Forest fires are natural disasters that can occur suddenly and can be very damaging,burning thousands of square kilometers.Prevention is better than suppression and prediction models of forest fire occurrence have dev...Forest fires are natural disasters that can occur suddenly and can be very damaging,burning thousands of square kilometers.Prevention is better than suppression and prediction models of forest fire occurrence have developed from the logistic regression model,the geographical weighted logistic regression model,the Lasso regression model,the random forest model,and the support vector machine model based on historical forest fire data from 2000 to 2019 in Jilin Province.The models,along with a distribution map are presented in this paper to provide a theoretical basis for forest fire management in this area.Existing studies show that the prediction accuracies of the two machine learning models are higher than those of the three generalized linear regression models.The accuracies of the random forest model,the support vector machine model,geographical weighted logistic regression model,the Lasso regression model,and logistic model were 88.7%,87.7%,86.0%,85.0%and 84.6%,respectively.Weather is the main factor affecting forest fires,while the impacts of topography factors,human and social-economic factors on fire occurrence were similar.展开更多
The occurrence characteristics of shale oil are of great significance to the movability of shale oil.In this study,the occurrence characteristics of oil in the shale matrix at Funing Formation shale in Subei Basin wer...The occurrence characteristics of shale oil are of great significance to the movability of shale oil.In this study,the occurrence characteristics of oil in the shale matrix at Funing Formation shale in Subei Basin were quantitatively evaluated by organic geochemistry and microscopic pore structure characterization experiments.The Multiple Isothermal Stages Pyrolysis(MIS)experiment results show that the content of total oil,adsorbed oil,and free oil in the shales are 3.15-11.25 mg/g,1.41-4.95 mg/g,and 1.74-6.51 mg/g,respectively.among which the silicon-rich shale has the best oil-bearing.The relative content of free oil shows an increasing trend in pores with pore diameters greater than 3 nm.When the relative content of free oil reaches 100%,the pore size of silicon-rich shale is about 200 nm,while that of calcium-rich shale,clay-rich shale,and siliceous mixed shale is about 10 nm.The occurrence law of adsorbed oil is opposite to that of free oil,which indicates that shale oil will occur in the pores and fractures in a free state in a more extensive pore size range(>200 nm).This study also enables us to further understand the occurrence characteristics of shale oil under the interaction of occurrence state and occurrence space.展开更多
Deep shale gas(3500-4500 m)will be the important succeeding field for the growth of shale gas production in China.Under the condition of high temperature and high pressure in deep shale gas reservoirs,its gas occurren...Deep shale gas(3500-4500 m)will be the important succeeding field for the growth of shale gas production in China.Under the condition of high temperature and high pressure in deep shale gas reservoirs,its gas occurrence characteristics are markedly different from those of medium and shallow layers.To elucidate the gas occurrence characteristics and controlling factors of deep shales in the Wufeng-Longmaxi Formation,methane adsorption,low-temperature N2,and cO2 adsorption experi-ments were conducted.The results show that in deep shales,the mesopores provide approximately 75%of the total specific surface area(SA)and 90%of the total pore volume(PV).Based on two hypotheses and comparing the theoretical and actual adsorption capacity,it is speculated that methane is adsorbed in deep shale in the form of micropore filling,and free gas is mainly stored in the mesopores.Correlation analysis demonstrated that ToC is the key material constraint for the adsorption capacity of deep shale,and micropore SSA is the key spatial constraint.Other minerals and mesopore parameters have limited effect on the amount of adsorbed gas.Moreover,the free gas content ranges from 2.72 m^(3)/t to 6.20 m^(3)/t,with an average value of 4.60 m^(3)/t,and the free gas content ratio is approximately 58%,suggesting that the deep shale gas reservoirs are dominated by free gas.This ratio may also increase to approximately 70%when considering the formation temperature effect on adsorbed gas.Gas density,porosity,and gas saturation are the main controlling factors of free gas content,resulting in significantly larger free gas content in deep shale than in shallower formations.展开更多
With the intensified depletion of high-grade iron ores,the increased aluminum content in iron ore concentrates has become unavoidable,which is detrimental to the pelletization process.Therefore,the effect mechanism of...With the intensified depletion of high-grade iron ores,the increased aluminum content in iron ore concentrates has become unavoidable,which is detrimental to the pelletization process.Therefore,the effect mechanism of aluminum on pellet quality must be identified.In this study,the influence of aluminum occurrence and content on the induration of hematite(H)and magnetite(M)pellets was investigated through the addition of corresponding Al-containing additives,including alumina,alumogoethite,gibbsite,and kaolinite.Systematic mineralogical analysis,combined with the thermodynamic properties of different aluminum occurrences and the quantitative characterization of consolidation behaviors,were conducted to determine the related mechanism.The results showed that the alumina from various aluminum occurrences adversely affected the induration characteristics of pellets,especially at an aluminum content of more than 2.0wt%.The thermal decomposition of gibbsite and kaolinite tends to generate internal stress and fine cracks,which hinder the respective microcrystalline bonding and recrystallization between Fe2O3particles.The adverse effect on the induration characteristics of fired pellets with different aluminum occurrences can be relieved to varying degrees through the formation of liquid phase bonds between the hematite particles.Kaolinite is more beneficial to the induration process than the other three aluminum occurrences because of the formation of more liquid phase,which improves pellet consolidation.The research results can further provide insights into the effect of aluminum occurrence and content in iron ore concentrates on downstream processing and serve as a guide for the utilization of high-alumina iron ore concentrates in pelletization.展开更多
BACKGROUND To evaluate the clinicopathological features and prognosis of gastric cancer(GC)occurring synchronously with gastrointestinal stromal tumor(GIST).CASE SUMMARY We report 19 patients with concurrent GC and GI...BACKGROUND To evaluate the clinicopathological features and prognosis of gastric cancer(GC)occurring synchronously with gastrointestinal stromal tumor(GIST).CASE SUMMARY We report 19 patients with concurrent GC and GIST(17 male and 2 female,median age 62 years).GC was most often located in the lower third of the stomach.GIST was diagnosed preoperatively in four patients.GIST was most often located in the gastric body(n=8,42%).The most common growth pattern in GIST was extraluminal(n=12,63%).The positive expression rates of CD117 and CD34 in GIST were 100% and 95%,respectively.Most patients with GIST(n=17,89%)were very low or low risk.There was no recurrence of GIST during follow-up.The 3-year cumulative survival rate was 73.9%,and the 5-year cumulative survival rate was 59.2%.The combined analysis of this study and literature reports(47 reports,157 patients)found that GC and GIST were usually located in the lower third(42%)and middle third(51%)of the stomach.GC was usually early(stage I:42%),poorly differentiated(42%)intestinal-type adenocarcinoma(51%).GISTs were primarily small in diameter(median:1.2 cm)and very low or low risk(89%).CONCLUSION Synchronous GC and GIST may not be rare.They have specific clinicopathological characteristics,and may have mutual inhibition in pathogenesis and progression.展开更多
The Dulong deposit,located in the Laojunshan area of southeastern Yunnan,China,is an important polymetallic deposit due to its high reserves of tin,zinc,and indium.The occurrence state of indium is critical for unders...The Dulong deposit,located in the Laojunshan area of southeastern Yunnan,China,is an important polymetallic deposit due to its high reserves of tin,zinc,and indium.The occurrence state of indium is critical for understanding its supernormal enrichment mechanism.Previous studies investigated the occurrence state of indium(including the valence state)based on the indium content in sphalerite and the correlation between metal concentrations.However,more evidence is needed to better constrain indium occurrence at the micro-,nano-,or even atomic scale.In this study,EPMA-FIB-SEM-TEM and XPS techniques were employed to investigate the indium distribution characteristics and occurrence state in sphalerite from the Dulong Sn–Zn–In polymetallic deposit.The maximum concentration of indium in the indium-rich sphalerite samples is 0.37%,and the results of the EPMA analysis showed a relatively homogeneous distribution of indium in sphalerite.The FIB-SEM-TEM results demonstrated that the lattice stripes of sphalerite were periodically and continuously distributed at the nanoscale,confirming that sphalerite in the deposit was an excellent single crystal structure,and the peak heights of the various characteristic peaks of indium in the EDX spectra were relatively close to each other,with no distinct peaks of high indium content.In addition,the XPS results indicate that the element valence state of indium in sphalerite is In^(3+),and it combines with S^(2-)to form a bond.These results indicate that indium in sphalerite of the Dulong deposit is uniformly distributed at both the micro-and nanoscale,and there is no indium-independent mineral.In^(3+)enters the crystal lattice of sphalerite by replacing Zn2+in the form of isomorphic substitution.展开更多
The Hashan area,neighboring the Mahu Sag that is rich in the shale oil resources,showed commercial oil flow in the corresponding lacustrine shales of the Lower Permian Fengcheng Formation(P)with reserve scale approxim...The Hashan area,neighboring the Mahu Sag that is rich in the shale oil resources,showed commercial oil flow in the corresponding lacustrine shales of the Lower Permian Fengcheng Formation(P)with reserve scale approximately 789 million tons,presenting great potential for oil exploration.Despite their geographical proximity,the hydrocarbon occurrence and oil-bearing capacity of shale in the Hashan area and Mahu Sag greatly differ owing to the complex tectonic evolution.Therefore,understanding the occurrence state and oil content of the Pif in the Hashan area is crucial for ongoing shale oil exploration activities and the development of the northwestern margin of the Junggar Basin.In this study,an in-tegrated investigation,including petrological observations,scanning electron microscopy(SEM)obser-vation,analysis of nuclear magnetic resonance(NMR)Ti-T2 spectra,and conventional and multistage Rock-Eval pyrolysis methods were conducted to evaluate the occurrence state and oil content of the Pif shale in the Hashan area.The results indicate that plagioclase(average 30.7%)and quartz(24.1%)dominate the mineral compositions of the Pf shale samples.A method involving quartz-plagioclase-carbonate minerals is proposed to conduct lithofacies classification.In the Hashan area,the organic matter abundance in the Pf shale is scaled in fair to good range,the thermal maturity ranges from immature to early mature stage,and the primary organic matter types are Types I and Ilj.Intergranular and dissolution pores are the two most common pore types.The free oil is mostly found in the pores and microfractures of the mineral matrix,whereas the adsorbed oil is mostly adsorbed on the surfaces of kerogen and clay minerals.The high organic matter abundance,quartz content,and porosity account for substantial increase in the oil content,the area rich in shale oil resources coincides with that rich in free oil.The most favorable lithofacies in the Hashan area is the calcareous mudstone/shale,which hosts the highest free oil content(average 2.49 mg),total oil content(15.02 mg/g),organic matter abundance CTOC:1.88% and S_(1)+S_(2)=20.54mg/g and orositv(5.97%)展开更多
The paper introduces the damage characteristics and occurrence regularity of Psylla chinensis in pear orchards in eastern Hebei Province,and summarizes the integrated prevention and control techniques of P.chinensis,i...The paper introduces the damage characteristics and occurrence regularity of Psylla chinensis in pear orchards in eastern Hebei Province,and summarizes the integrated prevention and control techniques of P.chinensis,in order to provide a reference for the prevention and control of P.chinensis in eastern Hebei Province.展开更多
The control of micro-wettability of pore-throat on shale oil occurrence in different types of reservoir spaces remains unclear.Take the shale oil reservoir of the Permian Lucaogou Formation in the Jimusar Sag,Junggar ...The control of micro-wettability of pore-throat on shale oil occurrence in different types of reservoir spaces remains unclear.Take the shale oil reservoir of the Permian Lucaogou Formation in the Jimusar Sag,Junggar Basin as an example,the reservoir space in laminated shale and the control of micro-wettability of pore-throat on shale oil occurrence were studied by using scanning electron microscope(SEM),multi-stage pyrolysis,quantitative fluorescence,nuclear magnetic resonance(NMR)and other techniques.The results show that there are mainly two types of laminated shale in the Lucaogou Formation,namely laminated shale rich in volcanic materials+terrigenous felsic,and laminated shale rich in volcanic materials+carbonate.The former type contains feldspar dissolution pores and intergranular pores,mainly with felsic mineral components around the pore-throats,which are water-wet and control the free shale oil.The latter type contains carbonate intercrystalline pores and organic pores,mainly with oil-wet mineral components around the pore-throats,which control the adsorbed shale oil.The oil-wet mineral components around the pore-throats are conducive to oil accumulation,but reduce the proportion of free oil.In the Lucaogou Formation,free oil,with high maturity and light quality,mainly occurs in the laminated shale rich in volcanic materials+terrigenous felsic.展开更多
Caregivers are highly exposed to blood exposure accidents (BEA). The objective of our study is to determine the frequency of BEA and to identify the predictive factors for the occurrence of BEAs among caregivers at th...Caregivers are highly exposed to blood exposure accidents (BEA). The objective of our study is to determine the frequency of BEA and to identify the predictive factors for the occurrence of BEAs among caregivers at the Kaolack Regional Hospital (KRH). It is a descriptive and analytical cross-sectional study of KRH’s caregivers. The data were collected during the period from 16 to 26 April 2018. The multivariate analysis was carried out using the binary logistic regression model with a dependent variable (occurrence of blood exposure accidents) and 5 explanatory variables (sex, age, service of belonging, professional category and seniority in the profession). A total of 115 caregivers were surveyed out of 144. It is noted that 68 caregivers (59.1%) have had at least one BEA in the previous 12 months. The age of caregivers significantly reduces the risk of developing a BEA (p = 0.004, CI [0.04 - 0.21]);belonging to the age group [20 - 40 years] increases the risk of a BEA by 6.66. Sex significantly influences the occurrence of BEA with a (p = 0.013, CI [1.47 - 19.4]);men are 5 times more likely to develop BEA. The risk of a BEA occurring varies according to the professional category. Senior health technicians have a significantly 50 times lower risk of occurrence of a BEA (p = 0.007, CI [0.00 - 0.24)]. Nurses and midwives have a 5.8 lower risk of developing BEAs (p = 0.031, CI [0.03 - 0.75]). The risk of occurrence of BEAs varies according to the service of belonging;Medicine service caregivers have a significantly 50-fold lower risk of developing BEAs (p = 0.004, CI [0.00 - 0.17]). The identified risk factors will be used to better guide our BEAs prevention interventions.展开更多
Occurrence and mobility of shale oil are prerequisites for evaluating shale oil reserves and prioritizing exploration targets,particularly for heterogeneous lacustrine shales.The Qingshankou Formation in the Gulong Sa...Occurrence and mobility of shale oil are prerequisites for evaluating shale oil reserves and prioritizing exploration targets,particularly for heterogeneous lacustrine shales.The Qingshankou Formation in the Gulong Sag,Songliao Basin is a classic lacustrine pure shale reservoir that contains abundant shale oil resources.The predicted geological reserves of the shale are 1.268×10^(9) t.In this study,field emission scanning electron microscope(FE-SEM),the modular automated processing system(MAPS),pyrolysisgas chromatography(Py-GC),low-pressure nitrogen gas adsorption(LPNA),Soxhlet extraction,pyrolysis,and 2-D nuclear magnetic resonance(NMR)were integrated to describe the shale oil components,microscopic occurrence,mobility,and the effective pore size distribution.Meanwhile,the related controlling factors are discussed.The shale oil in the Qingshankou Fm exists dominantly in the matrix pores of the clay minerals,with small amounts distributed in the intergranular pores of terrigenous clastic grains,intercrystalline pores of pyrite,intragranular pores of ostracod shells,and micro-fractures.Shale oil is distributed in the pore spaces of variable sizes in different lithofacies.The clay mineral-laminated shales are characterized by the broadest range of pore size and largest volume of pore spaces with shale oil distribution,while the ostracod-laminated shales have limited pore spaces retaining oil.Furthermore,the proposed integrated analysis evaluates the shale oil molecules existing in two states:movable,and adsorbed oil,respectively.The result illustrates that movable oil takes up 30.6%e79.4%of the total residual oil.TOC,mineral composition,and pore structures of the shale joint together to control the states and mobility of the shale oil.TOC values are positively correlated with the quantities of shale oil regardless of the state of oil.The mineral components significantly impact the state of shale oil.Noticeable differences in the states of oil were observed following the changing types of minerals,possibly due to their difference in adsorption capacity and wettability.Clay minerals attract more adsorbed oil than movable oil.Felsic minerals generally decrease the occurrence of total and adsorbed oil.Carbonate plays a positive role in hydrocarbon retention of all the shale oil states.As for the pore structure,the average pore size exerts a critical impact on the total,movable,and adsorbed oil content.The total pore volume and specific surface area of shales play a principal role in controlling the total yields and amounts of adsorbed oil.This research improves the understanding of the occurrence characteristics and enrichment mechanisms of shale oil in terrestrial pure shales and provides a reference for locating favorable shale oil exploration areas.展开更多
In order to promote the healthy and sustainable development of citrus industry in Guangxi and reduce the harm of Diaphorina citri and citrus Huanglongbing on citrus industry,the paper summarizes the occurrence of D.ci...In order to promote the healthy and sustainable development of citrus industry in Guangxi and reduce the harm of Diaphorina citri and citrus Huanglongbing on citrus industry,the paper summarizes the occurrence of D.citri in Guangxi,and put forward comprehensive control technique,so as to provide the reference for guiding prevention and control of major pests in citrus industry.展开更多
In order to find out the effects of soil fluorine on ecological environment and crop safety in the sorghum cultivation base of Renhuai City, Guizhou Province, the content and the occurrence forms of soil fluorine and ...In order to find out the effects of soil fluorine on ecological environment and crop safety in the sorghum cultivation base of Renhuai City, Guizhou Province, the content and the occurrence forms of soil fluorine and its influencing factors of Maoba Town were investigated and studied. The results showed that the total fluorine content in the soil of the sorghum base ranged from 668.60 to 2 596.80 mg/kg, with an average of 1 483.25 mg/kg, which was 3.10 and 1.85 times of the national soil background value and the average value of the soil in endemic areas, respectively. The spatial distribution of fluorine in the soil of the study area was uneven, and the fluorine content was in the order of Anliang Village>Yangliu Village>Houba Village>Xiongfeng Village. The soil fluorine contents of various forms varied greatly, and the distribution law was as follows: residual state>water soluble state>organically bound state>exchangeable state>Fe/Mn-F state. The residual fluorine content was the highest, accounting for more than 99% of total fluorine content, while the sum of other four forms was less than 1%, with their respective proportions ranging from 0.10% to 0.30%. The content and proportion of available fluorine in water-soluble and exchangeable states were relatively low, which had limited influence on the surrounding water environment and crop safety. The physicochemical properties of soil, such as pH, organic matter, cation exchange capacity and clay particles had a certain influence on the occurrence forms of soil fluorine, thus changing the availability and migration of soil fluorine, which might endanger the ecological environment safety, food safety and human health.展开更多
Based on practical work experience,this paper analyzed the occurrence characteristics and control measures of Spodoptera frugiperda in maize.The measures including forecasting and early warning,regional prevention and...Based on practical work experience,this paper analyzed the occurrence characteristics and control measures of Spodoptera frugiperda in maize.The measures including forecasting and early warning,regional prevention and control,agricultural prevention and control,physical prevention and control,chemical prevention and control,and biological prevention and control can effectively control the damage of S.frugiperda and guarantee the safety of food production.The results will provide some reference for the prevention and control of S.frugiperda.展开更多
Peanut stem rot caused by Sclerotium rolfsii is a soil-borne disease,and it has become the main disease of peanut in Yimeng mountainous area.S.rolfsii survives the winter as mycelia and sclerotia in soil and debris,be...Peanut stem rot caused by Sclerotium rolfsii is a soil-borne disease,and it has become the main disease of peanut in Yimeng mountainous area.S.rolfsii survives the winter as mycelia and sclerotia in soil and debris,becoming the primary source of infection in the following year.The disease resistance of peanut varieties,high temperature and humidity,and cultivation measures are the pathogenic factors affecting the occurrence of peanut stem rot.The disease can be effectively controlled by screening disease-resistant varieties and seed chemical treatment,improving soil by deep tillage and crop rotation,carrying out flowing water management of affected field,cutting off transmission routes,and strengthening seed dressing and triple spraying control.展开更多
Background and objectives: Breast Imaging Reporting and Data System in Category 3 (BIRADS-3) includes probably benign lesions which need a short-term imaging follow-up. However, in our context, the lesions graded BIRA...Background and objectives: Breast Imaging Reporting and Data System in Category 3 (BIRADS-3) includes probably benign lesions which need a short-term imaging follow-up. However, in our context, the lesions graded BIRADS-3 remain insufficiently evaluated. We therefore conducted this study to assess the cancer occurrence and associated factors in BIRADS-3 lesions during the follow-up in order to propose an adaptation of the management for lesions in this category in our setting. Patients and methods: A retrospective longitudinal study of patients with lesions initially classified as BIRADS-3 and who realised each at least one additional imaging check-up between January 2014 and December 2022 in five Yaoundé hospitals. All clinical and imaging data were analysed using SPSS<sup>®</sup> 21.0 software with a significant p-value Results: Patients were aged 13 to 73 (33.0 ± 13.4) years, with a history of breast mass (315 cases;79.7%), breast pain (25 patients;6.3%), nipple discharge (20 patients;5.1%) or past family history of breast cancer (25 cases;6.3%). The most common baseline abnormalities were mammogram opacities (64.8%) and microcalcifications (48.6%), whereas initial breast ultrasound showed solid masses (77.0%) and cystic lesions (11.1%). Compliance with imaging appointment periods was low with only 23.9% of all patients performing an imaging control at the scheduled moment. During the follow-up, 115 patients (29.1%) were upgraded to BIRADS-4 and histology performed revealed 43 cancers (10.9% of overall initial BIRADS-3 sample). The presence of malignancies was associated to age above 40 years (p = 0.0001) and to the presence of nipple discharge (p = 0.0375). Conclusion: The frequency of malignancies among initial BIRADS-3 lesions in our series is higher than that described in the guidelines. This study highlights the need to be more proactive in the management of BIRADS-3 lesions in our setting as the compliance with follow-up is low. So, biopsy should be considered as an alternative to long-term follow-up for patients above 40, non-compliant with imaging check-ups and presenting with nipple discharge.展开更多
Caregivers are highly exposed to blood exposure accidents (BEA). The objective of our study is to determine the frequency of BEA and to identify the predictive factors for the occurrence of BEAs among caregivers at th...Caregivers are highly exposed to blood exposure accidents (BEA). The objective of our study is to determine the frequency of BEA and to identify the predictive factors for the occurrence of BEAs among caregivers at the Kaolack Regional Hospital (KRH). It is a descriptive and analytical cross-sectional study of KRH’s caregivers. The data were collected during the period from 16 to 26 April 2018. The multivariate analysis was carried out using the binary logistic regression model with a dependent variable (occurrence of blood exposure accidents) and 5 explanatory variables (sex, age, service of belonging, professional category and seniority in the profession). A total of 115 caregivers were surveyed out of 144. It is noted that 68 caregivers (59.1%) have had at least one BEA in the previous 12 months. The age of caregivers significantly reduces the risk of developing a BEA (p = 0.004, CI [0.04 - 0.21]);belonging to the age group [20 - 40 years] increases the risk of a BEA by 6.66. Sex significantly influences the occurrence of BEA with a (p = 0.013, CI [1.47 - 19.4]);men are 5 times more likely to develop BEA. The risk of a BEA occurring varies according to the professional category. Senior health technicians have a significantly 50 times lower risk of occurrence of a BEA (p = 0.007, CI [0.00 - 0.24)]. Nurses and midwives have a 5.8 lower risk of developing BEAs (p = 0.031, CI [0.03 - 0.75]). The risk of occurrence of BEAs varies according to the service of belonging;Medicine service caregivers have a significantly 50-fold lower risk of developing BEAs (p = 0.004, CI [0.00 - 0.17]). The identified risk factors will be used to better guide our BEAs prevention interventions.展开更多
Prior to his initial diagnosis, a 21-year-old male had been experiencing facial acne for two years and had been treated by a doctor in private practice. The patient visited our department because the clinical manifest...Prior to his initial diagnosis, a 21-year-old male had been experiencing facial acne for two years and had been treated by a doctor in private practice. The patient visited our department because the clinical manifestations of mandibular acne did not improve. At the time of initial examination, telangiectasia (TE), post-inflammatory erythema (PIE), post-inflammatory hyperpigmentation (PIH), atrophic scars (ASs), and a hypertrophic scar (HS) with induration were observed on the right neck. We diagnosed this as an acne vulgaris complication. HS lesions were topically treated by injecting triamcinolone acetonide, and the patient was prescribed 8.1 g/day of oral Saireito (Japanese herb). Adapalene benzoyl peroxide gel and topical tacrolimus hydrate ointment were used to treat PIE and TE. Both HSs and PIE improved;however, TE and AS did not improve. Currently, the patient is under observation. We consider this to be a very rare concurrent occurrence of diverse complications of acne vulgaris, and present the following case study.展开更多
基金This research was funded by the National Natural Science Foundation of China(grant no.32271881).
文摘Forest fires are natural disasters that can occur suddenly and can be very damaging,burning thousands of square kilometers.Prevention is better than suppression and prediction models of forest fire occurrence have developed from the logistic regression model,the geographical weighted logistic regression model,the Lasso regression model,the random forest model,and the support vector machine model based on historical forest fire data from 2000 to 2019 in Jilin Province.The models,along with a distribution map are presented in this paper to provide a theoretical basis for forest fire management in this area.Existing studies show that the prediction accuracies of the two machine learning models are higher than those of the three generalized linear regression models.The accuracies of the random forest model,the support vector machine model,geographical weighted logistic regression model,the Lasso regression model,and logistic model were 88.7%,87.7%,86.0%,85.0%and 84.6%,respectively.Weather is the main factor affecting forest fires,while the impacts of topography factors,human and social-economic factors on fire occurrence were similar.
基金This work was financially supported by the National Natural Science Foundation of China(41972123,41922015)the Natural Science Foundation of Shandong Province(ZR2020QD036).
文摘The occurrence characteristics of shale oil are of great significance to the movability of shale oil.In this study,the occurrence characteristics of oil in the shale matrix at Funing Formation shale in Subei Basin were quantitatively evaluated by organic geochemistry and microscopic pore structure characterization experiments.The Multiple Isothermal Stages Pyrolysis(MIS)experiment results show that the content of total oil,adsorbed oil,and free oil in the shales are 3.15-11.25 mg/g,1.41-4.95 mg/g,and 1.74-6.51 mg/g,respectively.among which the silicon-rich shale has the best oil-bearing.The relative content of free oil shows an increasing trend in pores with pore diameters greater than 3 nm.When the relative content of free oil reaches 100%,the pore size of silicon-rich shale is about 200 nm,while that of calcium-rich shale,clay-rich shale,and siliceous mixed shale is about 10 nm.The occurrence law of adsorbed oil is opposite to that of free oil,which indicates that shale oil will occur in the pores and fractures in a free state in a more extensive pore size range(>200 nm).This study also enables us to further understand the occurrence characteristics of shale oil under the interaction of occurrence state and occurrence space.
基金funded by a PetroChina Basic Technology Research Project(No.2021DJ1905).
文摘Deep shale gas(3500-4500 m)will be the important succeeding field for the growth of shale gas production in China.Under the condition of high temperature and high pressure in deep shale gas reservoirs,its gas occurrence characteristics are markedly different from those of medium and shallow layers.To elucidate the gas occurrence characteristics and controlling factors of deep shales in the Wufeng-Longmaxi Formation,methane adsorption,low-temperature N2,and cO2 adsorption experi-ments were conducted.The results show that in deep shales,the mesopores provide approximately 75%of the total specific surface area(SA)and 90%of the total pore volume(PV).Based on two hypotheses and comparing the theoretical and actual adsorption capacity,it is speculated that methane is adsorbed in deep shale in the form of micropore filling,and free gas is mainly stored in the mesopores.Correlation analysis demonstrated that ToC is the key material constraint for the adsorption capacity of deep shale,and micropore SSA is the key spatial constraint.Other minerals and mesopore parameters have limited effect on the amount of adsorbed gas.Moreover,the free gas content ranges from 2.72 m^(3)/t to 6.20 m^(3)/t,with an average value of 4.60 m^(3)/t,and the free gas content ratio is approximately 58%,suggesting that the deep shale gas reservoirs are dominated by free gas.This ratio may also increase to approximately 70%when considering the formation temperature effect on adsorbed gas.Gas density,porosity,and gas saturation are the main controlling factors of free gas content,resulting in significantly larger free gas content in deep shale than in shallower formations.
基金financially supported by the National Natural Science Foundation of China(Nos.52004339 and 52174329)the Fundamental Research Funds for the Central Universities,China(No.N2325031)the China Baowu Low Carbon Metallurgy Innovation Foundation(No.BWLCF202216)。
文摘With the intensified depletion of high-grade iron ores,the increased aluminum content in iron ore concentrates has become unavoidable,which is detrimental to the pelletization process.Therefore,the effect mechanism of aluminum on pellet quality must be identified.In this study,the influence of aluminum occurrence and content on the induration of hematite(H)and magnetite(M)pellets was investigated through the addition of corresponding Al-containing additives,including alumina,alumogoethite,gibbsite,and kaolinite.Systematic mineralogical analysis,combined with the thermodynamic properties of different aluminum occurrences and the quantitative characterization of consolidation behaviors,were conducted to determine the related mechanism.The results showed that the alumina from various aluminum occurrences adversely affected the induration characteristics of pellets,especially at an aluminum content of more than 2.0wt%.The thermal decomposition of gibbsite and kaolinite tends to generate internal stress and fine cracks,which hinder the respective microcrystalline bonding and recrystallization between Fe2O3particles.The adverse effect on the induration characteristics of fired pellets with different aluminum occurrences can be relieved to varying degrees through the formation of liquid phase bonds between the hematite particles.Kaolinite is more beneficial to the induration process than the other three aluminum occurrences because of the formation of more liquid phase,which improves pellet consolidation.The research results can further provide insights into the effect of aluminum occurrence and content in iron ore concentrates on downstream processing and serve as a guide for the utilization of high-alumina iron ore concentrates in pelletization.
文摘BACKGROUND To evaluate the clinicopathological features and prognosis of gastric cancer(GC)occurring synchronously with gastrointestinal stromal tumor(GIST).CASE SUMMARY We report 19 patients with concurrent GC and GIST(17 male and 2 female,median age 62 years).GC was most often located in the lower third of the stomach.GIST was diagnosed preoperatively in four patients.GIST was most often located in the gastric body(n=8,42%).The most common growth pattern in GIST was extraluminal(n=12,63%).The positive expression rates of CD117 and CD34 in GIST were 100% and 95%,respectively.Most patients with GIST(n=17,89%)were very low or low risk.There was no recurrence of GIST during follow-up.The 3-year cumulative survival rate was 73.9%,and the 5-year cumulative survival rate was 59.2%.The combined analysis of this study and literature reports(47 reports,157 patients)found that GC and GIST were usually located in the lower third(42%)and middle third(51%)of the stomach.GC was usually early(stage I:42%),poorly differentiated(42%)intestinal-type adenocarcinoma(51%).GISTs were primarily small in diameter(median:1.2 cm)and very low or low risk(89%).CONCLUSION Synchronous GC and GIST may not be rare.They have specific clinicopathological characteristics,and may have mutual inhibition in pathogenesis and progression.
基金financially supported by the National Nature Science Foundation of China(42072094,42162012)。
文摘The Dulong deposit,located in the Laojunshan area of southeastern Yunnan,China,is an important polymetallic deposit due to its high reserves of tin,zinc,and indium.The occurrence state of indium is critical for understanding its supernormal enrichment mechanism.Previous studies investigated the occurrence state of indium(including the valence state)based on the indium content in sphalerite and the correlation between metal concentrations.However,more evidence is needed to better constrain indium occurrence at the micro-,nano-,or even atomic scale.In this study,EPMA-FIB-SEM-TEM and XPS techniques were employed to investigate the indium distribution characteristics and occurrence state in sphalerite from the Dulong Sn–Zn–In polymetallic deposit.The maximum concentration of indium in the indium-rich sphalerite samples is 0.37%,and the results of the EPMA analysis showed a relatively homogeneous distribution of indium in sphalerite.The FIB-SEM-TEM results demonstrated that the lattice stripes of sphalerite were periodically and continuously distributed at the nanoscale,confirming that sphalerite in the deposit was an excellent single crystal structure,and the peak heights of the various characteristic peaks of indium in the EDX spectra were relatively close to each other,with no distinct peaks of high indium content.In addition,the XPS results indicate that the element valence state of indium in sphalerite is In^(3+),and it combines with S^(2-)to form a bond.These results indicate that indium in sphalerite of the Dulong deposit is uniformly distributed at both the micro-and nanoscale,and there is no indium-independent mineral.In^(3+)enters the crystal lattice of sphalerite by replacing Zn2+in the form of isomorphic substitution.
基金co-funded by the National Natural Science Foundation of China(Grant No.42072172,41772120)Shandong Province Natural Science Fund for Distinguished Young Scholars(Grant No.JQ201311)the Graduate Scientific and Technological Innovation Project Financially Supported by Shandong University of Science and Technology(Grant No.YC20210825).
文摘The Hashan area,neighboring the Mahu Sag that is rich in the shale oil resources,showed commercial oil flow in the corresponding lacustrine shales of the Lower Permian Fengcheng Formation(P)with reserve scale approximately 789 million tons,presenting great potential for oil exploration.Despite their geographical proximity,the hydrocarbon occurrence and oil-bearing capacity of shale in the Hashan area and Mahu Sag greatly differ owing to the complex tectonic evolution.Therefore,understanding the occurrence state and oil content of the Pif in the Hashan area is crucial for ongoing shale oil exploration activities and the development of the northwestern margin of the Junggar Basin.In this study,an in-tegrated investigation,including petrological observations,scanning electron microscopy(SEM)obser-vation,analysis of nuclear magnetic resonance(NMR)Ti-T2 spectra,and conventional and multistage Rock-Eval pyrolysis methods were conducted to evaluate the occurrence state and oil content of the Pif shale in the Hashan area.The results indicate that plagioclase(average 30.7%)and quartz(24.1%)dominate the mineral compositions of the Pf shale samples.A method involving quartz-plagioclase-carbonate minerals is proposed to conduct lithofacies classification.In the Hashan area,the organic matter abundance in the Pf shale is scaled in fair to good range,the thermal maturity ranges from immature to early mature stage,and the primary organic matter types are Types I and Ilj.Intergranular and dissolution pores are the two most common pore types.The free oil is mostly found in the pores and microfractures of the mineral matrix,whereas the adsorbed oil is mostly adsorbed on the surfaces of kerogen and clay minerals.The high organic matter abundance,quartz content,and porosity account for substantial increase in the oil content,the area rich in shale oil resources coincides with that rich in free oil.The most favorable lithofacies in the Hashan area is the calcareous mudstone/shale,which hosts the highest free oil content(average 2.49 mg),total oil content(15.02 mg/g),organic matter abundance CTOC:1.88% and S_(1)+S_(2)=20.54mg/g and orositv(5.97%)
基金Supported by Basic Research Fund of Hebei Academy of Agriculture and Forestry Sciences(2021020201)Key Research and Development Program of Hebei Province(21326308D-1-2)Science and Technology Innovation Project of Hebei Academy of Agriculture and Forestry Sciences(2022KJCXZX-CGS-7)。
文摘The paper introduces the damage characteristics and occurrence regularity of Psylla chinensis in pear orchards in eastern Hebei Province,and summarizes the integrated prevention and control techniques of P.chinensis,in order to provide a reference for the prevention and control of P.chinensis in eastern Hebei Province.
基金Supported by the National Natural Scienceof China(42072161,41821002)Central University Basic Research Project(22CX07008A)。
文摘The control of micro-wettability of pore-throat on shale oil occurrence in different types of reservoir spaces remains unclear.Take the shale oil reservoir of the Permian Lucaogou Formation in the Jimusar Sag,Junggar Basin as an example,the reservoir space in laminated shale and the control of micro-wettability of pore-throat on shale oil occurrence were studied by using scanning electron microscope(SEM),multi-stage pyrolysis,quantitative fluorescence,nuclear magnetic resonance(NMR)and other techniques.The results show that there are mainly two types of laminated shale in the Lucaogou Formation,namely laminated shale rich in volcanic materials+terrigenous felsic,and laminated shale rich in volcanic materials+carbonate.The former type contains feldspar dissolution pores and intergranular pores,mainly with felsic mineral components around the pore-throats,which are water-wet and control the free shale oil.The latter type contains carbonate intercrystalline pores and organic pores,mainly with oil-wet mineral components around the pore-throats,which control the adsorbed shale oil.The oil-wet mineral components around the pore-throats are conducive to oil accumulation,but reduce the proportion of free oil.In the Lucaogou Formation,free oil,with high maturity and light quality,mainly occurs in the laminated shale rich in volcanic materials+terrigenous felsic.
文摘Caregivers are highly exposed to blood exposure accidents (BEA). The objective of our study is to determine the frequency of BEA and to identify the predictive factors for the occurrence of BEAs among caregivers at the Kaolack Regional Hospital (KRH). It is a descriptive and analytical cross-sectional study of KRH’s caregivers. The data were collected during the period from 16 to 26 April 2018. The multivariate analysis was carried out using the binary logistic regression model with a dependent variable (occurrence of blood exposure accidents) and 5 explanatory variables (sex, age, service of belonging, professional category and seniority in the profession). A total of 115 caregivers were surveyed out of 144. It is noted that 68 caregivers (59.1%) have had at least one BEA in the previous 12 months. The age of caregivers significantly reduces the risk of developing a BEA (p = 0.004, CI [0.04 - 0.21]);belonging to the age group [20 - 40 years] increases the risk of a BEA by 6.66. Sex significantly influences the occurrence of BEA with a (p = 0.013, CI [1.47 - 19.4]);men are 5 times more likely to develop BEA. The risk of a BEA occurring varies according to the professional category. Senior health technicians have a significantly 50 times lower risk of occurrence of a BEA (p = 0.007, CI [0.00 - 0.24)]. Nurses and midwives have a 5.8 lower risk of developing BEAs (p = 0.031, CI [0.03 - 0.75]). The risk of occurrence of BEAs varies according to the service of belonging;Medicine service caregivers have a significantly 50-fold lower risk of developing BEAs (p = 0.004, CI [0.00 - 0.17]). The identified risk factors will be used to better guide our BEAs prevention interventions.
基金funded by the National Natural Science Foundation of China(Project 42090025 and 42202152)Heilongjiang Province open competition projects:“Research on the shale oil phase state,seepage mechanism,and integrated geologicalengineering stimulation technology in the Gulong Sag”and“Research on the diagenetic dynamic evolution process and its coupling relationship with pores and fractures”.
文摘Occurrence and mobility of shale oil are prerequisites for evaluating shale oil reserves and prioritizing exploration targets,particularly for heterogeneous lacustrine shales.The Qingshankou Formation in the Gulong Sag,Songliao Basin is a classic lacustrine pure shale reservoir that contains abundant shale oil resources.The predicted geological reserves of the shale are 1.268×10^(9) t.In this study,field emission scanning electron microscope(FE-SEM),the modular automated processing system(MAPS),pyrolysisgas chromatography(Py-GC),low-pressure nitrogen gas adsorption(LPNA),Soxhlet extraction,pyrolysis,and 2-D nuclear magnetic resonance(NMR)were integrated to describe the shale oil components,microscopic occurrence,mobility,and the effective pore size distribution.Meanwhile,the related controlling factors are discussed.The shale oil in the Qingshankou Fm exists dominantly in the matrix pores of the clay minerals,with small amounts distributed in the intergranular pores of terrigenous clastic grains,intercrystalline pores of pyrite,intragranular pores of ostracod shells,and micro-fractures.Shale oil is distributed in the pore spaces of variable sizes in different lithofacies.The clay mineral-laminated shales are characterized by the broadest range of pore size and largest volume of pore spaces with shale oil distribution,while the ostracod-laminated shales have limited pore spaces retaining oil.Furthermore,the proposed integrated analysis evaluates the shale oil molecules existing in two states:movable,and adsorbed oil,respectively.The result illustrates that movable oil takes up 30.6%e79.4%of the total residual oil.TOC,mineral composition,and pore structures of the shale joint together to control the states and mobility of the shale oil.TOC values are positively correlated with the quantities of shale oil regardless of the state of oil.The mineral components significantly impact the state of shale oil.Noticeable differences in the states of oil were observed following the changing types of minerals,possibly due to their difference in adsorption capacity and wettability.Clay minerals attract more adsorbed oil than movable oil.Felsic minerals generally decrease the occurrence of total and adsorbed oil.Carbonate plays a positive role in hydrocarbon retention of all the shale oil states.As for the pore structure,the average pore size exerts a critical impact on the total,movable,and adsorbed oil content.The total pore volume and specific surface area of shales play a principal role in controlling the total yields and amounts of adsorbed oil.This research improves the understanding of the occurrence characteristics and enrichment mechanisms of shale oil in terrestrial pure shales and provides a reference for locating favorable shale oil exploration areas.
基金Supported by Science and Technology Major Project of Guangxi Province(GK AA20108003,GK AA22036002)Science and Technology Major Project of Nanning City(20212141)+6 种基金Collaborative Innovation Project of Chinese Academy of Agricultural Sciences-Guangxi Academy of Agricultural Sciences(CAAS-GXAAS-XTCX2019026-2)Guangxi Special Crops Experimental Station(G TS202201)Wuming District Science and Technology Project of Nanning City(2210201)Jiangnan District Science and Technology Project of Nanning City(2020020102)GNK(2021YT051,2022JM32)Guangxi Citrus Huanglongbing Prevention and Control Engineering Technology Research Center"Cultivation and Pest Control"Post Expert of Guangxi Citrus Innovation Team(nycytxgxcxtd-2021-05-02)。
文摘In order to promote the healthy and sustainable development of citrus industry in Guangxi and reduce the harm of Diaphorina citri and citrus Huanglongbing on citrus industry,the paper summarizes the occurrence of D.citri in Guangxi,and put forward comprehensive control technique,so as to provide the reference for guiding prevention and control of major pests in citrus industry.
基金Supported by Guizhou Provincial Science and Technology Projects (QKHJC(2019)1294)Innovation Group Project of Guizhou Provincial Department of Education (QJH-KY-Z[2020]023)+1 种基金Moutai Institute High-level Talents Research Project (MYGCCRC[2022]064)Innovation and Entrepreneurship Training Program for College Students of Moutai Institute (X202214625040)。
文摘In order to find out the effects of soil fluorine on ecological environment and crop safety in the sorghum cultivation base of Renhuai City, Guizhou Province, the content and the occurrence forms of soil fluorine and its influencing factors of Maoba Town were investigated and studied. The results showed that the total fluorine content in the soil of the sorghum base ranged from 668.60 to 2 596.80 mg/kg, with an average of 1 483.25 mg/kg, which was 3.10 and 1.85 times of the national soil background value and the average value of the soil in endemic areas, respectively. The spatial distribution of fluorine in the soil of the study area was uneven, and the fluorine content was in the order of Anliang Village>Yangliu Village>Houba Village>Xiongfeng Village. The soil fluorine contents of various forms varied greatly, and the distribution law was as follows: residual state>water soluble state>organically bound state>exchangeable state>Fe/Mn-F state. The residual fluorine content was the highest, accounting for more than 99% of total fluorine content, while the sum of other four forms was less than 1%, with their respective proportions ranging from 0.10% to 0.30%. The content and proportion of available fluorine in water-soluble and exchangeable states were relatively low, which had limited influence on the surrounding water environment and crop safety. The physicochemical properties of soil, such as pH, organic matter, cation exchange capacity and clay particles had a certain influence on the occurrence forms of soil fluorine, thus changing the availability and migration of soil fluorine, which might endanger the ecological environment safety, food safety and human health.
文摘Based on practical work experience,this paper analyzed the occurrence characteristics and control measures of Spodoptera frugiperda in maize.The measures including forecasting and early warning,regional prevention and control,agricultural prevention and control,physical prevention and control,chemical prevention and control,and biological prevention and control can effectively control the damage of S.frugiperda and guarantee the safety of food production.The results will provide some reference for the prevention and control of S.frugiperda.
基金Peanut Innovation Team Project of Shandong Agricultural Industry Research System(SDAIT-05-022)Special Fund Project of Agricultural Technology Extension of Shandong Province(SDTG-2016-08).
文摘Peanut stem rot caused by Sclerotium rolfsii is a soil-borne disease,and it has become the main disease of peanut in Yimeng mountainous area.S.rolfsii survives the winter as mycelia and sclerotia in soil and debris,becoming the primary source of infection in the following year.The disease resistance of peanut varieties,high temperature and humidity,and cultivation measures are the pathogenic factors affecting the occurrence of peanut stem rot.The disease can be effectively controlled by screening disease-resistant varieties and seed chemical treatment,improving soil by deep tillage and crop rotation,carrying out flowing water management of affected field,cutting off transmission routes,and strengthening seed dressing and triple spraying control.
文摘Background and objectives: Breast Imaging Reporting and Data System in Category 3 (BIRADS-3) includes probably benign lesions which need a short-term imaging follow-up. However, in our context, the lesions graded BIRADS-3 remain insufficiently evaluated. We therefore conducted this study to assess the cancer occurrence and associated factors in BIRADS-3 lesions during the follow-up in order to propose an adaptation of the management for lesions in this category in our setting. Patients and methods: A retrospective longitudinal study of patients with lesions initially classified as BIRADS-3 and who realised each at least one additional imaging check-up between January 2014 and December 2022 in five Yaoundé hospitals. All clinical and imaging data were analysed using SPSS<sup>®</sup> 21.0 software with a significant p-value Results: Patients were aged 13 to 73 (33.0 ± 13.4) years, with a history of breast mass (315 cases;79.7%), breast pain (25 patients;6.3%), nipple discharge (20 patients;5.1%) or past family history of breast cancer (25 cases;6.3%). The most common baseline abnormalities were mammogram opacities (64.8%) and microcalcifications (48.6%), whereas initial breast ultrasound showed solid masses (77.0%) and cystic lesions (11.1%). Compliance with imaging appointment periods was low with only 23.9% of all patients performing an imaging control at the scheduled moment. During the follow-up, 115 patients (29.1%) were upgraded to BIRADS-4 and histology performed revealed 43 cancers (10.9% of overall initial BIRADS-3 sample). The presence of malignancies was associated to age above 40 years (p = 0.0001) and to the presence of nipple discharge (p = 0.0375). Conclusion: The frequency of malignancies among initial BIRADS-3 lesions in our series is higher than that described in the guidelines. This study highlights the need to be more proactive in the management of BIRADS-3 lesions in our setting as the compliance with follow-up is low. So, biopsy should be considered as an alternative to long-term follow-up for patients above 40, non-compliant with imaging check-ups and presenting with nipple discharge.
文摘Caregivers are highly exposed to blood exposure accidents (BEA). The objective of our study is to determine the frequency of BEA and to identify the predictive factors for the occurrence of BEAs among caregivers at the Kaolack Regional Hospital (KRH). It is a descriptive and analytical cross-sectional study of KRH’s caregivers. The data were collected during the period from 16 to 26 April 2018. The multivariate analysis was carried out using the binary logistic regression model with a dependent variable (occurrence of blood exposure accidents) and 5 explanatory variables (sex, age, service of belonging, professional category and seniority in the profession). A total of 115 caregivers were surveyed out of 144. It is noted that 68 caregivers (59.1%) have had at least one BEA in the previous 12 months. The age of caregivers significantly reduces the risk of developing a BEA (p = 0.004, CI [0.04 - 0.21]);belonging to the age group [20 - 40 years] increases the risk of a BEA by 6.66. Sex significantly influences the occurrence of BEA with a (p = 0.013, CI [1.47 - 19.4]);men are 5 times more likely to develop BEA. The risk of a BEA occurring varies according to the professional category. Senior health technicians have a significantly 50 times lower risk of occurrence of a BEA (p = 0.007, CI [0.00 - 0.24)]. Nurses and midwives have a 5.8 lower risk of developing BEAs (p = 0.031, CI [0.03 - 0.75]). The risk of occurrence of BEAs varies according to the service of belonging;Medicine service caregivers have a significantly 50-fold lower risk of developing BEAs (p = 0.004, CI [0.00 - 0.17]). The identified risk factors will be used to better guide our BEAs prevention interventions.
文摘Prior to his initial diagnosis, a 21-year-old male had been experiencing facial acne for two years and had been treated by a doctor in private practice. The patient visited our department because the clinical manifestations of mandibular acne did not improve. At the time of initial examination, telangiectasia (TE), post-inflammatory erythema (PIE), post-inflammatory hyperpigmentation (PIH), atrophic scars (ASs), and a hypertrophic scar (HS) with induration were observed on the right neck. We diagnosed this as an acne vulgaris complication. HS lesions were topically treated by injecting triamcinolone acetonide, and the patient was prescribed 8.1 g/day of oral Saireito (Japanese herb). Adapalene benzoyl peroxide gel and topical tacrolimus hydrate ointment were used to treat PIE and TE. Both HSs and PIE improved;however, TE and AS did not improve. Currently, the patient is under observation. We consider this to be a very rare concurrent occurrence of diverse complications of acne vulgaris, and present the following case study.
