An experiment was conducted to investigate the effect of dietary supplementation with flavonoid from Scutellaria baicalensis Georgi(SBGFN) as SBGFN-zinc(SBGFN-Zn) on growth performance, meat quality, immune respon...An experiment was conducted to investigate the effect of dietary supplementation with flavonoid from Scutellaria baicalensis Georgi(SBGFN) as SBGFN-zinc(SBGFN-Zn) on growth performance, meat quality, immune responses and antioxidation of broilers. A total of 450 one-d-old Arbor Acres male broilers were randomly allocated to 5 treatments with 6 replicates of 15 birds per replicate for each treatment in a completely randomized design. Birds were fed a SBGFN-unsupplemented cornsoybean meal basal diet(control) or the basal diet supplemented with 60, 120, 180 or 240 mg SBGFN kg-(–1) from SBGFN-Zn for 42 d. Dietary SBGFN supplementation affected(P〈0.03) drip loss in thigh muscle, total superoxide dismutase(T-SOD) and glutathione peroxidase(GSH-Px) activity in liver of broilers at 42 d of age. Chicks fed the diets supplemented with 120, 180 and 240 mg SBGFN kg-(–1) had lower(P〈0.03) drip loss of thigh muscle than those fed the control diet. Chicks fed the diet supplemented with 180 mg SBGFN kg-(–1) had higher(P〈0.03) liver T-SOD and GSH-Px activity than those fed the diets supplemented with 0, 60 and 120 mg SBGFN kg-(–1). The results from the present study indicate that dietary supplementation with 180 mg SBGFN kg-(–1) as SBGFN-Zn improved both meat quality and antioxidative ability of broilers.展开更多
Background:The experiment evaluated the effect of nutrition levels and sex on the growth performance,carcass characteristics and meat quality of F1 Angus × Chinese Xiangxi yellow cattle.Methods:During the backg...Background:The experiment evaluated the effect of nutrition levels and sex on the growth performance,carcass characteristics and meat quality of F1 Angus × Chinese Xiangxi yellow cattle.Methods:During the background period of 184 d,23 steers and 24 heifers were fed the same ration,then put into a2×2×2 factorial arrangement under two levels of- dietary energy(TON:70/80%DM),protein(CP:11.9/14.3%DM)and sex(S:male/female) during the finishing phase of 146 d.The treatments were-(1) high energy/low protein(HELP),(2) high energy/high protein(HEHP),(3) low energy/low protein(LELP) and(4) low energy/high protein(LEHP).Each treatment used 6 steers and 6 heifers,except for HELP- 5 steers and 6 heifers.Results:Growth rate and final carcass weight were unaffected by dietary energy and protein levels or by sex.Compared with the LE diet group,the HE group had significantly lower dry matter intake(DMI,6.76 vs.7.48 kg DM/d),greater chest girth increments(46.1 vs.36.8 cm),higher carcass fat(19.9 vs.16.3%) and intramuscular fat content(29.9 vs.22.8%DM).The HE group also had improved yields of top and medium top grade commercial meat cuts(39.9 vs.36.5%).The dressing percentage was higher for the HP group than the LP group(53.4 vs.54.9%).Steers had a greater length increment(9.0 vs.8.3 cm),but lower carcass fat content(16.8 vs.19.4%) than heifers.The meat quality traits(shear force value,drip loss,cooking loss and water holding capacity) were not affected by treatments or sex,averaging 3.14 kg,2.5,31.5 and 52.9%,respectively.The nutritive profiles(both fatty and amino acid composition) were not influenced by the energy or protein levels or by sex.Conclusions:The dietary energy and protein levels and sex significantly influenced the carcass characteristics and chemical composition of meat but not thegrowth performance,meat quality traits and nutritive profiles.展开更多
[Objective]In order to research on effect of different content of cottonseed meals on production performance and egg quality of Hisex laying hens. [Methods]120 Hisex laying hens of 37 weeks old are chosen,randomly div...[Objective]In order to research on effect of different content of cottonseed meals on production performance and egg quality of Hisex laying hens. [Methods]120 Hisex laying hens of 37 weeks old are chosen,randomly divided into four groups and three repetitions are set in each group,there are 10 hens in each repetition. Group I is the control group,II,III and IV are experimental groups. Cottonseed meal contents are respectively 5%,10% and 15%,with test cycle of 10 weeks,effects of different cottonseed meal dosages on Hisex laying hens production performance and egg quality are observed. [Results]When the diet is added with 5% to 15% of cottonseed meal,the average laying rate,average egg weight and feed-gain ratio all show downward trends when compared with that of the control group,but with no significant difference( P 〉 0. 05); eggshell strength,eggshell thickness,Haugh unit,egg shape index all show no significant difference( P 〉0. 05),with the increasement of cottonseed meal,the color of egg yolk got brighter,egg yolk color of 15% added group increased by 12%,show a significant difference with that of control group( P 〈0. 05). [Conclusion]When the feed was added with 15% cottonseed meals,it has an unconspicuous effect on laying performance and egg quality of Hisex laying hens,but whether it had an effect on animal health and food safety or not,a further systematic research is needed.展开更多
In order to guide the construction of maintenance support system,the theory of complex network to maintenance support area is introduced,and a construction idea of maintenance support system based on complex network i...In order to guide the construction of maintenance support system,the theory of complex network to maintenance support area is introduced,and a construction idea of maintenance support system based on complex network is put forward.Firstly,from the perspective of the similarity,maintenance support system is abstracted into complex network to form maintenance support network.Secondly,the basic concepts and parameters of maintenance support network are also introduced.Thirdly,the maintenance support system in certain period is abstracted into a maintenance support network,and the network makes some changes.Finally,the correlative parameters of the network are calculated.The results show that the changed network is more conducive to the maintenance support.This provides a new thought and method to construct maintenance support system.展开更多
Background: The current study was carried out to determine effects of dietary protein source and crude protein(CP)level on carcass characteristics, meat quality, and muscle amino acid(AA) profile in finishing gil...Background: The current study was carried out to determine effects of dietary protein source and crude protein(CP)level on carcass characteristics, meat quality, and muscle amino acid(AA) profile in finishing gilts. The experiment was designed as a 2 × 2 factorial arrangement with two sources of dietary proteins(cottonseed meal, CSM vs. soybean meal, SBM) and two levels of CP(12 % vs. 14 %, as-fed basis). Seventy-two crossbred gilts(89.5 ± 0.9 kg) were allotted to one of four dietary treatments in a randomized complete block design for a period of 28 d. All diets were formulated to be isoenergetic and similar concentrations of standardized ileal digestible essential AA covering the nutrient requirements of pigs.Results: Growth, carcass characteristics and meat quality were not affected by dietary protein source nor crude protein level(P > 0.10) except that average daily feed intake was increased by CSM diets(P = 0.03). Gilts offered reduced protein diets had lower muscle p H45min(P 〈 0.05). Neither dietary protein source nor crude protein level influenced N deposition. However, reduced protein diets decreased N intake, N excretion, and serum urea nitrogen content, whilst improved N efficiency(P 〈 0.01). CSM diets increased N intake(P = 0.04),but did not depress N efficiency. The concentrations of phenylalanine, tryptophan, cysteine and tyrosine(P 〈 0.05) of the longissimus muscle were decreased when gilts offered CSM diets, while muscle intracellular free valine concentration was increased(P = 0.03). The gilts offered reduced protein diets had greater intracellular concentrations of free methionine, lysine, and total AA in muscle(P 〈 0.05).Conclusion: These results suggest that CSM could replace SBM as a primary protein source in finishing pig diets in terms of performance, N efficiency, carcass characteristics, and meat quality, but decrease the concentrations of muscle specific AA. Furthermore, the reduced protein diet played an important role in increasing muscle intracellular concentrations of specific free amino acids(FAA), and in reducing the relative ratios of specific FAA to lysine in longissimus dorsi muscle of pig, whose biological meaning needs further studies.展开更多
The whole performance of the networked control system (NCSs) depends on two interaction factors, namely the quality of control performance (QoP) and quality of network service (QoS). So, to optimize the whole pe...The whole performance of the networked control system (NCSs) depends on two interaction factors, namely the quality of control performance (QoP) and quality of network service (QoS). So, to optimize the whole perfor-mance of NCSs, the problem of guaranteeing QoP and QoS plays an important role in the design of NCSs. However, up to now, little work has been done in this field. In this paper, a synthesizing control model of NCSs to guarantee QoP and QoS is proposed, and a feasible condition of optimizing whole performance of NCSs is also suggested. Finally, the simulation results show that the proposed model is effective.展开更多
The present study was undertaken to investigate the effect of dietary replacement of commonly used vegetable oil(sunflower oil, SFO) with n-3 polyunsaturated fatty acids(PUFA) rich oil sources on broiler chicken perfo...The present study was undertaken to investigate the effect of dietary replacement of commonly used vegetable oil(sunflower oil, SFO) with n-3 polyunsaturated fatty acids(PUFA) rich oil sources on broiler chicken performance, carcass yield, meat fatty acid composition, keeping quality and sensory attributes of meat. In the current experiment, 300 day-old Krishibro broiler chicks were randomly distributed to 5 dietary groups(50 replicates with 6 chicks in each) prepared by replacing SFO(2% and 3% of diet during starter and finisher periods, respectively) with n-3 PUFA rich soybean oil(SO), mustard oil(MO), linseed oil(LO) or fish oil(FO) on weight basis. Variation in oil sources had no influence(P > 0.05) on performance and carcass yield. Supplementation of MO, LO or FO significantly(P < 0.01) increased the n-3 PUFA, lowered the n-6 PUFA deposition and n-6:n-3 ratio in breast and thigh without affecting the organoleptic characters(appearance, flavour, juiciness, tenderness and overall acceptability) of meat.However, thiobarbituric acid reacting substances concentration in meat was increased(P < 0.01) with LO and FO supplementation compared with SFO. It is concluded that, dietary incorporation of MO, LO or FO at 2% and 3% levels during starter and finisher phase can enrich broiler chicken meat with n-3 PUFA without affecting the bird's performance and sensory characters of meat.展开更多
Warehouse scheduling efficiency has to do with the length-height ratio of location (LHRL) to some extent, which hasn't been well investigated until now. In this paper a mathematic model is built by analyzing the re...Warehouse scheduling efficiency has to do with the length-height ratio of location (LHRL) to some extent, which hasn't been well investigated until now. In this paper a mathematic model is built by analyzing the relation between the travel time of the stacker and LHRL. Mean- while, warehouse scheduling strategy is studied combining with the project on the automatic production line of an enterprise, and a warehouse scheduling strategy is pro- posed based on index of quality (IoQ) parameters. Besides, the process of getting the value of IoQ is also simplified with the idea of sparse matrix. Finally, the IoQ scheduling strategy is compared with random strategy and First Come First Out strategy in different LHRLs. The simulation results show that the IoQ scheduling strategy not only improves the quality of the product effectively, but also improves the efficiency of the scheduling substantially.展开更多
Bi_(2)Te_(3)-based thermoelectric(TE)materials have been demonstrated to be a potential candidate for mainly thermoelectric cooling/refrigeration applications.However,minority charge carriers excitation at high temper...Bi_(2)Te_(3)-based thermoelectric(TE)materials have been demonstrated to be a potential candidate for mainly thermoelectric cooling/refrigeration applications.However,minority charge carriers excitation at high temperature reduces thermopower which restricts these materials for the use in power generation.In present work,substitution of Ni on Sb site in Bi_(0.5)Sb_(1.5-x)NixTe_(3)(x=0,0.01,0.04 and 0.08)actuates the system to supress the intrinsic excitation leading to shift in highest ZT to higher temperature regime.The Density functional theory(DFT)calculations and experimental results reveal that Ni in Bi_(0.5)Sb_(1.5)Te3 provides the extra holes and slightly reduces the band gap Eg which enhances the s of Ni-doped Bi_(0.5)Sb_(1.5-x)NixTe_(3) samples and a at elevated temperature.Moreover,Ni-doping in Bi_(0.5)Sb_(1.5)Te_(3) also reduces kL which is attributed to the phonon scattering due to mass fluctuations and microstructural features such as grain boundary and strain field domain observed from HRTEM investigation.These favourable condition leads to maximum ZT~1.38 at 433K for Bi_(0.5)Sb_(1.46)Ni_(0.04)Te_(3) and ZT_(avg)~1.1 between 300K and 503K.Interestingly the calculated theoretical TE conversion device efficiency h of Bi_(0.5)Sb_(1.46)Ni_(0.04)Te3(η~5.5%)was achieved to be nearly twice than the efficiency of matrix Bi_(0.5)Sb_(1.5)Te3(h~3%).Experimental electronic transport is well corroborated with theoretically estimated DFT results.展开更多
Background and Aims:It is critical but challenging to predict the prognosis of hepatitis B virus-related acute-on-chronic liver failure(HBV-ACLF).This study systematically summarized and evaluated the quality and perf...Background and Aims:It is critical but challenging to predict the prognosis of hepatitis B virus-related acute-on-chronic liver failure(HBV-ACLF).This study systematically summarized and evaluated the quality and performance of available clinical prediction models(CPMs).Methods:A keyword search of articles on HBV-ACLF CPMs published in PubMed from January 1995 to April 2020 was performed.Both the quality and performance of the CPMs were assessed.Results:Fifty-two CPMs were identified,of which 31 were HBV-ACLF specific.The modeling data were mostly derived from retrospective(83.87%)and single-center(96.77%)cohorts,with sample sizes ranging from 46 to 1,202.Three-month mortality was the most common endpoint.The Asian Pacific Association for the Study of the Liver consensus(51.92%)and Chinese Medical Association liver failure guidelines(40.38%)were commonly used for HBV-ACLF diagnosis.Serum bilirubin(67.74%),the international normalized ratio(54.84%),and hepatic encephalopathy(51.61%)were the most frequent variables used in models.Model discrimination was commonly evaluated(88.46%),but model calibration was seldom performed.The model for end-stage liver disease score was the most widely used(84.62%);however,varying performance was reported among the studies.Conclusions:Substantial limitations lie in the quality of HBV-ACLF-specific CPMs.Disease severity of study populations may impact model performance.The clinical utility of CPMs in predicting short-term prognosis of HBV-ACLF remains to be undefined.展开更多
基金supported by the earmarked fund for China Agriculture Research System (CARS-41)the Agricultural Science and Technology Innovation Program, China (ASTIP-IAS08)
文摘An experiment was conducted to investigate the effect of dietary supplementation with flavonoid from Scutellaria baicalensis Georgi(SBGFN) as SBGFN-zinc(SBGFN-Zn) on growth performance, meat quality, immune responses and antioxidation of broilers. A total of 450 one-d-old Arbor Acres male broilers were randomly allocated to 5 treatments with 6 replicates of 15 birds per replicate for each treatment in a completely randomized design. Birds were fed a SBGFN-unsupplemented cornsoybean meal basal diet(control) or the basal diet supplemented with 60, 120, 180 or 240 mg SBGFN kg-(–1) from SBGFN-Zn for 42 d. Dietary SBGFN supplementation affected(P〈0.03) drip loss in thigh muscle, total superoxide dismutase(T-SOD) and glutathione peroxidase(GSH-Px) activity in liver of broilers at 42 d of age. Chicks fed the diets supplemented with 120, 180 and 240 mg SBGFN kg-(–1) had lower(P〈0.03) drip loss of thigh muscle than those fed the control diet. Chicks fed the diet supplemented with 180 mg SBGFN kg-(–1) had higher(P〈0.03) liver T-SOD and GSH-Px activity than those fed the diets supplemented with 0, 60 and 120 mg SBGFN kg-(–1). The results from the present study indicate that dietary supplementation with 180 mg SBGFN kg-(–1) as SBGFN-Zn improved both meat quality and antioxidative ability of broilers.
基金the National Beef Cattle Industry and Technology System for their financial support
文摘Background:The experiment evaluated the effect of nutrition levels and sex on the growth performance,carcass characteristics and meat quality of F1 Angus × Chinese Xiangxi yellow cattle.Methods:During the background period of 184 d,23 steers and 24 heifers were fed the same ration,then put into a2×2×2 factorial arrangement under two levels of- dietary energy(TON:70/80%DM),protein(CP:11.9/14.3%DM)and sex(S:male/female) during the finishing phase of 146 d.The treatments were-(1) high energy/low protein(HELP),(2) high energy/high protein(HEHP),(3) low energy/low protein(LELP) and(4) low energy/high protein(LEHP).Each treatment used 6 steers and 6 heifers,except for HELP- 5 steers and 6 heifers.Results:Growth rate and final carcass weight were unaffected by dietary energy and protein levels or by sex.Compared with the LE diet group,the HE group had significantly lower dry matter intake(DMI,6.76 vs.7.48 kg DM/d),greater chest girth increments(46.1 vs.36.8 cm),higher carcass fat(19.9 vs.16.3%) and intramuscular fat content(29.9 vs.22.8%DM).The HE group also had improved yields of top and medium top grade commercial meat cuts(39.9 vs.36.5%).The dressing percentage was higher for the HP group than the LP group(53.4 vs.54.9%).Steers had a greater length increment(9.0 vs.8.3 cm),but lower carcass fat content(16.8 vs.19.4%) than heifers.The meat quality traits(shear force value,drip loss,cooking loss and water holding capacity) were not affected by treatments or sex,averaging 3.14 kg,2.5,31.5 and 52.9%,respectively.The nutritive profiles(both fatty and amino acid composition) were not influenced by the energy or protein levels or by sex.Conclusions:The dietary energy and protein levels and sex significantly influenced the carcass characteristics and chemical composition of meat but not thegrowth performance,meat quality traits and nutritive profiles.
基金Supported by Modern Agricultural Industry Technology System Construction Special Fund(nycytx-41-2B)Social Development Project of Yangzhou(yz2010080)
文摘[Objective]In order to research on effect of different content of cottonseed meals on production performance and egg quality of Hisex laying hens. [Methods]120 Hisex laying hens of 37 weeks old are chosen,randomly divided into four groups and three repetitions are set in each group,there are 10 hens in each repetition. Group I is the control group,II,III and IV are experimental groups. Cottonseed meal contents are respectively 5%,10% and 15%,with test cycle of 10 weeks,effects of different cottonseed meal dosages on Hisex laying hens production performance and egg quality are observed. [Results]When the diet is added with 5% to 15% of cottonseed meal,the average laying rate,average egg weight and feed-gain ratio all show downward trends when compared with that of the control group,but with no significant difference( P 〉 0. 05); eggshell strength,eggshell thickness,Haugh unit,egg shape index all show no significant difference( P 〉0. 05),with the increasement of cottonseed meal,the color of egg yolk got brighter,egg yolk color of 15% added group increased by 12%,show a significant difference with that of control group( P 〈0. 05). [Conclusion]When the feed was added with 15% cottonseed meals,it has an unconspicuous effect on laying performance and egg quality of Hisex laying hens,but whether it had an effect on animal health and food safety or not,a further systematic research is needed.
基金National Natural Science Foundation of China(No.61271152)
文摘In order to guide the construction of maintenance support system,the theory of complex network to maintenance support area is introduced,and a construction idea of maintenance support system based on complex network is put forward.Firstly,from the perspective of the similarity,maintenance support system is abstracted into complex network to form maintenance support network.Secondly,the basic concepts and parameters of maintenance support network are also introduced.Thirdly,the maintenance support system in certain period is abstracted into a maintenance support network,and the network makes some changes.Finally,the correlative parameters of the network are calculated.The results show that the changed network is more conducive to the maintenance support.This provides a new thought and method to construct maintenance support system.
基金financially supported by the National Key Basic Research Program of China (2012CB124702, 2013CB127302)National Natural Science Foundation of China (31272452)the National Key Technology R&D Program of China (2011BAD26B01)
文摘Background: The current study was carried out to determine effects of dietary protein source and crude protein(CP)level on carcass characteristics, meat quality, and muscle amino acid(AA) profile in finishing gilts. The experiment was designed as a 2 × 2 factorial arrangement with two sources of dietary proteins(cottonseed meal, CSM vs. soybean meal, SBM) and two levels of CP(12 % vs. 14 %, as-fed basis). Seventy-two crossbred gilts(89.5 ± 0.9 kg) were allotted to one of four dietary treatments in a randomized complete block design for a period of 28 d. All diets were formulated to be isoenergetic and similar concentrations of standardized ileal digestible essential AA covering the nutrient requirements of pigs.Results: Growth, carcass characteristics and meat quality were not affected by dietary protein source nor crude protein level(P &gt; 0.10) except that average daily feed intake was increased by CSM diets(P = 0.03). Gilts offered reduced protein diets had lower muscle p H45min(P 〈 0.05). Neither dietary protein source nor crude protein level influenced N deposition. However, reduced protein diets decreased N intake, N excretion, and serum urea nitrogen content, whilst improved N efficiency(P 〈 0.01). CSM diets increased N intake(P = 0.04),but did not depress N efficiency. The concentrations of phenylalanine, tryptophan, cysteine and tyrosine(P 〈 0.05) of the longissimus muscle were decreased when gilts offered CSM diets, while muscle intracellular free valine concentration was increased(P = 0.03). The gilts offered reduced protein diets had greater intracellular concentrations of free methionine, lysine, and total AA in muscle(P 〈 0.05).Conclusion: These results suggest that CSM could replace SBM as a primary protein source in finishing pig diets in terms of performance, N efficiency, carcass characteristics, and meat quality, but decrease the concentrations of muscle specific AA. Furthermore, the reduced protein diet played an important role in increasing muscle intracellular concentrations of specific free amino acids(FAA), and in reducing the relative ratios of specific FAA to lysine in longissimus dorsi muscle of pig, whose biological meaning needs further studies.
文摘The whole performance of the networked control system (NCSs) depends on two interaction factors, namely the quality of control performance (QoP) and quality of network service (QoS). So, to optimize the whole perfor-mance of NCSs, the problem of guaranteeing QoP and QoS plays an important role in the design of NCSs. However, up to now, little work has been done in this field. In this paper, a synthesizing control model of NCSs to guarantee QoP and QoS is proposed, and a feasible condition of optimizing whole performance of NCSs is also suggested. Finally, the simulation results show that the proposed model is effective.
文摘The present study was undertaken to investigate the effect of dietary replacement of commonly used vegetable oil(sunflower oil, SFO) with n-3 polyunsaturated fatty acids(PUFA) rich oil sources on broiler chicken performance, carcass yield, meat fatty acid composition, keeping quality and sensory attributes of meat. In the current experiment, 300 day-old Krishibro broiler chicks were randomly distributed to 5 dietary groups(50 replicates with 6 chicks in each) prepared by replacing SFO(2% and 3% of diet during starter and finisher periods, respectively) with n-3 PUFA rich soybean oil(SO), mustard oil(MO), linseed oil(LO) or fish oil(FO) on weight basis. Variation in oil sources had no influence(P > 0.05) on performance and carcass yield. Supplementation of MO, LO or FO significantly(P < 0.01) increased the n-3 PUFA, lowered the n-6 PUFA deposition and n-6:n-3 ratio in breast and thigh without affecting the organoleptic characters(appearance, flavour, juiciness, tenderness and overall acceptability) of meat.However, thiobarbituric acid reacting substances concentration in meat was increased(P < 0.01) with LO and FO supplementation compared with SFO. It is concluded that, dietary incorporation of MO, LO or FO at 2% and 3% levels during starter and finisher phase can enrich broiler chicken meat with n-3 PUFA without affecting the bird's performance and sensory characters of meat.
基金supported by the National Natural Science Foundation of China (Grant Nos. 61074032 and 61273040)the Project of Science and Technology Commission of Shanghai Municipality (Grant No. 10JC1405000)the Shanghai Rising-Star Program (Grant No. 12QA1401100)
文摘Warehouse scheduling efficiency has to do with the length-height ratio of location (LHRL) to some extent, which hasn't been well investigated until now. In this paper a mathematic model is built by analyzing the relation between the travel time of the stacker and LHRL. Mean- while, warehouse scheduling strategy is studied combining with the project on the automatic production line of an enterprise, and a warehouse scheduling strategy is pro- posed based on index of quality (IoQ) parameters. Besides, the process of getting the value of IoQ is also simplified with the idea of sparse matrix. Finally, the IoQ scheduling strategy is compared with random strategy and First Come First Out strategy in different LHRLs. The simulation results show that the IoQ scheduling strategy not only improves the quality of the product effectively, but also improves the efficiency of the scheduling substantially.
文摘Bi_(2)Te_(3)-based thermoelectric(TE)materials have been demonstrated to be a potential candidate for mainly thermoelectric cooling/refrigeration applications.However,minority charge carriers excitation at high temperature reduces thermopower which restricts these materials for the use in power generation.In present work,substitution of Ni on Sb site in Bi_(0.5)Sb_(1.5-x)NixTe_(3)(x=0,0.01,0.04 and 0.08)actuates the system to supress the intrinsic excitation leading to shift in highest ZT to higher temperature regime.The Density functional theory(DFT)calculations and experimental results reveal that Ni in Bi_(0.5)Sb_(1.5)Te3 provides the extra holes and slightly reduces the band gap Eg which enhances the s of Ni-doped Bi_(0.5)Sb_(1.5-x)NixTe_(3) samples and a at elevated temperature.Moreover,Ni-doping in Bi_(0.5)Sb_(1.5)Te_(3) also reduces kL which is attributed to the phonon scattering due to mass fluctuations and microstructural features such as grain boundary and strain field domain observed from HRTEM investigation.These favourable condition leads to maximum ZT~1.38 at 433K for Bi_(0.5)Sb_(1.46)Ni_(0.04)Te_(3) and ZT_(avg)~1.1 between 300K and 503K.Interestingly the calculated theoretical TE conversion device efficiency h of Bi_(0.5)Sb_(1.46)Ni_(0.04)Te3(η~5.5%)was achieved to be nearly twice than the efficiency of matrix Bi_(0.5)Sb_(1.5)Te3(h~3%).Experimental electronic transport is well corroborated with theoretically estimated DFT results.
基金the Chinese National Natural Science Foundation(Nos.81670567 and 81870425)the Fundamental Research Funds for the Central Universities.
文摘Background and Aims:It is critical but challenging to predict the prognosis of hepatitis B virus-related acute-on-chronic liver failure(HBV-ACLF).This study systematically summarized and evaluated the quality and performance of available clinical prediction models(CPMs).Methods:A keyword search of articles on HBV-ACLF CPMs published in PubMed from January 1995 to April 2020 was performed.Both the quality and performance of the CPMs were assessed.Results:Fifty-two CPMs were identified,of which 31 were HBV-ACLF specific.The modeling data were mostly derived from retrospective(83.87%)and single-center(96.77%)cohorts,with sample sizes ranging from 46 to 1,202.Three-month mortality was the most common endpoint.The Asian Pacific Association for the Study of the Liver consensus(51.92%)and Chinese Medical Association liver failure guidelines(40.38%)were commonly used for HBV-ACLF diagnosis.Serum bilirubin(67.74%),the international normalized ratio(54.84%),and hepatic encephalopathy(51.61%)were the most frequent variables used in models.Model discrimination was commonly evaluated(88.46%),but model calibration was seldom performed.The model for end-stage liver disease score was the most widely used(84.62%);however,varying performance was reported among the studies.Conclusions:Substantial limitations lie in the quality of HBV-ACLF-specific CPMs.Disease severity of study populations may impact model performance.The clinical utility of CPMs in predicting short-term prognosis of HBV-ACLF remains to be undefined.