Heat-resistant energetic materials refer to a type of energetic materials that possess a high melting point,high stability and operational safety. By studying the structures of these energetic materials has showed tha...Heat-resistant energetic materials refer to a type of energetic materials that possess a high melting point,high stability and operational safety. By studying the structures of these energetic materials has showed that the thermal stability can be enhanced by introducing amino groups to form intra/inter-molecular hydrogen bonds, constructing conjugate systems and designing symmetrical structures. This article aims to review the physical and chemical properties of ultra-high temperature heat-resistant energetic compounds and provide valuable theoretical insights for the preparation of ultra-high temperature heatresistant energetic materials. We also analyze the selected 20 heat-resistant energetic materials with decomposition temperatures higher than 350℃, serving as templates for the synthesis of various highperformance heat-resistant energetic materials.展开更多
The reliable welding of T91 heat-resistant steel to 316L stainless steel is a considerable issue for ensuring the safety in service of ultrasupercritical power generation unit and nuclear fusion reactor,but the high-q...The reliable welding of T91 heat-resistant steel to 316L stainless steel is a considerable issue for ensuring the safety in service of ultrasupercritical power generation unit and nuclear fusion reactor,but the high-quality dissimilar joint of these two steels was difficult to be obtained by traditional fusion welding methods.Here we improved the structure-property synergy in a dissimilar joint of T91 steel to 316L steel via friction stir welding.A defect-free joint with a large bonding interface was produced using a small-sized tool under a relatively high welding speed.The bonding interface was involved in a mixing zone with both mechanical mixing and metallurgical bonding.No obvious material softening was detected in the joint except a negligible hardness decline of only HV~10 in the heat-affected zone of the T91 steel side due to the formation of ferrite phase.The welded joint exhibited an excellent ultimate tensile strength as high as that of the 316L parent metal and a greatly enhanced yield strength on account of the dependable bonding and material renovation in the weld zone.This work recommends a promising technique for producing high-strength weldments of dissimilar nuclear steels.展开更多
Microstructure,mechanical properties and phase transformation of a heat-resistant rare-earth(RE)Mg-16.1Gd-3.5Nd-0.38Zn-0.26Zr-0.15Y(wt.%)alloy were investigated.The as-cast alloy is composed of equiaxedα-Mg matrix,ne...Microstructure,mechanical properties and phase transformation of a heat-resistant rare-earth(RE)Mg-16.1Gd-3.5Nd-0.38Zn-0.26Zr-0.15Y(wt.%)alloy were investigated.The as-cast alloy is composed of equiaxedα-Mg matrix,net-shaped Mg5RE and Zr-rich phases.According to aging hardening curves and tensile properties variation,the optimized condition of solution treatment at 520℃for 8 h and subsequent aging at 204℃for 12 h was selected.The continuous secondary Mg5RE phase predominantly formed at grain boundaries during solidification transforms to residual discontinuousβ-Mg5RE phase and fine cuboid REH2particles after heat treatment.The annealed alloy exhibits good comprehensive tensile property at 350℃,with ultimate tensile strength of 153 MPa and elongation to fracture of 6.9%.Segregation of RE elements and eventually RE-rich precipitation at grain boundaries are responsible for the high strength at elevated temperature.展开更多
The molecular mechanisms of energy status related to the umami taste of postharvest shiitake mushrooms during spore release remain poorly understood.In this study,the variations of energy status and umami taste of mus...The molecular mechanisms of energy status related to the umami taste of postharvest shiitake mushrooms during spore release remain poorly understood.In this study,the variations of energy status and umami taste of mushrooms were measured at 25℃.At 24 h storage,slight spore prints of mushrooms were first pictured,respiration peaked.Significant ATP decrease and ADP increase were also observed as the initiation of postharvest senescence(P<0.05).Meanwhile,the activities of phosphohexose isomerase,succinate dehydrogenase,glucose-6-phosphate dehydrogenase and cytochrome c oxidase and the contents of umami nucleotides and amino acids were maintained at higher levels in mushrooms with spore release.Notably,the equivalent umami concentration(EUC)was strongly correlated with energy levels(R=0.80).Fifteen related gene expression levels in the energy metabolism pathway were downregulated.LecpdP1 and LeAK were significantly expressed in the conversion of ATP into AMP and played key roles in connecting the energy state and umami level.These results provided valuable insights on the umami taste associated with energy metabolism mechanism during postharvest mushroom spore release.展开更多
Green tides caused by the bloom of Ulva prolifera have affected the Yellow Sea annually since 2007.To explore the intrinsic causes of successive blooms,field investigations and indoor simulation experiments were condu...Green tides caused by the bloom of Ulva prolifera have affected the Yellow Sea annually since 2007.To explore the intrinsic causes of successive blooms,field investigations and indoor simulation experiments were conducted using micro-propagules of U.prolifera.From January to February 2014,micro-propagules of various green algae,including U.prolifera,Ulva flexuosa,and Ulva linza,were prevalent in the coastal waters of Rudong,Lianyungang,and Qingdao.However,in March 2014,micro-propagules of U.prolifera were not detected in the coastal waters of Lianyungang and Qingdao.Neither the spores nor gametes of U.prolifera can germinate at temperatures below 5℃.At 2℃and 5℃,U.prolifera spores and gametes could survive for 1-3 months at a light intensity range of 0-30μmol m^(-2)s^(-1)and for less than 1 month if the light intensity exceeded 30μmol m^(-2)s^(-1).By integrating indoor experiments and field investigations,this study found that U.prolifera spores and gametes could overwinter in the Rudong coastal area,which is an important factor for the annual emergence of recurring green tides in the Yellow Sea.展开更多
In light of the low yields and complex reaction routes of some well-known 5,5-fused and 5,6-fused bicyclic compounds,a series of 5,7-fused bicyclic imidazole-diazepine compounds were developed with high yields by only...In light of the low yields and complex reaction routes of some well-known 5,5-fused and 5,6-fused bicyclic compounds,a series of 5,7-fused bicyclic imidazole-diazepine compounds were developed with high yields by only two efficient steps.Significantly,the seven-membered heterocyclic ring has a stable energetic skeleton with multiple modifiable sites.However,the 5,7-fused bicyclic energetic compounds were rarely reported in the area of energetic materials.Three neutral compounds 1,2 and 4 were synthesized in this work.To improve the detonation performances of the 5,7-fused neutral compounds,corresponding perchlorate 1a and 2a were further developed.The physicochemical and energetic performances of all newly developed compounds were experimentally determined.All newly prepared energetic compounds exhibit high decomposition temperatures(Td:243.8-336℃)and low mechanical sensitivities(IS:>15 J,FS:>280 N).Among them,the velocities performances of 1a(Dv=7651 m/s)and 4(Dv=7600 m/s)are comparable to that of typical heat-resistant energetic material HNS(Dv=7612 m/s).Meanwhile,the high decomposition temperature and low mechanical sensitivities(Td=336℃;IS=32 J;FS>353 N)of 4 are superior to that of HNS(Td=318℃;IS=5 J;FS=250 N).Hence,the 5,7-fused bicyclic compounds with high thermostability,low sensitivities and adjustable detonation performance have a clear tendency to open up a new space for the development of heat-resistant energetic materials.展开更多
Edible mushroom sexual spores have been gaining more interest due to their bioactive components and functions.Spore discharge(SD)is an important factor affecting the quality of edible mushrooms.In this review,the bioa...Edible mushroom sexual spores have been gaining more interest due to their bioactive components and functions.Spore discharge(SD)is an important factor affecting the quality of edible mushrooms.In this review,the bioactive nutrients of sexual spores of edible mushrooms were summarized,the SD mechanism was described,and the relationship between postharvest SD and the quality of edible mushrooms was analyzed.Spores contain various bioactive nutrients that are benefi cial to the human body.Mature mushrooms can actively discharge spores in a process affected by light,relative humidity,and temperature.During storage,the physiological metabolism of spore-bearing gill tissue is vigorous,promoting the release of postharvest spores and changing the nutritional value of fruiting bodies.The flavor of the fruiting bodies also varied signifi cantly during SD.Edible mushroom sexual spores have the potential to become new raw materials for functional food and medical resources.Research on the effect of the mechanism of SD on the quality of edible mushrooms and the development of SD regulation technology may be a new trend in the quality control of edible mushrooms,which will promote the development of the edible mushroom industry.展开更多
Bacterial-based antitumor immunity has become a promising strategy to activate the immune system for fighting cancer.However,the potential application of bacterial therapy is hindered by the presence of instability an...Bacterial-based antitumor immunity has become a promising strategy to activate the immune system for fighting cancer.However,the potential application of bacterial therapy is hindered by the presence of instability and susceptibility to infections within bacterial populations.Furthermore,monotherapy is ineffective in completely eliminating complex cancer with multiple contributing factors.In this study,based on our discovery that spore shell(SS)of Bacillus coagulans exhibits excellent tumor-targeting ability and adjuvant activity,we develop a biomimetic spore nanoplatform to boost bacteria-mediated antitumor therapy,chemodynamic therapy and antitumor immunity for synergistic cancer treatment.In detail,SS is separated from probiotic spores and then attached to the surface of liposome(Lipo)that was loaded with hemoglobin(Hb),glucose oxidase(GOx)and JQ1to construct SS@Lipo/Hb/GOx/JQ1.In tumor tissue,highly toxic hydroxyl radicals(·OH)are generated via sequential catalytic reactions:GOx catalyzing glucose into H_(2)O_(2)and Fe^(2+)in Hb decomposing H_(2)O_(2)into·OH.The combination of·OH and SS adjuvant can improve tumor immunogenicity and activate immune system.Meanwhile,JQ1-mediated down-regulation of PD-L1 and Hb-induced hypoxia alleviation synergistically reshape immunosuppressive tumor microenvironment and potentiate immune response.In this manner,SS@Lipo/Hb/GOx/JQ1 significantly suppresses tumor growth and metastasis.To summarize,the nanoplatform represents an optimum strategy to potentiate bacteria-based cancer immunotherapy.展开更多
Purpose:This study aims to investigate whether Ganoderma lucidum spore oil(GLSO)could enhance the effect of paclitaxel(PTX),improve the tolerance to PTX and prolong the overall survival of Lewis tumor-bearing mice,whi...Purpose:This study aims to investigate whether Ganoderma lucidum spore oil(GLSO)could enhance the effect of paclitaxel(PTX),improve the tolerance to PTX and prolong the overall survival of Lewis tumor-bearing mice,which has never been reported before.Methods:The tumor,spleen,and thymus were weighed at the end of the experiment.Whole blood was collected for hematological index analysis,and the intact femur was removed to determine the bone marrow nucleated cell count(BMN).The percentage of lymphocytes in the spleen of mice was detected by flow cytometry,the activity of NK cells was detected by LDH assay,and the proliferation index of lymphocytes was determined by CCK-8 assay.The overall and mean survival time and life extension rate were calculated using SPSS software.Results:Our data showed that GLSO could enhance the anti-tumor effect of PTX and prolong the survival of mice.The underlying mechanisms of the above effects might be related to the toxic reduction effect of GLSO by relieving hematotoxicity,myelosuppression and immunosuppression.Specifically,GLSO could increase the number of blood cells and bone marrow cells,alleviate the thymic index,and elevate the number and activity of NK cells in mice treated with PTX.Conclusion:GLSO may enhance the efficacy of PTX by boosting the activity of immune NK cells and prolong survival by counteracting PTX-induced bone marrow alterations and improving hematopoiesis.These findings suggested the promising role of GLSO in combination with PTX to extend the survival and increase the tolerance of patients in clinical chemotherapy of lung cancer.展开更多
The microstructures and phase compositions of the as-cast and die-cast Mg-6.02Al-1.03 Sm, Mg-6.05Al-0.98Sm-0.56 Bi and Mg-5.95Al-1.01Sm-0.57 Zn alloys were investigated. Meanwhile, the tensile mechanical and flow prop...The microstructures and phase compositions of the as-cast and die-cast Mg-6.02Al-1.03 Sm, Mg-6.05Al-0.98Sm-0.56 Bi and Mg-5.95Al-1.01Sm-0.57 Zn alloys were investigated. Meanwhile, the tensile mechanical and flow properties were tested. The results show that the as-cast microstructure of Mg-6.02Al-1.03 Sm alloy is composed of δ-Mg matrix, discontinuous δ-Mg17Al12 phase and small block Al2 Sm phase with high thermal stability. Rod Mg3Bi2 phase precipitates when Bi is added, while the added metal Zn dissolves into δ-Mg matrix and δ-Mg17Al12 phase. The as-cast alloys exhibit the excellent tensile mechanical property. The tensile strength(δb) and elongation(δ) can reach 205-235 MPa and 8.5%-16.0% at ambient temperature, respectively. Meanwhile, they can also exceed 160 MPa and 14.0% at 423 K, respectively. The die-cast microstructures are refined obviously, and meanwhile the broken second phases distribute dispersedly. The die-cast alloys exhibit better tensile mechanical properties with the values of δb and δ of 240-285 MPa and 8.5%-16.5% at ambient temperature, respectively, and excellent flow property with the flow length of 1870-2420 mm. The die-cast tensile fractures at ambient temperature exhibit a typical character of ductile fracture.展开更多
Five compounds were isolated from the ether-soluble fraction of the spores of Gano- derma lucidum.On the basis of their chemical properties and spectral data(MS,UV,IR,~1H and ^(13)CNMR),they were identified as 3,7,11,...Five compounds were isolated from the ether-soluble fraction of the spores of Gano- derma lucidum.On the basis of their chemical properties and spectral data(MS,UV,IR,~1H and ^(13)CNMR),they were identified as 3,7,11,12,15,23-hexaoxo-5α-lanosta-8-en-26-oic acid(Ⅰ),gano- deric acid B(Ⅱ),C(Ⅲ),D(Ⅳ)and ganodermanontriol(Ⅴ).Compound Ⅰ is a new natural product, named ganosporeric acid A.Compounds Ⅱ,Ⅲ,Ⅳ and Ⅴ are known compounds and were obtained for the first time from the spores of Ganoderma lucidum.Pharmacological experiments showed that ganosporeric acid A has an activity for lowering the levels GPT in mice with liver injury by CCl_4 and GaNI and exhibits heptoprotective effects.展开更多
A water soluble, (1 -->6)-branched, (1 -->4) linked D-glucan (LB-B1), [alpha](D)(21) = +174.2 degrees (c 0.87, H2O), was obtained from a hot-water extract of the sporoderm-broken spores of Ganoderma lucidun (Fr....A water soluble, (1 -->6)-branched, (1 -->4) linked D-glucan (LB-B1), [alpha](D)(21) = +174.2 degrees (c 0.87, H2O), was obtained from a hot-water extract of the sporoderm-broken spores of Ganoderma lucidun (Fr.) Karst by HPSEC, with 0.001 mol/L sodium hydroxide as the eluant, the molecular weight (Mw) of LB-B1 was estimated to be 9.3 x 10(3). From the results of total hydrolysis, methylation analysis, acetolysis and 1D, 2D-NMR experimentation, it was concluded that LB-B1 was composed of repeating units with the following structure: alpha -D-Glc(p)-(1 -->6)-alpha -D-Glc(p)-(1 -->6)-alpha -D-Glc(p) 1 down arrow 6 (-->4)-alpha -D-Glc(p)-(1 -->4)-alpha -D-Glc(p)-(1 -->4)-alpha -D-Glc(p)-(1 -->4)-alpha -D-Glc(p)-(1 -->4-)-alpha -D-Glc(p)-(1 -->)(n)展开更多
With validamycin A.(0.2 billion spores/ml) Paenibacillus polymyxa DN-1 3% AS as the test agent, the effects of different dosage and different application time on the control efficacy for' rich sheath blight were in...With validamycin A.(0.2 billion spores/ml) Paenibacillus polymyxa DN-1 3% AS as the test agent, the effects of different dosage and different application time on the control efficacy for' rich sheath blight were investigated. The results of two- year test showed that when the application amount was in the range of 45-90 g.a.i/ hm^2, the field efficacy of validamycin A-(0.2 billion spores/ml) P. polymyxa DN-1 3% AS in the initial infection stage of rich sheath blight (Le., the diseased plant rate was below 5%) reached 80.38%-89.06%, and that in the peak infection stage (i.e., the diseased plant rate was higher than 10%) reached only 41.12%-53.26%. The field efficacy of validamycin A.(0.2 billion spores/ml) P. polymyxa DN-1 3% AS at the early onset of rich sheath blight was significantly better than that at the onset, so that the application time of validamycin A .(0.2 billion spores/ml) P. polymyxa DN-1 3% AS should be appropriately brought forward in the prevention and control of rice sheath blight.展开更多
Coniopteris was a ubiquitous plant of the Jurassic and Cretaceous periods and played an important role in the flora of the time. However, its anatomical structure is relatively poorly known. The specimens of Coniopter...Coniopteris was a ubiquitous plant of the Jurassic and Cretaceous periods and played an important role in the flora of the time. However, its anatomical structure is relatively poorly known. The specimens of Coniopteris hymenophylloides(Brongniart) Seward described here were collected from the Yaojie Formation in Gansu Province, northwestern China. The sterile fronds are characterized as being at least bipinnate with alternate arranged linear pinnae covered by thin cuticles. Fertile fronds are linear-lanceolate, with single sorus at the margin of each fertile pinnule. In situ spores are typically trilete, triangle to subcircular in polar view, cap-shaped in equatorial view, and 37 μm in average diameter. The trilete marking is straight and narrow, generally extends to 4/5 of the spore radius. The spore surface is smooth, and parts of the exine are granulated. The epidermal cells of cuticles are irregular in shape, approximately 40-60μm long and 10-20 μm wide. The elliptical stomatal complexes are paracytic,approximately 30 μm long and 19 μm wide,and irregularly distributed. On the basis of its epidermal structures and comparisons with extant ferns, we consider that Coniopteris displays combined features of the related extant genera.展开更多
BACKGROUND: Previous research has revealed that somatostatin can induce epilepsy, and that the levels of neuropeptide Y may increase and become more active in brain areas with epileptic seizures. OBJECTIVE: To obser...BACKGROUND: Previous research has revealed that somatostatin can induce epilepsy, and that the levels of neuropeptide Y may increase and become more active in brain areas with epileptic seizures. OBJECTIVE: To observe the effect of Ganoderma luciclum spore powder on the neuropeptide Y and somatostatin content in the cerebral cortex and hippocampal regions of seizure rats induced by pentylenetetrazol (PTZ). Furthermore, to verify any effect of Ganoderma lucidum spore powder on inhibition of epileptic seizures. DESIGN, TIME AND SETTING: A randomized group animal study was performed in August 2007 in the School of Basic Medical Sciences, Jiamusi University (Jiamusi, Heilongjiang, China). MATERIALS: Thirty healthy, male, Wistar rats, aged 12 weeks and weighing 180-220 g, were taken as the experimental animals. PTZ (Sigma Company, United States) was used to induce epilepsy. Ganoderma lucidum spores (Leyss, ex Fr variety) were purchased from Jiamusi City Wild Growing Case of the Ganoderma Lucidum (China). Rabbit anti-somatostatin antibodies and secondary antibodies were purchased from Wuhan Boster Company (China). Neuropeptide Y radioimmunoassay kit was purchased from Beijing Furui Biotechnology Company (China). METHODS: Thirty rats were randomly divided into three groups: a control group, an epilepsy model group and a Ganoderma lucidum spore-treated group. Each group contained 10 animals. Rats in the epilepsy model group were treated with intraperitoneal injections of PTZ and gastric perfusion of physiologic saline. In the Ganoderma lucidum spore-treated group, intraperitoneal injection of PTZ and gastric perfusion of Ganoderma lucidum spore powder were administered. The blank control group was only administered with the physiological saline by intraperitoneal injection and gastric perfusion. MAIN OUTCOME MEASURES: Immunohistochemical staining and radioimmunoassay methods were used to observe the changes of somatostatin and neuropeptide Y content in brain tissue of epileptic rats, as well as the morphology of neurons. RESULTS: All 30 rats were involved in the result analysis, without any loss. The number of somatostatin immunoreacted positive cells in the cerebral cortex and hippocampus was significantly increased in the epilepsy model group compared to the blank control group (P 〈 0.01). The number of somatostatin immunoreacted positive cells in cerebral cortex and hippocampus was significantly decreased in the Ganoderma lucidum spore-treated group compared to the epilepsy model group (P 〈 0.01). The contents of neuropeptide Y in cerebral cortex and hippocampus were significantly increased in the epilepsy model group compared to the blank control group (P 〈 0.01). The contents of neuropeptide Y in the cerebral cortex and hippocampus were significantly decreased in the Ganoderma lucidum spore-treated group compared to the epilepsy model group (P 〈 0.05). The epilepsy seizures in the Ganoderma lucidum spore-treated group were obviously reduced compared to the epilepsy model group. CONCLUSION: Ganoderma lucidum spore powder was able to reduce the somatostatin and neuropeptide Y content in the cerebral cortex and hippocampus effectively, so as to achieve an anti-epileptic function and protect neurons from being damaged.展开更多
Boosting the utilization efficiency of sulfur electrodes and suppressing the“shuttle effect”of intermediate polysulfides remain the critical challenge for high-performance lithium-sulfur batteries(LSBs).However,most...Boosting the utilization efficiency of sulfur electrodes and suppressing the“shuttle effect”of intermediate polysulfides remain the critical challenge for high-performance lithium-sulfur batteries(LSBs).However,most of reported sulfur electrodes are not competent to realize the fast conversion of polysulfides into insoluble lithium sulfides when applied with high sulfur loading,as well as to mitigate the more serious shuttle effect of polysulfides,especially when worked at an elevated temperature.Herein,we reported a unique structural engineering strategy of crafting a unique hierarchical multifunctional electrode architecture constructed by rooting MOF-derived CoS2/carbon nanoleaf arrays(CoS2-CNA)into a nitrogen-rich 3D conductive scaffold(CTNF@CoS2-CNA)for LSBs.An accelerated electrocatalytic effect and improved polysulfide redox kinetics arising from CoS2-CNA were investigated.Besides,the strong capillarity effect and chemisorption of CTNF@CoS2-CNA to polysulfides enable high loading and efficient utilization of sulfur,thus leading to high-performance LIBs performed not only at room temperature but also up to an elevated temperature(55°C).Even with the ultrahigh sulfur loading of 7.19 mg cm?2,the CTNF@CoS2-CNA/S cathode still exhibits high rate capacity at 55°C.展开更多
The effect of RE addition on solidification process and high-temperature strength of Al-12%Si-4%Cu-1.6%Mn(in wt.%)heat-resistant alloy was investigated by microstructure observation and tensile test.A great number of ...The effect of RE addition on solidification process and high-temperature strength of Al-12%Si-4%Cu-1.6%Mn(in wt.%)heat-resistant alloy was investigated by microstructure observation and tensile test.A great number of fine needle-like RE-rich phases are observed in the alloys with RE addition. Solutionizing treatment does not change their morphologies and sizes, indicating that they have good thermal stability. The addition of RE totally alters the solidification process of eutectic CruAl2 phase, from network-like phase in the form of segregation at the final eutectic grain boundaries to discretely blocky phase growing on the hair-filamentous RE-rich needles. In the alloys with Ce addition, blocky CuAl2, particulate Al15Mn3Si2 and needle-like RE-rich needle phases grow together, but they did not occur in the alloy with only La addition. The addition of RE does not considerably improve the strength of the alloy at high temperatures. The formation of RE-rich phases also does not significantly alter the originating and propagating of micro-cracks in the alloy during tensile test.展开更多
The spores of Ganoderma lucidum were ground and broken to ultrafine particles by high speed centrifugal shearing(HSCS) pulverizer. The characteristics of Ganoderma lucidum spores were analyzed by scanning electron m...The spores of Ganoderma lucidum were ground and broken to ultrafine particles by high speed centrifugal shearing(HSCS) pulverizer. The characteristics of Ganoderma lucidum spores were analyzed by scanning electron microscope (SEM), Fourier transform infrared spectrophotometry (FTIR). Ultraviolet-visible pectrophotometer was used to determine the extraction ratio of aqueous solubility polysaccharide between the raw and broken spores. The immunological function on the mice before and after the breaking of spores wan investigated. The experimental results show that after being ground, the sporoderm-broken ratio reachs 100%, the original active ingredients of ganoderma lucidum spores do not change, and the extraction ratio of aqueous solubility polysaccharide is greatly increased by 40.08%. The broken spores show much higher immunological activity comparing with original spores of Ganoderma lucidum.展开更多
Aims: The objective of this study was to investigate the effect of free fatty acid length chain and unsaturated bond number on the heat resistance and recovery media of bacterial spores. Methods and results: For 6 spe...Aims: The objective of this study was to investigate the effect of free fatty acid length chain and unsaturated bond number on the heat resistance and recovery media of bacterial spores. Methods and results: For 6 species, bacterial spore heat resistances were estimated at different free fatty acid concentrations added to heating media or in recovery media. The addition of free fatty acids to heating media has a slight influence on the heat resistance of bacterial spores whatever the species or type of acid studied. On the contrary, the addition of free fatty acids to the recovery medium after the heat treatment greatly reduces the ability to bacterial spores to recover and form colonies. This effect varies depending on chain length, unsaturated bond number of fatty acid and on the bacterial strain studied. Conclusion: The presence of free acids in the recovery media is an additive stress which decreases the capability of injured spores to germinate and grow thereafter. Significance and impact of this study: The impact of free fatty acids presented in this study can be taken into account to reduce the thermal intensity of food sterilization in relation to their availability in food matrix.展开更多
In order to study the airborne pollen and Spores, a circular year airborne Samples werecollected at 10m height above ground from Taoyuan ecological station, which is located in TaoyuanCounty of Hunan Province. The ana...In order to study the airborne pollen and Spores, a circular year airborne Samples werecollected at 10m height above ground from Taoyuan ecological station, which is located in TaoyuanCounty of Hunan Province. The analytical results showed that there are 188 plant families and generain airborne pollen and spores. of them, 102 are xylophyte plants, 68 are herbase plat, and 18are pteridophyta plants. The plant families and genera account for 80% of the local plant families andgenera. Among them, 54 are specific families and genera, Which are peculiar tO tropics andsubtropics. The main pollen and spore families and genera are Pinus. Cunninghamia Juglans,Quercus, Cupressaceae, Urticaceac, and Gleicheniaceae. There are two peak stages of airbornepollen and spore concentration throughout the year. One is the peak stage of xylophyte plants fromMarch to May and the other, herbaceous plants from niddle dekad of August to early October. Themaximum year round value is 850 000 grains/1000m3.air in middle dekad of September and theminimum is 1500 grains/1000m3.air in early December. In the local district, the airbome pollen andSpores which can induce respiratory tract disease in spring are Taxodiaceae, Cupresaseeae, CastrieaCastanopsis, Queme, Juglans, Platycarya, and that can induce disease in autumn are Canabis,Gramineae, and Artmisia.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.21975127,22105102,and 22135003)Young Elite Scientist Sponsorship Program by CAST(Grant No.YESS20210074)the Fundamental Research Funds for the Central Universities(Grant No.30921011204)。
文摘Heat-resistant energetic materials refer to a type of energetic materials that possess a high melting point,high stability and operational safety. By studying the structures of these energetic materials has showed that the thermal stability can be enhanced by introducing amino groups to form intra/inter-molecular hydrogen bonds, constructing conjugate systems and designing symmetrical structures. This article aims to review the physical and chemical properties of ultra-high temperature heat-resistant energetic compounds and provide valuable theoretical insights for the preparation of ultra-high temperature heatresistant energetic materials. We also analyze the selected 20 heat-resistant energetic materials with decomposition temperatures higher than 350℃, serving as templates for the synthesis of various highperformance heat-resistant energetic materials.
基金financially supported by the National Natural Science Foundation of China (Nos. 52171057, 52034005, 51901225, and 12027813)the Liaoning Province Excellent Youth Foundation, China (No. 2021-YQ-01)the Youth Innovation Promotion Association of the Chinese Academy of Sciences (No. Y2021061)
文摘The reliable welding of T91 heat-resistant steel to 316L stainless steel is a considerable issue for ensuring the safety in service of ultrasupercritical power generation unit and nuclear fusion reactor,but the high-quality dissimilar joint of these two steels was difficult to be obtained by traditional fusion welding methods.Here we improved the structure-property synergy in a dissimilar joint of T91 steel to 316L steel via friction stir welding.A defect-free joint with a large bonding interface was produced using a small-sized tool under a relatively high welding speed.The bonding interface was involved in a mixing zone with both mechanical mixing and metallurgical bonding.No obvious material softening was detected in the joint except a negligible hardness decline of only HV~10 in the heat-affected zone of the T91 steel side due to the formation of ferrite phase.The welded joint exhibited an excellent ultimate tensile strength as high as that of the 316L parent metal and a greatly enhanced yield strength on account of the dependable bonding and material renovation in the weld zone.This work recommends a promising technique for producing high-strength weldments of dissimilar nuclear steels.
基金support of the National Natural Science Foundation of China(Grant number 52071088)。
文摘Microstructure,mechanical properties and phase transformation of a heat-resistant rare-earth(RE)Mg-16.1Gd-3.5Nd-0.38Zn-0.26Zr-0.15Y(wt.%)alloy were investigated.The as-cast alloy is composed of equiaxedα-Mg matrix,net-shaped Mg5RE and Zr-rich phases.According to aging hardening curves and tensile properties variation,the optimized condition of solution treatment at 520℃for 8 h and subsequent aging at 204℃for 12 h was selected.The continuous secondary Mg5RE phase predominantly formed at grain boundaries during solidification transforms to residual discontinuousβ-Mg5RE phase and fine cuboid REH2particles after heat treatment.The annealed alloy exhibits good comprehensive tensile property at 350℃,with ultimate tensile strength of 153 MPa and elongation to fracture of 6.9%.Segregation of RE elements and eventually RE-rich precipitation at grain boundaries are responsible for the high strength at elevated temperature.
基金supported by Liaoning Province Science and Technology Planning Project (2021JH5/10400011& 2020JH2/10200013)the Central Guidance on Local Science and Technology Development Project of Liaoning Province (2021JH6/10500133)Shenyang Agricultural University, high-end talent introduction fund (SYAU20160003)
文摘The molecular mechanisms of energy status related to the umami taste of postharvest shiitake mushrooms during spore release remain poorly understood.In this study,the variations of energy status and umami taste of mushrooms were measured at 25℃.At 24 h storage,slight spore prints of mushrooms were first pictured,respiration peaked.Significant ATP decrease and ADP increase were also observed as the initiation of postharvest senescence(P<0.05).Meanwhile,the activities of phosphohexose isomerase,succinate dehydrogenase,glucose-6-phosphate dehydrogenase and cytochrome c oxidase and the contents of umami nucleotides and amino acids were maintained at higher levels in mushrooms with spore release.Notably,the equivalent umami concentration(EUC)was strongly correlated with energy levels(R=0.80).Fifteen related gene expression levels in the energy metabolism pathway were downregulated.LecpdP1 and LeAK were significantly expressed in the conversion of ATP into AMP and played key roles in connecting the energy state and umami level.These results provided valuable insights on the umami taste associated with energy metabolism mechanism during postharvest mushroom spore release.
基金The work was supported by the Key Laboratory of Ecological Prewarning,Protection and Restoration of Bohai Sea,Ministry of Natural Resources(No.2022107)the Qingdao Postdoctoral Applied Research Project(No.QDBSH202001).
文摘Green tides caused by the bloom of Ulva prolifera have affected the Yellow Sea annually since 2007.To explore the intrinsic causes of successive blooms,field investigations and indoor simulation experiments were conducted using micro-propagules of U.prolifera.From January to February 2014,micro-propagules of various green algae,including U.prolifera,Ulva flexuosa,and Ulva linza,were prevalent in the coastal waters of Rudong,Lianyungang,and Qingdao.However,in March 2014,micro-propagules of U.prolifera were not detected in the coastal waters of Lianyungang and Qingdao.Neither the spores nor gametes of U.prolifera can germinate at temperatures below 5℃.At 2℃and 5℃,U.prolifera spores and gametes could survive for 1-3 months at a light intensity range of 0-30μmol m^(-2)s^(-1)and for less than 1 month if the light intensity exceeded 30μmol m^(-2)s^(-1).By integrating indoor experiments and field investigations,this study found that U.prolifera spores and gametes could overwinter in the Rudong coastal area,which is an important factor for the annual emergence of recurring green tides in the Yellow Sea.
基金support from the National Natural Science Foundation of China(Grant No.22075143,21875110)the Science Challenge Project(Grant No.TZ2018004)the Qing Lan Project for the grant。
文摘In light of the low yields and complex reaction routes of some well-known 5,5-fused and 5,6-fused bicyclic compounds,a series of 5,7-fused bicyclic imidazole-diazepine compounds were developed with high yields by only two efficient steps.Significantly,the seven-membered heterocyclic ring has a stable energetic skeleton with multiple modifiable sites.However,the 5,7-fused bicyclic energetic compounds were rarely reported in the area of energetic materials.Three neutral compounds 1,2 and 4 were synthesized in this work.To improve the detonation performances of the 5,7-fused neutral compounds,corresponding perchlorate 1a and 2a were further developed.The physicochemical and energetic performances of all newly developed compounds were experimentally determined.All newly prepared energetic compounds exhibit high decomposition temperatures(Td:243.8-336℃)and low mechanical sensitivities(IS:>15 J,FS:>280 N).Among them,the velocities performances of 1a(Dv=7651 m/s)and 4(Dv=7600 m/s)are comparable to that of typical heat-resistant energetic material HNS(Dv=7612 m/s).Meanwhile,the high decomposition temperature and low mechanical sensitivities(Td=336℃;IS=32 J;FS>353 N)of 4 are superior to that of HNS(Td=318℃;IS=5 J;FS=250 N).Hence,the 5,7-fused bicyclic compounds with high thermostability,low sensitivities and adjustable detonation performance have a clear tendency to open up a new space for the development of heat-resistant energetic materials.
基金supported by Liaoning Provincial Department of Educational Annual(2019)Scientific Research Fund Project(LSNZD201903)Shenyang Bureau of Science and Technology Annual(2021)Scientific Research Fund Project(21110319)Shenyang Agricultural University,high-end talent introduction fund project(SYAU20160003).
文摘Edible mushroom sexual spores have been gaining more interest due to their bioactive components and functions.Spore discharge(SD)is an important factor affecting the quality of edible mushrooms.In this review,the bioactive nutrients of sexual spores of edible mushrooms were summarized,the SD mechanism was described,and the relationship between postharvest SD and the quality of edible mushrooms was analyzed.Spores contain various bioactive nutrients that are benefi cial to the human body.Mature mushrooms can actively discharge spores in a process affected by light,relative humidity,and temperature.During storage,the physiological metabolism of spore-bearing gill tissue is vigorous,promoting the release of postharvest spores and changing the nutritional value of fruiting bodies.The flavor of the fruiting bodies also varied signifi cantly during SD.Edible mushroom sexual spores have the potential to become new raw materials for functional food and medical resources.Research on the effect of the mechanism of SD on the quality of edible mushrooms and the development of SD regulation technology may be a new trend in the quality control of edible mushrooms,which will promote the development of the edible mushroom industry.
基金supported by the National Natural Science Foundation of China(No.82272847,82202318,82304417,82303529)The Henan Province Fund for Cultivating Advantageous Disciplines(No.222301420012)+2 种基金Central Plains science and technology innovation leading talent project(No.234200510005)The project tackling of key scientific and technical problems of Henan Provine(No.232102311163)China Postdoctoral Science Foundation(2022TQ0310,2023TQ0307,2023M730971)。
文摘Bacterial-based antitumor immunity has become a promising strategy to activate the immune system for fighting cancer.However,the potential application of bacterial therapy is hindered by the presence of instability and susceptibility to infections within bacterial populations.Furthermore,monotherapy is ineffective in completely eliminating complex cancer with multiple contributing factors.In this study,based on our discovery that spore shell(SS)of Bacillus coagulans exhibits excellent tumor-targeting ability and adjuvant activity,we develop a biomimetic spore nanoplatform to boost bacteria-mediated antitumor therapy,chemodynamic therapy and antitumor immunity for synergistic cancer treatment.In detail,SS is separated from probiotic spores and then attached to the surface of liposome(Lipo)that was loaded with hemoglobin(Hb),glucose oxidase(GOx)and JQ1to construct SS@Lipo/Hb/GOx/JQ1.In tumor tissue,highly toxic hydroxyl radicals(·OH)are generated via sequential catalytic reactions:GOx catalyzing glucose into H_(2)O_(2)and Fe^(2+)in Hb decomposing H_(2)O_(2)into·OH.The combination of·OH and SS adjuvant can improve tumor immunogenicity and activate immune system.Meanwhile,JQ1-mediated down-regulation of PD-L1 and Hb-induced hypoxia alleviation synergistically reshape immunosuppressive tumor microenvironment and potentiate immune response.In this manner,SS@Lipo/Hb/GOx/JQ1 significantly suppresses tumor growth and metastasis.To summarize,the nanoplatform represents an optimum strategy to potentiate bacteria-based cancer immunotherapy.
基金Authors of this research are in deep gratitude toward Professor Qin Wang from the Nanchang Research Institute,Sun Yat-sen University for her dedicated guidance and support to this work.This work was supported by the National Key R&D Program of China(2022YFC3500302)the Ministry of Science and Technology of China(No.2017YFC1703104)+1 种基金the Key Laboratory Project of Pharmaceutical Lipids in Guangdong Province(No.2020B1212070024)the Guangdong Province Key Areas R&D Program Project(No.2020B1111120002).
文摘Purpose:This study aims to investigate whether Ganoderma lucidum spore oil(GLSO)could enhance the effect of paclitaxel(PTX),improve the tolerance to PTX and prolong the overall survival of Lewis tumor-bearing mice,which has never been reported before.Methods:The tumor,spleen,and thymus were weighed at the end of the experiment.Whole blood was collected for hematological index analysis,and the intact femur was removed to determine the bone marrow nucleated cell count(BMN).The percentage of lymphocytes in the spleen of mice was detected by flow cytometry,the activity of NK cells was detected by LDH assay,and the proliferation index of lymphocytes was determined by CCK-8 assay.The overall and mean survival time and life extension rate were calculated using SPSS software.Results:Our data showed that GLSO could enhance the anti-tumor effect of PTX and prolong the survival of mice.The underlying mechanisms of the above effects might be related to the toxic reduction effect of GLSO by relieving hematotoxicity,myelosuppression and immunosuppression.Specifically,GLSO could increase the number of blood cells and bone marrow cells,alleviate the thymic index,and elevate the number and activity of NK cells in mice treated with PTX.Conclusion:GLSO may enhance the efficacy of PTX by boosting the activity of immune NK cells and prolong survival by counteracting PTX-induced bone marrow alterations and improving hematopoiesis.These findings suggested the promising role of GLSO in combination with PTX to extend the survival and increase the tolerance of patients in clinical chemotherapy of lung cancer.
基金Project(2013AA031001)supported by the National High-tech Research and Development Program of ChinaProject(2011A080403008)supported by the Major Science and Technology Project of Guangdong Province,China
文摘The microstructures and phase compositions of the as-cast and die-cast Mg-6.02Al-1.03 Sm, Mg-6.05Al-0.98Sm-0.56 Bi and Mg-5.95Al-1.01Sm-0.57 Zn alloys were investigated. Meanwhile, the tensile mechanical and flow properties were tested. The results show that the as-cast microstructure of Mg-6.02Al-1.03 Sm alloy is composed of δ-Mg matrix, discontinuous δ-Mg17Al12 phase and small block Al2 Sm phase with high thermal stability. Rod Mg3Bi2 phase precipitates when Bi is added, while the added metal Zn dissolves into δ-Mg matrix and δ-Mg17Al12 phase. The as-cast alloys exhibit the excellent tensile mechanical property. The tensile strength(δb) and elongation(δ) can reach 205-235 MPa and 8.5%-16.0% at ambient temperature, respectively. Meanwhile, they can also exceed 160 MPa and 14.0% at 423 K, respectively. The die-cast microstructures are refined obviously, and meanwhile the broken second phases distribute dispersedly. The die-cast alloys exhibit better tensile mechanical properties with the values of δb and δ of 240-285 MPa and 8.5%-16.5% at ambient temperature, respectively, and excellent flow property with the flow length of 1870-2420 mm. The die-cast tensile fractures at ambient temperature exhibit a typical character of ductile fracture.
基金This project was supported by National Natural Science Foundation of China
文摘Five compounds were isolated from the ether-soluble fraction of the spores of Gano- derma lucidum.On the basis of their chemical properties and spectral data(MS,UV,IR,~1H and ^(13)CNMR),they were identified as 3,7,11,12,15,23-hexaoxo-5α-lanosta-8-en-26-oic acid(Ⅰ),gano- deric acid B(Ⅱ),C(Ⅲ),D(Ⅳ)and ganodermanontriol(Ⅴ).Compound Ⅰ is a new natural product, named ganosporeric acid A.Compounds Ⅱ,Ⅲ,Ⅳ and Ⅴ are known compounds and were obtained for the first time from the spores of Ganoderma lucidum.Pharmacological experiments showed that ganosporeric acid A has an activity for lowering the levels GPT in mice with liver injury by CCl_4 and GaNI and exhibits heptoprotective effects.
文摘A water soluble, (1 -->6)-branched, (1 -->4) linked D-glucan (LB-B1), [alpha](D)(21) = +174.2 degrees (c 0.87, H2O), was obtained from a hot-water extract of the sporoderm-broken spores of Ganoderma lucidun (Fr.) Karst by HPSEC, with 0.001 mol/L sodium hydroxide as the eluant, the molecular weight (Mw) of LB-B1 was estimated to be 9.3 x 10(3). From the results of total hydrolysis, methylation analysis, acetolysis and 1D, 2D-NMR experimentation, it was concluded that LB-B1 was composed of repeating units with the following structure: alpha -D-Glc(p)-(1 -->6)-alpha -D-Glc(p)-(1 -->6)-alpha -D-Glc(p) 1 down arrow 6 (-->4)-alpha -D-Glc(p)-(1 -->4)-alpha -D-Glc(p)-(1 -->4)-alpha -D-Glc(p)-(1 -->4)-alpha -D-Glc(p)-(1 -->4-)-alpha -D-Glc(p)-(1 -->)(n)
基金Supported by National Agricultural Science and Technology Achievement Transformation Fund of China(2010GB2C300196)Modern Agricultural Production Development Fund(Rice Industry)Project of Anhui Academy of Agricultural SciencesIntegration and Demonstration of Chemical Fertilizer and Agrochemical Reduction and Efficiency Increasing Technology for Rice in Rice-wheat(rape)Rotation Areas in Anhui(2016YFD0200806)~~
文摘With validamycin A.(0.2 billion spores/ml) Paenibacillus polymyxa DN-1 3% AS as the test agent, the effects of different dosage and different application time on the control efficacy for' rich sheath blight were investigated. The results of two- year test showed that when the application amount was in the range of 45-90 g.a.i/ hm^2, the field efficacy of validamycin A-(0.2 billion spores/ml) P. polymyxa DN-1 3% AS in the initial infection stage of rich sheath blight (Le., the diseased plant rate was below 5%) reached 80.38%-89.06%, and that in the peak infection stage (i.e., the diseased plant rate was higher than 10%) reached only 41.12%-53.26%. The field efficacy of validamycin A.(0.2 billion spores/ml) P. polymyxa DN-1 3% AS at the early onset of rich sheath blight was significantly better than that at the onset, so that the application time of validamycin A .(0.2 billion spores/ml) P. polymyxa DN-1 3% AS should be appropriately brought forward in the prevention and control of rice sheath blight.
基金project received financial support from the National Natural Science Foundation of China (No. 41262001)the Science and Technology Support Fund of Gansu Province (No. 1104FKCA116)
文摘Coniopteris was a ubiquitous plant of the Jurassic and Cretaceous periods and played an important role in the flora of the time. However, its anatomical structure is relatively poorly known. The specimens of Coniopteris hymenophylloides(Brongniart) Seward described here were collected from the Yaojie Formation in Gansu Province, northwestern China. The sterile fronds are characterized as being at least bipinnate with alternate arranged linear pinnae covered by thin cuticles. Fertile fronds are linear-lanceolate, with single sorus at the margin of each fertile pinnule. In situ spores are typically trilete, triangle to subcircular in polar view, cap-shaped in equatorial view, and 37 μm in average diameter. The trilete marking is straight and narrow, generally extends to 4/5 of the spore radius. The spore surface is smooth, and parts of the exine are granulated. The epidermal cells of cuticles are irregular in shape, approximately 40-60μm long and 10-20 μm wide. The elliptical stomatal complexes are paracytic,approximately 30 μm long and 19 μm wide,and irregularly distributed. On the basis of its epidermal structures and comparisons with extant ferns, we consider that Coniopteris displays combined features of the related extant genera.
基金Science and Technology Research Projects of Heilongjiang Provincial Education Department, No. 11521276
文摘BACKGROUND: Previous research has revealed that somatostatin can induce epilepsy, and that the levels of neuropeptide Y may increase and become more active in brain areas with epileptic seizures. OBJECTIVE: To observe the effect of Ganoderma luciclum spore powder on the neuropeptide Y and somatostatin content in the cerebral cortex and hippocampal regions of seizure rats induced by pentylenetetrazol (PTZ). Furthermore, to verify any effect of Ganoderma lucidum spore powder on inhibition of epileptic seizures. DESIGN, TIME AND SETTING: A randomized group animal study was performed in August 2007 in the School of Basic Medical Sciences, Jiamusi University (Jiamusi, Heilongjiang, China). MATERIALS: Thirty healthy, male, Wistar rats, aged 12 weeks and weighing 180-220 g, were taken as the experimental animals. PTZ (Sigma Company, United States) was used to induce epilepsy. Ganoderma lucidum spores (Leyss, ex Fr variety) were purchased from Jiamusi City Wild Growing Case of the Ganoderma Lucidum (China). Rabbit anti-somatostatin antibodies and secondary antibodies were purchased from Wuhan Boster Company (China). Neuropeptide Y radioimmunoassay kit was purchased from Beijing Furui Biotechnology Company (China). METHODS: Thirty rats were randomly divided into three groups: a control group, an epilepsy model group and a Ganoderma lucidum spore-treated group. Each group contained 10 animals. Rats in the epilepsy model group were treated with intraperitoneal injections of PTZ and gastric perfusion of physiologic saline. In the Ganoderma lucidum spore-treated group, intraperitoneal injection of PTZ and gastric perfusion of Ganoderma lucidum spore powder were administered. The blank control group was only administered with the physiological saline by intraperitoneal injection and gastric perfusion. MAIN OUTCOME MEASURES: Immunohistochemical staining and radioimmunoassay methods were used to observe the changes of somatostatin and neuropeptide Y content in brain tissue of epileptic rats, as well as the morphology of neurons. RESULTS: All 30 rats were involved in the result analysis, without any loss. The number of somatostatin immunoreacted positive cells in the cerebral cortex and hippocampus was significantly increased in the epilepsy model group compared to the blank control group (P 〈 0.01). The number of somatostatin immunoreacted positive cells in cerebral cortex and hippocampus was significantly decreased in the Ganoderma lucidum spore-treated group compared to the epilepsy model group (P 〈 0.01). The contents of neuropeptide Y in cerebral cortex and hippocampus were significantly increased in the epilepsy model group compared to the blank control group (P 〈 0.01). The contents of neuropeptide Y in the cerebral cortex and hippocampus were significantly decreased in the Ganoderma lucidum spore-treated group compared to the epilepsy model group (P 〈 0.05). The epilepsy seizures in the Ganoderma lucidum spore-treated group were obviously reduced compared to the epilepsy model group. CONCLUSION: Ganoderma lucidum spore powder was able to reduce the somatostatin and neuropeptide Y content in the cerebral cortex and hippocampus effectively, so as to achieve an anti-epileptic function and protect neurons from being damaged.
基金financial support from the National Key Research and Development Program of China(2018YFB0104201).
文摘Boosting the utilization efficiency of sulfur electrodes and suppressing the“shuttle effect”of intermediate polysulfides remain the critical challenge for high-performance lithium-sulfur batteries(LSBs).However,most of reported sulfur electrodes are not competent to realize the fast conversion of polysulfides into insoluble lithium sulfides when applied with high sulfur loading,as well as to mitigate the more serious shuttle effect of polysulfides,especially when worked at an elevated temperature.Herein,we reported a unique structural engineering strategy of crafting a unique hierarchical multifunctional electrode architecture constructed by rooting MOF-derived CoS2/carbon nanoleaf arrays(CoS2-CNA)into a nitrogen-rich 3D conductive scaffold(CTNF@CoS2-CNA)for LSBs.An accelerated electrocatalytic effect and improved polysulfide redox kinetics arising from CoS2-CNA were investigated.Besides,the strong capillarity effect and chemisorption of CTNF@CoS2-CNA to polysulfides enable high loading and efficient utilization of sulfur,thus leading to high-performance LIBs performed not only at room temperature but also up to an elevated temperature(55°C).Even with the ultrahigh sulfur loading of 7.19 mg cm?2,the CTNF@CoS2-CNA/S cathode still exhibits high rate capacity at 55°C.
基金Project(BM2007204)supported by the Jiangsu Key Laboratory of Advanced Metallic Materials,ChinaProject(2242016K40011)supported by the Fundamental Research Funds for the Central Universities,China
文摘The effect of RE addition on solidification process and high-temperature strength of Al-12%Si-4%Cu-1.6%Mn(in wt.%)heat-resistant alloy was investigated by microstructure observation and tensile test.A great number of fine needle-like RE-rich phases are observed in the alloys with RE addition. Solutionizing treatment does not change their morphologies and sizes, indicating that they have good thermal stability. The addition of RE totally alters the solidification process of eutectic CruAl2 phase, from network-like phase in the form of segregation at the final eutectic grain boundaries to discretely blocky phase growing on the hair-filamentous RE-rich needles. In the alloys with Ce addition, blocky CuAl2, particulate Al15Mn3Si2 and needle-like RE-rich needle phases grow together, but they did not occur in the alloy with only La addition. The addition of RE does not considerably improve the strength of the alloy at high temperatures. The formation of RE-rich phases also does not significantly alter the originating and propagating of micro-cracks in the alloy during tensile test.
基金the National Natural Science Foundation of China(No.50272047)Ministry of Education of China(No.704034)
文摘The spores of Ganoderma lucidum were ground and broken to ultrafine particles by high speed centrifugal shearing(HSCS) pulverizer. The characteristics of Ganoderma lucidum spores were analyzed by scanning electron microscope (SEM), Fourier transform infrared spectrophotometry (FTIR). Ultraviolet-visible pectrophotometer was used to determine the extraction ratio of aqueous solubility polysaccharide between the raw and broken spores. The immunological function on the mice before and after the breaking of spores wan investigated. The experimental results show that after being ground, the sporoderm-broken ratio reachs 100%, the original active ingredients of ganoderma lucidum spores do not change, and the extraction ratio of aqueous solubility polysaccharide is greatly increased by 40.08%. The broken spores show much higher immunological activity comparing with original spores of Ganoderma lucidum.
文摘Aims: The objective of this study was to investigate the effect of free fatty acid length chain and unsaturated bond number on the heat resistance and recovery media of bacterial spores. Methods and results: For 6 species, bacterial spore heat resistances were estimated at different free fatty acid concentrations added to heating media or in recovery media. The addition of free fatty acids to heating media has a slight influence on the heat resistance of bacterial spores whatever the species or type of acid studied. On the contrary, the addition of free fatty acids to the recovery medium after the heat treatment greatly reduces the ability to bacterial spores to recover and form colonies. This effect varies depending on chain length, unsaturated bond number of fatty acid and on the bacterial strain studied. Conclusion: The presence of free acids in the recovery media is an additive stress which decreases the capability of injured spores to germinate and grow thereafter. Significance and impact of this study: The impact of free fatty acids presented in this study can be taken into account to reduce the thermal intensity of food sterilization in relation to their availability in food matrix.
文摘In order to study the airborne pollen and Spores, a circular year airborne Samples werecollected at 10m height above ground from Taoyuan ecological station, which is located in TaoyuanCounty of Hunan Province. The analytical results showed that there are 188 plant families and generain airborne pollen and spores. of them, 102 are xylophyte plants, 68 are herbase plat, and 18are pteridophyta plants. The plant families and genera account for 80% of the local plant families andgenera. Among them, 54 are specific families and genera, Which are peculiar tO tropics andsubtropics. The main pollen and spore families and genera are Pinus. Cunninghamia Juglans,Quercus, Cupressaceae, Urticaceac, and Gleicheniaceae. There are two peak stages of airbornepollen and spore concentration throughout the year. One is the peak stage of xylophyte plants fromMarch to May and the other, herbaceous plants from niddle dekad of August to early October. Themaximum year round value is 850 000 grains/1000m3.air in middle dekad of September and theminimum is 1500 grains/1000m3.air in early December. In the local district, the airbome pollen andSpores which can induce respiratory tract disease in spring are Taxodiaceae, Cupresaseeae, CastrieaCastanopsis, Queme, Juglans, Platycarya, and that can induce disease in autumn are Canabis,Gramineae, and Artmisia.