Insects have become an efficient and eco-friendly bioreactor for plastics and even micro/nano-plastics biodegradation.However,the optimal conditions for rearing insects to maximize plastic biodegradation and the under...Insects have become an efficient and eco-friendly bioreactor for plastics and even micro/nano-plastics biodegradation.However,the optimal conditions for rearing insects to maximize plastic biodegradation and the underlying mechanisms remain unclear,hindering its practical applications.We investigated the effects of multiple rearing factors on plastics degradation efficiency of Tenebrio molitor larvae,including larval instar,water addition frequency,plastic specific surface area and plastic types.The functional gut microbes and enzymes associated with the improved efficiency were further explored.Our findings revealed that adult larvae achieved the highest plastics degradation efficiency when receiving regular water additions without causing drowning of insects on hydrophobic plastics.Additionally,they effectively ingested foam plastics of polystyrene,polyethylene and polyurethane without prior comminution and densification.The biodegradation processes involving oxidation,cleavage and depolymerization of plastics were all demonstrated.Furthermore,foam plastic type-dependent functional microbes and enzymes that contributed to the efficient plastic degradationwere identified.Thiswork provides valuable insights into the practical applications of insects for sustainable plastics biodegradation.展开更多
A typical Whipple shield consists of double-layered plates with a certain gap.The space debris impacts the outer plate and is broken into a debris cloud(shattered,molten,vaporized)with dispersed energy and momentum,wh...A typical Whipple shield consists of double-layered plates with a certain gap.The space debris impacts the outer plate and is broken into a debris cloud(shattered,molten,vaporized)with dispersed energy and momentum,which reduces the risk of penetrating the bulkhead.In the realm of hypervelocity impact,strain rate(>10^(5)s^(-1))effects are negligible,and fluid dynamics is employed to describe the impact process.Efficient numerical tools for precisely predicting the damage degree can greatly accelerate the design and optimization of advanced protective structures.Current hypervelocity impact research primarily focuses on the interaction between projectile and front plate and the movement of debris cloud.However,the damage mechanism of debris cloud impacts on rear plates-the critical threat component-remains underexplored owing to complex multi-physics processes and prohibitive computational costs.Existing approaches,ranging from semi-empirical equations to a machine learningbased ballistic limit prediction method,are constrained to binary penetration classification.Alternatively,the uneven data from experiments and simulations caused these methods to be ineffective when the projectile has irregular shapes and complicate flight attitude.Therefore,it is urgent to develop a new damage prediction method for predicting the rear plate damage,which can help to gain a deeper understanding of the damage mechanism.In this study,a machine learning(ML)method is developed to predict the damage distribution in the rear plate.Based on the unit velocity space,the discretized information of debris cloud and rear plate damage from rare simulation cases is used as input data for training the ML models,while the generalization ability for damage distribution prediction is tested by other simulation cases with different attack angles.The results demonstrate that the training and prediction accuracies using the Random Forest(RF)algorithm significantly surpass those using Artificial Neural Networks(ANNs)and Support Vector Machine(SVM).The RF-based model effectively identifies damage features in sparsely distributed debris cloud and cumulative effect.This study establishes an expandable new dataset that accommodates additional parameters to improve the prediction accuracy.Results demonstrate the model's ability to overcome data imbalance limitations through debris cloud features,enabling rapid and accurate rear plate damage prediction across wider scenarios with minimal data requirements.展开更多
[ Objective] The aim of this experiment was to explore the effects of different rearing modes on muscle histological traits and muscle ten demess and to provide theoretical basis for regulating chicken meat quality. [...[ Objective] The aim of this experiment was to explore the effects of different rearing modes on muscle histological traits and muscle ten demess and to provide theoretical basis for regulating chicken meat quality. [ Method] The effects of outdoor rearing, indoor rearing and cage rea ring modes on the muscular histological traits and meat tenderness of Hetian chicken at the age of 8 weeks, 12 weeks and 16 weeks were re searched. [Result] The results showed that the breast and thigh muscle fibre diameter and muscle shear force of outdoor rearing chicken were sig nificently higher than that of cage rearing chicken （ P 〈 0.05）, and muscle fibre density was significantly lower than that of cage rearing chicken （ P 〈 0.05）. With aging, the muscle fibre diameter and shear force increased and muscle fibre density decreased （ P 〈 0.05）. The muscle fibre di ameter and shear force of male were higher than that of female. The correlation analysis showed that the breast muscle shear force had a signifi cantly positive relation with fibre diameter and negative relation with fibre density （ P 〈 0.05）, but thigh muscle shear force had an insignificantly pos itive relation with fibre diameter and fibre density. [ Condusion] Muscular histological traits varied in different rearing modes, and the outdoor rearing promoted the muscular fibre development and increased the muscular shear force.展开更多
[Objective] The aim was to seek the optimal choice of hormones,induced temperature,and initial feed for cultivating loach.[Method] Different hormones were injected to Ioaches for artificial reproduction in water at di...[Objective] The aim was to seek the optimal choice of hormones,induced temperature,and initial feed for cultivating loach.[Method] Different hormones were injected to Ioaches for artificial reproduction in water at different temperatures.During cultivation,varied initial feeds were put in to explore the optimal choice of hormones,temperature and initial feed.[Result] According to the test,fecundity of female loach is directly proportional to gonad maturity,namely,the higher gonad maturity,the more fecundity.For example,for a female loach whose maturity coefficient was 24％,absolute and relative fecundity rates were 62 142 and 990.In contrast,for a female whose maturity coefficient was 9％,the rates were 18 207 and 367,respectively.The induced effect differs upon hormones and the test demonstrated that LRH-A2 is better in improving fertility rate compared with HCG.For example,the fertility rate in the group with HCG was 78.84 and in the group with LRH-A2 was 83.04％.It is notable that the mixture of the two at a certain ratio would enhance induced effect and the fertility rate can be as high as 89.17％.With temperature in a certain range,the higher temperature,the better induced effect.The test indicated that water temperature at （30±0.5） ℃ is an optimal one and the effect horizon is 6-8 h.In group 4,induced rate was 93.33％ and the fertility rate was 89.26％.The research indicated that the survival rate was the highest if wheel animalcule,dominated by Brachionus calyciflorus and Brachionus angularis,was taken as an initial feed,followed by artemia nauplii and corpuscule.In addition,loach fry in the group with yolk and wheel animalcule grew about 1.21 times than the group with only yolk,1.04 times than the group with only fairy shrimp,and 1.1 times than the group with fairy shrimp.[Conclusion] The research provides scientific references for scale loach farming.展开更多
[Objective] The research aimed to optimize laboratory artificial rearing methods for Plutella xylostella L. and to select out effective insecticides against this pest species. [Method] Brassica chinensis seedlings wer...[Objective] The research aimed to optimize laboratory artificial rearing methods for Plutella xylostella L. and to select out effective insecticides against this pest species. [Method] Brassica chinensis seedlings were cultivated in the laboratory at （25±1）℃, 60-75% RH, and a photoperiod of 14：10 （L：D） h. The green blow molding papers were used to collect eggs, and Brassica oleracea seedlings were cultivated to breed Plutella xylostella L. until the insects were ready for use. Mean-while, the susceptibility of 3rd instar larvae of Plutella xylostella L. to five types of insecticides was tested by leaf-dipping method. [Result] Plutella xylostella L. larvae were found well-grown and uniform in developmental stages with average pupa weight of 5.4 mg, pupa emergence percentage of 94.0 % and egg number of 135.1 per female. The LCso values of 3rd instar Plutella xylostella L. larvae against 200 g/L chlorantraniliprole SC, 20% flubendiamide WG, 150 g/L indoxacarb EC, 200 g/L tebufenozide SC and 1.8% abamectin EC, were 0.152, 0.223, 1.151, 93.340 and 0.128 mg/L, respectively. [Conclusion] This rearing method is easy to be implemented and of great practicality, suitable for mass propagation of P. xylostella L. Abamectin, chlorantraniliprole and flubendiamide showed high insecticidal activities, so these three insecticides can be used alternately for the field prevention and control of Plutella xylostella L.展开更多
[Objective]The paper was to develop a standardized rearing technique of Spodoptera frugiperda.[Method]A set of simple,practical and long-term scale standard feeding technique was summarized through indoor rearing of S...[Objective]The paper was to develop a standardized rearing technique of Spodoptera frugiperda.[Method]A set of simple,practical and long-term scale standard feeding technique was summarized through indoor rearing of S.frugiperda from the aspects of feeding vessels,artificial feed components,feeding methods and procedures,notes,etc.[Result]S.frugiperda population maintained under the standard rearing technique for successive five generations which had high fitness parameters.[Conclusion]The new feed formula and rearing technique are suitable for massive rearing of S.frugiperda,which also provide a reference for scale rearing of other Noctuidae insects.展开更多
Calves are the reserve forces for dairy cattle. Scientific rearing strategy of calves is the basis of efficient cattle breeding. However, many problems exist in current rearing systems of calves and restrict the susta...Calves are the reserve forces for dairy cattle. Scientific rearing strategy of calves is the basis of efficient cattle breeding. However, many problems exist in current rearing systems of calves and restrict the sustainable development of dairy cattle in China. The absence of basic research is the most highlighted problem among them. Recent researches on growth performance, nutrient digestibility, blood biochemical indices and rumen development in calves were summarized in this paper. Additionally, the optimal levels of energy and protein in milk replacer and starter diets for calves were indicated, and limiting amino acids for calves fed different diets were discussed. A variety of additives, such as acidifiers, probiotics and polysaccharides, are regarded as promising alternatives to antibiotics to reduce disease in calves. Dietary supplementations of these additives have positive effects on growth and health of calves. However, studies on the nutrition of vitamins and minerals in calves have been seldom done, and deserve our further researches. To sum up, the postnatal period is one of the most critical “windows” for rumen manipulation and epigenetic regulation. Any changes from environments, especially early nutrition, may produce long-term effects on growth, health and milk yields in adult cattle.展开更多
In this study,firstly,for the axisymmetric RVABI,the change-rule of adverse pressure gradient caused by radial velocity during the transition of internal flow mode in variable geometry is summarized,and a Bypass Ratio...In this study,firstly,for the axisymmetric RVABI,the change-rule of adverse pressure gradient caused by radial velocity during the transition of internal flow mode in variable geometry is summarized,and a Bypass Ratio(BR) iterative algorithm based on the empirical correlation of non-equilibrium pressure is proposed.The algorithm can estimate the nonlinear relationship between area ratio and BR,with an error range falling below 6.5%.Then,we discuss the favorable effect of uniform mixing on the thrust augmentation of mixed exhaust under variable BR conditions.From this point of view,the characteristics of vortices evolution in different shear strength jets are compared,to clarify the effect of variable cycle parameters on jet mixing.As the results suggest,when ■ is as low as 0.22,the K-H disturbance is of high-frequency wavelet property,and it is difficult to induce large-scale spanwise vortices.The macro migrations of fluid elements in span wise vortices and the diffusion effect caused by edge tearing is weak,which is not conducive to the energy exchange between the two streams.However,the low ■ jet will also correspondingly weaken the viscous dissipation effect of vortices.It is concluded that the dissipation level is proportional to the 2.31 power of the ■.展开更多
Objective:Empathy can help establish harmonious nurse-patient relationships.We aimed to assess the status of empathy,and explore the relationship between learning burnout,parental rearing patterns and empathy amongst ...Objective:Empathy can help establish harmonious nurse-patient relationships.We aimed to assess the status of empathy,and explore the relationship between learning burnout,parental rearing patterns and empathy amongst nursing students.Method:A questionnaire survey that employed the Learning Burnout Scale,the Short-Form Egna Minnenav Barndoms Uppfostran(s-EMBU)and the Jefferson Scale of Empathy was conducted amongst 562 nursing students.The data were analysed on the basis of descriptive statistic and correlation analysis was used.Results:Empathy is negatively correlated with learning burnout,parental rejection and overprotection and showed no positive correlation with parental emotional warmth.Conclusions:Educators should pay attention to nursing students'feelings and learning burnout status and take positive measures to improve the empathy level of the students.Positive parental rearing patterns also help cultivate empathy.展开更多
The bacterial flora in the digestive tract of B. exarata Philippi and its rearing shoal were investigated, respectively. A total of 107 strains of heterotrophic bacteria, isolated from crop, stomach and intestine, mai...The bacterial flora in the digestive tract of B. exarata Philippi and its rearing shoal were investigated, respectively. A total of 107 strains of heterotrophic bacteria, isolated from crop, stomach and intestine, mainly belong to genera Photobacterium, Bacillus, Pseudomonas and Vibrio. Varieties of bacteria in crop were significantly more than that in stomach and in intestine. A total of 173 strains of bacteria were isolated from the rearing shoal, belonging to 13 genera. The 5 predominant genera are Photobacterium, Bacillus, Pseudomonas, Vibrio and some genera of Enterobacteriaceae. The number of heterotrophic bacteria and Vibrio in rearing shoal changed in line with the alteration of the temperature, and were significantly affected by the use of pesticide.展开更多
Objective:To carry out an experimental study with the main objective of mass rearing of sheep flies(Lucilia sericata).Methods:Hand collection and beef- or cattle liver-baited net traps were used for field fly sampling...Objective:To carry out an experimental study with the main objective of mass rearing of sheep flies(Lucilia sericata).Methods:Hand collection and beef- or cattle liver-baited net traps were used for field fly sampling from April,2010 to November,2010.The samples collected from different places were placed in properly labeled tubes and sent to the Entomology Laboratory. Since maggot identification is important in inducing mortality,they were kept under insectary condition to develop to adult stage and identified using systematic keys.Results:A total of 218 flies were collected in three rounds of sampling from the field of Tehran and Karaj Counties.In the first generation,433 flies including 135(31.17%) male,and 298(68.82%) female were yielded. The female/male of parent ratio was calculated as 1.72 in Tehran and in Karaj areas,whereas it was 2,20%and 1.81%,respectively in Fl and F2 generations,respectively.Conclusions:During this study,the mass rearing of sheep blow fly has been established at the School of Public Health, Tehran University of Medical Sciences and can be used for producing flies for maggot therapy.展开更多
Mono-crystalline silicon solar cells with a passivated emitter rear contact(PERC)configuration have attracted extensive attention from both industry and scientific communities.A record efficiency of 24.06%on p-type si...Mono-crystalline silicon solar cells with a passivated emitter rear contact(PERC)configuration have attracted extensive attention from both industry and scientific communities.A record efficiency of 24.06%on p-type silicon wafer and mass production efficiency around 22%have been demonstrated,mainly due to its superior rear side passivation.In this work,the PERC solar cells with a p-type silicon wafer were numerically studied in terms of the surface passivation,quality of silicon wafer and metal electrodes.A rational way to achieve a 24%mass-production efficiency was proposed.Free energy loss analyses were adopted to address the loss sources with respect to the limit efficiency of 29%,which provides a guideline for the design and manufacture of a high-efficiency PERC solar cell.展开更多
Early life intervention is important to shape the gut microbiome profiles of adult animals due to the tremendous alteration of diet components. Nevertheless, there is still no unified understanding about its long-term...Early life intervention is important to shape the gut microbiome profiles of adult animals due to the tremendous alteration of diet components. Nevertheless, there is still no unified understanding about its long-term effects in lambs. In this study, sixty 20-day-old lambs were assigned into ewe-rearing(ER) and artificial-rearing(AR) treatments to evaluate the effects of AR strategy on ruminal microbiota, fermentation, and morphology of pre-weaning lambs(from 20 to 60 days of age) and its long-term effects in the fattening stage(from 61 to 180 days of age). During the pre-weaning stage, ER lambs were breastfed and supplemented starter, while AR lambs were artificially fed with milk replacer and starter. During the fattening stage, all lambs in both treatments were fed with the same fattening diets. At 60, 120 and 180 days of age, 6 lambs from each group were slaughtered to collect rumen content and tissue samples. Compared with ER lambs, the dry matter feed intakes of AR lambs increased(P<0.05) from 20 to 180 days of age, companying an increased average daily gain(ADG) from 61 to 120 days of age(P<0.05) and from 121 to 180 days of age(0.05<P<0.1). Although there was no difference in short-chain fatty acid(SCFA, including acetate, propionate, and butyrate) between treatments before weaning(P>0.05), it was higher(P<0.05) in AR lambs compared with ER lambs at the fattening stage. The rumen keratin layer of AR lambs was thinner(P<0.05) than that of ER lambs. Along with lamb growth from 60 to 180 days of age, the differences in rumen bacterial diversity between AR and ER treatments grew more distinct(P<0.05). Compared with ER lambs, AR lambs increased(P<0.05) rumen bacteria abundance, such as phylum Spirochaetes and genus Treponema at 60 days of age, phylum Actinobacteria and genus Succiniclasticum at 120 days of age, and phylum Proteobacteria at 180 days of age, but decreased genus Selenomonas from 60 to 180 days of age, and Anaerovibrio at 180 days of age. In summary, the early interventions before weaning could improve dry matter feed intake of lambs, which triggered robust rumen development and produced positive long-term effects on rumen fermentation and noticeable weight gain of fattening lambs. It suggests that the artificial rearing strategy is effective in improving rumen fermentation and microbial maturity of intensive fattening lambs.展开更多
The damage to the rear surface of fused silica under the action of high power laser is more severe than that incurred by the front surface,which hinders the improvement in the energy of the high power laser device.For...The damage to the rear surface of fused silica under the action of high power laser is more severe than that incurred by the front surface,which hinders the improvement in the energy of the high power laser device.For optical components,the ionization breakdown by laser is a main factor causing damage,particularly with laser plasma shock waves,which can cause large-scale fracture damage in fused silica.In this study,the damage morphology is experimentally investigated,and the characteristics of the damage point are obtained.In the theoretical study,the coupling and transmission of the shock wave in glass are investigated based on the finite element method.Thus,both the magnitude and the orientation of stress are obtained.The damage mechanism of the glass can be explained based on the fracture characteristics of glass under different stresses and also on the variation of the damage zone’s Raman spectrum.In addition,the influence of the glass thickness on the damage morphology is investigated.The results obtained in this study can be used as a reference in understanding the characteristics and mechanism of damage characteristics induced by laser plasma shock waves.展开更多
Numerical investigation was performed to examine the effect of rear barrier pillar on stress distribution around a longwall face. Salamon theoretical formula was used to calculate the parameters of the caving zone, wh...Numerical investigation was performed to examine the effect of rear barrier pillar on stress distribution around a longwall face. Salamon theoretical formula was used to calculate the parameters of the caving zone, which was later assigned to double yield constitutive model in FLAC3 D. Numerical results demonstrate that high stress concentration zone exists above the region where the second open-off cut intersects with the rear barrier pillar due to stress transfer and plastic zone expansion. It is also found that the maximum vertical stresses with varied distance to the seam floor are all within the projective plane of the rear barrier pillar and their positions concentrate on the barrier pillar adjacent to the connection corner of the second open-off cut. In addition, position of the maximum vertical stresses abruptly transfer from the connection corner adjacent to former panel to that adjacent to current panel along the panel direction.展开更多
Early rearing experiences are important in one＇s whole life, whereas early adverse rearing experience（EARE） is usually related to various physical and mental disorders in later life. Although there were many studie...Early rearing experiences are important in one＇s whole life, whereas early adverse rearing experience（EARE） is usually related to various physical and mental disorders in later life. Although there were many studies on human and animals, regarding the effect of EARE on brain development, neuroendocrine systems, as well as the consequential mental disorders and behavioral abnormalities, the underlying mechanisms remain unclear. Due to the close genetic relationship and similarity in social organizations with humans, non-human primate（NHP） studies were performed for over 60 years. Various EARE models were developed to disrupt the early normal interactions between infants and mothers or peers. Those studies provided important insights of EARE induced effects on the physiological and behavioral systems of NHPs across life span, such as social behaviors（including disturbance behavior, social deficiency, sexual behavior, etc）, learning and memory ability, brain structural and functional developments（including influences on neurons and glia cells, neuroendocrine systems, e.g., hypothalamic-pituitary-adrenal（HPA） axis, etc）. In this review, the effects of EARE and the underlying epigenetic mechanisms were comprehensively summarized and the possibility of rehabilitation was discussed.展开更多
The mixing effectiveness of the airflow between the inner and outer bypass inlets of a Rear Variable-Area Bypass Injector(RVABI)is the key to the afterburner performance of variable cycle engines.This paper describes ...The mixing effectiveness of the airflow between the inner and outer bypass inlets of a Rear Variable-Area Bypass Injector(RVABI)is the key to the afterburner performance of variable cycle engines.This paper describes an optimized RVABI design based on an alternating area regulator to improve the velocity/temperature uniformity of the incoming flow at the afterburner.Compared with a classical RVABI,numerical simulations show that the proposed alternating RVABI performs better in terms of thermal mixing efficiency and total pressure loss in different variable cycle engine modes.Both the increasing air contact area between the inner and outer bypass of alternating structure RVABI,and a larger streamwise vortex in the inner bypass inlet due to the proposed alternating lobe structure in the RVABI contribute to the significantly increase of mixing effectiveness.Besides,the alternating regulator induces strong streamwise vortex,which helps to improve the airflow mixing with its vortex-induced velocity.The interaction between the streamwise vortex and azimuthal vortex further promises the velocity/temperature uniformity after the RVABI.With the increase of alternating lobe’s height ratio,the covering area of the streamwise vortex and the azimuthal vortex is enlarged,which further enhances the thermal mixing efficiency of the RVABI.This design gives an insight into the future design and optimization of RVABI.展开更多
In organisms with complex life cycles, such as amphibians, morphological variation is strongly influenced by environmental factors （e.g. temperature） and maternal effects （e.g. diet）. Although temperature and food...In organisms with complex life cycles, such as amphibians, morphological variation is strongly influenced by environmental factors （e.g. temperature） and maternal effects （e.g. diet）. Although temperature and food level exert a strong influence on larval growth, little is known about the interacting effects of these factors on age and size at metamorphosis. In this study, plasticity in growth rates, survival, larval period, and size at metamorphosis were examined in Rice field Frog （Rana limnocharis） under different combinations of rearing temperature and food level. Rearing temperature did not affect age at metamorphosis, but a significant interaction between temperature and food level revealed that of tadpoles feeding at a high food level, those reared at 32℃ had a shorter length of larval period than those reared at 29℃ or 26℃. Similarly, our results also showed high food level produced a larger growth rate and mass at metamorphosis at 32℃, but not at 29 and 26℃. Therefore, our results revealed that the effects of food level on larval growth and metamorphosis were highly dependent on developmental temperature.展开更多
The present study examined changes in retinal tyrosine hydroxylase （TH） expression in rats having undergone optic nerve transection and housed under a normal day/night cycle or in the dark. The aim was to investigat...The present study examined changes in retinal tyrosine hydroxylase （TH） expression in rats having undergone optic nerve transection and housed under a normal day/night cycle or in the dark. The aim was to investigate the effects of amacrine cells on axonal regeneration in retinal ganglion cells and on the synapses that transmit visual signals. The results revealed that retinal TH expression gradually decreased following optic nerve transection in rats housed under a normal day/night cycle reaching a minimum at 5 days. In contrast, retinal TH expression decreased to a minimum at 1 day following optic nerve transection in dark reared rats, gradually increasing afterward and reaching a normal level at 5 7 days. The number of TH-positive synaptic particles correlated with the TH levels indicating that dark rearing can help maintain TH expression during the synaptic degeneration stage （5 7 days after optic nerve injury） in retinal amacrine cells.展开更多
The breeding activities aimed to create a natural green cocoon variety for spring rearing with the characteristics of stable natural cocoon color,easy rearing and good silk quality.Four different lines from the excell...The breeding activities aimed to create a natural green cocoon variety for spring rearing with the characteristics of stable natural cocoon color,easy rearing and good silk quality.Four different lines from the excellent silkworm variety Jingsong×Haoyue were taken as recurrent parents,using the natural green cocoon variety G 9202 as donor parent.After other excellent parents were introduced to cross with these different lines,four new breeding materials were selected by recurrent backcross breeding.The characters of these breeding materials showed not only natural green cocoon but also excellent comprehensive traits.A naturally colored cocoon quaternary hybrid with excellent practical characters was selected based on multiple hybrids.It is suitable for spring rearing in Yangtze valley which includes Hunan Province.It was approved by Hunan Provincial Crop Variety Approval Committee and designated Xiangcailu No.1 in 2016.展开更多
基金supported by the National Natural Science Foundation of China(No.22241603).
文摘Insects have become an efficient and eco-friendly bioreactor for plastics and even micro/nano-plastics biodegradation.However,the optimal conditions for rearing insects to maximize plastic biodegradation and the underlying mechanisms remain unclear,hindering its practical applications.We investigated the effects of multiple rearing factors on plastics degradation efficiency of Tenebrio molitor larvae,including larval instar,water addition frequency,plastic specific surface area and plastic types.The functional gut microbes and enzymes associated with the improved efficiency were further explored.Our findings revealed that adult larvae achieved the highest plastics degradation efficiency when receiving regular water additions without causing drowning of insects on hydrophobic plastics.Additionally,they effectively ingested foam plastics of polystyrene,polyethylene and polyurethane without prior comminution and densification.The biodegradation processes involving oxidation,cleavage and depolymerization of plastics were all demonstrated.Furthermore,foam plastic type-dependent functional microbes and enzymes that contributed to the efficient plastic degradationwere identified.Thiswork provides valuable insights into the practical applications of insects for sustainable plastics biodegradation.
基金supported by National Natural Science Foundation of China(Grant No.12432018,12372346)the Innovative Research Groups of the National Natural Science Foundation of China(Grant No.12221002).
文摘A typical Whipple shield consists of double-layered plates with a certain gap.The space debris impacts the outer plate and is broken into a debris cloud(shattered,molten,vaporized)with dispersed energy and momentum,which reduces the risk of penetrating the bulkhead.In the realm of hypervelocity impact,strain rate(>10^(5)s^(-1))effects are negligible,and fluid dynamics is employed to describe the impact process.Efficient numerical tools for precisely predicting the damage degree can greatly accelerate the design and optimization of advanced protective structures.Current hypervelocity impact research primarily focuses on the interaction between projectile and front plate and the movement of debris cloud.However,the damage mechanism of debris cloud impacts on rear plates-the critical threat component-remains underexplored owing to complex multi-physics processes and prohibitive computational costs.Existing approaches,ranging from semi-empirical equations to a machine learningbased ballistic limit prediction method,are constrained to binary penetration classification.Alternatively,the uneven data from experiments and simulations caused these methods to be ineffective when the projectile has irregular shapes and complicate flight attitude.Therefore,it is urgent to develop a new damage prediction method for predicting the rear plate damage,which can help to gain a deeper understanding of the damage mechanism.In this study,a machine learning(ML)method is developed to predict the damage distribution in the rear plate.Based on the unit velocity space,the discretized information of debris cloud and rear plate damage from rare simulation cases is used as input data for training the ML models,while the generalization ability for damage distribution prediction is tested by other simulation cases with different attack angles.The results demonstrate that the training and prediction accuracies using the Random Forest(RF)algorithm significantly surpass those using Artificial Neural Networks(ANNs)and Support Vector Machine(SVM).The RF-based model effectively identifies damage features in sparsely distributed debris cloud and cumulative effect.This study establishes an expandable new dataset that accommodates additional parameters to improve the prediction accuracy.Results demonstrate the model's ability to overcome data imbalance limitations through debris cloud features,enabling rapid and accurate rear plate damage prediction across wider scenarios with minimal data requirements.
文摘[ Objective] The aim of this experiment was to explore the effects of different rearing modes on muscle histological traits and muscle ten demess and to provide theoretical basis for regulating chicken meat quality. [ Method] The effects of outdoor rearing, indoor rearing and cage rea ring modes on the muscular histological traits and meat tenderness of Hetian chicken at the age of 8 weeks, 12 weeks and 16 weeks were re searched. [Result] The results showed that the breast and thigh muscle fibre diameter and muscle shear force of outdoor rearing chicken were sig nificently higher than that of cage rearing chicken （ P 〈 0.05）, and muscle fibre density was significantly lower than that of cage rearing chicken （ P 〈 0.05）. With aging, the muscle fibre diameter and shear force increased and muscle fibre density decreased （ P 〈 0.05）. The muscle fibre di ameter and shear force of male were higher than that of female. The correlation analysis showed that the breast muscle shear force had a signifi cantly positive relation with fibre diameter and negative relation with fibre density （ P 〈 0.05）, but thigh muscle shear force had an insignificantly pos itive relation with fibre diameter and fibre density. [ Condusion] Muscular histological traits varied in different rearing modes, and the outdoor rearing promoted the muscular fibre development and increased the muscular shear force.
文摘[Objective] The aim was to seek the optimal choice of hormones,induced temperature,and initial feed for cultivating loach.[Method] Different hormones were injected to Ioaches for artificial reproduction in water at different temperatures.During cultivation,varied initial feeds were put in to explore the optimal choice of hormones,temperature and initial feed.[Result] According to the test,fecundity of female loach is directly proportional to gonad maturity,namely,the higher gonad maturity,the more fecundity.For example,for a female loach whose maturity coefficient was 24％,absolute and relative fecundity rates were 62 142 and 990.In contrast,for a female whose maturity coefficient was 9％,the rates were 18 207 and 367,respectively.The induced effect differs upon hormones and the test demonstrated that LRH-A2 is better in improving fertility rate compared with HCG.For example,the fertility rate in the group with HCG was 78.84 and in the group with LRH-A2 was 83.04％.It is notable that the mixture of the two at a certain ratio would enhance induced effect and the fertility rate can be as high as 89.17％.With temperature in a certain range,the higher temperature,the better induced effect.The test indicated that water temperature at （30±0.5） ℃ is an optimal one and the effect horizon is 6-8 h.In group 4,induced rate was 93.33％ and the fertility rate was 89.26％.The research indicated that the survival rate was the highest if wheel animalcule,dominated by Brachionus calyciflorus and Brachionus angularis,was taken as an initial feed,followed by artemia nauplii and corpuscule.In addition,loach fry in the group with yolk and wheel animalcule grew about 1.21 times than the group with only yolk,1.04 times than the group with only fairy shrimp,and 1.1 times than the group with fairy shrimp.[Conclusion] The research provides scientific references for scale loach farming.
基金Supported by Key Technologies of R&D Program of Shanxi Province(20120311019-1)Research Project Supported by Shanxi Scholarship Council of China(2012-110)+1 种基金Doctoral Research Fund of Shanxi Academy of Agricultural Sciences(YBSJJ1006)Key Technologies of R&D Program of Shanxi Academy of Agricultural Sciences(2012ygg16)~~
文摘[Objective] The research aimed to optimize laboratory artificial rearing methods for Plutella xylostella L. and to select out effective insecticides against this pest species. [Method] Brassica chinensis seedlings were cultivated in the laboratory at （25±1）℃, 60-75% RH, and a photoperiod of 14：10 （L：D） h. The green blow molding papers were used to collect eggs, and Brassica oleracea seedlings were cultivated to breed Plutella xylostella L. until the insects were ready for use. Mean-while, the susceptibility of 3rd instar larvae of Plutella xylostella L. to five types of insecticides was tested by leaf-dipping method. [Result] Plutella xylostella L. larvae were found well-grown and uniform in developmental stages with average pupa weight of 5.4 mg, pupa emergence percentage of 94.0 % and egg number of 135.1 per female. The LCso values of 3rd instar Plutella xylostella L. larvae against 200 g/L chlorantraniliprole SC, 20% flubendiamide WG, 150 g/L indoxacarb EC, 200 g/L tebufenozide SC and 1.8% abamectin EC, were 0.152, 0.223, 1.151, 93.340 and 0.128 mg/L, respectively. [Conclusion] This rearing method is easy to be implemented and of great practicality, suitable for mass propagation of P. xylostella L. Abamectin, chlorantraniliprole and flubendiamide showed high insecticidal activities, so these three insecticides can be used alternately for the field prevention and control of Plutella xylostella L.
基金Supported by Key-Area Research and Development Program of Guangdong Province(2020B020223004)Innovation Team of Modern Agricultural Industry Research System of Guangdong Province(2019KJ113)+1 种基金National Key Research and Development Program of China(2018YFD0200702-4)Science and Technology Development Project of Guangdong Academy of Sciences(2019GDASYL-0302007)。
文摘[Objective]The paper was to develop a standardized rearing technique of Spodoptera frugiperda.[Method]A set of simple,practical and long-term scale standard feeding technique was summarized through indoor rearing of S.frugiperda from the aspects of feeding vessels,artificial feed components,feeding methods and procedures,notes,etc.[Result]S.frugiperda population maintained under the standard rearing technique for successive five generations which had high fitness parameters.[Conclusion]The new feed formula and rearing technique are suitable for massive rearing of S.frugiperda,which also provide a reference for scale rearing of other Noctuidae insects.
基金funded by the Collaborative Innovation Task of the Agricultural Science and Technology Innovation Program in Chinese Academy of Agricultural Sciences (CAAS)the Fundamental Research Funds for Central Non-profit Scientific Institution of CAAS
文摘Calves are the reserve forces for dairy cattle. Scientific rearing strategy of calves is the basis of efficient cattle breeding. However, many problems exist in current rearing systems of calves and restrict the sustainable development of dairy cattle in China. The absence of basic research is the most highlighted problem among them. Recent researches on growth performance, nutrient digestibility, blood biochemical indices and rumen development in calves were summarized in this paper. Additionally, the optimal levels of energy and protein in milk replacer and starter diets for calves were indicated, and limiting amino acids for calves fed different diets were discussed. A variety of additives, such as acidifiers, probiotics and polysaccharides, are regarded as promising alternatives to antibiotics to reduce disease in calves. Dietary supplementations of these additives have positive effects on growth and health of calves. However, studies on the nutrition of vitamins and minerals in calves have been seldom done, and deserve our further researches. To sum up, the postnatal period is one of the most critical “windows” for rumen manipulation and epigenetic regulation. Any changes from environments, especially early nutrition, may produce long-term effects on growth, health and milk yields in adult cattle.
基金supported by National Major Science and Technology Projects of China(J2019-Ⅱ-0007-0027)Fundamental Research Funds for the Central Universities,China(3082018NP2018102)+1 种基金National Natural Science Foundation of China(12002162)Jiangsu Province Natural Science Foundation,China(BK20200449)。
文摘In this study,firstly,for the axisymmetric RVABI,the change-rule of adverse pressure gradient caused by radial velocity during the transition of internal flow mode in variable geometry is summarized,and a Bypass Ratio(BR) iterative algorithm based on the empirical correlation of non-equilibrium pressure is proposed.The algorithm can estimate the nonlinear relationship between area ratio and BR,with an error range falling below 6.5%.Then,we discuss the favorable effect of uniform mixing on the thrust augmentation of mixed exhaust under variable BR conditions.From this point of view,the characteristics of vortices evolution in different shear strength jets are compared,to clarify the effect of variable cycle parameters on jet mixing.As the results suggest,when ■ is as low as 0.22,the K-H disturbance is of high-frequency wavelet property,and it is difficult to induce large-scale spanwise vortices.The macro migrations of fluid elements in span wise vortices and the diffusion effect caused by edge tearing is weak,which is not conducive to the energy exchange between the two streams.However,the low ■ jet will also correspondingly weaken the viscous dissipation effect of vortices.It is concluded that the dissipation level is proportional to the 2.31 power of the ■.
文摘Objective:Empathy can help establish harmonious nurse-patient relationships.We aimed to assess the status of empathy,and explore the relationship between learning burnout,parental rearing patterns and empathy amongst nursing students.Method:A questionnaire survey that employed the Learning Burnout Scale,the Short-Form Egna Minnenav Barndoms Uppfostran(s-EMBU)and the Jefferson Scale of Empathy was conducted amongst 562 nursing students.The data were analysed on the basis of descriptive statistic and correlation analysis was used.Results:Empathy is negatively correlated with learning burnout,parental rejection and overprotection and showed no positive correlation with parental emotional warmth.Conclusions:Educators should pay attention to nursing students'feelings and learning burnout status and take positive measures to improve the empathy level of the students.Positive parental rearing patterns also help cultivate empathy.
文摘The bacterial flora in the digestive tract of B. exarata Philippi and its rearing shoal were investigated, respectively. A total of 107 strains of heterotrophic bacteria, isolated from crop, stomach and intestine, mainly belong to genera Photobacterium, Bacillus, Pseudomonas and Vibrio. Varieties of bacteria in crop were significantly more than that in stomach and in intestine. A total of 173 strains of bacteria were isolated from the rearing shoal, belonging to 13 genera. The 5 predominant genera are Photobacterium, Bacillus, Pseudomonas, Vibrio and some genera of Enterobacteriaceae. The number of heterotrophic bacteria and Vibrio in rearing shoal changed in line with the alteration of the temperature, and were significantly affected by the use of pesticide.
文摘Objective:To carry out an experimental study with the main objective of mass rearing of sheep flies(Lucilia sericata).Methods:Hand collection and beef- or cattle liver-baited net traps were used for field fly sampling from April,2010 to November,2010.The samples collected from different places were placed in properly labeled tubes and sent to the Entomology Laboratory. Since maggot identification is important in inducing mortality,they were kept under insectary condition to develop to adult stage and identified using systematic keys.Results:A total of 218 flies were collected in three rounds of sampling from the field of Tehran and Karaj Counties.In the first generation,433 flies including 135(31.17%) male,and 298(68.82%) female were yielded. The female/male of parent ratio was calculated as 1.72 in Tehran and in Karaj areas,whereas it was 2,20%and 1.81%,respectively in Fl and F2 generations,respectively.Conclusions:During this study,the mass rearing of sheep blow fly has been established at the School of Public Health, Tehran University of Medical Sciences and can be used for producing flies for maggot therapy.
基金supported by the National Natural Science Foundation of China(No.61504155)。
文摘Mono-crystalline silicon solar cells with a passivated emitter rear contact(PERC)configuration have attracted extensive attention from both industry and scientific communities.A record efficiency of 24.06%on p-type silicon wafer and mass production efficiency around 22%have been demonstrated,mainly due to its superior rear side passivation.In this work,the PERC solar cells with a p-type silicon wafer were numerically studied in terms of the surface passivation,quality of silicon wafer and metal electrodes.A rational way to achieve a 24%mass-production efficiency was proposed.Free energy loss analyses were adopted to address the loss sources with respect to the limit efficiency of 29%,which provides a guideline for the design and manufacture of a high-efficiency PERC solar cell.
基金funded by the National Natural Science Foundation of China(31872385)the Fundamental Research Funds for Central Non-profit Scientific Institution,China(Y2019CG08)the National Key R&D Program of China(2017YFD0502001)。
文摘Early life intervention is important to shape the gut microbiome profiles of adult animals due to the tremendous alteration of diet components. Nevertheless, there is still no unified understanding about its long-term effects in lambs. In this study, sixty 20-day-old lambs were assigned into ewe-rearing(ER) and artificial-rearing(AR) treatments to evaluate the effects of AR strategy on ruminal microbiota, fermentation, and morphology of pre-weaning lambs(from 20 to 60 days of age) and its long-term effects in the fattening stage(from 61 to 180 days of age). During the pre-weaning stage, ER lambs were breastfed and supplemented starter, while AR lambs were artificially fed with milk replacer and starter. During the fattening stage, all lambs in both treatments were fed with the same fattening diets. At 60, 120 and 180 days of age, 6 lambs from each group were slaughtered to collect rumen content and tissue samples. Compared with ER lambs, the dry matter feed intakes of AR lambs increased(P<0.05) from 20 to 180 days of age, companying an increased average daily gain(ADG) from 61 to 120 days of age(P<0.05) and from 121 to 180 days of age(0.05<P<0.1). Although there was no difference in short-chain fatty acid(SCFA, including acetate, propionate, and butyrate) between treatments before weaning(P>0.05), it was higher(P<0.05) in AR lambs compared with ER lambs at the fattening stage. The rumen keratin layer of AR lambs was thinner(P<0.05) than that of ER lambs. Along with lamb growth from 60 to 180 days of age, the differences in rumen bacterial diversity between AR and ER treatments grew more distinct(P<0.05). Compared with ER lambs, AR lambs increased(P<0.05) rumen bacteria abundance, such as phylum Spirochaetes and genus Treponema at 60 days of age, phylum Actinobacteria and genus Succiniclasticum at 120 days of age, and phylum Proteobacteria at 180 days of age, but decreased genus Selenomonas from 60 to 180 days of age, and Anaerovibrio at 180 days of age. In summary, the early interventions before weaning could improve dry matter feed intake of lambs, which triggered robust rumen development and produced positive long-term effects on rumen fermentation and noticeable weight gain of fattening lambs. It suggests that the artificial rearing strategy is effective in improving rumen fermentation and microbial maturity of intensive fattening lambs.
基金Project supported by the Key Research and Development Projects of Science and Technology Department of Sichuan Province,China(Grant No.2018FZ0032)the National Natural Science Foundation of China(Grant No.U1730141)
文摘The damage to the rear surface of fused silica under the action of high power laser is more severe than that incurred by the front surface,which hinders the improvement in the energy of the high power laser device.For optical components,the ionization breakdown by laser is a main factor causing damage,particularly with laser plasma shock waves,which can cause large-scale fracture damage in fused silica.In this study,the damage morphology is experimentally investigated,and the characteristics of the damage point are obtained.In the theoretical study,the coupling and transmission of the shock wave in glass are investigated based on the finite element method.Thus,both the magnitude and the orientation of stress are obtained.The damage mechanism of the glass can be explained based on the fracture characteristics of glass under different stresses and also on the variation of the damage zone’s Raman spectrum.In addition,the influence of the glass thickness on the damage morphology is investigated.The results obtained in this study can be used as a reference in understanding the characteristics and mechanism of damage characteristics induced by laser plasma shock waves.
基金Projects(5147420851304208)supported by the National Natural Science Foundation of China+3 种基金Project supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)ChinaProject(SKLCRSM12X01)supported by the State Key Laboratory of Coal Resources and Mine SafetyChina University of Mining and Technology
文摘Numerical investigation was performed to examine the effect of rear barrier pillar on stress distribution around a longwall face. Salamon theoretical formula was used to calculate the parameters of the caving zone, which was later assigned to double yield constitutive model in FLAC3 D. Numerical results demonstrate that high stress concentration zone exists above the region where the second open-off cut intersects with the rear barrier pillar due to stress transfer and plastic zone expansion. It is also found that the maximum vertical stresses with varied distance to the seam floor are all within the projective plane of the rear barrier pillar and their positions concentrate on the barrier pillar adjacent to the connection corner of the second open-off cut. In addition, position of the maximum vertical stresses abruptly transfer from the connection corner adjacent to former panel to that adjacent to current panel along the panel direction.
基金supported by Hainan special fund project for science and technology(KJHZ2015-20)
文摘Early rearing experiences are important in one＇s whole life, whereas early adverse rearing experience（EARE） is usually related to various physical and mental disorders in later life. Although there were many studies on human and animals, regarding the effect of EARE on brain development, neuroendocrine systems, as well as the consequential mental disorders and behavioral abnormalities, the underlying mechanisms remain unclear. Due to the close genetic relationship and similarity in social organizations with humans, non-human primate（NHP） studies were performed for over 60 years. Various EARE models were developed to disrupt the early normal interactions between infants and mothers or peers. Those studies provided important insights of EARE induced effects on the physiological and behavioral systems of NHPs across life span, such as social behaviors（including disturbance behavior, social deficiency, sexual behavior, etc）, learning and memory ability, brain structural and functional developments（including influences on neurons and glia cells, neuroendocrine systems, e.g., hypothalamic-pituitary-adrenal（HPA） axis, etc）. In this review, the effects of EARE and the underlying epigenetic mechanisms were comprehensively summarized and the possibility of rehabilitation was discussed.
基金This study was supported by the National Science and Technology Major Project,China(No.J2019-III-0016-0060)。
文摘The mixing effectiveness of the airflow between the inner and outer bypass inlets of a Rear Variable-Area Bypass Injector(RVABI)is the key to the afterburner performance of variable cycle engines.This paper describes an optimized RVABI design based on an alternating area regulator to improve the velocity/temperature uniformity of the incoming flow at the afterburner.Compared with a classical RVABI,numerical simulations show that the proposed alternating RVABI performs better in terms of thermal mixing efficiency and total pressure loss in different variable cycle engine modes.Both the increasing air contact area between the inner and outer bypass of alternating structure RVABI,and a larger streamwise vortex in the inner bypass inlet due to the proposed alternating lobe structure in the RVABI contribute to the significantly increase of mixing effectiveness.Besides,the alternating regulator induces strong streamwise vortex,which helps to improve the airflow mixing with its vortex-induced velocity.The interaction between the streamwise vortex and azimuthal vortex further promises the velocity/temperature uniformity after the RVABI.With the increase of alternating lobe’s height ratio,the covering area of the streamwise vortex and the azimuthal vortex is enlarged,which further enhances the thermal mixing efficiency of the RVABI.This design gives an insight into the future design and optimization of RVABI.
基金funded by Program for Innovative Research Team (in Science and Technology) in universities of Henan Province (Grant No.17IRTSTHN019)Henan Scientific and Technological Project (Grant No.162102310124)
文摘In organisms with complex life cycles, such as amphibians, morphological variation is strongly influenced by environmental factors （e.g. temperature） and maternal effects （e.g. diet）. Although temperature and food level exert a strong influence on larval growth, little is known about the interacting effects of these factors on age and size at metamorphosis. In this study, plasticity in growth rates, survival, larval period, and size at metamorphosis were examined in Rice field Frog （Rana limnocharis） under different combinations of rearing temperature and food level. Rearing temperature did not affect age at metamorphosis, but a significant interaction between temperature and food level revealed that of tadpoles feeding at a high food level, those reared at 32℃ had a shorter length of larval period than those reared at 29℃ or 26℃. Similarly, our results also showed high food level produced a larger growth rate and mass at metamorphosis at 32℃, but not at 29 and 26℃. Therefore, our results revealed that the effects of food level on larval growth and metamorphosis were highly dependent on developmental temperature.
基金supported by the National Natural Science Foundation of China (Influence of visual deprivation on bipolar cell synaptic formation and degeneration following opticnerve transection), No. 30671100
文摘The present study examined changes in retinal tyrosine hydroxylase （TH） expression in rats having undergone optic nerve transection and housed under a normal day/night cycle or in the dark. The aim was to investigate the effects of amacrine cells on axonal regeneration in retinal ganglion cells and on the synapses that transmit visual signals. The results revealed that retinal TH expression gradually decreased following optic nerve transection in rats housed under a normal day/night cycle reaching a minimum at 5 days. In contrast, retinal TH expression decreased to a minimum at 1 day following optic nerve transection in dark reared rats, gradually increasing afterward and reaching a normal level at 5 7 days. The number of TH-positive synaptic particles correlated with the TH levels indicating that dark rearing can help maintain TH expression during the synaptic degeneration stage （5 7 days after optic nerve injury） in retinal amacrine cells.
基金Supported by Earmarked Fund for China Agriculture Research System(CARS-18)Hunan Provincial Science and Technology Support Program(2013NK3071)+1 种基金Natural Science Foundation of Hunan Province(2017JJ2137)Silkworm Germplasm Resources Multi-element Application Research and Development Innovation Team(2017XC01)
文摘The breeding activities aimed to create a natural green cocoon variety for spring rearing with the characteristics of stable natural cocoon color,easy rearing and good silk quality.Four different lines from the excellent silkworm variety Jingsong×Haoyue were taken as recurrent parents,using the natural green cocoon variety G 9202 as donor parent.After other excellent parents were introduced to cross with these different lines,four new breeding materials were selected by recurrent backcross breeding.The characters of these breeding materials showed not only natural green cocoon but also excellent comprehensive traits.A naturally colored cocoon quaternary hybrid with excellent practical characters was selected based on multiple hybrids.It is suitable for spring rearing in Yangtze valley which includes Hunan Province.It was approved by Hunan Provincial Crop Variety Approval Committee and designated Xiangcailu No.1 in 2016.
