Properties of collective flow and pion production in intermediate-energy heavy-ion collisions with a relativistic quantum molecular dynamics model

The relativistic mean-field approach was implemented in the Lanzhou quantum molecular dynamics transport model(LQMD.RMF). Using the LQMD.RMF, the properties of collective flow and pion production were investigated systematically for nuclear reactions with various isospin asymmetries. The directed and elliptic flows of the LQMD.RMF are able to describe the experimental data of STAR Collaboration. The directed flow difference between free neutrons and protons was associated with the stiffness of the symmetry energy, that is, a softer symmetry energy led to a larger flow difference. For various collision energies, the ratio between the π^(-) and π^(+) yields increased with a decrease in the slope parameter of the symmetry energy. When the collision energy was 270 MeV/nucleon, the single ratio of the pion transverse momentum spectra also increased with decreasing slope parameter of the symmetry energy in both nearly symmetric and neutron-rich systems.However, it is difficult to constrain the stiffness of the symmetry energy with the double ratio because of the lack of threshold energy correction on the pion production.

Analysis of the Production and Operation Status of Silkworm Eggs Producing Farms in China——Based on Questionnaire Survey to 136 Silkworm Eggs Producing Farms Nationwide

Through statistical analysis on questionnaire survey data from 136 silkworm eggs producing farms in China,it was concluded that most silkworm eggs producing farms had such problems as follows: old production facilities and poor production condition,heavy staff burden,weak scientific and technological support,small operation scale and heavy surplus production capacity; narrow silkworm eggs sale channels and stubborn regional segmentation,insufficient innovation and lack of technological support for diversified expansion. All these problems led to low labor productivity,low asset utilization rate and poor economic benefit in silkworm eggs producing farms in China. Except the provinces( regions) of Guangxi,Guangdong and Yunnan,the silkworm eggs producing farms in other provinces were generally at deficit condition. In the light of ownership,although silkworm eggs producing farms of different ownership systems were in the red,those of the private sector had the minimum deficit. Based on these findings,it is proposed to deepen system reformation of silkworm eggs producing farms,loosen control to price and circulation of silkworm eggs,implement large-scaled production and operation,speed up scientific and technological innovation,expand diversified development channels,and reinforce government support so as to increase production and operation benefits of silkworm eggs producing farms in China.

Theoretical Reflection on Meaning Production of Media Discourse in Intercultural Communications

Media discourse in the context of intercultural communications is an important channel that countries and cultures use to communicate. It is also a process of meaning interpretation and knowledge production, which exerts a great impact on the establishment of the world's cultural order. This paper discusses media discourse in intercultural communications theoretically from the perspective of knowledge production, media dialogue and meaning construction. It is suggested that an effective ideographic mechanism be developed and improved, and the essential meaning of Chinese culture be initiatively exported and integrated into a knowledge system of cognition and understanding about the world to promote the understanding and exchange between China and other countries and to help create an equal and reasonable world cultural order.

Spatial and temporal relationships between precipitation and ANPP of four types of grasslands in northern China

Precipitation is considered to be the primary resource limiting terrestrial biological activity in water-limited regions. Its overriding effect on the production of grassland is complex. In this paper, field data of 48 sites （including temperate meadow steppe, temperate steppe, temperate desert steppe and alpine meadow） were gathered from 31 published papers and monographs to analyze the relationship between above-ground net primary productivity （ANPP） and precipitation by the method of regression analysis. The results indicated that there was a great difference between spatial pattern and temporal pattern by which precipitation influenced grassland ANPP. Mean annual precipitation （MAP） was the main factor determining spatial distribution of grassland ANPP （r^2 = 0.61, P 〈 0.01）; while temporally, no significant relationship was found between the variance of AN PP and inter-annual precipitation for the four types of grassland. However, after dividing annual preeipitation into monthly value and taking time lag effect into account, the study found significant relationships between ANPP and precipitation. For the temperate meadow steppe, the key variable determining inter-annual change of ANPP was last August-May precipitation （r^2 = 0.47, P = 0.01）; for the temperate steppe, the key variable was July precipitation （r^2 = 0.36, P = 0.02）; for the temperate desert steppe, the key variable was April-June precipitation （r^2 = 0.51, P 〈 0.01）; for the alpine meadow, the key variable was last September-May precipitation （r^2 = 0.29, P 〈 0.05）. In comparison with analogous research, the study demonstrated that the key factor determining inter-annual changes of grassland ANPP was the cumulative precipitation in certain periods of that year or the previous year.

As Could We Assure Safety in Large-Scale Manufacturing of Nanoparticles for the Biomedical Use

Nanoparticles provide great advantages but also great risks. Risks associating with nanoparticles are the problem of all technologies, but they increase in many times in nanotechnologies. Adequate methods of outgoing production inspection are necessary to solve the problem of risks, and the inspection must be based on the safety standard. Existing safety standard results from a principle of “maximum permissible concentrations or MPC”. This principle is not applicable to nanoparticles, but a safety standard reflecting risks inherent in nanoparticles doesn’t exist. Essence of the risks is illustrated by the example from pharmacology, since its safety assurance is conceptually based on MPC and it has already come against this problem. Possible formula of safety standard for nanoparticles is reflected in many publications, but conventional inspection methods cannot provide its realization, and this gap is an obstacle to assumption of similar formulas. Therefore the development of nanoparticle industry as a whole (also development of the pharmacology in particular) is impossible without the creation of an adequate inspection method. There are suggested new inspection methods founded on the new physical principle and satisfying to the adequate safety standard for nanoparticles. These methods demonstrate that creation of the adequate safety standard and the outgoing production inspection in a large-scale manufacturing of nanoparticles are the solvable problems. However there is a great distance between the physical principle and its hardware realization, and a transition from the principle to the hardware demands great intellectual and material costs. Therefore it is desirable to call attention of the public at large to the necessity of urgent expansions of investigations associated with outgoing inspections in nanoparticles technologies. It is necessary also to attract attention, first, of representatives of state structures controlling approvals of the adequate safety standard to this problem, since it is impossible to compel producers providing the safety without the similar standard, and, second, of leaders of pharmacological industry, since their industry already entered into the nanotechnology era, and they have taken an interest in a forthcoming development of inspection methods.

Production of Meaning--A Critical Study of Narrative Ethics in Joyce Carol Oates＇s New Century Fiction

Narrative ethics shows multiple representing methods in Oates' s novels,including not only a variety of characters' narrative construction processes of self-narrative,other-narrative and social narrative but also the meaninggenerating process of the characters' interpretation and reorganization of the external and internal world.In so doing,the characters are able to obtain personal identity,the ethical communication and existence transcendence by the way of narrative.

Exploiting Virtual Elasticity of Production Systems to Respect OTD—Part 3: Basic Considerations for Modelling CPPS Characterized by Non-Ergodic Order Entry and Non-Deterministic Product-Mix for Fully Flexible Addressable Workstations

The recently experienced hype concerning the so-called “4th Industrial Revolution” of production systems has prompted several papers of various subtopics regarding Cyber-Phdysical Production Systems (CPPS). However, important aspects such as the modelling of CPPS to understand the theory regarding the performance of highly non-ergodic and non-deterministic flexible manufacturing systems in terms of Exit Rate (ER), Manufacturing Lead Time (MLT), and On-Time Delivery (OTD) have not yet been examined systematically and even less modeled analytically. To develop the topic, in this paper, the prerequisites for modelling such systems are defined in order to be able to derive an explicit and dedicated production mathematics-based understanding of CPPS and its dynamics: switching from explorative simulation to rational modelling of the manufacturing “physics” led to an own and specific manufacturing theory. The findings have led to enouncing, among others, the Theorem of Non-Ergodicity as well as the Batch Cycle Time Deviation Function giving important insights to model digital twin-based CPPS for complying with the mandatory OTD.

基于二分K-means理论的织机了机预测

织布车间内各机台的排产方案与纺织企业生产效率密切相关,为解决现有织机了机时间主要依靠人工经验且难预测导致的排产不及时、不合理等问题,提出一种基于K均值理论的了机预测算法,通过建立织机了机预测理论模型把喷气织机生产全过程合理分为5个生产状态,并按时间序列记录车间内织机生产过程的实时生产状态信息等数据,最后通过Python内置数学处理模块进行求解。结果表明:预测了机时间及实际了机时间之间误差较小,证明了机预测理论模型的正确性,且最大绝对误差不超过2 h,满足织布车间排产所需的时效性及准确性要求。此外,该了机预测模型对具有相似工序的喷水、剑杆等纺机设备同样适用,具有工程应用价值。

应用K-MEANS聚类的数据驱动产品创新模型研究

为了适应互联网技术的发展,使设计创新结果更好地满足用户需求,研究数据方式对设计创新的驱动作用。通过文献综述介绍数据驱动产品创新的基本特征,应用K-Means聚类方法构建数据驱动产品创新模型,根据模型分析结果指导产品设计。构建K-Means聚类的数据驱动产品创新模型,并应用该模型设计一款儿童陪伴机器人。使用本模型指导产品创新具有缩短产品开发时间、减少设计资源投入、提高产品设计效率等优点,有助于提高产品创新内容质量。

Effect of Stem Density on Leaf Nutrient Dynamics and Nutrient Use Efficiency of Dwarf Bamboo

The monthly dynamics of nitrogen （N） and phosphorus （P） concentrations and stocks in leaves, resorption efficiency, and resorption proficiency as well as leaf-level use efficiency, nutrient productivity, and mean residence time were studied to understand the effect of stem density of dwarf bamboo （Fargesia denudata Yi） on leaf-level N and P use efficiency in three dwarf bamboo stands with different stem densities under bamboo-fir （Picea puvpurea Mast.） forest over one growing period in the Wanglang National Nature Reserve, Sichuan, China. Dwarf bamboo density had little effect on the dynamics pattern of both N and P concentrations, stocks, resorption efficiency, and resorption proficiency, but strongly affected their absolute values and leaf-level use efficiency. Higher density stands stored more nutrients but had lower concentrations. There was a clear difference in the resorption of limiting nutrient （N） and non-limiting nutrient （P） among the stands. Phosphorus resorption efficiency, N resorption proficiency, and P resorption proficiency increased with increase of stem density, but no significant variation of N resorption efficiency was found among the stands. Moreover, the higher density stands used both N and P more efficiently with higher N productivity and higher P mean residence time, respectively. Higher P productivity was found in the lower density stands, but there was no clear variation in the N mean residence time among stands. These suggested that the higher density stands may have more efficient strategies for utilizing nutrients, especially those which are limiting .

A Class of Estimators for Population Ratio in Simple Random Sampling Using Variable Transformation

This paper is an extension and generalization of the study carried out by [1] on the estimation of the population ratio (R) of the population means of two variables (y and x) under Simple Random Sampling (SRS) scheme, using a variable transformation of the auxiliary variable, x. All the six estimators proposed by [1] are easily identified as special cases of the proposed class of estimators. Asymptotic properties of the proposed class of estimators are derived theoretically and subsequently verified using empirical illustrations. Some of the proposed estimators are found to have relatively large gains in efficiency over the customary ratio estimator, ?for the given data set.

基于K-means与SVR的致密油藏水平井压裂产能预测研究

水平井体积压裂是致密油藏高效开采的主要技术手段,准确预测产能对油田施工方案编制具有重要的指导意义,开采效果受地层因素、原油物性因素、压裂施工因素等影响,基于机理计算公式的传统预测方法存在一定局限性,提出一种基于K-means聚类与支持向量回归的产能预测组合模型,采用主成分分析算法解决K-means中欧氏距离对所有特征贡献程度一致性问题,K-means聚类结果与压裂施工参数结合作为SVR预测样本,有效解决不同区域间差异较大等问题。通过实验对比SVR、BP神经网络,预测准确性和稳定性优于单一模型,具有较高的合理性,可为致密油田高效开发提供指导性建议。

Analytical Solution for Three-dimensional Forging Taking into Account Bulging of Sides by Mean Yield Criterion

Currently, for some complex plastic deformations, the analytical solution can not be obtained by using Mises yield criterion, because Mises yield criterion is nine dimensions, the velocity field is complex, and the solving methods are not innovative. Corresponding solutions of these problems are that yield criterion is linearized to reduce the variable numbers, and the velocity field and the solving methods are reasonably simplified, respectively. In this paper, a new linear yield criterion--mean yield（MY） criterion and inner-product of strain rate vector are used to analytically solve 3D forging taking into account bugling of sides. The velocity field is expressed as a vector in three dimensions, and rotation and divergence are applied to confirm that the velocity field is kinematically admissible. Then, the corresponding strain rate tensor of the velocity field is transformed into principal one by making the determinant of coefficients of the tensor cubic equation be zero. By using MY criterion, the plastic power is term by term integrated and summed according to inner-product of strain rate vector. An upper bound analytical solution is obtained for the forging, and verified by a pure lead press test. The test result turns out that the total pressure calculated by MY criterion is higher by 2.5%-15% than measuring value. In addition, a measuring formula of bulging parameter （a） is proposed, but the values of a measured by the formula are lower than those optimized by the golden section search. The total pressure calculated by MY criterion is compared with the ones by twin shear, Trasca yield, and Mises yield criterion. The comparing result shows that the total pressure calculated by MY criterion is slightly higher than the mean value of that by twin shear and Trasca yield criterion, and lower than that by Mises yield criterion, but more close to that by Mises yield criterion compared with that by other two. The proposed analytical solving methods can be effectively used to other complex plastic deformation, simplifying the solving process and obtaining the reasonable results.

Estimation of Population Ratio in Post-Stratified Sampling Using Variable Transformation

Extending the work carried out by [1], this paper proposes six combined-type estimators of population ratio of two variables in post-stratified sampling scheme, using variable transformation. Properties of the proposed estimators were obtained up to first order approximations,(on–1), both for achieved sample configurations (conditional argument) and over repeated samples of fixed size n (unconditional argument). Efficiency conditions were obtained. Under these conditions the proposed combined-type estimators would perform better than the associated customary combined-type estimator. Furthermore, optimum estimators among the proposed combined-type estimators were obtained both under the conditional and unconditional arguments. An empirical work confirmed the theoretical results.

Using Biophysical Variables and Stand Density to Estimate Growth and Yield of <i>Pinus patula</i>in Antioquia, Colombia

Timberland investment opportunities in Colombia are expected to increase as a result of the peace agreement recently signed between the Colombian government and the Revolutionary Armed Forces of Colombia. This new socio-political environment may facilitate the expansion of commercial forest plantations on a wider range of site conditions that are currently considered in existing biometric tools. Data from 1119 temporary plots of unthinned, unmanaged, and genetically unimproved Pinus patula plantations in the Antioquia region were combined with a large set of biophysical attributes to identify spatial variation in yield. A wide array of biophysical covariates was explored to characterize the most favorable environmental conditions for the species, and to identify potential explanatory variables to be included in forest yield models. The mathematical form of the model is the von Bertalanffy-Chapman-Richards type, with parameters: asymptote, intrinsic growth rate and allometric constant. The parameters were expressed as linear functions of soil pH, terrain slope, the mean annual temperature to mean annual precipitation ratio, and stand density. The statistical contribution of selected covariates was evaluated using the likelihood ratio test. The model was validated using an independent set of 133 observations. The spatial representation of the model depicts the timber production potential and allows for the identification of the most suitable geographical areas to establish Pinus patula plantations in Antioquia, Colombia. The estimated yield model provides a reliable baseline for timber production, and insight into timberland investments in Colombia.

Generalized Class of Mean Estimators with Known Measures for Outliers Treatment

In estimation theory,the researchers have put their efforts to develop some estimators of population mean which may give more precise results when adopting ordinary least squares(OLS)method or robust regression techniques for estimating regression coefficients.But when the correlation is negative and the outliers are presented,the results can be distorted and the OLS-type estimators may give misleading estimates or highly biased estimates.Hence,this paper mainly focuses on such issues through the use of non-conventional measures of dispersion and a robust estimation method.Precisely,we have proposed generalized estimators by using the ancillary information of non-conventional measures of dispersion(Gini’s mean difference,Downton’s method and probabilityweighted moment)using ordinary least squares and then finally adopting the Huber M-estimation technique on the suggested estimators.The proposed estimators are investigated in the presence of outliers in both situations of negative and positive correlation between study and auxiliary variables.Theoretical comparisons and real data application are provided to show the strength of the proposed generalized estimators.It is found that the proposed generalized Huber-M-type estimators are more efficient than the suggested generalized estimators under the OLS estimation method considered in this study.The new proposed estimators will be useful in the future for data analysis and making decisions.

A KERNEL ESTIMATOR OF A DENSITY FUNCTION IN MULTIVARIATE CASE FROM RANDOMLY CENSORED DATA

A kernel density estimator is proposed when tile data are subject to censorship in multivariate case. The asymptotic normality, strong convergence and asymptotic optimal bandwidth which minimize the mean square error of the estimator are studied.

数据产权法律构造论

在数字经济环境中,数据已成为一种新型生产要素,需要更好地挖掘和开发其经济价值。数据不同于传统有体物以及知识产权客体的特征和属性使其在法律制度构建和运行上也具有特殊性。数据产权制度是数据基础制度的核心内容,其应涵盖保护数据主体合法权益、协调和平衡数据利益关系、促进数据有序流动和分享、促进数据要素利益公平分配等内容。数据产权的法律构造旨在建立数据资源持有权、数据加工使用权和数据产品经营权的数据动态流转和价值实现机制,最终服务于数字经济发展目标。

设计驱动的产品颠覆性创新方法研究

通过设计驱动创新与颠覆性创新的理论研究,提出了包含意义发掘、功能系统调整、产品语言表达3个阶段的设计驱动产品颠覆性创新过程模型,以完善设计领域对于颠覆性创新方法的研究。首先基于SET洞察市场趋势设想新意义,由内而外接受批评以发掘可行性意义;然后对目标用户进行研究,运用AD将功能需求转化为设计参数,并与源产品技术对比进而进行技术调整,获得颠覆性创新技术解;接着将新意义特征及提升、添加技术所对应的部件确定为意义诠释区域,并采用类比推理选取样本;最后通过相似性分析确定设计原型并提取其特征要素,利用可拓变换优化产品语言表达,获得颠覆性创新产品语言解。以电动轮椅设计为实例验证了该模型的可行性,为其他设计驱动的产品颠覆性创新提供参考。

生产力和生产关系的质量互变规律与混合所有制经济的产生及运行分析

生产力具有各要素发展的不平衡性与总体水平发展的一致性特点,各要素发展的量变积累会引起生产力总体发展的根本质变,生产力总体发展的全局量变又会引起生产关系要素的局部质变,这为混合所有制经济的产生和运行提供了可能性和现实性。混合所有制经济是社会主义公有制的重要实现形式,具有强大的生命力,在促进国民经济发展、推动技术创新、提供就业岗位、增加居民收入以及实现乡村振兴战略等方面发挥极其重要的功能。