While studies have examined physical access to services, cognitive and psychosocial barriers to contraceptive use have received less attention, despite their impact on access. Research shows that fours main dimensions...While studies have examined physical access to services, cognitive and psychosocial barriers to contraceptive use have received less attention, despite their impact on access. Research shows that fours main dimensions exist under the broad concept of cognitive and psychosocial access. This study aims to validate the construction of these dimensions and measure the relation between them and their links with modern contraceptive use. We utilized a questionnaire module to collect 15 questions measuring these dimensions through the 6<sup>th</sup> round of the Performance monitoring and accountability 2020 (PMA2020) survey in Burkina in 2019. We employed the scale validation technique to choose appropriate measures (observable indicators or items) for constructing each latent dimension (unobservable) in our study. The items consisted of questions that utilized a 5-point Likert scale or dichotomous responses to capture various psychosocial aspects. To assess the validity, reliability, convergence, and divergence of the latent dimensions and items, we utilized the validscale command in Stata. The validation process confirmed the reliability of all the dimensions. Contraceptive approval is more aligned with birth spacing rather than birth limiting, reflecting prevailing social perceptions. Women’s contraceptive agency was found to be more associated with their ability to discuss and negotiate with their partners rather than independent decision-making. Correlations between dimensions were generally weak, but the levels of knowledge, agency, and approval of contraception are positively correlated with contraceptive use and intention to use. Giving women more decision-making power and providing information to address side-effect concerns can enhance contraceptive approval.展开更多
Nowadays, more than ever, the improvement of access to family planning (FP) has become an international goal. What constitutes access to FP? Current human rights-based contraceptive guidelines indicate that access beg...Nowadays, more than ever, the improvement of access to family planning (FP) has become an international goal. What constitutes access to FP? Current human rights-based contraceptive guidelines indicate that access begins as soon as women or couples express a desire to avoid pregnancy and their risk of unintended pregnancy is established. However, few studies have sought to define and measure cognitive and psychosocial access to contraception. To propose a comprehensive framework for the cognitive and psychosocial accessibility of contraception, we critically analyzed the literature on attitudes toward FP. The main dimensions that emerged were knowledge about FP, fear of side effects, approval of contraception, and contraceptive agency. We then identified and adjusted some questions that can capture these dimensions more comprehensively. As a result, we developed a questionnaire module comprising 15 questions, which was integrated into the 6th round of the PMA2020 survey in Burkina Faso in 2019. This research highlighted that previous studies have collected separate dimensions of contraceptive access, and the psychosocial dimension tended to be neglected. Our results demonstrate that it is possible to collect comprehensive data on cognitive and psychosocial dimensions of access to family planning.展开更多
Transmission electron microscopy and surface- and bulk-sensitive spectroscopic methods were used to study the morphology and the electronic structure of a hybrid organic-inorganic system composed of gold nanoparticles...Transmission electron microscopy and surface- and bulk-sensitive spectroscopic methods were used to study the morphology and the electronic structure of a hybrid organic-inorganic system composed of gold nanoparticles （NP＇s） which were distributed in an organic matrix. Au atoms deposited onto a copper phthalocyanine （CuPc） surface diffuse into the organic matrix and self-assemble in well defined NP＇s with metallic properties. No formation of a continuous metallic Au film on top of the CuPc film is observed up to nominal coverages as large as 130 A.展开更多
Anthracene group features fluorescence,πconjugation,and stimulus-responsive characteristics,and therefore,anthracene-containing supramolecular assemblies have attracted much more extensive attention from supramolecul...Anthracene group features fluorescence,πconjugation,and stimulus-responsive characteristics,and therefore,anthracene-containing supramolecular assemblies have attracted much more extensive attention from supramolecular chemists.Anthracene moiety is susceptible to attack by singlet oxygen(^(1)O_(2)),and it undergoes[4+2]photooxygenation via capturing^(1)O_(2)under 365 nm irradiation,generating endoperoxide photoproducts that could release^(1)O_(2)through heat.A variety of anthracene-based supramolecular assemblies are elegantly designed and synthesized to further explore their properties.In the past few decades,numerous articles and few reviews about the[4+4]photodimerization of anthracene moiety have been published.Howerer,to the best of our knowledge,very few reviews focusing on anthracene-based supramolecular systems and their reversible[4+2]photochemical oxidation have hardly been reported.The minor review primarily highlights typical examples of anthracene-containing supramolecular assemblies in terms of construction strategy,properties,and the[4+2]photooxygenation.In this review,the main content will be classified into four categories:(I)chirality in anthracene-based supramolecular assemblies;(II)luminescence regulation in anthracene-containing supramolecular assemblies;(III)π···πinteractions in anthracene-based supramolecular assemblies;(IV)[4+2]photooxygenation in anthracene-based supramolecular assemblies including discrete,polymeric,and anion-directed structures.We wish this mini-review could provide fundamental inspiration for supramolecular scientists to further develop novel anthracene-containing assemblies based on coordination-driven self-assembly and study their photochemical reactions,which is showing potential for application in smart materials.展开更多
Spontaneous symmetry breaking has been a paradigm to describe the phase transitions in condensed matter physics.In addition to the continuous electromagnetic gauge symmetry,an unconventional superconductor can break d...Spontaneous symmetry breaking has been a paradigm to describe the phase transitions in condensed matter physics.In addition to the continuous electromagnetic gauge symmetry,an unconventional superconductor can break discrete symmetries simultaneously,such as time reversal and lattice rotational symmetry.In this work we report a characteristic in-plane 2-fold behaviour of the resistive upper critical field and point-contact spectra on the superconducting semimetal PbTaSe2 with topological nodal-rings,despite its hexagonal lattice symmetry(or D3 h in bulk while C3 v on surface,to be precise).The 2-fold behaviour persists up to its surface upper critical field Hc2R even though bulk superconductivity has been suppressed at its bulk upper critical field Hc2HC<<Hc2R,signaling its probable surface-only electronic nematicity.In addition,we do not observe any lattice rotational symmetry breaking signal from field-angle-dependent specific heat within the resolution.It is worth noting that such surface-only electronic nematicity is in sharp contrast to the observation in the topological superconductor candidate,CuxBi2Se3,where the nematicity occurs in various bulk measurements.In combination with theory,superconducting nematicity is likely to emerge from the topological surface states of PbTaSe2,rather than the proximity effect.The issue of time reversal symmetry breaking is also addressed.Thus,our results on PbTaSe2 shed new light on possible routes to realize nematic superconductivity with nontrivial topology.展开更多
The stability of the polarization state in Na_(0.5)Bi_(0.5)TiO_(3)(NBT)ceramics has been a long-standing problem for its use in piezoelectric applications at elevated temperatures.It has been generally believed that t...The stability of the polarization state in Na_(0.5)Bi_(0.5)TiO_(3)(NBT)ceramics has been a long-standing problem for its use in piezoelectric applications at elevated temperatures.It has been generally believed that the polarization state,depolarization temperature,and depolarization process are all linked to the grain size in these materials.In this work,we perform a thorough Piezoresponse Force Microscopy(PFM)study of the NBT ceramic samples with substantially different grain sizes sintered as a function of temperature.As-grown,macroscopically poled,and locally poled samples were investigated focusing on the polarization behavior at depolarization temperature.Switching Spectroscopy PFM(SS-PFM)measurements were conducted as a function of grain size and temperature.No direct correlation is observed between the grain size and the switching parameters in any sample.However,temperature-dependent measurements reveal significant differences that are explained by different concentrations of oxygen vacancies.We rationalized the observed behavior,e.g.apparent stabilization of the locally probed polarization above the depolarization temperature,by accumulation and depletion of oxygen vacancies in the vicinity of the internal boundary of the poled region.Significant asymmetry of the PFM hysteresis loops at elevated temperatures confirms this assumption.展开更多
文摘While studies have examined physical access to services, cognitive and psychosocial barriers to contraceptive use have received less attention, despite their impact on access. Research shows that fours main dimensions exist under the broad concept of cognitive and psychosocial access. This study aims to validate the construction of these dimensions and measure the relation between them and their links with modern contraceptive use. We utilized a questionnaire module to collect 15 questions measuring these dimensions through the 6<sup>th</sup> round of the Performance monitoring and accountability 2020 (PMA2020) survey in Burkina in 2019. We employed the scale validation technique to choose appropriate measures (observable indicators or items) for constructing each latent dimension (unobservable) in our study. The items consisted of questions that utilized a 5-point Likert scale or dichotomous responses to capture various psychosocial aspects. To assess the validity, reliability, convergence, and divergence of the latent dimensions and items, we utilized the validscale command in Stata. The validation process confirmed the reliability of all the dimensions. Contraceptive approval is more aligned with birth spacing rather than birth limiting, reflecting prevailing social perceptions. Women’s contraceptive agency was found to be more associated with their ability to discuss and negotiate with their partners rather than independent decision-making. Correlations between dimensions were generally weak, but the levels of knowledge, agency, and approval of contraception are positively correlated with contraceptive use and intention to use. Giving women more decision-making power and providing information to address side-effect concerns can enhance contraceptive approval.
文摘Nowadays, more than ever, the improvement of access to family planning (FP) has become an international goal. What constitutes access to FP? Current human rights-based contraceptive guidelines indicate that access begins as soon as women or couples express a desire to avoid pregnancy and their risk of unintended pregnancy is established. However, few studies have sought to define and measure cognitive and psychosocial access to contraception. To propose a comprehensive framework for the cognitive and psychosocial accessibility of contraception, we critically analyzed the literature on attitudes toward FP. The main dimensions that emerged were knowledge about FP, fear of side effects, approval of contraception, and contraceptive agency. We then identified and adjusted some questions that can capture these dimensions more comprehensively. As a result, we developed a questionnaire module comprising 15 questions, which was integrated into the 6th round of the PMA2020 survey in Burkina Faso in 2019. This research highlighted that previous studies have collected separate dimensions of contraceptive access, and the psychosocial dimension tended to be neglected. Our results demonstrate that it is possible to collect comprehensive data on cognitive and psychosocial dimensions of access to family planning.
文摘Transmission electron microscopy and surface- and bulk-sensitive spectroscopic methods were used to study the morphology and the electronic structure of a hybrid organic-inorganic system composed of gold nanoparticles （NP＇s） which were distributed in an organic matrix. Au atoms deposited onto a copper phthalocyanine （CuPc） surface diffuse into the organic matrix and self-assemble in well defined NP＇s with metallic properties. No formation of a continuous metallic Au film on top of the CuPc film is observed up to nominal coverages as large as 130 A.
基金supported by the National Natural Science Foundation of China(22471215,22171226 and 22401224)the Natural Science Basic Research Program of Shaanxi(2024JC-YBQN-0133,2025JC-QYCX-009 and 2024JC-YBQN-0159)+1 种基金the Funding for Scientific Research of Shangluo University(22SKY116)the Youth Innovation Team of Shaanxi Universities(22JCS046).
文摘Anthracene group features fluorescence,πconjugation,and stimulus-responsive characteristics,and therefore,anthracene-containing supramolecular assemblies have attracted much more extensive attention from supramolecular chemists.Anthracene moiety is susceptible to attack by singlet oxygen(^(1)O_(2)),and it undergoes[4+2]photooxygenation via capturing^(1)O_(2)under 365 nm irradiation,generating endoperoxide photoproducts that could release^(1)O_(2)through heat.A variety of anthracene-based supramolecular assemblies are elegantly designed and synthesized to further explore their properties.In the past few decades,numerous articles and few reviews about the[4+4]photodimerization of anthracene moiety have been published.Howerer,to the best of our knowledge,very few reviews focusing on anthracene-based supramolecular systems and their reversible[4+2]photochemical oxidation have hardly been reported.The minor review primarily highlights typical examples of anthracene-containing supramolecular assemblies in terms of construction strategy,properties,and the[4+2]photooxygenation.In this review,the main content will be classified into four categories:(I)chirality in anthracene-based supramolecular assemblies;(II)luminescence regulation in anthracene-containing supramolecular assemblies;(III)π···πinteractions in anthracene-based supramolecular assemblies;(IV)[4+2]photooxygenation in anthracene-based supramolecular assemblies including discrete,polymeric,and anion-directed structures.We wish this mini-review could provide fundamental inspiration for supramolecular scientists to further develop novel anthracene-containing assemblies based on coordination-driven self-assembly and study their photochemical reactions,which is showing potential for application in smart materials.
基金the National Key R&D Program of China(2016FYA0300402 and 2017YFA0303101)the National Natural Science Foundation of China(NSFC)(11674279 and 11374257)+8 种基金supported in part by the NSFC(U1732162 and 11974061)support from the Zhejiang Provincial Natural Science Foundation(LR18A04001)supported in part by the National Key Research and Development Program of China(2016YFA0300202)the National Natural Science Foundation of China(11774306)the Strategic Priority Research Program of Chinese Academy of Sciences(XDB28000000)partly supported by KAKENHI(JP20H05164,19K14661,15H05883,18H01161,and JP17K05553)from JSPS‘‘JPhysics”(18H04306)financial support provided by the Project Number MOST-108-2112-M-001-049-MY2the Academia Sinica for the budget of AS-iMATE-109-13。
文摘Spontaneous symmetry breaking has been a paradigm to describe the phase transitions in condensed matter physics.In addition to the continuous electromagnetic gauge symmetry,an unconventional superconductor can break discrete symmetries simultaneously,such as time reversal and lattice rotational symmetry.In this work we report a characteristic in-plane 2-fold behaviour of the resistive upper critical field and point-contact spectra on the superconducting semimetal PbTaSe2 with topological nodal-rings,despite its hexagonal lattice symmetry(or D3 h in bulk while C3 v on surface,to be precise).The 2-fold behaviour persists up to its surface upper critical field Hc2R even though bulk superconductivity has been suppressed at its bulk upper critical field Hc2HC<<Hc2R,signaling its probable surface-only electronic nematicity.In addition,we do not observe any lattice rotational symmetry breaking signal from field-angle-dependent specific heat within the resolution.It is worth noting that such surface-only electronic nematicity is in sharp contrast to the observation in the topological superconductor candidate,CuxBi2Se3,where the nematicity occurs in various bulk measurements.In combination with theory,superconducting nematicity is likely to emerge from the topological surface states of PbTaSe2,rather than the proximity effect.The issue of time reversal symmetry breaking is also addressed.Thus,our results on PbTaSe2 shed new light on possible routes to realize nematic superconductivity with nontrivial topology.
基金funded by the German Research Foundation DFG within the framework of the project“Tuning the electrocaloric efficiency in lead-free ceramics”(DFG Project SH 709/4-1(project number 448662623))the European Union HORIZON-WIDERA-2023-TALENTS-01 program within the framework of the project“Low-dimensional ferroelectrics for advanced electronic and biomedical devices”(FeLow-D)(Grant agreement number 101186499)+1 种基金the scope of the project CICECO-Aveiro Institute of Materials,UIDB/50011/2020,UIDP/50011/2020&LA/P/0006/2020,financed by national funds through the FCT/MECPartial support through the Horizon MSCA project“Piezo2D”(GA#101131229)is acknowledged.
文摘The stability of the polarization state in Na_(0.5)Bi_(0.5)TiO_(3)(NBT)ceramics has been a long-standing problem for its use in piezoelectric applications at elevated temperatures.It has been generally believed that the polarization state,depolarization temperature,and depolarization process are all linked to the grain size in these materials.In this work,we perform a thorough Piezoresponse Force Microscopy(PFM)study of the NBT ceramic samples with substantially different grain sizes sintered as a function of temperature.As-grown,macroscopically poled,and locally poled samples were investigated focusing on the polarization behavior at depolarization temperature.Switching Spectroscopy PFM(SS-PFM)measurements were conducted as a function of grain size and temperature.No direct correlation is observed between the grain size and the switching parameters in any sample.However,temperature-dependent measurements reveal significant differences that are explained by different concentrations of oxygen vacancies.We rationalized the observed behavior,e.g.apparent stabilization of the locally probed polarization above the depolarization temperature,by accumulation and depletion of oxygen vacancies in the vicinity of the internal boundary of the poled region.Significant asymmetry of the PFM hysteresis loops at elevated temperatures confirms this assumption.
