对BJH方法计算孔径分布过程的解读

介绍了用BJH方法计算介孔孔径分布时对孔隙做了哪些几何假设和忽略、为简化计算做了哪些算术近似,以及各个参数的推导过程、孔径分布计算步骤和要点;还介绍了在目前仪器水平下BJH方法的适用范围,如何对数据进一步整理以便得到所需要的分析测试报告。文章为后续调整测试参数、改进测试方法也有一定的参考作用,还讨论了在阅读实验报告时经常遇到的一些问题。

防范风险 提高效率——以改变高压吸附仪周边设备为例

文章列举了高压吸附实验室在日常测试中普遍存在的各种风险,提出了改变高压吸附仪外围设备的具体措施,经过实践验证,这些措施能有效防范风险发生,同时减轻了工作强度、提高了测试效率。

Calibration and experimental verification of discrete element parameters of Panax notoginseng root

Existing discrete element method-based simulation analysis of Panax notoginseng root soil separation still has the challenge to get the accurate and reliable basic parameters,which are necessary for discrete element simulation.In this paper,the P.notoginseng roots suitable for harvesting period were taken as the experimental object.Then using 3D scanning reverse modeling technology and EDEM software to establish the discrete element model of P.notoginseng,based on which,the physical and virtual tests were carried out to calibrate the simulation parameters.First,the basic physical parameters(density,triaxial geometric size,moisture content,shear modulus,and elastic modulus)and contact coefficients(static friction coefficient,rolling friction coefficient,and crash recovery coefficient between P.notoginseng roots and 65Mn steel)were measured by physical tests.Furthermore,treating the contact coefficients of P.notoginseng roots as the influence factor,the steepest uphill test,and four factors combing five levels of rotational virtual simulation are conducted.The measured relative error accumulation angle and simulation accumulation angle are set as the performance indices.The results show that the static friction coefficient,rolling friction coefficient,crash recovery coefficient,and surface energy coefficient of P.notoginseng roots are 0.55,0.35,0.16,and 19.5 J/m2,respectively.Using calibration results as parameters of the vibration separation simulation test of P.notoginseng soil,the Box-Behnken vibration separation simulation tests were carried out,in which the vibration frequency,inclination angle,and vibration amplitude of separation device as factors,screening rate and damage rate of P.notoginseng soil complex are regarded as indices.The results show that the optimal operating parameters of the separation device are the vibration frequency of 10 Hz,the inclination angle of 5°,and the amplitude of 6 cm.Based on the optimal operation parameters,the discrete element simulation experiment and field experiment of P.notoginseng roots soil separation are also performed to compare the soil three-dimensional trajectory space coordinates of P.notoginseng roots.From the results,three axis coordinate error is less than 15%.This proves that the calibration results are reliable.It can also provide the theoretical basis and technical support for the further study of the P.notoginseng root soil separation platform.

Observed levels and trends of gaseous SO_2 and HNO_3 at Mt.Waliguan,China:Results from 1997 to 2009

Long-term measurements of SO2 and HNO3, particularly those from the background sites, are rarely reported. We present for the first time the long-term measurements of SO2 and HNO3 at Waliguan （WLG）, the only global baseline station in the back-land of the Eurasian Continent. The concentrations of SO2 and HNO3 were observed at WLG from 1997 to 2009. The observed annual mean concentrations of SO2 and HNO3 at WLG were 1.28 ± 0.41 and 0.22 ± 0.19 μg/m3, respectively. The HNO3 concentrations were much higher in warmer seasons than in colder seasons, while the SO2 concentrations showed a nearly reversed seasonal pattern. In most months, the concentration of HNO3 was significantly correlated with that of SO2, suggesting that some common factors influence the variations of both gases and the precursors of HNO3 may partially be from the SO2-emitting sources. The SO2 concentration had a very significant （P 〈 0.0001） decreasing trend （-0.2 μg/（m3.yr）） in 1997-2002, but a significant （P 〈 0.05） increasing trend （＋0.06 μg/（m3-yr）） in 2003-2009. The HNO3 concentration showed no statistically significant trend during 1997-2009. While the decrease of SO2 in 1997-2002 agrees with the trend of global SO2 emissions, the increase in 2003-2009 is not consistent with the decreasing trends in many other regions over the world. Trajectory analysis suggests that the airmasses from the northern Qinghai-Tibetan Plateau and the Takla Makan Desert regions contributed significantly to the increasing trends of SO2 and HNO3 at WLG in 2003-2009, with a rate of ＋0.13 μg/（m3.yr） and ＋0.007μg/（m3.yr）, respectively.

Indecomposable Calabi-Yau Objects in Stable Module Categories of Finite Type

The authors give a discription of the finite representation type over an algebraically stable categories of selfinjective algebras of closed field, which admits indecomposable Calabi-Yau obdjects. For selfinjective algebras with such properties, the ones whose stable categories are not Calabi-Yau are determined. For the remaining ones, i.e., those selfinjective algebras whose stable categories are actually Calabi-Yau, the difference between the Calabi-Yau dimensions of the indecomposable Calabi-Yau objects and the Calabi-Yau dimensions of the stable categories is described.

Allocating Personal Data Rights: Toward Resolving Conflicts of Interest over Personal Data

Conflicts of interest over personal data arise from the variety of legal subjects involved and the value of personal data in today’s information society.This article attempts to resolve such conflicts of interest by examining the possibility of allocating data rights which balance competing interests.It suggests that the allocation of personal data rights should follow certain rules to ensure that the interests of relevant data subjects are protected.By examining the reasons for conflicts of interest over personal data,as well as the subjects and substance of such conflicts,the article puts forward an appropriate approach for allocating personal data rights by balancing the interests of different data subjects.For source data subjects,personal data rights are allocated,to protect personal information and data property interests;for data controllers,data property rights are allocated to protect their data property interests when they make data valuable,meanwhile liabilities are allocated to data controller,in case of infringing on other subjects'interests;for data supervisors(mostly the government),allocating the right to protect or make use of data on behalf of public interests and the power of supervising data use industry;for the data users,they are allocated data property rights with the consents of source data subjects and data controllers when make use of data.

Stimuli-Responsive Molecules: Emerging Materials for Advanced Data-Encryption and Anti-Counterfeiting

Data security is a long-term challenge that spans the whole history of human society, particularly in the field of commercial activities and military actions. To date, a variety of data protection techniques have been developed. Early examples include watermarks and holograms.[1] Later, color-shifting inks and luminescent patterns had been developed as well.

Legal Coordination of Conflicts of Interests among Stakeholders in the Processing of Personal Data

The processing of personal data involves various stakeholders,such as natural persons,personal data processors,and supervisors.These stakeholders process or supervise personal data based on their respective interests or duties.However,because several interests are involved,conflicts may occur due to the value of the data in question.This paper builds a theoretical framework based on the methodology of interest measurement to alleviate conflicts of interest concerning data.It explores,from the perspectives of rights,obligations,and liabilities,the supervisors’duty of protecting the public interest.Regarding personal data of natural persons,corresponding rights are allocated according to the relevant provisions of the Civil Code and the Personal Information Protection Law of the People’s Republic of China.For personal data processors in superior positions,obligations and liabilities are allocated according to the relevant provisions of the above laws,and in light of the core of reasonable restrictions on individual standards against society’s standards,the duties of supervisors and protection of public interests are clearly defined.