AIM:To summarize 10 surgical pearls for managing proliferative diabetic retinopathy(PDR)adapted from the ancient Chinese allusions and analyze the application of these pearls in a real-world fashion.METHODS:Retrospect...AIM:To summarize 10 surgical pearls for managing proliferative diabetic retinopathy(PDR)adapted from the ancient Chinese allusions and analyze the application of these pearls in a real-world fashion.METHODS:Retrospective,noncomparative,interventional study.Ten surgical pearls were summarized and adapted from the ancient Chinese philosophy.Totally 346 cases(443 eyes)that underwent pars plana vitrectomy(PPV)at our hospial from January 2016 to February 2024 were selected.Flexible combinations of these pearls were applied according to the specific condition of each patient during surgeries.The efficacy and safety were analyzed,as well as the application frequencies according to the existence of tractional retinal detachment or not.RESULTS:A total of 473 times of surgeries were performed on all the patients.According to ancient Chinese allusions,ten surgical pearls were summarized from these surgeries.All PPVs went smoothly with the application of different combinations.Finally,almost all proliferative membranes were successfully peeled except for 10 patients(11 eyes),who went through strategy No.10(minimal membranectomy)that,only necessary relaxation incisions were made with most of the proliferative membranes left on purpose.The final visual acuities were mostly improved or stable(1.92±0.83 LogMAR preoperatively vs 1.16±0.85 LogMAR postoperatively,P<0.01).Postoperative complications mainly included early inflammatory responses in the anterior chamber and nuclear sclerosis.Recurrent vitreous hemorrhage,retinal detachment,and hyphema or neovascular glaucoma occurred in 1.9%(9/473),3.2%(15/473),0.4%(2/473)and 0.4%(2/473)times of PPVs,respectively.After 12/473(2.5%)times of PPVs,retinal detachment at the macular area still existed,and multiple times of subsequent PPVs were conducted.Final retinal attachment at the macular area was realized in 98.9%eyes.Those 5 unattached eyes were with heavily reproliferated membranes and subsequent tractional retinal detachment recurrence under the oil,and three of them were scleral buckled additionally.CONCLUSION:These 10 surgical strategies and technique pearls were mostly effective and safe in the management of severe PDR patients.They were relatively easy to be memorized and applicated once the meaning of each Chinese idiom was understood.One can use different combinations flexibly according to a patient’s specific condition.展开更多
On the tranquil waters of Xiaoshanyang,a small lake in Deqing County,Zhejiang Province,rows of white,spherical buoys are lined up in perfect order,resembling strands of pearl necklaces.Once a thousand-year-old pearl-f...On the tranquil waters of Xiaoshanyang,a small lake in Deqing County,Zhejiang Province,rows of white,spherical buoys are lined up in perfect order,resembling strands of pearl necklaces.Once a thousand-year-old pearl-farming site,this heritage-rich waterbody has emerged as a global benchmark for the preservation of agricultural heritage.展开更多
Black tents,also known as black yak-wool tents due to their construction from yak wool,serve as the traditional accommodation for ethnic Tibetan nomads.From ancient times till now,these tents have long captured the no...Black tents,also known as black yak-wool tents due to their construction from yak wool,serve as the traditional accommodation for ethnic Tibetan nomads.From ancient times till now,these tents have long captured the nomadic life of herdsmen living on the Qinghai-Xizang Plateau.展开更多
The transition of the superficial microstmcture of freshwater pearls induced by Ce was investigated by means of scanning electron microscopy. The pearls were cultured in freshwater containing 0 （control group ）, 0.5...The transition of the superficial microstmcture of freshwater pearls induced by Ce was investigated by means of scanning electron microscopy. The pearls were cultured in freshwater containing 0 （control group ）, 0.5, 1, and 1.5 mg·L^-1 of a Ce additive. X-ray photoelectron spectroscopy （XPS） measurement showed that the concentration of Ce absorbed in the superficial microstmcture of pearls was positively correlated to the additive Ce. At the same time, the surface microstmcture of pearls changed greatly with Ce concentration, the shape of the blocks changed from spindly to perfect regular hexagonal sheets and finally to round discs. The glossiness of the pearls changed correspondingly with the microstmcture, pearls possessing the regular hexagonal blocks having the highest glossiness. Therefore, the REE Ce exerted a significant influence on the microstructure and glossiness of freshwater pearls. An appropriate quantity of Ce may improve the glossiness of pearls.展开更多
Optical and micro-infrared microscope were used to observe the internal structure and mineral composition of high and low quality Chinese seawater and freshwater cultured pearls.Results clearly reveal that aragonite a...Optical and micro-infrared microscope were used to observe the internal structure and mineral composition of high and low quality Chinese seawater and freshwater cultured pearls.Results clearly reveal that aragonite and calcite are found in seawater cultured pearls,but vaterite is not found.In contrast,vaterite and aragonite are found in freshwater cultured pearls,but calcite is not found.Based on our analysis and observations of the internal structure of high and low quality cultured pearls,a modified integrated model of the internal structure of Chinese cultured pearls was established.Our revisions to the previous model focus on significant differences within the prismatic layer of Chinese cultured pearls.展开更多
AIM: To compare surgical peeling and aspiration and neodymium yttrium garnet laser capsulotomy for pearl form of posterior capsule opacification(PCO).METHODS: A prospective, randomized, double blind,study was done at ...AIM: To compare surgical peeling and aspiration and neodymium yttrium garnet laser capsulotomy for pearl form of posterior capsule opacification(PCO).METHODS: A prospective, randomized, double blind,study was done at Rotary Eye Hospital, Maranda,Palampur, India, Santosh Medical College Hospital,Ghaziabad, India and Laser Eye Clinic, Noida India.Consecutive patients with pearl form of PCO following surgery, phacoemulsification, manual small incision cataract surgery and conventional extracapsular cataract extraction(ECCE) for age related cataract, were randomized to have peeling and aspiration or neodymium yttrium garnet laser capsulotomy. Corrected distance visual acuity(CDVA), intra-operative and postoperative complications were compared.RESULTS: A total of 634 patients participated in the study, and 314(49.5%) patients were randomized to surgical peeling and aspiration group and 320(50.5%) to the Nd:YAG laser group. The mean pre-procedural log MAR CDVA in peeling and neodymium: yttrium-aluminium-garnet(Nd:YAG) laser group was 0.80 ±0.25 and 0.86 ±0.22, respectively. The mean final CDVA in peeling group(0.22 ±0.23) was comparable to Nd:YAG group(0.24 ±0.28; t-test, P =0.240). There was a significant improvement in vision after both the procedures(P 【0.001). A slightly higher percentage of patients in Nd:YAG laser group(283/88.3%) than in peeling group(262/83.4%) had a CDVA of 0.5(20/63) or better at 9mo(P 【0.001). On the contrary, patients havingCDVA worse than 1.00(20/200) was also significantly higher in Nd:YAG laser group as compared to peeling group(25/7.7% vs 15/4.7%, respectively). On application of ANCOVA, there was less than 0.001% risk that PCO thickness and total laser energy had no effect on rate of complications in Nd:YAG laser group and less than 0.001% risk that PCO thickness had no effect on complications in peeling group respectively. Sum of square analysis suggests that in the Nd:YAG laser group,thick PCO had a stronger impact on complications(Fischer test probability, P r 【0.0001) than thin PCO and total laser energy(Fischer test probability, P r 【0.002),respectively; similarly, in peeling group, thick PCO and preoperative vision had a stronger effect on complications than thin PCO, respectively(Fischer test probability, P r 【0.001). The rate of complications like uveitis(P =0.527) and cystoid macular edema(P =0.068),did not differ significantly between both the groups.However, intraocular pressure spikes(P =0.046) and retinal detachment(P【0.001) were significantly higher in Nd:YAG laser group as compared to peeling group.Retinal detachment was more common in patients having degenerative myopia(7/87.5%, P 【0.001). Recurrence of pearls was the most common cause of reduction of vision in the peeling group(24/7.6%, P 【0.001).CONCLUSION: There is no alternative to Nd:YAG laser capsulotomy for fibrous subtype of PCO. For pearl form of PCO, both techniques are comparable with regard to visual outcomes. Nd:YAG laser capsulotomy has a higher incidence of IOP spikes and retinal detachment whereas recurrence of pearls may occur after successful peeling and aspiration. When posterior capsulotomy is needed in patients with retinal degenerations,retinopathies and pre-existing retinal breaks, the clinician should be cautious about increased risks of possible complications of Nd:YAG laser capsulotomy.展开更多
In this article we explored the crystal structure of a few pearls and shellfish's shell of fresh water and sea water, and found that pearls and nacreous layer (perhaps and prismatic layer) of shells are all the sa...In this article we explored the crystal structure of a few pearls and shellfish's shell of fresh water and sea water, and found that pearls and nacreous layer (perhaps and prismatic layer) of shells are all the same: CaCO3, orthorhombic system, aragonite structure and the value of lattice spacings are almost identical. This shows that the pearls of fresh water and sea water are all the same in nature.展开更多
The effects of gamma-aminobutyric acid(GABA)on gelatinization,pasting and rheological properties of the blend of hydroxypropyl distarch phosphate and tapioca starch were studied to examine the in vitro digestive chara...The effects of gamma-aminobutyric acid(GABA)on gelatinization,pasting and rheological properties of the blend of hydroxypropyl distarch phosphate and tapioca starch were studied to examine the in vitro digestive characteristics of tapioca pearls.The addition of higher GABA contents resulted in lower starch hydrolysis rates and release rates of GABA during the digestion process,which indicated that GABA could modulate the digestive properties of tapioca pearls.RVA and DSC results showed that GABA inhibited the gelatinization of mixed starch and hindered the recrystallization of starch,leading to enhanced thermal stability and reduced viscosity.Also,the addition of GABA limited the water absorption and expansion of starch to some extent,resulting in decreased elastic and viscous moduli.XRD results showed that GABA changed the crystal structure of original mixed starch with reduced crystallinity.Moreover,the addition of GABA resulted in a reduction of RDS content and a significant increase in RS,which would provide potential applications for GABA in starchy health food.展开更多
An experimental study of the influence of external magnetic field on the fluidization behavior of magnetic pearls was carried out. Magnetic pearls are a magnetic form of iron oxide that mainly consists of Fe2O3 which ...An experimental study of the influence of external magnetic field on the fluidization behavior of magnetic pearls was carried out. Magnetic pearls are a magnetic form of iron oxide that mainly consists of Fe2O3 which are recovered from a high-volume power plant fly ash from pulverized coal combustion. Due to its abundance, low price and particular physical and chemical properties, magnetic pearls can be used as a heavy medium for minerals or solid waste dry separation based on density difference. This paper introduces the properties of magnetic pearls and compares the performance of magnetic pearls fluidised bed operation with or without an external magnetic field. Experimental results show that an external magnetic field significantly improves the fluidization performance of magnetic pearls such as uniformity and stability.展开更多
Quantifying the timing and amplitude of multiple subsidence or uplift stages in sedimentary basins is crucial for understanding their tectonic evolution.In this study,18 samples from 10 drilling wells in the Pearl Riv...Quantifying the timing and amplitude of multiple subsidence or uplift stages in sedimentary basins is crucial for understanding their tectonic evolution.In this study,18 samples from 10 drilling wells in the Pearl River Mouth Basin(PRMB)were subjected to apatite and zircon fission track analyses,and suitable samples were selected for thermal history simulation using Hefty.The thermal history simulation results,combined with balanced cross-section analysis,constrain the Cenozoic tectonothermal history of the PRMB.The results indicate that the PRMB underwent differential uplift in the early Paleogene,followed by regional thermal subsidence in the late Paleogene.Subsequently,the PRMB began tectonic activation in the late Miocene due to the Dongsha movement,marked by two rapid cooling events of ca.11–6.5 and 6.5 Myr to the present.These cooling events are characterized by a gradual migration from east to west.The first rapid cooling event can be attributed to the NW-SE compressive stress field in the northeastern South China Sea,driven by the clockwise rotation of the Philippine Sea Plate during the late Miocene.The second rapid cooling event is linked to intensive arc-continental collision and the Taiwan Orogeny triggered by the rapid WNW-ward migration of the Philippine Sea Plate.展开更多
Traditional source-to-sink analyses cannot effectively characterize deep-time sedimentary processes involving multiple sediment sources and the spatiotemporal evolution of sediment contributions from different sources...Traditional source-to-sink analyses cannot effectively characterize deep-time sedimentary processes involving multiple sediment sources and the spatiotemporal evolution of sediment contributions from different sources.In this study,a dynamic,quantitative source-to-sink analysis approach using stratigraphic forward modeling(SFM)is proposed,and it is applied to the Paleogene Enping Formation in the Baiyun Sag,Pearl River Mouth Basin.The built-in spatiotemporal provenance tagging of the model assigns a unique time-source label to sediments from each provenance,making each source's contribution identifiably“labeled”in the simulated formation,and thus enabling a direct precise tracking and high spatiotemporal resolution quantification of such contributions.Five pseudo-wells(from proximal to distal locations)in the Baiyun Sag were analyzed.The simulation results quantitatively represent the varied proportion of contribution of each source at different locations and in different periods and verify the proposed approach's operability and accuracy of the proposed approach.The simulated 3D deposit distribution shows a high agreement with the measured stratigraphic data,validating the model's reliability.Results reveal significant spatiotemporal changes in the Enping sedimentary system.In the late stage of Enping Formation deposition,a distal source supply from the northern part of the sag became dominant,the depocenter migrated northward to the deepwater area,and large-scale deltaic sand bodies extensively progradating into the sag were formed.The modeled 3D deposit distribution indicates that extensive high-quality reservoir sandstones are likely present across the deepwater area of the Baiyun Sag,which are identified as key exploration targets.Compared to traditional static approaches,the SFM-based dynamic simulation markedly enhances the spatiotemporal resolution of source-to-sink analysis and quantitatively captures the sedimentary system's responses to tectonic activity,base-level fluctuations and other external drivers.The proposed approach provides a novel quantitative framework for investigating complex,deep-time,multi-source systems,and offers an effective tool for reservoir prediction and hydrocarbon exploration planning in underexplored deepwater areas.展开更多
For the next exploration direction and integrated evaluation and optimization of targets for the northern continental margin of the South China Sea,this paper proposes the concept of the“total natural gas play system...For the next exploration direction and integrated evaluation and optimization of targets for the northern continental margin of the South China Sea,this paper proposes the concept of the“total natural gas play system”based on the principles of systems theory.Integrating over 60 years of exploration achievements in the four major basins,the paper studies the basic geological conditions,hydrocarbon accumulation models and distribution characteristics of the system.With the core principle of“source-heat controlling natural gas and play-stratigraphy controlling accumulation”,it analyzes the distribution law of natural gas reservoirs covering“intra-sag,sag margin,extra-sag”and multi-stratigraphic sequences.The study shows that under the joint control of source and heat,the northern continental margin of the South China Sea can be divided into two major gas areas:the southern area dominated by coal-type gas and the northern area dominated by oil-type gas,with the former as the main body.Based on the distribution location of hydrocarbon kitchen,the total gas plays are classified into three types:intra-sag,sag margin and extra-sag.In the oil-type gas area of the northern coastal zone,the proportion of intra-sag natural gas is relatively high;in the coal-type gas area of the southern offshore zone,the proportions of intra-sag and sag margin natural gas are relatively large;while the scale of gas accumulation in the extra-sag plays is relatively small.Finally,it is clearly pointed out that the southern offshore zone is the main direction for the next natural gas exploration in the northern South China Sea.Specifically,in the offshore zone,the intra-sag play and middle-deep layers of the sag margin play in the Yingzhong sag should be focused for the Yinggehai Basin;the intra-sag play and sag margin play in the central depression are targets for the Qiongdongnan Basin;the middle-deep layers of the intra-sag play are targets for the Baiyun sag of the Pearl River Mouth Basin.Furthermore,in the northern depression zone of the Pearl River Mouth Basin within the coastal zone,the main exploration directions include the middle-deep layers of the intra-sag play in the Huizhou sag and the middle-deep layers of the intra-sag play in the Enping sag;in the Beibu Gulf Basin,the main directions are the middle-deep layers of the intra-sag play in the Weixinan sag and the middle-deep layers of the intra-sag play in the Haizhong sag.展开更多
WANG Mingzhen is a wellknown Chinese physicist. Recently the 91-year-old woman looked back over the profoundly affecting experiences of her life. A Series of Setbacks As soon as she graduated from Peking University in...WANG Mingzhen is a wellknown Chinese physicist. Recently the 91-year-old woman looked back over the profoundly affecting experiences of her life. A Series of Setbacks As soon as she graduated from Peking University in 1930, Wang Mingzhen received an offer of admission from the University of Michigan in the United States. Although the school offered her a four-year scholarship for her tuition, she was penniless and could not afford the steamer ticket. Unwilling to seek help from her friends and relatives, Wang sent a letter declining admission, using her mother’s illness as an excuse. She could not know that this action would展开更多
On the night of the Qixi Festival,Chinese Valentine's Day,which fell on August 22 this year,Yao Xiaofang,a 71-year-old pearl wholesaler,livestreamed until midnight,later than usual.She did so because of the extrao...On the night of the Qixi Festival,Chinese Valentine's Day,which fell on August 22 this year,Yao Xiaofang,a 71-year-old pearl wholesaler,livestreamed until midnight,later than usual.She did so because of the extraordinary enthusiasm of her viewers.With the username Pearl Grandma on video-sharing platform Douyin,China's TikTok,she has more than 1 million fans and has gained popularity online for her profound knowledge of pearls.展开更多
文摘AIM:To summarize 10 surgical pearls for managing proliferative diabetic retinopathy(PDR)adapted from the ancient Chinese allusions and analyze the application of these pearls in a real-world fashion.METHODS:Retrospective,noncomparative,interventional study.Ten surgical pearls were summarized and adapted from the ancient Chinese philosophy.Totally 346 cases(443 eyes)that underwent pars plana vitrectomy(PPV)at our hospial from January 2016 to February 2024 were selected.Flexible combinations of these pearls were applied according to the specific condition of each patient during surgeries.The efficacy and safety were analyzed,as well as the application frequencies according to the existence of tractional retinal detachment or not.RESULTS:A total of 473 times of surgeries were performed on all the patients.According to ancient Chinese allusions,ten surgical pearls were summarized from these surgeries.All PPVs went smoothly with the application of different combinations.Finally,almost all proliferative membranes were successfully peeled except for 10 patients(11 eyes),who went through strategy No.10(minimal membranectomy)that,only necessary relaxation incisions were made with most of the proliferative membranes left on purpose.The final visual acuities were mostly improved or stable(1.92±0.83 LogMAR preoperatively vs 1.16±0.85 LogMAR postoperatively,P<0.01).Postoperative complications mainly included early inflammatory responses in the anterior chamber and nuclear sclerosis.Recurrent vitreous hemorrhage,retinal detachment,and hyphema or neovascular glaucoma occurred in 1.9%(9/473),3.2%(15/473),0.4%(2/473)and 0.4%(2/473)times of PPVs,respectively.After 12/473(2.5%)times of PPVs,retinal detachment at the macular area still existed,and multiple times of subsequent PPVs were conducted.Final retinal attachment at the macular area was realized in 98.9%eyes.Those 5 unattached eyes were with heavily reproliferated membranes and subsequent tractional retinal detachment recurrence under the oil,and three of them were scleral buckled additionally.CONCLUSION:These 10 surgical strategies and technique pearls were mostly effective and safe in the management of severe PDR patients.They were relatively easy to be memorized and applicated once the meaning of each Chinese idiom was understood.One can use different combinations flexibly according to a patient’s specific condition.
文摘On the tranquil waters of Xiaoshanyang,a small lake in Deqing County,Zhejiang Province,rows of white,spherical buoys are lined up in perfect order,resembling strands of pearl necklaces.Once a thousand-year-old pearl-farming site,this heritage-rich waterbody has emerged as a global benchmark for the preservation of agricultural heritage.
文摘Black tents,also known as black yak-wool tents due to their construction from yak wool,serve as the traditional accommodation for ethnic Tibetan nomads.From ancient times till now,these tents have long captured the nomadic life of herdsmen living on the Qinghai-Xizang Plateau.
基金Project supported by the Chinese Ministry of Education (205065)
文摘The transition of the superficial microstmcture of freshwater pearls induced by Ce was investigated by means of scanning electron microscopy. The pearls were cultured in freshwater containing 0 （control group ）, 0.5, 1, and 1.5 mg·L^-1 of a Ce additive. X-ray photoelectron spectroscopy （XPS） measurement showed that the concentration of Ce absorbed in the superficial microstmcture of pearls was positively correlated to the additive Ce. At the same time, the surface microstmcture of pearls changed greatly with Ce concentration, the shape of the blocks changed from spindly to perfect regular hexagonal sheets and finally to round discs. The glossiness of the pearls changed correspondingly with the microstmcture, pearls possessing the regular hexagonal blocks having the highest glossiness. Therefore, the REE Ce exerted a significant influence on the microstructure and glossiness of freshwater pearls. An appropriate quantity of Ce may improve the glossiness of pearls.
基金Funded by the National Natural Science Foundation of China(No.20966002)
文摘Optical and micro-infrared microscope were used to observe the internal structure and mineral composition of high and low quality Chinese seawater and freshwater cultured pearls.Results clearly reveal that aragonite and calcite are found in seawater cultured pearls,but vaterite is not found.In contrast,vaterite and aragonite are found in freshwater cultured pearls,but calcite is not found.Based on our analysis and observations of the internal structure of high and low quality cultured pearls,a modified integrated model of the internal structure of Chinese cultured pearls was established.Our revisions to the previous model focus on significant differences within the prismatic layer of Chinese cultured pearls.
文摘AIM: To compare surgical peeling and aspiration and neodymium yttrium garnet laser capsulotomy for pearl form of posterior capsule opacification(PCO).METHODS: A prospective, randomized, double blind,study was done at Rotary Eye Hospital, Maranda,Palampur, India, Santosh Medical College Hospital,Ghaziabad, India and Laser Eye Clinic, Noida India.Consecutive patients with pearl form of PCO following surgery, phacoemulsification, manual small incision cataract surgery and conventional extracapsular cataract extraction(ECCE) for age related cataract, were randomized to have peeling and aspiration or neodymium yttrium garnet laser capsulotomy. Corrected distance visual acuity(CDVA), intra-operative and postoperative complications were compared.RESULTS: A total of 634 patients participated in the study, and 314(49.5%) patients were randomized to surgical peeling and aspiration group and 320(50.5%) to the Nd:YAG laser group. The mean pre-procedural log MAR CDVA in peeling and neodymium: yttrium-aluminium-garnet(Nd:YAG) laser group was 0.80 ±0.25 and 0.86 ±0.22, respectively. The mean final CDVA in peeling group(0.22 ±0.23) was comparable to Nd:YAG group(0.24 ±0.28; t-test, P =0.240). There was a significant improvement in vision after both the procedures(P 【0.001). A slightly higher percentage of patients in Nd:YAG laser group(283/88.3%) than in peeling group(262/83.4%) had a CDVA of 0.5(20/63) or better at 9mo(P 【0.001). On the contrary, patients havingCDVA worse than 1.00(20/200) was also significantly higher in Nd:YAG laser group as compared to peeling group(25/7.7% vs 15/4.7%, respectively). On application of ANCOVA, there was less than 0.001% risk that PCO thickness and total laser energy had no effect on rate of complications in Nd:YAG laser group and less than 0.001% risk that PCO thickness had no effect on complications in peeling group respectively. Sum of square analysis suggests that in the Nd:YAG laser group,thick PCO had a stronger impact on complications(Fischer test probability, P r 【0.0001) than thin PCO and total laser energy(Fischer test probability, P r 【0.002),respectively; similarly, in peeling group, thick PCO and preoperative vision had a stronger effect on complications than thin PCO, respectively(Fischer test probability, P r 【0.001). The rate of complications like uveitis(P =0.527) and cystoid macular edema(P =0.068),did not differ significantly between both the groups.However, intraocular pressure spikes(P =0.046) and retinal detachment(P【0.001) were significantly higher in Nd:YAG laser group as compared to peeling group.Retinal detachment was more common in patients having degenerative myopia(7/87.5%, P 【0.001). Recurrence of pearls was the most common cause of reduction of vision in the peeling group(24/7.6%, P 【0.001).CONCLUSION: There is no alternative to Nd:YAG laser capsulotomy for fibrous subtype of PCO. For pearl form of PCO, both techniques are comparable with regard to visual outcomes. Nd:YAG laser capsulotomy has a higher incidence of IOP spikes and retinal detachment whereas recurrence of pearls may occur after successful peeling and aspiration. When posterior capsulotomy is needed in patients with retinal degenerations,retinopathies and pre-existing retinal breaks, the clinician should be cautious about increased risks of possible complications of Nd:YAG laser capsulotomy.
基金The project supported by National Natural Science Foundation of China(NSFC)
文摘In this article we explored the crystal structure of a few pearls and shellfish's shell of fresh water and sea water, and found that pearls and nacreous layer (perhaps and prismatic layer) of shells are all the same: CaCO3, orthorhombic system, aragonite structure and the value of lattice spacings are almost identical. This shows that the pearls of fresh water and sea water are all the same in nature.
基金supported by National Natural Science Foundation of China(32302282,32272470)Natural Science Foundation of Jiangsu Province(BK20210460)The research was also supported by the program of“Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province”,China.
文摘The effects of gamma-aminobutyric acid(GABA)on gelatinization,pasting and rheological properties of the blend of hydroxypropyl distarch phosphate and tapioca starch were studied to examine the in vitro digestive characteristics of tapioca pearls.The addition of higher GABA contents resulted in lower starch hydrolysis rates and release rates of GABA during the digestion process,which indicated that GABA could modulate the digestive properties of tapioca pearls.RVA and DSC results showed that GABA inhibited the gelatinization of mixed starch and hindered the recrystallization of starch,leading to enhanced thermal stability and reduced viscosity.Also,the addition of GABA limited the water absorption and expansion of starch to some extent,resulting in decreased elastic and viscous moduli.XRD results showed that GABA changed the crystal structure of original mixed starch with reduced crystallinity.Moreover,the addition of GABA resulted in a reduction of RDS content and a significant increase in RS,which would provide potential applications for GABA in starchy health food.
基金The authors wish to thank the National Natural Science Foundation of China （No. 90510002 and No. 90210035） for financing the project.
文摘An experimental study of the influence of external magnetic field on the fluidization behavior of magnetic pearls was carried out. Magnetic pearls are a magnetic form of iron oxide that mainly consists of Fe2O3 which are recovered from a high-volume power plant fly ash from pulverized coal combustion. Due to its abundance, low price and particular physical and chemical properties, magnetic pearls can be used as a heavy medium for minerals or solid waste dry separation based on density difference. This paper introduces the properties of magnetic pearls and compares the performance of magnetic pearls fluidised bed operation with or without an external magnetic field. Experimental results show that an external magnetic field significantly improves the fluidization performance of magnetic pearls such as uniformity and stability.
基金funded by the National Natural Science Foundation of China(Nos.42121005,92358302,42302233)the Science and Technology Innovation Project of Laoshan Laboratory(No.LSKJ202204400)the Fundamental Research Funds for the Central Universities(No.202172003)。
文摘Quantifying the timing and amplitude of multiple subsidence or uplift stages in sedimentary basins is crucial for understanding their tectonic evolution.In this study,18 samples from 10 drilling wells in the Pearl River Mouth Basin(PRMB)were subjected to apatite and zircon fission track analyses,and suitable samples were selected for thermal history simulation using Hefty.The thermal history simulation results,combined with balanced cross-section analysis,constrain the Cenozoic tectonothermal history of the PRMB.The results indicate that the PRMB underwent differential uplift in the early Paleogene,followed by regional thermal subsidence in the late Paleogene.Subsequently,the PRMB began tectonic activation in the late Miocene due to the Dongsha movement,marked by two rapid cooling events of ca.11–6.5 and 6.5 Myr to the present.These cooling events are characterized by a gradual migration from east to west.The first rapid cooling event can be attributed to the NW-SE compressive stress field in the northeastern South China Sea,driven by the clockwise rotation of the Philippine Sea Plate during the late Miocene.The second rapid cooling event is linked to intensive arc-continental collision and the Taiwan Orogeny triggered by the rapid WNW-ward migration of the Philippine Sea Plate.
基金Supported by the National Natural Science Foundation of China(92055204)Strategic Priority Research Program of the Chinese Academy of Sciences(Class A)(XDA14010401)China National Offshore Oil Corporation(CNOOC)(CCL2021SKPS0118)。
文摘Traditional source-to-sink analyses cannot effectively characterize deep-time sedimentary processes involving multiple sediment sources and the spatiotemporal evolution of sediment contributions from different sources.In this study,a dynamic,quantitative source-to-sink analysis approach using stratigraphic forward modeling(SFM)is proposed,and it is applied to the Paleogene Enping Formation in the Baiyun Sag,Pearl River Mouth Basin.The built-in spatiotemporal provenance tagging of the model assigns a unique time-source label to sediments from each provenance,making each source's contribution identifiably“labeled”in the simulated formation,and thus enabling a direct precise tracking and high spatiotemporal resolution quantification of such contributions.Five pseudo-wells(from proximal to distal locations)in the Baiyun Sag were analyzed.The simulation results quantitatively represent the varied proportion of contribution of each source at different locations and in different periods and verify the proposed approach's operability and accuracy of the proposed approach.The simulated 3D deposit distribution shows a high agreement with the measured stratigraphic data,validating the model's reliability.Results reveal significant spatiotemporal changes in the Enping sedimentary system.In the late stage of Enping Formation deposition,a distal source supply from the northern part of the sag became dominant,the depocenter migrated northward to the deepwater area,and large-scale deltaic sand bodies extensively progradating into the sag were formed.The modeled 3D deposit distribution indicates that extensive high-quality reservoir sandstones are likely present across the deepwater area of the Baiyun Sag,which are identified as key exploration targets.Compared to traditional static approaches,the SFM-based dynamic simulation markedly enhances the spatiotemporal resolution of source-to-sink analysis and quantitatively captures the sedimentary system's responses to tectonic activity,base-level fluctuations and other external drivers.The proposed approach provides a novel quantitative framework for investigating complex,deep-time,multi-source systems,and offers an effective tool for reservoir prediction and hydrocarbon exploration planning in underexplored deepwater areas.
基金Supported by the NSFC-Industry Joint Fund for Innovative Development(U24B2016)China National Science and Technology Major Project(2025ZD1402700)。
文摘For the next exploration direction and integrated evaluation and optimization of targets for the northern continental margin of the South China Sea,this paper proposes the concept of the“total natural gas play system”based on the principles of systems theory.Integrating over 60 years of exploration achievements in the four major basins,the paper studies the basic geological conditions,hydrocarbon accumulation models and distribution characteristics of the system.With the core principle of“source-heat controlling natural gas and play-stratigraphy controlling accumulation”,it analyzes the distribution law of natural gas reservoirs covering“intra-sag,sag margin,extra-sag”and multi-stratigraphic sequences.The study shows that under the joint control of source and heat,the northern continental margin of the South China Sea can be divided into two major gas areas:the southern area dominated by coal-type gas and the northern area dominated by oil-type gas,with the former as the main body.Based on the distribution location of hydrocarbon kitchen,the total gas plays are classified into three types:intra-sag,sag margin and extra-sag.In the oil-type gas area of the northern coastal zone,the proportion of intra-sag natural gas is relatively high;in the coal-type gas area of the southern offshore zone,the proportions of intra-sag and sag margin natural gas are relatively large;while the scale of gas accumulation in the extra-sag plays is relatively small.Finally,it is clearly pointed out that the southern offshore zone is the main direction for the next natural gas exploration in the northern South China Sea.Specifically,in the offshore zone,the intra-sag play and middle-deep layers of the sag margin play in the Yingzhong sag should be focused for the Yinggehai Basin;the intra-sag play and sag margin play in the central depression are targets for the Qiongdongnan Basin;the middle-deep layers of the intra-sag play are targets for the Baiyun sag of the Pearl River Mouth Basin.Furthermore,in the northern depression zone of the Pearl River Mouth Basin within the coastal zone,the main exploration directions include the middle-deep layers of the intra-sag play in the Huizhou sag and the middle-deep layers of the intra-sag play in the Enping sag;in the Beibu Gulf Basin,the main directions are the middle-deep layers of the intra-sag play in the Weixinan sag and the middle-deep layers of the intra-sag play in the Haizhong sag.
文摘WANG Mingzhen is a wellknown Chinese physicist. Recently the 91-year-old woman looked back over the profoundly affecting experiences of her life. A Series of Setbacks As soon as she graduated from Peking University in 1930, Wang Mingzhen received an offer of admission from the University of Michigan in the United States. Although the school offered her a four-year scholarship for her tuition, she was penniless and could not afford the steamer ticket. Unwilling to seek help from her friends and relatives, Wang sent a letter declining admission, using her mother’s illness as an excuse. She could not know that this action would
文摘On the night of the Qixi Festival,Chinese Valentine's Day,which fell on August 22 this year,Yao Xiaofang,a 71-year-old pearl wholesaler,livestreamed until midnight,later than usual.She did so because of the extraordinary enthusiasm of her viewers.With the username Pearl Grandma on video-sharing platform Douyin,China's TikTok,she has more than 1 million fans and has gained popularity online for her profound knowledge of pearls.
