Adjustment Model and Algorithm Based on Ellipsoid Uncertainty

In surveying adjustment models,there is usually some uncertain additional information or prior information on parameters,which can constrain the parameters,and guarantee the uniqueness and stability of parameter solution.In this paper,we firstly use ellipsoidal sets to describe uncertainty,and establish a new adjustment model with ellipsoidal uncertainty.Furthermore,we give a new adjustment criterion based on minimization trace of an outer ellipsoid with two ellipsoid intersections,and analyze the propagation law of uncertainty.Correspondingly,we give a new algorithm for the adjustment model with ellipsoid uncertainty.Finally,we give three examples to test and verify the effectiveness of our algorithm,and illustrate the relation between our result and the weighted mixed estimation.

电催化产氢:从原理到应用

全球人口增长及对能源需求的不断增大使能源安全问题日益严峻,开发可持续的非化石燃料能源是解决问题的有效途径.氢能具有无二氧化碳排放、能量密度高等特点,因此氢气被认为是理想的能源载体.在能量转换过程中,氢气可经由电能从再生能源中产生,以化学键的形式储存能量,亦可在需要时通过燃料电池或其他设备转换回电能并输送给终端.因此,探究高效的氢气制造方法和转换途径是实现氢能应用的重中之重.在氢气的制造策略中,电催化途径因具有快速、高效、高选择性和高性价比等特点成为目前高效制氢的最优选方案之一.自1833年Faraday首先提出电解水的概念,到19世纪20~30年代陆续出现不同种类的电解池装置,再至目前已发展的多种电催化制氢及耦合反应的设计,电解水制氢技术已取得了很大进步.本文从电催化制氢的基本原理、性能评价方法、电催化剂种类及电池结构对电催化制氢进行了总结,并评述了电催化制氢的最新研究进展,指出了目前研究中存在的问题及可能的解决方案.

Androgen signaling regulates the transcription of anti-Müllerian hormone via synergy with SRY-related protein SOX9A

Anti-Mullerian hormone （amh） is one of the earliest functional genes expressed during testicular differentiation. It has been suggested that androgen signaling regulates critical genes for the differentiation and development of the testis. To elucidate the exact regulatory mechanisms involved in arnh transcription mediated by androgen signaling, androgen signaling was manipulated in zebrafish by cytochrome P450 17al （cyplTal） knockout and Flutamide treatment. In cyp17a1-deficient and Flutamide-treated testes, up-regulated sry-box9a （soxga） and down-regulated amh were observed. Moreover, a physical association of the zebrafish androgen receptor （AR） and SOX9A was found. The interaction between AR and SOX9A was mediated via the DNA binding domain （DBD） of AR and the transactivation domain （TA） of SOX9A, and was further enhanced by 5-alpha dihydrotestosterone （DHT）, one of the most potent androgens. Intriguingly, together with SOX9A, androgen signaling synergistically promoted amh transcription, mainly through the proximal 1 kb of the amh promoter region. Taken together, our data demonstrate a critical mechanism underlying the direct synergy of androgen signaling and SOX9A in the regulation of amh transcription.

Eliminating the original cargos of glioblastoma cell-derived small extracellular vesicles for efficient drug delivery to glioblastoma with improved biosafety

Tumor derived small extracellular vesicles(TsEVs)display a great potential as efficient nanocarriers for chemotherapy because of their intrinsic targeting ability.However,the inherited risks of their original cargos(like loaded proteins or RNAs)from parent cancer cells in tumor progression severely hinder the practical application.In this study,a saponin-mediated cargo elimination strategy was established and practiced in glioblastoma(GBM)cell-derived small extracellular vesicles(GBM-sEVs).A high eliminating efficacy of the cargo molecules was confirmed by systematic analysis of the original proteins and RNAs in GBM-sEVs.In addition,the inherited functions of GBM-sEVs to promote GBM progression vanished after saponin treatment.Moreover,the results of cellular uptake analysis and in vivo imaging analysis demonstrated that saponin treatment preserved the homotypic targeting ability of GBM-sEVs.Thus,we developed an efficient nanocarrier with improved biosafety for GBM suppression.Furthermore,doxorubicin(DOX)transported by the saponin-treated GBM-sEVs(sa-GBM-sEVs)displayed an effective tumor suppression in both subcutaneous and orthotopic GBM models of mouse.Collectively,this study provides a feasible way to avoid the potential protumoral risks of TsEVs and can advance the clinical application of TsEVs in chemotherapy.

Strong interface interaction and internal electric field promote electron transfer of Bi_(2)O_(2)S/NiFe_(2)O_(4) heterojunction for photocatalytic antibiotic degradation

Heterojunction photocatalysts have shown considerable activities for organic pollutants degradation.However,the faint connection interface and inferior charge shift efficiency critically block the property of heterojunction photocatalysis.Herein,Bi_(2)O_(2)S/NiFe_(2)O_(4) nanosheets heterojunction with ultrastrong inter-face interaction and high internal electric field are designed by an in-situ growth method.Tentative and theoretical consequences prove that the interfacial interaction and internal electric field not only act as the electron flow bridge but also decrease the electrons shift energy obstacle,thus speeding up electrons transfer and achieving effective spatial electron-hole separation.Therefore,a large amount of·O_(2)^(-)and holes as active species were generated.Remarkably,Bi_(2)O_(2) S/NiFe_(2)O_(4) establishes a considerably boosted photocatalytic performance for tetracycline degradation(0.032 min^(-1)),which is about 14.2-fold and 7.8-fold of the pristine BOS and NFO,respectively.This work provides a promising motivation for modulating charge transfer by interface control and internal electric field to boost photocatalytic performance.

Temperature-induced lattice distortion in CuGeO_(3) nanocrystals

Lattice distortion represents the fundamental factor of crystalline materials and contributes significantly to structural-related properties.Herein,we discover an unexpected temperature-induced lattice distortion in CuGeO_(3) nanocrystals,resulting in color changes of CuGeO_(3).The structural distortions in CuGeO_(3) nanocrystals are characterized by Rietveld analysis in detail,where its cell parameter b and cell volume reveal first decrease and then increase characteristics and correspond well with the XRD patterns and Raman spectra.Besides,both the experimental characterizations and theoretical calculations confirm that the optical and band structural changes mainly arise from the twisted octahedral field of[CuO_(6)],where the lattice distortions regulate the crystal field splitting energy of[CuO_(6)]and account for its changed d-d transition.Furthermore,tetracycline photodegradation is employed as an example to evaluate the effect of lattice distortion on photocatalytic performance,which also highlights the importance of modulating lattice distortion in photocatalysis.This work provides an approach to simply regulate the lattice distortion for nanorods by manipulating calcination temperatures.