In the first round of returning farmland to forest,many places in Hubei Province have vigorously developed ecological forests dominated by pine,fir and cypress,to improve the fragile ecological situation as soon as po...In the first round of returning farmland to forest,many places in Hubei Province have vigorously developed ecological forests dominated by pine,fir and cypress,to improve the fragile ecological situation as soon as possible.At present,this kind of ecological forests are facing the dilemma of more pure forests,higher density and less management,with worse economic benefits.To realize high-quality development of these stands,it is necessary to carry out forest management guided by the close-to-nature concept.These stands will be transformed into permanent forests with multi tree species,multi age classes,multi levels and continuous coverage,to realize organic unity of economic,ecological and social benefits.展开更多
Chronic atrophic gastritis(CAG)is a complex syndrome in which long-term chronic inflammatory stimulation causes gland atrophy in the gastric mucosa,reducing the stomach's ability to secrete gastric juice and pepsi...Chronic atrophic gastritis(CAG)is a complex syndrome in which long-term chronic inflammatory stimulation causes gland atrophy in the gastric mucosa,reducing the stomach's ability to secrete gastric juice and pepsin,and interfering with its normal physiological function.Multiple pathogenic factors contribute to CAG incidence,the most common being Helicobacter pylori infection and the immune reactions resulting from gastric autoimmunity.Furthermore,CAG has a broad spectrum of clinical manifestations,including gastroenterology and extraintestinal symptoms and signs,such as hematology,neurology,and oncology.Therefore,the initial CAG evaluation should involve the examination of clinical and serological indicators,as well as diagnosis confirmation via gastroscopy and histopathology if necessary.Depending on the severity and scope of atrophy affecting the gastric mucosa,a histologic staging system(Operative Link for Gastritis Assessment or Operative Link on Gastritis intestinal metaplasia)could also be employed.Moreover,chronic gastritis has a higher risk of progressing to gastric cancer(GC).In this regard,early diagnosis,treatment,and regular testing could reduce the risk of GC in CAG patients.However,the optimal interval for endoscopic monitoring in CAG patients remains uncertain,and it should ideally be tailored based on individual risk evaluations and shared decision-making processes.Although there have been many reports on CAG,the precise etiology and histopathological features of the disease,as well as the diagnosis of CAG patients,are yet to be fully elucidated.Consequently,this review offers a detailed account of CAG,including its key clinical aspects,aiming to enhance the overall understanding of the disease.展开更多
We compared the chemical components and essential oils of ancient buried Zhennan（Phoebe zhennan）wood with those in samples from living trees.After removal of the carbon layer the recovered Zhennan exhibited a dark g...We compared the chemical components and essential oils of ancient buried Zhennan（Phoebe zhennan）wood with those in samples from living trees.After removal of the carbon layer the recovered Zhennan exhibited a dark green color,which differed from the yellow color of the living samples.Low molecular weight components（including hot-water and toluene-alcohol extractives）,hemicellulose,and 1 % Na OH solubility in the recovered wood were greatly degraded.Degradation of cellulose was minor.Moreover,the ancient wood had somewhat more klason lignin than the modern wood.Fourier transform infrared（FTIR） analysis gave further evidence on the differences in chemical components.According to the GC–MS results,naphthalene derivatives were detected in the essential oils from both the modern and recovered wood.The delicate fragrance of the modern and recovered wood may be attributed to the aromatic constituents as identified by GC–MS.展开更多
As a new technology of analyzing crude oils, comprehensive two-dimensional gas chromatography cou- pled with time-of-flight mass spectrometry （GCxGC- TOFMS） has received much research attention. Here we present a ca...As a new technology of analyzing crude oils, comprehensive two-dimensional gas chromatography cou- pled with time-of-flight mass spectrometry （GCxGC- TOFMS） has received much research attention. Here we present a case study in the Junggar Basin of NW China. Results show that the hydrocarbons, including saturates and aromatics, were all well-separated without large co- elution, which cannot be realized by conventional one-dimensional GC-MS. The GC×GC technique is especially effective for analyzing aromatics and low-to-middle- molecular-weight hydrocarbons, such as diamondoids. The geochemical characteristics of crude oils in the study area were investigated through geochemical parameters extracted by GC×GC-TOFMS, improving upon the understanding obtained by GC-MS. Thus, the work here represents a new successful application of GC×GC- TOFMS, showing its broad usefulness in petroleum geochemistry.展开更多
The Mesozoic and Cenozoic strata in the Junggar basin developed two sets of shallow to semi-deep lacustrine shale, namely, the Cretaceous Qingshuihe Formation (K_(1q)) and the Paleogene Anjihaihe Formation (E_(2-3a))....The Mesozoic and Cenozoic strata in the Junggar basin developed two sets of shallow to semi-deep lacustrine shale, namely, the Cretaceous Qingshuihe Formation (K_(1q)) and the Paleogene Anjihaihe Formation (E_(2-3a)). Through organic petrology and scanning electron microscope (SEM) observation, it is found that the primary hydrocarbon-generating organic matter (OM) in the two sets of strata is different. The biological precursor of the E_(2-3a) OM is mainly green algae (Pediastrum), while the precursor of K_(1q) kerogen is mainly cyanobacteria (Oscillatoria). Then, the E_(2-3a) green algae-rich shale and K_(1q) cyanobacteria-rich shale were subjected to hydrous pyrolysis and kinetic analysis, respectively. The results show that the evolution modes of hydrocarbon generation of the typical shales are very different. Green algae have the characteristics of a low oil generation threshold, heavy oil quality, and no prominent oil peak, while cyanobacteria have the characteristics of late oil generation, concentrated hydrocarbon generation, and relatively light oil quality. The characteristics of oil generation can also be well reflected in the composition evolution of the crude oil components. The carbon isotope of gas, kerogen, and extracts of the E_(2-3a) green algae-rich shale are significantly heavier than the K_(1q) cyanobacteria-rich shale, which may be related to the living habits of their biological precursors, carbon source usage, photosynthesis efficiency, and carbon fixation efficiency.展开更多
Evaluating the hydrocarbon generation potential of highly mature organic matter is a key and critically challenging area of research in petroleum geochemistry. To explore this issue, we used negative ion electrospray ...Evaluating the hydrocarbon generation potential of highly mature organic matter is a key and critically challenging area of research in petroleum geochemistry. To explore this issue, we used negative ion electrospray ionization-Fourier transform-ion cyclotron resonance-mass spectrometry to investigate the molecular evolution of N-containing compounds in Carboniferous-lower Permian source rocks with a range of maturities in the northwestern Junggar Basin, China. The N1compounds formed from on-fluorescent chlorophyll catabolites(NCCs), which record the characteristics of the residual soluble organic matter. These components remain in the source rocks after hydrocarbon generation and expulsion, and enable evaluation of the hydrocarbon generation potential. The newly defined indexes of molecular evolution, which are the polymerization index P1([DBE 18+DBE 15]/[DBE 12+DBE 9]_N1) and alkylation index R1(RC_(6–35)/RC_(0–5)), combined with the vitrinite reflectance(VR_(o)) and paleo-salinity index(β-carotane/n Cmax), can identify the factors that control the evolution of highly mature organic matter. The main factor for source rocks deposited in a weakly saline environment is the maturity, but for a highly saline environment both the maturity and salinity are key factors. The high salinity inhibits the molecular polymerization of organic matter and extends the oil generation peak. Given the differences in the bio-precursors in saline source rocks, we propose a new model for hydrocarbon generation that can be used to determine the oil generation potential of highly mature organic matter.展开更多
基金Supported by Sino-German Technical Cooperation Close-to-Nature Forest Management Research(ZDJSHZ202001)Applied Research of English Translation in Sino-German Financial Cooperation Forestry Project(2018zdhzky01).
文摘In the first round of returning farmland to forest,many places in Hubei Province have vigorously developed ecological forests dominated by pine,fir and cypress,to improve the fragile ecological situation as soon as possible.At present,this kind of ecological forests are facing the dilemma of more pure forests,higher density and less management,with worse economic benefits.To realize high-quality development of these stands,it is necessary to carry out forest management guided by the close-to-nature concept.These stands will be transformed into permanent forests with multi tree species,multi age classes,multi levels and continuous coverage,to realize organic unity of economic,ecological and social benefits.
文摘Chronic atrophic gastritis(CAG)is a complex syndrome in which long-term chronic inflammatory stimulation causes gland atrophy in the gastric mucosa,reducing the stomach's ability to secrete gastric juice and pepsin,and interfering with its normal physiological function.Multiple pathogenic factors contribute to CAG incidence,the most common being Helicobacter pylori infection and the immune reactions resulting from gastric autoimmunity.Furthermore,CAG has a broad spectrum of clinical manifestations,including gastroenterology and extraintestinal symptoms and signs,such as hematology,neurology,and oncology.Therefore,the initial CAG evaluation should involve the examination of clinical and serological indicators,as well as diagnosis confirmation via gastroscopy and histopathology if necessary.Depending on the severity and scope of atrophy affecting the gastric mucosa,a histologic staging system(Operative Link for Gastritis Assessment or Operative Link on Gastritis intestinal metaplasia)could also be employed.Moreover,chronic gastritis has a higher risk of progressing to gastric cancer(GC).In this regard,early diagnosis,treatment,and regular testing could reduce the risk of GC in CAG patients.However,the optimal interval for endoscopic monitoring in CAG patients remains uncertain,and it should ideally be tailored based on individual risk evaluations and shared decision-making processes.Although there have been many reports on CAG,the precise etiology and histopathological features of the disease,as well as the diagnosis of CAG patients,are yet to be fully elucidated.Consequently,this review offers a detailed account of CAG,including its key clinical aspects,aiming to enhance the overall understanding of the disease.
基金supported by "Key Laboratory of Wood Industry and Furniture Engineering of Sichuan Provincial Colleges and Universities"
文摘We compared the chemical components and essential oils of ancient buried Zhennan（Phoebe zhennan）wood with those in samples from living trees.After removal of the carbon layer the recovered Zhennan exhibited a dark green color,which differed from the yellow color of the living samples.Low molecular weight components（including hot-water and toluene-alcohol extractives）,hemicellulose,and 1 % Na OH solubility in the recovered wood were greatly degraded.Degradation of cellulose was minor.Moreover,the ancient wood had somewhat more klason lignin than the modern wood.Fourier transform infrared（FTIR） analysis gave further evidence on the differences in chemical components.According to the GC–MS results,naphthalene derivatives were detected in the essential oils from both the modern and recovered wood.The delicate fragrance of the modern and recovered wood may be attributed to the aromatic constituents as identified by GC–MS.
基金funded by the Major State Basic Research Development Program of China(973 project,Grant No.2012CB214803)National Science and Technology Major Project of China(Grant No. 2016ZX05003-005)National Natural Science Foundation of China(Grant Nos.41322017 and 41472100)
文摘As a new technology of analyzing crude oils, comprehensive two-dimensional gas chromatography cou- pled with time-of-flight mass spectrometry （GCxGC- TOFMS） has received much research attention. Here we present a case study in the Junggar Basin of NW China. Results show that the hydrocarbons, including saturates and aromatics, were all well-separated without large co- elution, which cannot be realized by conventional one-dimensional GC-MS. The GC×GC technique is especially effective for analyzing aromatics and low-to-middle- molecular-weight hydrocarbons, such as diamondoids. The geochemical characteristics of crude oils in the study area were investigated through geochemical parameters extracted by GC×GC-TOFMS, improving upon the understanding obtained by GC-MS. Thus, the work here represents a new successful application of GC×GC- TOFMS, showing its broad usefulness in petroleum geochemistry.
基金supported by Xinjiang Oilfield Company of China(No.2020-C4006).
文摘The Mesozoic and Cenozoic strata in the Junggar basin developed two sets of shallow to semi-deep lacustrine shale, namely, the Cretaceous Qingshuihe Formation (K_(1q)) and the Paleogene Anjihaihe Formation (E_(2-3a)). Through organic petrology and scanning electron microscope (SEM) observation, it is found that the primary hydrocarbon-generating organic matter (OM) in the two sets of strata is different. The biological precursor of the E_(2-3a) OM is mainly green algae (Pediastrum), while the precursor of K_(1q) kerogen is mainly cyanobacteria (Oscillatoria). Then, the E_(2-3a) green algae-rich shale and K_(1q) cyanobacteria-rich shale were subjected to hydrous pyrolysis and kinetic analysis, respectively. The results show that the evolution modes of hydrocarbon generation of the typical shales are very different. Green algae have the characteristics of a low oil generation threshold, heavy oil quality, and no prominent oil peak, while cyanobacteria have the characteristics of late oil generation, concentrated hydrocarbon generation, and relatively light oil quality. The characteristics of oil generation can also be well reflected in the composition evolution of the crude oil components. The carbon isotope of gas, kerogen, and extracts of the E_(2-3a) green algae-rich shale are significantly heavier than the K_(1q) cyanobacteria-rich shale, which may be related to the living habits of their biological precursors, carbon source usage, photosynthesis efficiency, and carbon fixation efficiency.
基金supported by the National Natural Science Foundation of China(Grant Nos.42230808 and 42102148)China Postdoctoral Science Foundation(Grant No.2021M691497)。
文摘Evaluating the hydrocarbon generation potential of highly mature organic matter is a key and critically challenging area of research in petroleum geochemistry. To explore this issue, we used negative ion electrospray ionization-Fourier transform-ion cyclotron resonance-mass spectrometry to investigate the molecular evolution of N-containing compounds in Carboniferous-lower Permian source rocks with a range of maturities in the northwestern Junggar Basin, China. The N1compounds formed from on-fluorescent chlorophyll catabolites(NCCs), which record the characteristics of the residual soluble organic matter. These components remain in the source rocks after hydrocarbon generation and expulsion, and enable evaluation of the hydrocarbon generation potential. The newly defined indexes of molecular evolution, which are the polymerization index P1([DBE 18+DBE 15]/[DBE 12+DBE 9]_N1) and alkylation index R1(RC_(6–35)/RC_(0–5)), combined with the vitrinite reflectance(VR_(o)) and paleo-salinity index(β-carotane/n Cmax), can identify the factors that control the evolution of highly mature organic matter. The main factor for source rocks deposited in a weakly saline environment is the maturity, but for a highly saline environment both the maturity and salinity are key factors. The high salinity inhibits the molecular polymerization of organic matter and extends the oil generation peak. Given the differences in the bio-precursors in saline source rocks, we propose a new model for hydrocarbon generation that can be used to determine the oil generation potential of highly mature organic matter.
