With the improvement of living standards and the shift in societal consumption attitudes,consumers demand for the quality of aquatic products is increasingly stringent.Freshness and quality have become primary factors...With the improvement of living standards and the shift in societal consumption attitudes,consumers demand for the quality of aquatic products is increasingly stringent.Freshness and quality have become primary factors determining consumers purchasing decisions.However,due to the high moisture content,active endogenous enzymes,and rich nutrients in aquatic products,both fresh and processed products are highly susceptible to quality deterioration during procurement,distribution,and storage,which leads to a significant decline in sensory quality and nutritional value,while also compromising safety.Today,the consumption of high-quality aquatic products has become a prevailing trend.This paper reviewed the methods for freshness evaluation and quality grading of aquatic products in terms of sensory and nutritional aspects,aiming to support the market circulation principle of"higher price for better quality"and"price based on quality",and better meeting consumer demands.Therefore,it is imperative to enhance the analysis and evaluation of aquatic product quality and to continuously refine assessment systems and methods,which is crucial for promoting industry transformation and fostering a healthy market-consumer economic cycle.展开更多
We assessed the potential of marine ciliate community as an indicator to coastal water quality using water samples collected from four stations in thc Yellow Sea in the summer 2000. The four stations were characterize...We assessed the potential of marine ciliate community as an indicator to coastal water quality using water samples collected from four stations in thc Yellow Sea in the summer 2000. The four stations were characterized by different levels of pollution. The ciliate communities consisted primarily of tintinnids and aloricate ciliates that were 〈30 um. A total of 78 species were classified： 55 species at Station 2, 51 species each at Stations l and 4, and 47 species at Station 3. The mean number of species at each site was 29.2±2.0 （Station 1）, 28.5±2.9 （Station 2）, 27.8±1.7 （Station 3）, and 24.5±2.3 （Station 4）. The abundance was highly variable： 19 331±11 187 ind./L at Station 1, 7 960±5 639 ind./L at Station 2, 29 015±12 999 ind./L at Station 3, and 8 190±4 658 ind./L at Station 4. Our results suggest that neither the simple chemical analysis （e.g. chemical oxygen demand, dissolved inorganic nitrogen, and phosphate） nor the eutrophication/pollution index adequately described the water quality at the four stations. The same was true of the number of species and their abundance, both of which had no correlation with the chemical indices. In contrast, Margalef＇s diversity index values （3.12 at Station 2, 2.89 at Station 1, and 2.64 at Stations 3 and 4） generally discriminated the water quality status of the four stations. The difference in water quality among the stations was strongly supported by the pattern of species richness （i.e. the total number of species） of ciliates at each station. Our evaluation was consistent with the results of long-term water quality monitoring at the four stations. With increasing eutrophication, we observed also a compositional and functional shift in the ciliate assemblages from algivorous oligotrich/choreotrich to nonselective-omnivorous gymnostomatids to bacterivorous-detrivorous scuticociliatids. Thus, eiliates may be used to indicate the coastal water quality status of a given site.展开更多
The neutral and cationic 1-tris(pyrazolyl)borate(Tp)organo-beryllium complexes TpBe(R)(R=Ph,nBu,Me,Cp,Cp^(*))and[TpBe(carbene)]^(+)(carbene=IMe,IiPr,IDipp,CAAC(Dipp))have been synthesized.These compounds were analyzed...The neutral and cationic 1-tris(pyrazolyl)borate(Tp)organo-beryllium complexes TpBe(R)(R=Ph,nBu,Me,Cp,Cp^(*))and[TpBe(carbene)]^(+)(carbene=IMe,IiPr,IDipp,CAAC(Dipp))have been synthesized.These compounds were analyzed via NMR and IR spectroscopy,mass spectrometry as well as X-ray diffraction.A comparison of the Be-C bonds in solution and the solid state revealed no significant differences in the nature of this bond.Extensive quantum chemical evaluation of the bonding within the DFT framework showed that the Be-C bonds in all cases are dative covalent.展开更多
基金Supported by Tangshan Talent Funding Project in 2025(B202304018).
文摘With the improvement of living standards and the shift in societal consumption attitudes,consumers demand for the quality of aquatic products is increasingly stringent.Freshness and quality have become primary factors determining consumers purchasing decisions.However,due to the high moisture content,active endogenous enzymes,and rich nutrients in aquatic products,both fresh and processed products are highly susceptible to quality deterioration during procurement,distribution,and storage,which leads to a significant decline in sensory quality and nutritional value,while also compromising safety.Today,the consumption of high-quality aquatic products has become a prevailing trend.This paper reviewed the methods for freshness evaluation and quality grading of aquatic products in terms of sensory and nutritional aspects,aiming to support the market circulation principle of"higher price for better quality"and"price based on quality",and better meeting consumer demands.Therefore,it is imperative to enhance the analysis and evaluation of aquatic product quality and to continuously refine assessment systems and methods,which is crucial for promoting industry transformation and fostering a healthy market-consumer economic cycle.
基金Supported by the Korea Research Foundation Grant to J.K.CHOI (No.KRF-2008-013-C00064)the Knowledge Innovation Program of Chinese Academy of Sciences (No.KZCX2-YW-417)the National Natural Science Foundation of China (No.40576072,40706047)
文摘We assessed the potential of marine ciliate community as an indicator to coastal water quality using water samples collected from four stations in thc Yellow Sea in the summer 2000. The four stations were characterized by different levels of pollution. The ciliate communities consisted primarily of tintinnids and aloricate ciliates that were 〈30 um. A total of 78 species were classified： 55 species at Station 2, 51 species each at Stations l and 4, and 47 species at Station 3. The mean number of species at each site was 29.2±2.0 （Station 1）, 28.5±2.9 （Station 2）, 27.8±1.7 （Station 3）, and 24.5±2.3 （Station 4）. The abundance was highly variable： 19 331±11 187 ind./L at Station 1, 7 960±5 639 ind./L at Station 2, 29 015±12 999 ind./L at Station 3, and 8 190±4 658 ind./L at Station 4. Our results suggest that neither the simple chemical analysis （e.g. chemical oxygen demand, dissolved inorganic nitrogen, and phosphate） nor the eutrophication/pollution index adequately described the water quality at the four stations. The same was true of the number of species and their abundance, both of which had no correlation with the chemical indices. In contrast, Margalef＇s diversity index values （3.12 at Station 2, 2.89 at Station 1, and 2.64 at Stations 3 and 4） generally discriminated the water quality status of the four stations. The difference in water quality among the stations was strongly supported by the pattern of species richness （i.e. the total number of species） of ciliates at each station. Our evaluation was consistent with the results of long-term water quality monitoring at the four stations. With increasing eutrophication, we observed also a compositional and functional shift in the ciliate assemblages from algivorous oligotrich/choreotrich to nonselective-omnivorous gymnostomatids to bacterivorous-detrivorous scuticociliatids. Thus, eiliates may be used to indicate the coastal water quality status of a given site.
文摘The neutral and cationic 1-tris(pyrazolyl)borate(Tp)organo-beryllium complexes TpBe(R)(R=Ph,nBu,Me,Cp,Cp^(*))and[TpBe(carbene)]^(+)(carbene=IMe,IiPr,IDipp,CAAC(Dipp))have been synthesized.These compounds were analyzed via NMR and IR spectroscopy,mass spectrometry as well as X-ray diffraction.A comparison of the Be-C bonds in solution and the solid state revealed no significant differences in the nature of this bond.Extensive quantum chemical evaluation of the bonding within the DFT framework showed that the Be-C bonds in all cases are dative covalent.
