以鲜牛乳为原料,添加植物乳杆菌和嗜酸乳杆菌微胶囊制备酸奶。以产品的酸度、黏度、pH、感官评分为评价指标,通过单因素试验、正交试验和主成分分析(PCA)对结果进行综合分析,优化酸奶工艺,且通过体外模拟胃肠液试验,探究微胶囊酸奶中乳...以鲜牛乳为原料,添加植物乳杆菌和嗜酸乳杆菌微胶囊制备酸奶。以产品的酸度、黏度、pH、感官评分为评价指标,通过单因素试验、正交试验和主成分分析(PCA)对结果进行综合分析,优化酸奶工艺,且通过体外模拟胃肠液试验,探究微胶囊酸奶中乳酸菌的存活率。结果表明,酸奶的最佳配方为以鲜牛乳为原料,发酵剂添加量0.2%,白砂糖添加量8%,果胶添加量0.2%,微胶囊添加量2%,发酵温度41℃,发酵时间9 h。在此优化条件下制作的酸奶质地细腻,组织状态均匀,感官评分为85分,其黏度、酸度、pH值分别为410 m Pa·s、137°T、5.2,其理化和微生物指标均符合国家标准。体外模拟试验结果表明,与添加乳酸菌菌粉制成的酸奶相比,添加乳酸菌微胶囊制成的酸奶经胃液和肠液后,存活率达到67.60%和62.00%,分别增加了36.21%和33.94%。乳酸菌微胶囊添加到酸奶中,为新型酸奶食品的研发提供参考依据。展开更多
To meet the demand for an accurate and highly efficient damage model with a distinct physical meaning for performance-based earthquake engineering applications, a stiffness degradation-based damage model for reinforce...To meet the demand for an accurate and highly efficient damage model with a distinct physical meaning for performance-based earthquake engineering applications, a stiffness degradation-based damage model for reinforced concrete （RC） members and structures was developed using fiber beam-column elements. In this model, damage indices for concrete and steel fibers were defined by the degradation of the initial reloading modulus and the low-cycle fatigue law. Then, section, member, story and structure damage was evaluated by the degradation of the sectional bending stiffness, rod-end bending stiffness, story lateral stiffness and structure lateral stiffness, respectively. The damage model was realized in Matlab by reading in the outputs of OpenSees. The application of the damage model to RC columns and a RC frame indicates that the damage model is capable of accurately predicting the magnitude, position, and evolutionary process of damage, and estimating stow damage more precisely than inter-story drift. Additionally, the damage model establishes a close connection between damage indices at various levels without introducing weighting coefficients or force-displacement relationships. The development of the model has perfected the damage assessment function of OpenSees, laying a solid foundation for damage estimation at various levels of a large-scale structure subjected to seismic loading.展开更多
Benefiting from the improvements of Internet infrastructure and video coding technology, online video services are becoming a new favorite form of video entertainment.However, most of the existing video quality assess...Benefiting from the improvements of Internet infrastructure and video coding technology, online video services are becoming a new favorite form of video entertainment.However, most of the existing video quality assessment methods are designed for broadcasting/cable televisions and it is still an open issue how to assess and measure the quality of online video services. In this paper, we survey the state-of-the-art video streaming technologies, and present a framework of quality assessment and measurement for Internet video streaming. This paper introduces several metrics for user's quality of experience(QoE).These QoE metrics are classified into two categories: objective metrics and subjective metrics. It is different for service participators to measure objective and subjective metrics.The QoE measurement methodologies consist of client-side, server-side, and in-network measurement.展开更多
A monotonicity formula for stable solutions to a class of weighted semilinear elliptic equations with ＂negative exponent＂ is established. It is well known that such a monotonieity formula plays an essential role in ...A monotonicity formula for stable solutions to a class of weighted semilinear elliptic equations with ＂negative exponent＂ is established. It is well known that such a monotonieity formula plays an essential role in the study of finite Morse index solutions of equations with ＂positive exponent＂. Unlike the positive exponent case, we will see that both the monotonicity formula and the sub-harmonicity play crucial roles in classifying positive finite Morse index solutions to the equations with negative exponent and obtaining sharp results for their asymptotic behaviors.展开更多
New Sobolev type embeddings for some weighted Banach spaces are established. Using such embeddings and the singular positive radial entire solutions, we construct singular positive weak solutions with a prescribed sin...New Sobolev type embeddings for some weighted Banach spaces are established. Using such embeddings and the singular positive radial entire solutions, we construct singular positive weak solutions with a prescribed singular set for a weighted elliptic equation. Our main results in this paper also provide positive weak solutions with a prescribed singular set to an equation with Hardy potential.展开更多
A Liouville type result is established for non-negative entire solutions of a weighted elliptic equation.This provides a positive answer to a problem left open by Du and Guo(2015) and Phan and Souplet(2012)(see(CJ) by...A Liouville type result is established for non-negative entire solutions of a weighted elliptic equation.This provides a positive answer to a problem left open by Du and Guo(2015) and Phan and Souplet(2012)(see(CJ) by Du and Guo(2015) and Conjecture B by Phan and Souplet(2012)). Meanwhile, some regularity results are also obtained. The main results in this paper imply that the number ps is the critical value of the Dirichlet problems of the related equation, even though there are still some open problems left. Our results also apply for the equation with a Hardy potential.展开更多
New embeddings of some weighted Sobolev spaces with weights a(x)and b(x)are established.The weights a(x)and b(x)can be singular.Some applications of these embeddings to a class of degenerate elliptic problems of the f...New embeddings of some weighted Sobolev spaces with weights a(x)and b(x)are established.The weights a(x)and b(x)can be singular.Some applications of these embeddings to a class of degenerate elliptic problems of the form-div(a(x)?u)=b(x)f(x,u)in?,u=0 on??,where?is a bounded or unbounded domain in RN,N 2,are presented.The main results of this paper also give some generalizations of the well-known Caffarelli-Kohn-Nirenberg inequality.展开更多
文摘以鲜牛乳为原料,添加植物乳杆菌和嗜酸乳杆菌微胶囊制备酸奶。以产品的酸度、黏度、pH、感官评分为评价指标,通过单因素试验、正交试验和主成分分析(PCA)对结果进行综合分析,优化酸奶工艺,且通过体外模拟胃肠液试验,探究微胶囊酸奶中乳酸菌的存活率。结果表明,酸奶的最佳配方为以鲜牛乳为原料,发酵剂添加量0.2%,白砂糖添加量8%,果胶添加量0.2%,微胶囊添加量2%,发酵温度41℃,发酵时间9 h。在此优化条件下制作的酸奶质地细腻,组织状态均匀,感官评分为85分,其黏度、酸度、pH值分别为410 m Pa·s、137°T、5.2,其理化和微生物指标均符合国家标准。体外模拟试验结果表明,与添加乳酸菌菌粉制成的酸奶相比,添加乳酸菌微胶囊制成的酸奶经胃液和肠液后,存活率达到67.60%和62.00%,分别增加了36.21%和33.94%。乳酸菌微胶囊添加到酸奶中,为新型酸奶食品的研发提供参考依据。
基金the National Natural Science Foundation of China under Grant Nos.51278218 and 51078166
文摘To meet the demand for an accurate and highly efficient damage model with a distinct physical meaning for performance-based earthquake engineering applications, a stiffness degradation-based damage model for reinforced concrete （RC） members and structures was developed using fiber beam-column elements. In this model, damage indices for concrete and steel fibers were defined by the degradation of the initial reloading modulus and the low-cycle fatigue law. Then, section, member, story and structure damage was evaluated by the degradation of the sectional bending stiffness, rod-end bending stiffness, story lateral stiffness and structure lateral stiffness, respectively. The damage model was realized in Matlab by reading in the outputs of OpenSees. The application of the damage model to RC columns and a RC frame indicates that the damage model is capable of accurately predicting the magnitude, position, and evolutionary process of damage, and estimating stow damage more precisely than inter-story drift. Additionally, the damage model establishes a close connection between damage indices at various levels without introducing weighting coefficients or force-displacement relationships. The development of the model has perfected the damage assessment function of OpenSees, laying a solid foundation for damage estimation at various levels of a large-scale structure subjected to seismic loading.
基金supported by National Key R&D Program of China No.2018YFB0803702Beijing Culture Development Funding under Grant No.2016-288Toutiao Funding No.ZN20171224003
文摘Benefiting from the improvements of Internet infrastructure and video coding technology, online video services are becoming a new favorite form of video entertainment.However, most of the existing video quality assessment methods are designed for broadcasting/cable televisions and it is still an open issue how to assess and measure the quality of online video services. In this paper, we survey the state-of-the-art video streaming technologies, and present a framework of quality assessment and measurement for Internet video streaming. This paper introduces several metrics for user's quality of experience(QoE).These QoE metrics are classified into two categories: objective metrics and subjective metrics. It is different for service participators to measure objective and subjective metrics.The QoE measurement methodologies consist of client-side, server-side, and in-network measurement.
基金supported by National Natural Science Foundation of China(Grant Nos.11171092 and 11271133)Innovation Scientists and Technicians Troop Construction Projects of Henan Province(Grant No.114200510011)
文摘A monotonicity formula for stable solutions to a class of weighted semilinear elliptic equations with ＂negative exponent＂ is established. It is well known that such a monotonieity formula plays an essential role in the study of finite Morse index solutions of equations with ＂positive exponent＂. Unlike the positive exponent case, we will see that both the monotonicity formula and the sub-harmonicity play crucial roles in classifying positive finite Morse index solutions to the equations with negative exponent and obtaining sharp results for their asymptotic behaviors.
基金supported by National Natural Science Foundation of China (Grant Nos. 11171092 and 11571093)
文摘New Sobolev type embeddings for some weighted Banach spaces are established. Using such embeddings and the singular positive radial entire solutions, we construct singular positive weak solutions with a prescribed singular set for a weighted elliptic equation. Our main results in this paper also provide positive weak solutions with a prescribed singular set to an equation with Hardy potential.
基金supported by National Natural Science Foundation of China (Grant No. 11571093)
文摘A Liouville type result is established for non-negative entire solutions of a weighted elliptic equation.This provides a positive answer to a problem left open by Du and Guo(2015) and Phan and Souplet(2012)(see(CJ) by Du and Guo(2015) and Conjecture B by Phan and Souplet(2012)). Meanwhile, some regularity results are also obtained. The main results in this paper imply that the number ps is the critical value of the Dirichlet problems of the related equation, even though there are still some open problems left. Our results also apply for the equation with a Hardy potential.
基金supported by National Natural Science Foundation of China (Grant Nos. 11171092, 11571093 and 11371117)
文摘New embeddings of some weighted Sobolev spaces with weights a(x)and b(x)are established.The weights a(x)and b(x)can be singular.Some applications of these embeddings to a class of degenerate elliptic problems of the form-div(a(x)?u)=b(x)f(x,u)in?,u=0 on??,where?is a bounded or unbounded domain in RN,N 2,are presented.The main results of this paper also give some generalizations of the well-known Caffarelli-Kohn-Nirenberg inequality.
