Facing the pressure of fossil energy exhaustion and environment pollution, people begin to search for clean and renewable energy to partly substitute fossil energy and realize sustainable development. As the fourth ty...Facing the pressure of fossil energy exhaustion and environment pollution, people begin to search for clean and renewable energy to partly substitute fossil energy and realize sustainable development. As the fourth type of energy, biomass energy has many advantages: wide distribution, large quantity, being renewable, clean, storable and transportable and so on. By adopting thermo-chemical and biochemical technologies, biomass energy can be converted to high quality solid, liquid and gaseous energy products, and provide convenient heat and power energy for human being’s production and daily life. This paper presented the status quo of biomass power generation industry in China and also introduced briefly the future development models.展开更多
Energy saving and CO2 emissions reduction are critical tasks currently,and great effort has been made by Chinese government. Renewable energy consumption and CO2 emissions and reduction plan in China are introduced in...Energy saving and CO2 emissions reduction are critical tasks currently,and great effort has been made by Chinese government. Renewable energy consumption and CO2 emissions and reduction plan in China are introduced in this paper. Analysis is also made on present status and prospect of geothermal power generation and direct use in China respectively. Now,there is a new understanding of geothermal resources,and hot dry rock,considered as the future of geothermal resources,is likely used to generate electricity.展开更多
Background Malnutrition is common in patients with cancer,and can negatively impact their quality of life(QoL)and even survival.However,there is currently no large data available on the prevalence of malnutrition in C...Background Malnutrition is common in patients with cancer,and can negatively impact their quality of life(QoL)and even survival.However,there is currently no large data available on the prevalence of malnutrition in Chinese cancer patients.This study evaluated the prevalence of malnutrition and the QoL of Chinese patients with locoregional,recurrent or metastatic cancer.Methods We conducted a nationwide observational,multi-center,hospital-based cross-sectional study within the Chinese Society of Nutritional Oncology(CSNO)Network.All of the patients were diagnosed with one of the following 18 different types of malignant tumors:lung cancer,gastric cancer,liver cancer,colorectal cancer,breast cancer,esophageal cancer,cervical cancer,endometrial cancer,nasopharyngeal carcinoma,malignant lymphoma,leukemia,pancreatic cancer,ovarian cancer,prostate cancer,bladder cancer,brain cancer,biliary tract malignant tumors or gastrointestinal stromal tumors.These patients were enrolled from 72 hospitals located in different regions of China.The patients’nutritional status was evaluated based on the body mass index(BMI),loss of bodyweight,laboratory measurements and patient generated-subjective global assessment(PG-SGA)scores.The cancer patients’physical status and QoL were assessed by the Karnofsky Performance Status(KPS)questionnaire and the European Organization for Research and Treatment of Cancer(EORTC)QLQ-C30 questionnaire,respectively.Results From December 2013 to April 2016,23,994 patients hospitalized for cancer treatment(such as surgery,chemotherapy or radiotherapy)were enrolled in the study.The patients included 12,494(52.9%)males and 11,124(47.1%)females.The mean age was 55.8±13.7 years.The proportions of patients in cancer stagesⅠ,Ⅱ,Ⅲ,Ⅳand uncertain were 11.5%,20.3%,27.5%,30.2%and 10.5%,respectively.Among the 23,994 inpatients,the proportions of patients who were underweight(BMI<18.5 kg/m2),normal(18.5 kg/m2<BMI<24 kg/m2),overweight(24 kg/m2≤BMI<28 kg/m2)and obese(BMI≥28 kg/m2)were 9.3%,59.9%,26.1%and 4.7%,respectively.A total of 18.3%(4,101/22,424)of patients had lost 5%or more of their bodyweight within the past month and 19.6%(2,463/12,538)of patients had lost 10%or more of their bodyweight within the past 6 months.According to the PG-SGA scores,26.6%of the patients were severely malnourished(score≥9),31.3%were moderately malnourished(scores 4~8).A total of 22.2%of patients had a serum albumin level lower than 35g/L.Only 8.6%(2056/23,991)of the patients had severe KPS scores(≤60).The patients with these severe KPS scores were most frequently among those with cancers of the brain(19.7%),prostate(18.0%),pancreas(15.5%)and bladder(15.0%).Based on the QLQ-C30 score,11.6%of patients had a poor QoL.The PG-SGA score and global QoL were correlated(r=-0.593,P<0.001).Conclusion The prevalence of malnutrition in patients with cancer is relatively high,and is related to a poorer QoL.The present findings should be kept in mind when assessing cancer patients,because addressing the patient’s problems in nutritional status would be expected to improve both the clinical outcomes and QoL in cancer patients with malnutrition.展开更多
We study theoretically the heat originated from electron-phonon coupling in a spintronic device composed of a semi- conductor quantum dot attached to one spin battery and one ferromagnetic lead. It is found that the p...We study theoretically the heat originated from electron-phonon coupling in a spintronic device composed of a semi- conductor quantum dot attached to one spin battery and one ferromagnetic lead. It is found that the phenomenon of the negative differential of the heat current, which has previously been predicted in the charge-based device, disappears due to the Pauli exclusion principle resulted from the presence of the spin battery. Under some conditions, huge heat in the heat generation induced by resonant phonon emitting processes also disappears in this spin-based device. Furthermore, we find that the ferromagnetism of the lead can be used to effectively adjust the magnitude of the heat current in different dot level ranges. The proposed system is realizable by current technology and may be useful in designing high-efficiency spintronic components.展开更多
Heat generated by electric current in a quantum dot device contacting a phonon bath is studied using the non- equilibrium Green function technique. Spin-polarized current is generated owing to the Zeeman splitting of ...Heat generated by electric current in a quantum dot device contacting a phonon bath is studied using the non- equilibrium Green function technique. Spin-polarized current is generated owing to the Zeeman splitting of the dot level. The current's strength and the spin polarization are further manipulated by changing the frequency of an applied photon field and the ferromagnetism on the leads. We find that the associated heat by this spin- polarized current emerges even if the bias voltage is smaller than the phonon energy quanta and obvious negative differential of the heat generation develops when the photon frequency exceeds that of the phonon. It is also found that both the strength and the resonant peaks' position of the heat generation can be tuned by changing the value and the arrangement configurations of the magnetic moments of the two leads, and then provides an effective method to generate large spin-polarized current with weak heat. Such a result may be useful in designing low energy consumption spintronic devices.展开更多
With the rapid development of its national economy,China has become a major producer and consumer of energy.To guarantee the sustainable development of power industry and national economy,China should exploit fossil a...With the rapid development of its national economy,China has become a major producer and consumer of energy.To guarantee the sustainable development of power industry and national economy,China should exploit fossil and renewable energy efficiently according to the development situation of generation resources.Firstly,this paper analyzes the utilization status of main generation resources in China,such as coal,hydropower and wind energy.Secondly,this paper illustrates the STEP model,which analyzes some issues for China’s generation resource utilization from political,economic,social and technological aspects.For example,the resource distribution is inconsistent with electricity demand,the renewable energy power output is intermittent,and there is some disruption in coal mining.Finally,combined with the utilization status and issues,this paper presents some improvement approaches from the perspectives of cost,efficiency and external influence.展开更多
To better understand the generation of electric power for piezoelectric Pb Zr Ti O3(PZT)ceramic plate(?25 mm),an attempt was made to investigate experimentally and numerically electricpower generation characteristics ...To better understand the generation of electric power for piezoelectric Pb Zr Ti O3(PZT)ceramic plate(?25 mm),an attempt was made to investigate experimentally and numerically electricpower generation characteristics during cyclic bending under various loading fixtures(?0–?20 mm),i.e.,different contact areas.Increasing the load-contact area on the PZT ceramic leads to a nonlinear decrease in the generated voltage.Decreasing contact area basically enhances the generated voltage,although the voltage saturates during loading when the contact area is less than?5 mm.A similar voltage is generated for?0 and?5 mm,which is attributed to strain status(ratio of compressive and tensile strain)and material failure due to different stress distribution in the PZT ceramic.On the basis of the obtained electric generation voltage,suitable loading conditions are clarified by loading with the?5 mm fixture,which generates a higher voltage and a longer lifetime of the PZT ceramic.From this approach,it is appeared that the area contact with the area ratio of 0.04(?5 mm/?20 mm)is suitable to obtain the high efficiency of the electric voltage.展开更多
The design of new ligands with high affinity and specificity against the targets of interest has been a central focus in drug discovery.As one of the most commonly used methods in drug discovery,the cyclization repres...The design of new ligands with high affinity and specificity against the targets of interest has been a central focus in drug discovery.As one of the most commonly used methods in drug discovery,the cyclization represents a feasible strategy to identify new lead compounds by increasing structural novelty,scaffold diversity and complexity.Such strategy could also be potentially used for the follow-on drug discovery without patent infringement.In recent years,the cyclization strategy has witnessed great success in the discovery of new lead compounds against different targets for treating various diseases.Herein,we first briefly summarize the use of the cyclization strategy in the discovery of new small-molecule lead compounds,including the proteolysis targeting chimeras(PROTAC)molecules.Particularly,we focus on four main strategies including fused ring cyclization,chain cyclization,spirocyclization and macrocyclization and highlight the use of the cyclization strategy in lead generation.Finally,the challenges including the synthetic intractability,relatively poor pharmacokinetics(PK)profiles and the absence of the structural information for rational structure-based cyclization are also briefly discussed.We hope this review,not exhaustive,could provide a timely overview on the cyclization strategy for the discovery of new lead compounds.展开更多
Heat current exchanged between a two-level quantum dot(QD) and a phonon reservoir coupled to it is studied within the nonequilibrium Green's function method. We consider that the QD is connected to the left and ri...Heat current exchanged between a two-level quantum dot(QD) and a phonon reservoir coupled to it is studied within the nonequilibrium Green's function method. We consider that the QD is connected to the left and right ferromagnetic leads. It is found that the negative differential of the heat generation(NDHG) phenomenon,i.e.,the intensity of the heat generation decreases with increasing bias voltage,is obviously enhanced as compared to that in single-level QD system. The NDHG can emerge in the absence of the negative differential conductance of the electric current,and occurs in different bias voltage regions when the magnetic moments of the two leads are arranged in parallel or antiparallel configurations. The characteristics of the found phenomena can be understood by examining the change of the electron number on the dot.展开更多
Abstract This research is based on a short hand-written genealogy (shou chaoben 手抄本) of the kind that are appearing in flea markets in China these days. I surmise it was written in Shandong in 1944. Although its ...Abstract This research is based on a short hand-written genealogy (shou chaoben 手抄本) of the kind that are appearing in flea markets in China these days. I surmise it was written in Shandong in 1944. Although its entries are brief, an analysis reveals much about the family, including female family members (often omitted from family genealogies), inter-family marriages practiced over hundreds of years, status markers used by the family such as the taking of second wives, the prevalence of patriarchal views. in 1944 plays a role in my analysis of how The Japanese occupation of Shandong this manuscript was compiled.展开更多
We study the properties of the heat flow generated by electric current in a quantum dot(QD) molecular sandwiched between two ferromagnetic leads. The heat is exchanged between the QD and the phonon reservoir coupled t...We study the properties of the heat flow generated by electric current in a quantum dot(QD) molecular sandwiched between two ferromagnetic leads. The heat is exchanged between the QD and the phonon reservoir coupled to it. We find that when the leads' magnetic moments are in parallel configuration, the total heat generation is independent on the leads' spin-polarization regardless of the magnitude of the intradot Coulomb interaction. This behavior is similar to that of the electronic current. In the antiparallel configuration, however, the influences of the leads' ferromagnetism on the heat generation are quite different from those on the electric current. Under the conditions of weak intradot Coulomb interaction and small bias voltage, the heat generation is monotonously suppressed by increasing leads' spin-polarization.Whereas for sufficient large intradot Coulomb interaction and bias voltage, the heat generation shows non-monotonous behavior due to the electron-phonon interaction and the spin accumulation induced on the dot. Furthermore, the magnitude of the negative differential of the heat generation previously found in a QD connected to nonmagnetic leads can be weakened by the increase of the spin-polarization of the ferromagnetic leads.展开更多
Our lead zinc industry maintained a smooth operation in 2018 while downward pressure continued.Downstream consumption was in recession.Price fell after shock and benefits decreased.Firstly,yield of concentrate decreas...Our lead zinc industry maintained a smooth operation in 2018 while downward pressure continued.Downstream consumption was in recession.Price fell after shock and benefits decreased.Firstly,yield of concentrate decreased and secondary metal presented significant increase.In 2018,due to the factors of environment governance and restrictions on newly constructed mines,yield of lead concentrate and zinc concentrate was 1.33 million tons and 2.84 million tons,respectively YOY down by 5.9%and 4.9%.展开更多
The increasing demand for sustainable and green energy supply spurred the surging research on high- efficiency, low-cost photovoltaics. Colloidal quantum dot solar cell (CQDSC) is a new type of photovoltaic device u...The increasing demand for sustainable and green energy supply spurred the surging research on high- efficiency, low-cost photovoltaics. Colloidal quantum dot solar cell (CQDSC) is a new type of photovoltaic device using lead chalcogenide quantum dot film as absorber materials. It not only has a potential to break the 33% Shockley-Queisser efficiency limit for single junction solar cell, but also possesses low-temperature, high-throughput solution processing. Since its first report in 2005, CQDSCs experienced rapid progress achieving a certified 7% efficiency in 2012, an averaged 1% efficiency gain per year. In this paper, we reviewed the research progress reported in the last two years. We started with background introduction and motivation for CQDSC research. We then briefly introduced the evolution history of CQDSC development as well as multiple exciton generation effect. We further focused on the latest efforts in improving the light absorption and carrier collection efficiency, including the bulk-heterojunction structure, quantum funnel concept, band alignment optimization and quantum dot passivation. Afterwards, we discussed the tandem solar cell and device stability, and concluded this article with a perspective. Hopefully, this review paper covers the major achievement in this field in year 2011-2012 and provides readers with a concise and clear understanding of recent CQDSC development.展开更多
Owing to the diversity of structure and potential applications in the field of electrics,sensors,and light-emitting diodes,lead halide perovskites have attracted great attention in recent years.Especially those lead h...Owing to the diversity of structure and potential applications in the field of electrics,sensors,and light-emitting diodes,lead halide perovskites have attracted great attention in recent years.Especially those lead halide perovskites with non-centrosymmetric crystal structures usually exhibit nonlinear optical(NLO) characteristics,which may endow them photoelectricity switching functionality.In this work,a lead-based hybrid organic-inorganic perovskite(HOIP) material,trimethyliodomethylammonium lead trichloride(TMIM·PbCl_(3)),is obtained on the basis of tetramethylammonium lead chloride through halogen substitution on the cation part.It shows dual-phase-transition behavior around 345 and 358 K, which is significantly improved.TMIM·PbCl_(3)crystallizes in the chiral space group,P2_(1)2_(1)2_(1), and shows a welldefined second harmonic generation(SHG) response,and good switching endurance,which makes it an excellent candidate for SHG switching material.This work highlights the importance of halogen substitution for crystal engineering and may pave way for the further exploration of the optoelectronic devices.展开更多
基金Technical Supporting Programs funded by Ministry of Science and Technology (MOST) of China(No. 2006BAD07A14 No. 2006BDA11A11)
文摘Facing the pressure of fossil energy exhaustion and environment pollution, people begin to search for clean and renewable energy to partly substitute fossil energy and realize sustainable development. As the fourth type of energy, biomass energy has many advantages: wide distribution, large quantity, being renewable, clean, storable and transportable and so on. By adopting thermo-chemical and biochemical technologies, biomass energy can be converted to high quality solid, liquid and gaseous energy products, and provide convenient heat and power energy for human being’s production and daily life. This paper presented the status quo of biomass power generation industry in China and also introduced briefly the future development models.
文摘Energy saving and CO2 emissions reduction are critical tasks currently,and great effort has been made by Chinese government. Renewable energy consumption and CO2 emissions and reduction plan in China are introduced in this paper. Analysis is also made on present status and prospect of geothermal power generation and direct use in China respectively. Now,there is a new understanding of geothermal resources,and hot dry rock,considered as the future of geothermal resources,is likely used to generate electricity.
基金This work was supported by the National Key Research to Han Ping Shi and Development Program(No.2017YFC1309200)National Natural Science Foundation of China(No.81673167 to Hong Xia Xu).
文摘Background Malnutrition is common in patients with cancer,and can negatively impact their quality of life(QoL)and even survival.However,there is currently no large data available on the prevalence of malnutrition in Chinese cancer patients.This study evaluated the prevalence of malnutrition and the QoL of Chinese patients with locoregional,recurrent or metastatic cancer.Methods We conducted a nationwide observational,multi-center,hospital-based cross-sectional study within the Chinese Society of Nutritional Oncology(CSNO)Network.All of the patients were diagnosed with one of the following 18 different types of malignant tumors:lung cancer,gastric cancer,liver cancer,colorectal cancer,breast cancer,esophageal cancer,cervical cancer,endometrial cancer,nasopharyngeal carcinoma,malignant lymphoma,leukemia,pancreatic cancer,ovarian cancer,prostate cancer,bladder cancer,brain cancer,biliary tract malignant tumors or gastrointestinal stromal tumors.These patients were enrolled from 72 hospitals located in different regions of China.The patients’nutritional status was evaluated based on the body mass index(BMI),loss of bodyweight,laboratory measurements and patient generated-subjective global assessment(PG-SGA)scores.The cancer patients’physical status and QoL were assessed by the Karnofsky Performance Status(KPS)questionnaire and the European Organization for Research and Treatment of Cancer(EORTC)QLQ-C30 questionnaire,respectively.Results From December 2013 to April 2016,23,994 patients hospitalized for cancer treatment(such as surgery,chemotherapy or radiotherapy)were enrolled in the study.The patients included 12,494(52.9%)males and 11,124(47.1%)females.The mean age was 55.8±13.7 years.The proportions of patients in cancer stagesⅠ,Ⅱ,Ⅲ,Ⅳand uncertain were 11.5%,20.3%,27.5%,30.2%and 10.5%,respectively.Among the 23,994 inpatients,the proportions of patients who were underweight(BMI<18.5 kg/m2),normal(18.5 kg/m2<BMI<24 kg/m2),overweight(24 kg/m2≤BMI<28 kg/m2)and obese(BMI≥28 kg/m2)were 9.3%,59.9%,26.1%and 4.7%,respectively.A total of 18.3%(4,101/22,424)of patients had lost 5%or more of their bodyweight within the past month and 19.6%(2,463/12,538)of patients had lost 10%or more of their bodyweight within the past 6 months.According to the PG-SGA scores,26.6%of the patients were severely malnourished(score≥9),31.3%were moderately malnourished(scores 4~8).A total of 22.2%of patients had a serum albumin level lower than 35g/L.Only 8.6%(2056/23,991)of the patients had severe KPS scores(≤60).The patients with these severe KPS scores were most frequently among those with cancers of the brain(19.7%),prostate(18.0%),pancreas(15.5%)and bladder(15.0%).Based on the QLQ-C30 score,11.6%of patients had a poor QoL.The PG-SGA score and global QoL were correlated(r=-0.593,P<0.001).Conclusion The prevalence of malnutrition in patients with cancer is relatively high,and is related to a poorer QoL.The present findings should be kept in mind when assessing cancer patients,because addressing the patient’s problems in nutritional status would be expected to improve both the clinical outcomes and QoL in cancer patients with malnutrition.
基金supported by the National Natural Science Foundation of China(Grant No.61274101)
文摘We study theoretically the heat originated from electron-phonon coupling in a spintronic device composed of a semi- conductor quantum dot attached to one spin battery and one ferromagnetic lead. It is found that the phenomenon of the negative differential of the heat current, which has previously been predicted in the charge-based device, disappears due to the Pauli exclusion principle resulted from the presence of the spin battery. Under some conditions, huge heat in the heat generation induced by resonant phonon emitting processes also disappears in this spin-based device. Furthermore, we find that the ferromagnetism of the lead can be used to effectively adjust the magnitude of the heat current in different dot level ranges. The proposed system is realizable by current technology and may be useful in designing high-efficiency spintronic components.
基金Supported by the National Natural Science Foundation of China under Grant No 61274101
文摘Heat generated by electric current in a quantum dot device contacting a phonon bath is studied using the non- equilibrium Green function technique. Spin-polarized current is generated owing to the Zeeman splitting of the dot level. The current's strength and the spin polarization are further manipulated by changing the frequency of an applied photon field and the ferromagnetism on the leads. We find that the associated heat by this spin- polarized current emerges even if the bias voltage is smaller than the phonon energy quanta and obvious negative differential of the heat generation develops when the photon frequency exceeds that of the phonon. It is also found that both the strength and the resonant peaks' position of the heat generation can be tuned by changing the value and the arrangement configurations of the magnetic moments of the two leads, and then provides an effective method to generate large spin-polarized current with weak heat. Such a result may be useful in designing low energy consumption spintronic devices.
基金support by the National Natural Science Foundation of China(No.71273090)Fundamental Research Funds for the Central Universities(No.2015XS44)
文摘With the rapid development of its national economy,China has become a major producer and consumer of energy.To guarantee the sustainable development of power industry and national economy,China should exploit fossil and renewable energy efficiently according to the development situation of generation resources.Firstly,this paper analyzes the utilization status of main generation resources in China,such as coal,hydropower and wind energy.Secondly,this paper illustrates the STEP model,which analyzes some issues for China’s generation resource utilization from political,economic,social and technological aspects.For example,the resource distribution is inconsistent with electricity demand,the renewable energy power output is intermittent,and there is some disruption in coal mining.Finally,combined with the utilization status and issues,this paper presents some improvement approaches from the perspectives of cost,efficiency and external influence.
文摘To better understand the generation of electric power for piezoelectric Pb Zr Ti O3(PZT)ceramic plate(?25 mm),an attempt was made to investigate experimentally and numerically electricpower generation characteristics during cyclic bending under various loading fixtures(?0–?20 mm),i.e.,different contact areas.Increasing the load-contact area on the PZT ceramic leads to a nonlinear decrease in the generated voltage.Decreasing contact area basically enhances the generated voltage,although the voltage saturates during loading when the contact area is less than?5 mm.A similar voltage is generated for?0 and?5 mm,which is attributed to strain status(ratio of compressive and tensile strain)and material failure due to different stress distribution in the PZT ceramic.On the basis of the obtained electric generation voltage,suitable loading conditions are clarified by loading with the?5 mm fixture,which generates a higher voltage and a longer lifetime of the PZT ceramic.From this approach,it is appeared that the area contact with the area ratio of 0.04(?5 mm/?20 mm)is suitable to obtain the high efficiency of the electric voltage.
基金This work is supported by the National Natural Science Foundation of China(Nos.22277110,81973177 and 31900875,China)the Natural Science Foundation of Henan Province(Nos.222300420069 and 222301420049,China)Program for Science&Technology Innovation Talents in Universities of Henan Province(No.21HASTIT045,China).
文摘The design of new ligands with high affinity and specificity against the targets of interest has been a central focus in drug discovery.As one of the most commonly used methods in drug discovery,the cyclization represents a feasible strategy to identify new lead compounds by increasing structural novelty,scaffold diversity and complexity.Such strategy could also be potentially used for the follow-on drug discovery without patent infringement.In recent years,the cyclization strategy has witnessed great success in the discovery of new lead compounds against different targets for treating various diseases.Herein,we first briefly summarize the use of the cyclization strategy in the discovery of new small-molecule lead compounds,including the proteolysis targeting chimeras(PROTAC)molecules.Particularly,we focus on four main strategies including fused ring cyclization,chain cyclization,spirocyclization and macrocyclization and highlight the use of the cyclization strategy in lead generation.Finally,the challenges including the synthetic intractability,relatively poor pharmacokinetics(PK)profiles and the absence of the structural information for rational structure-based cyclization are also briefly discussed.We hope this review,not exhaustive,could provide a timely overview on the cyclization strategy for the discovery of new lead compounds.
基金Supported by the National Natural Science Foundation of China under Grant No.61274101the Liaoning Excellent Talents Programand(LJQ2013118)the Foundation of State Key Laboratory of Explosion Science and Technology of Beijing Institute of Technology(KFJJ14-08M)
文摘Heat current exchanged between a two-level quantum dot(QD) and a phonon reservoir coupled to it is studied within the nonequilibrium Green's function method. We consider that the QD is connected to the left and right ferromagnetic leads. It is found that the negative differential of the heat generation(NDHG) phenomenon,i.e.,the intensity of the heat generation decreases with increasing bias voltage,is obviously enhanced as compared to that in single-level QD system. The NDHG can emerge in the absence of the negative differential conductance of the electric current,and occurs in different bias voltage regions when the magnetic moments of the two leads are arranged in parallel or antiparallel configurations. The characteristics of the found phenomena can be understood by examining the change of the electron number on the dot.
文摘Abstract This research is based on a short hand-written genealogy (shou chaoben 手抄本) of the kind that are appearing in flea markets in China these days. I surmise it was written in Shandong in 1944. Although its entries are brief, an analysis reveals much about the family, including female family members (often omitted from family genealogies), inter-family marriages practiced over hundreds of years, status markers used by the family such as the taking of second wives, the prevalence of patriarchal views. in 1944 plays a role in my analysis of how The Japanese occupation of Shandong this manuscript was compiled.
基金Supported by National Natural Science Foundation of China under Grant No.61274101
文摘We study the properties of the heat flow generated by electric current in a quantum dot(QD) molecular sandwiched between two ferromagnetic leads. The heat is exchanged between the QD and the phonon reservoir coupled to it. We find that when the leads' magnetic moments are in parallel configuration, the total heat generation is independent on the leads' spin-polarization regardless of the magnitude of the intradot Coulomb interaction. This behavior is similar to that of the electronic current. In the antiparallel configuration, however, the influences of the leads' ferromagnetism on the heat generation are quite different from those on the electric current. Under the conditions of weak intradot Coulomb interaction and small bias voltage, the heat generation is monotonously suppressed by increasing leads' spin-polarization.Whereas for sufficient large intradot Coulomb interaction and bias voltage, the heat generation shows non-monotonous behavior due to the electron-phonon interaction and the spin accumulation induced on the dot. Furthermore, the magnitude of the negative differential of the heat generation previously found in a QD connected to nonmagnetic leads can be weakened by the increase of the spin-polarization of the ferromagnetic leads.
文摘Our lead zinc industry maintained a smooth operation in 2018 while downward pressure continued.Downstream consumption was in recession.Price fell after shock and benefits decreased.Firstly,yield of concentrate decreased and secondary metal presented significant increase.In 2018,due to the factors of environment governance and restrictions on newly constructed mines,yield of lead concentrate and zinc concentrate was 1.33 million tons and 2.84 million tons,respectively YOY down by 5.9%and 4.9%.
文摘The increasing demand for sustainable and green energy supply spurred the surging research on high- efficiency, low-cost photovoltaics. Colloidal quantum dot solar cell (CQDSC) is a new type of photovoltaic device using lead chalcogenide quantum dot film as absorber materials. It not only has a potential to break the 33% Shockley-Queisser efficiency limit for single junction solar cell, but also possesses low-temperature, high-throughput solution processing. Since its first report in 2005, CQDSCs experienced rapid progress achieving a certified 7% efficiency in 2012, an averaged 1% efficiency gain per year. In this paper, we reviewed the research progress reported in the last two years. We started with background introduction and motivation for CQDSC research. We then briefly introduced the evolution history of CQDSC development as well as multiple exciton generation effect. We further focused on the latest efforts in improving the light absorption and carrier collection efficiency, including the bulk-heterojunction structure, quantum funnel concept, band alignment optimization and quantum dot passivation. Afterwards, we discussed the tandem solar cell and device stability, and concluded this article with a perspective. Hopefully, this review paper covers the major achievement in this field in year 2011-2012 and provides readers with a concise and clear understanding of recent CQDSC development.
基金supported by the National Natural Science Foundation of China (No. 21901099)。
文摘Owing to the diversity of structure and potential applications in the field of electrics,sensors,and light-emitting diodes,lead halide perovskites have attracted great attention in recent years.Especially those lead halide perovskites with non-centrosymmetric crystal structures usually exhibit nonlinear optical(NLO) characteristics,which may endow them photoelectricity switching functionality.In this work,a lead-based hybrid organic-inorganic perovskite(HOIP) material,trimethyliodomethylammonium lead trichloride(TMIM·PbCl_(3)),is obtained on the basis of tetramethylammonium lead chloride through halogen substitution on the cation part.It shows dual-phase-transition behavior around 345 and 358 K, which is significantly improved.TMIM·PbCl_(3)crystallizes in the chiral space group,P2_(1)2_(1)2_(1), and shows a welldefined second harmonic generation(SHG) response,and good switching endurance,which makes it an excellent candidate for SHG switching material.This work highlights the importance of halogen substitution for crystal engineering and may pave way for the further exploration of the optoelectronic devices.