseudomonasoryzihabitans OK447649, Aspergillus flavus, A. niger, Penicillium chrysogenum and Cladosporium cladosporoids were the most representative. B. cereus OK447647 and B. subtilis OK447648 have shown ability for calcium carbonate dissolving. The minimal inhibitory concentrations (MICs) of sodium azide were investigated against the growth of microbial isolates. Sodium azide at 100 ppm was found to be the best treatment for bacterial isolates although it had no significant effect against fungi.