Artificial intelligent aided design and manufacturing have been recognized as one kind of robust data-driven and data-intensive technologies in the integrated computational material engi-neering(ICME)era.Motivated by ...Artificial intelligent aided design and manufacturing have been recognized as one kind of robust data-driven and data-intensive technologies in the integrated computational material engi-neering(ICME)era.Motivated by the dramatical developments of the services of China Railway High-speed series for more than a decade,it is essential to reveal the foundations of lifecycle man-agement of those trains under environmental conditions.Here,the smart design and manufacturing of welded Q350 steel frames of CR200J series are introduced,presenting the capability and opportu-nity of ICME in weight reduction and lifecycle management at a cost-effective approach.In order to address the required fatigue life time enduring more than 9×10^(6)km,the response of optimized frames to the static and the dynamic loads are comprehensively investigated.It is highlighted that the maximum residual stress of the optimized welded frame is reduced to 69 MPa from 477 MPa of previous existing one.Based on the measured stress and acceleration from the railways,the fatigue life of modified frame under various loading modes could fulfil the requirements of the lifecycle man-agement.Moreover,our recent developed intelligent quality control strategy of welding process mediated by machine learning is also introduced,envisioning its application in the intelligent weld-ing.展开更多
Using 110 newly revised Holocene sea level indicators categorized into three types,sediments(67),shelly cheniers(27)and oyster reefs(16),this paper firstly provides a Holocene relative sea level curve,based on multipl...Using 110 newly revised Holocene sea level indicators categorized into three types,sediments(67),shelly cheniers(27)and oyster reefs(16),this paper firstly provides a Holocene relative sea level curve,based on multiple approaches of litho-and biostratigraphies and sedimentary faces analysis,for the west coast of Bohai Bay,China.Following considerations,including indicative meaning,the paleo tidal pattern and range and conversion from mean tidal level to mean sea level,an apparent relative mean sea level(RMSL)curve was further reconstructed.After systematical calibration using CALIB,those of the 48 reworked samples were further corrected for the residence-time effect.Similarly,the younger ages for another 35 samples were chosen at the subsample level.These result in a younger-oriented shift for about 0.5 ka.Three local spatial factors,including neotectonic subsidence(average rate about 0.1 mm/a),self-compaction of unconsolidated sediments(between a few decimeters to about 6 m)and subsidence due to groundwater withdrawal(between a few centimeters to about 2.5 m),were quantitatively corrected.Finally,the amended RMSL curve after eliminating all these local temporo-spatial factors is very likely to show non-existence of mid-Holocene highstand and imply potential influences of both ice-volume equivalent sea level and regional glacial isostatic adjustment.Although it is still unable to divide both global and regional factors,the slowdown of sea level rise,in 7.5–6.8 ka with a maximum height less than+1 m,may constrain the model effort in the near future.展开更多
BACKGROUND: Several studies have demonstrated that sustained cognitive tasks can induce cognitive fatigue and that the mean cerebral blood flow velocity changes in some cerebral regions during cerebral fatigue. OBJEC...BACKGROUND: Several studies have demonstrated that sustained cognitive tasks can induce cognitive fatigue and that the mean cerebral blood flow velocity changes in some cerebral regions during cerebral fatigue. OBJECTIVE: To dynamically monitor the changes in mean cerebral blood flow velocity in different brain regions of high performance fighter pilots during mental arithmetic tasks and consecutive performance tasks. DESIGN, TIME AND SETTING: The present neurophysiological trial, based on controlled observation, was performed at the Laboratory of Neurophysiology, Institute of Aviation Medicine, Air Force of China between January 2003 and December 2005. PARTICIPANTS: Forty-five males, high performance fighter pilots, averaging (27.6±2.5) years, were recruited for this study. METHODS: The mean cerebral blood flow velocity in the anterior cerebral artery, middle cerebral artery, and posterior cerebral artery of subjects was dynamically tested using transcranial Doppler during 5- hour mental arithmetic tasks and during 5- hour consecutive performance tasks. The neurobehavioral ability index was analyzed throughout each trial according to the number of correct responses, false responses, and lost responses. Simultaneously, cerebral cognitive fatigue-induced lethargy was assessed by the Stanford Sleepiness Scale. MAIN OUTCOME MEASURES: Changes in mean cerebral blood flow velocity in the anterior cerebral artery, middle cerebral artery, and posterior cerebral artery; neurobehavioral ability index of mental arithmetic and consecutive performance tasks; Stanford Sleepiness Scale scores. RESULTS: During mental arithmetic tasks, the mean cerebral blood flow velocity in the anterior cerebral artery increased during hour 2 and decreased after hour 4. There was no significant change in mean cerebral blood flow velocity in the middle cerebral artery and posterior cerebral artery. During hour 4, cerebral cognitive fatigue was observed and, simultaneously, Stanford Sleepiness Scale scores demonstrated the presence of fatigue. During such a stage, the neurobehavioral ability index decreased, indicating a decline in performance ability. During consecutive performance tasks, the mean cerebral blood flow velocity declined earlier in the posterior cerebral artery compared to the middle cerebral artery. CONCLUSION: Five- hour mental arithmetic tasks have few effects on cerebral functions and do not lead to a significant change in mean cerebral blood flow velocity. Five-hour consecutive performance tasks can induce cerebral cognitive fatigue, and a marked decline in mean cerebral blood flow velocity.展开更多
East Asia has long been recognized as a major center for temperate woody plants diversity.Although several theories have been proposed to explain how the diversity of these temperate elements accumulated in the region...East Asia has long been recognized as a major center for temperate woody plants diversity.Although several theories have been proposed to explain how the diversity of these temperate elements accumulated in the region,the specific process remains unclear.Here we describe six species of Carpinus,a typical northern hemisphere temperate woody plant,from the early Miocene of the Maguan Basin,southwestern China,southern East Asia.This constitutes the southernmost,and the earliest occurrence that shows a high species diversity of the genus.Together with other Carpinus fossil records from East Asia,we show that the genus had achieved a high diversity in East Asia at least by the middle Miocene.Of the six species here described,three have become extinct,indicating that the genus has experienced apparent species loss during its evolutionary history in East Asia.In contrast,the remaining three species closely resemble extant species,raising the possibility that these species may have persisted in East Asia at least since the early Miocene.These findings indicate that the accumulation of species diversity of Carpinus in East Asia is a complex process involving extinction,persistence,and possible subsequent speciation.展开更多
Tonle Sap Lake is the largest river-connected lake, buffer area and ecological zone of Mekong River, which plays a huge role in dispelling flood peak and compensating water, and the conservation of biological diversit...Tonle Sap Lake is the largest river-connected lake, buffer area and ecological zone of Mekong River, which plays a huge role in dispelling flood peak and compensating water, and the conservation of biological diversity. The river-lake relationship between Mekong River and Tonle Sap Lake is unique and has always been a major focus in the international community. The land terrain and under-water topography were used to analyze the morphological characteristics of Cambodia Mekong Delta and Tonle Sap Lake. Long series of hydrological data of river-lake controlling stations were used to analyze the water level variation characteristics and water volume exchange pattern between Mekong River and Tonle Sap Lake, and the response relationship to river-lake morphological characteristics were also researched. The results show that: Cambodia Mekong Delta and Tonle Sap Lake Area is low-lying and flat with gentle channel gradient and water surface gradient, making the relationship between water level and area (or volume) smooth. The channel storage capacity of Mekong River and Tonle Sap River is not enough compared to the inflow, so vast flooding plain is extremely prone to be inundated, making the flood relationships between the left and right banks become very complicated. Tonle Sap Lake is a seasonal freshwater lake with water flowing in and flowing out, and the timing and intensity of water exchange with Mekong River are closely related to the water flow resistance at the exit section of Tonle Sap Lake and the cross-sectional area of Tonle Sap River, which can be reflected by the river-lake water level difference and the water level of Tonle Sap River. Affected by the river-lake morphological characteristics, the water exchange intensity between Mekong River and Tonle Sap Lake is great. Tonle Sap Lake not only stores 14.4% of flood volume (39.7 billion m3) from the Mekong River every year, but also supplies 29.7% of dry water (69.4 billion m3) to the Mekong River. Influenced by the adjustment of the floodplain, the water level fluctuation of Mekong River and Tonle Sap Lake is slow, and the rising and droop rates of water level are positively correlated with the floodplain storage area. The research results will help to understand the relationship mechanism between Mekong River and Tonle Sap Lake and provide a scientific basis for the comprehensive governance of Cambodia Mekong Delta and Tonle Sap Lake Area.展开更多
SBA-15 supported Mo catalysts (Moy/SBA-15) were prepared by an ultrasonic assisted incipient-wetness impregnation method. The physical and chemical properties of the catalysts were characterized by means of N2-adsor...SBA-15 supported Mo catalysts (Moy/SBA-15) were prepared by an ultrasonic assisted incipient-wetness impregnation method. The physical and chemical properties of the catalysts were characterized by means of N2-adsorption-desorption, XRD, TEM, UV-Vis, Raman, XANES and H2-TPR. The results showed that a trace amount of MoO3 was produced on high Mo content samples. Tum-over frequency (TOF) and product selectivity are dependent on the molybdenum content. Both Mo0.75/SBA-15 and Mo1.75/SBA-15 catalysts give the higher catalytic activity and the selectivity to the total aldehydes for the selective oxidation of C2H6. At the reaction temperature of 625℃, the maximum yield of aldehydes reached 4.2% over Mo0.75/SBA-15 catalyst. The improvement of the activity and selectivity was related with the state of MoOx species.展开更多
Six sugarcane plant lines were selected from seedlings owing to good performance in agronomic characters under drought conditions.A special test with drought stress to death under groove was carried out to select the ...Six sugarcane plant lines were selected from seedlings owing to good performance in agronomic characters under drought conditions.A special test with drought stress to death under groove was carried out to select the best drought tolerant clones among them. The proportion of bound water to free water content in leaves,cell cytoplasm membrane permeability in leaves,yield components,etc.,which were regarded as reasonable indexes to identify drought resistance of sugarcane,were measured. The results showed that both YT06-868 and YT05-339 were winners. The two were high-class drought-resistant clones. On some measured indexes,both of them had higher values than ROC22( the main check variety) and on the other ones,they both had the same values as ROC22. The drought resistance of YT05-291 was moderate and between ROC22 and ROC16( the secondary check variety),while the others had poor drought-resistant according to these indexes.展开更多
The present study reports a rare primitive neuroectodermal tumor (PNET) of prostate.A 27-year-old male was admitted to Harbin Medical University Cancer Hospital (Harbin,China) for dysuria and dyschezia. Magnetic reson...The present study reports a rare primitive neuroectodermal tumor (PNET) of prostate.A 27-year-old male was admitted to Harbin Medical University Cancer Hospital (Harbin,China) for dysuria and dyschezia. Magnetic resonance imaging (MRI) revealed a large mass thatmay involve the bladder and rectum next to the prostate. Histopathological analysis of biopsyof prostate indicated mesenchymal origin tumor, and immunohistochemistric stainingconfirmed diagnosis of PNET of prostate. En bloc total pelvic exenteration and double barrelsigmoidostomy were performed. Double stomas in the skin incision were used for fecal andurinary diversion, respectively. Short-term outcome is satisfactory, while long-term efficacyremains to be poor. Clinical features of PNET of prostate should be paid much more attentionand radical surgery and adjuvant chemotherapy should be recommended.展开更多
HKT transport protein is an ion transporter thai exists on plasmalemma and a ubiquitous transmembrane protein responsible for Na + transport and K+ - Na + symport. HKT transport protein is regulated by the expressi...HKT transport protein is an ion transporter thai exists on plasmalemma and a ubiquitous transmembrane protein responsible for Na + transport and K+ - Na + symport. HKT transport protein is regulated by the expression of ItKT family genes. The overexpression of HKT family genes can improve activity of Na+ transport and K+ - Na+ s.vmport proteins in plants, lead to Na + recycle, reduce Na + concentration in vivo, maintain K +/Na+ ratio, and ensure normal physiological functions of eells, thereby improving salt toleranee of plants. This paper introduced the discovery and claning of HKT family genes, revealed interactions between HKT family genes and SOS, NHX genes, and summarized the relationship between the structure, function of HKT protein and salt tolerance of plants to clarify the function and mechanism of action of HKT transport protein, aiming at laying the foundation for genetic engineering of plants for salt tolerauee and providing basis for breeding haloduric transgenie plant.展开更多
Background: Most of the reports on tumor relapse are recurrence of the same type of tumor after months to few years of a successful initial cancer treatment. It is generally unusual and unexpected that a different typ...Background: Most of the reports on tumor relapse are recurrence of the same type of tumor after months to few years of a successful initial cancer treatment. It is generally unusual and unexpected that a different type of the second tumor occurs after several decades of the curative treatment of the original tumor. Case Presentation: We report a case of 74-year-old man with intrahepatic cholangiocarcinoma (ICC) diagnosed 38 years after curative resection of hepatocellular carcinoma (HCC). In addition to the uniqueness of longer survival and developed a new type of tumor, both the original HCC and the later occurred ICC were detected through a cancer surveillance program by screening alpha-fetoprotein (AFP) and ultrasonography of the liver for the general population and/or high risk group of people who were asymptomatic. Conclusion: This report provides evidence demonstrating occurrence of new type of tumor following initial curative therapy of the original tumor. In addition, this case report also highlights the importance of cancer surveillance program for earlier detection of the tumors to achieve a remarkably improved prognosis of the cancer patients for a prolonged cancer free survival time.展开更多
With practical interest in the future applications of next-generation electronic devices,it is imperative to develop new conductive interconnecting materials appropriate for modern electronic devices to replace tradit...With practical interest in the future applications of next-generation electronic devices,it is imperative to develop new conductive interconnecting materials appropriate for modern electronic devices to replace traditional rigid solder tin and silver paste of high melting temperature or corrosive solvent requirements.Herein,we design highly stretchable shape memory self-soldering conductive(SMSC)tape with reversible adhesion switched by temperature,which is composed of silver particles encapsulated by shape memory polymer.SMSC tape has perfect shape and conductivity memory property and anti-fatigue ability even under the strain of 90%.It also exhibits an initial conductivity of 2772 S cm^(−1) and a maximum tensile strain of~100%.The maximum conductivity could be increased to 5446 S cm^(−1) by decreasing the strain to 17%.Meanwhile,SMSC tape can easily realize a heating induced reversible strong-to-weak adhe-sion transition for self-soldering circuit.The combination of stable conductivity,excellent shape memory performance,and temperature-switching reversible adhesion enables SMSC tape to serve two functions of electrode and solder simultaneously.This provides a new way for conductive interconnecting materials to meet requirements of modern electronic devices in the future.展开更多
[Objective] This study aimed to establish an effective detection technology for rapidly identifying Bt transgenic sugarcane, promptly removing non-Bt transgenic plants and increasing breeding efficiency of Bt transgen...[Objective] This study aimed to establish an effective detection technology for rapidly identifying Bt transgenic sugarcane, promptly removing non-Bt transgenic plants and increasing breeding efficiency of Bt transgenic plants, thereby improving breeding efficiency of insect-resistant sugarcane cultivars in China. [ Method] Approximately 1 mg of root tips and other materials were crushed, placed in the bottom of PCR tubes, added successively with solution I and mineral oil, headed at 95 ℃ for 15 rain, added with solution Ⅱ, and finally added with solution III containing GBt primer for PCR. After separated by using electrophoresis on agarese gel, amplification products were observed and photographed under a gel imaging system. [ Result] Various materials treated with different concentrations of solution led to different amplification results. Specifically, the appropriate concentration of NaOH in solution I was 0.1 -0.2 mol/L; the appropriate pH value of solution II was 2. No bands were amplified from mature leaves, tender leaves and old roots of Bt transgenic sugarcane, while root tips successfully amplified 545 bp target bands. The established method was used to identify and analyze 63 hybrid seedlings of YT 91 -976 × SBR216, results showed that a total of 17 samples exhibited 545 bp bands, accounting for approximately 27% of the total number of hybrid seedlings, indicating that these 17 seedlings were Bt transgenic sugarcane plants. [ Conclusion] The rapid detection method established in this study is conducive to identifying Bt transgenic sugarcane and improving breeding efficiency of insect-resistant sugarcane lines, which provides basis for screening of other transgenic materials.展开更多
[ Objective] A large number of high-quality Bt transgenic sugarcane lines were obtained using transgenic technologies. This study aimed to explore the genetic background, genetic diversity, important traits and relati...[ Objective] A large number of high-quality Bt transgenic sugarcane lines were obtained using transgenic technologies. This study aimed to explore the genetic background, genetic diversity, important traits and relationship between the heredity and phenotype of these transgenic sugarcane lines, thereby providing basis for further effective utilization and preservation of insect-resistant germplasm resources and improving breeding efficiency of insect-resistant sugarcane in China. [Method] By using six AFLP primers with high polymorphism, the genetic diversity of 13 Bt transgenic sugarcane lines and their donor varieties was analyzed. Growth assay and insect-resistance identification were carried out in a quarantine greenhouse with conventional methods. Evaluation of important economic traits was conducted in the field with conventional methods. [ Result] The polymorphism rate was relatively low. Specifically, the polymorphism rate of the first group was 21.00%, the polymorphism rate of the second group was 31.80%, and the total polymorphism rate was 42.50%. Cluster analysis showed that 13 Bt transgenic sugarcane lines and their donor varieties were divided into two categories, the genetic similarity coefficient between two categories was 0.54. All the six materials in the first group were clustered into category Ⅰ, with genetic similarity of 0. 921 ; nine materials in the second group were clustered into category Ⅱ, with genetic similarity of 0. 898. Bt transgenic sugarcane lines showed abundant phenotypic types and significant trait variations, and the economic traits were generally worse than donor varieties. The insect resistance of 13 Bt transgenic sugarcane lines was divided into five grades. [ Conclusion] The first-generation Bt transgenic sugarcane lines have low genetic diversity, abundant trait variations, high insect resistance and generally poor economic traits, which can only be used as germplasm resources for hybridization. Introducing Bt gene into multiple donors will to some extent improve the genetic diversity of sugarcane germplasm resources, but the increasing rate is relatively low. It is preliminarily considered that the genetic diversity of insect-resistant sugarcane germplasm resources should be improved by continuous hybridization and backcrossing of Bt transgenic lines with high-quality parents, thus laying foundation for breeding high-quality insect-resistant sugarcane varieties.展开更多
Functional dyspepsia(FD)is a regularly diagnosed clinical gastrointestinal ailment with a high incidence rate that can considerably impact patients’health and quality of life and impose a substantial financial burden...Functional dyspepsia(FD)is a regularly diagnosed clinical gastrointestinal ailment with a high incidence rate that can considerably impact patients’health and quality of life and impose a substantial financial burden.Modern research on the pathophysiology of functional dyspepsia has not thoroughly explained the underlying reasons.The condition does not manifest any significant organ abnormalities,which raises the disease’s difficulty coefficient.Major pathogenic exceptions in FD include gastrointestinal motor dysfunction,gastrointestinal hormone secretion problem,visceral hypersensitivity,and brain-gut axis.Several ion channels have reportedly been implicated in the pathophysiological process of FD.Therefore,it is crucial to comprehend the probable activities of various ion channels in FD.This study focuses on the current state of research on the possible role of several ion channels in the pathogenesis of FD.展开更多
The Convention on Biological Diversity seeks to conserve at least 30%of global land and water areas by 2030,which is a challenge but also an opportunity to better preserve biodiversity,including flowering plants(angio...The Convention on Biological Diversity seeks to conserve at least 30%of global land and water areas by 2030,which is a challenge but also an opportunity to better preserve biodiversity,including flowering plants(angiosperms).Herein,we compiled a large database on distributions of over 300,000 angiosperm species and the key functional traits of 67,024 species.Using this database,we constructed biodiversity-environment models to predict global patterns of taxonomic,phylogenetic,and functional diversity in terrestrial angiosperms and provide a comprehensive mapping of the three diversity facets.We further evaluated the current protection status of the biodiversity centers of these diversity facets.Our results showed that geographical patterns of the three facets of plant diversity exhibited substantial spatial mismatches and nonoverlapping conservation priorities.Idiosyncratic centers of functional diversity,particularly of herbaceous species,were primarily distributed in temperate regions and under weaker protection compared with other biodiversity centers of taxonomic and phylogenetic facets.Our global assessment of multifaceted biodiversity patterns and centers highlights the insufficiency and unbalanced conservation among the three diversity facets and the two growth forms(woody vs.herbaceous),thus providing directions for guiding the future conservation of global plant diversity.展开更多
Chiral organic-inorganic hybrid metal halides(OIHMHs)have attracted broader scientific community recently in spin lightemitting diodes,and circularly polarized light-emitting diodes.However,the emission peaks of the r...Chiral organic-inorganic hybrid metal halides(OIHMHs)have attracted broader scientific community recently in spin lightemitting diodes,and circularly polarized light-emitting diodes.However,the emission peaks of the reported chiral OIHMHs mainly locate in the visible region,and chiral OIHMH with ultraviolet(UV)circularly polarized luminescence(CPL)has been rarely reported.To fill this gap,cerium,a unique rare-earth(RE)element with tunable luminescence from UV to the visible region owing to the 4 f-related electronic transition,was introduced to construct the first RE-based chiral OIHMHs,R/S-MCC.The chirality is successfully transferred from the chiral organic cations to the inorganic cerium chloride framework in R/S-MCC,as confirmed by the single crystal structures,circular dichroism,and CPL.The emission spectra of R/S-MCC are in the UV region,originating from the characteristic d-f transition of Ce^(3+),which making the Ce-based metal halides are ideal candidates towards CPL light sources in the UV region.Notably,R-and S-MCC are the first RE-based OIHMHs,also the first chiral metalhalides with UV CPL.Our work opens a new avenue for the development of the chiral OIHMH family towards RE-based chiral OIHMH.The RE-based chiral metal halides couple the unique and superior optical,electrical,magnetic,and spintronic properties of RE elements with chirality could accelerate the development of chiral optoelectronics and spintronics toward real applications.展开更多
Dimerized small-molecule acceptors(SMAs) built by the conventional connection of terminal groups of monomers have contributed to exciting long-term stabilities of organic solar cells(OSCs). However, device efficiencie...Dimerized small-molecule acceptors(SMAs) built by the conventional connection of terminal groups of monomers have contributed to exciting long-term stabilities of organic solar cells(OSCs). However, device efficiencies, especially fill factors(FFs), still need to be improved. This probably originates from unsymmetrical molecular structure/conformation-determined less compact/ordered molecular stackings, such as ineffective stackings of constraint terminals. Herein, an exotic dimerized SMA of BC-Th is established by bridging the branched groups(BC-type, branch coupling) of two monomers rather than conventional terminal units(TC-type, terminal coupling). Benefiting from the three-dimensional conformation and more uncurbed terminals,BC-Th exhibits multiple molecular orientations along with a larger dielectric constant and electron mobility compared with TCTh. Finally, an efficiency of 17.43% is achieved by BC-Th-based OSCs, along with the highest FF of 79.13% among all dimerized SMAs-based OSCs to date. When introducing L8-BO as the third component, overall enhanced efficiency of 18.05%and FF of 80.11% are further afforded. Contrarily, TC-Th-based OSCs exhibit much inferior PCE of 16.29% and FF of 74.81%,demonstrating the great advantages of “branch coupling” over “terminal coupling” when building dimerized SMAs.展开更多
Inspired by the success of CH-series acceptors, a small-molecular acceptor, CH-Tz was reported by adopting a new conjugationextended electron-deficient unit([1,2,5]thiadiazolo[3,4-b]pyrazine) on the central core. Owin...Inspired by the success of CH-series acceptors, a small-molecular acceptor, CH-Tz was reported by adopting a new conjugationextended electron-deficient unit([1,2,5]thiadiazolo[3,4-b]pyrazine) on the central core. Owing to the enhanced inter-/intramolecular interactions, CH-Tz exhibited near-infrared absorption and an effective three-dimensional molecular packing network in its single crystal. When blended with polymer donor PM6, the binary device achieved a high power conversion efficiency(PCE) of 18.54%, with a notable short-circuit current density(J_(sc)) of 27.54 m A cm-2and an excellent fill factor(FF) over 80%,which can be partly ascribed to the balanced charge transport properties in the blend film. After employing D18-Cl as the third component, an enhanced PCE of 18.85% was achieved due to a more obvious fiber network. Impressively, the CH-Tz-based OSC devices show excellent thermal stability and thickness insensitivity. Record-breaking Jscof 28.92 m A cm-2was reached for PM6:D18-Cl:CH-Tz ternary device with a thickness of 560 nm. Besides, CH-Tz shows potential in fabricating multicomponent high-performance organic solar cells, where over 19% efficiency could be realized in the quaternary device. Our work advances the strong influence of electron-deficient central units on molecular photovoltaic properties and guides the design of acceptors for stable and large-thickness organic solar cells.展开更多
基金supported by the National Basic Scientific Research Project of China (No.JCKY2020607B003)CRRC (No.202CDA001)
文摘Artificial intelligent aided design and manufacturing have been recognized as one kind of robust data-driven and data-intensive technologies in the integrated computational material engi-neering(ICME)era.Motivated by the dramatical developments of the services of China Railway High-speed series for more than a decade,it is essential to reveal the foundations of lifecycle man-agement of those trains under environmental conditions.Here,the smart design and manufacturing of welded Q350 steel frames of CR200J series are introduced,presenting the capability and opportu-nity of ICME in weight reduction and lifecycle management at a cost-effective approach.In order to address the required fatigue life time enduring more than 9×10^(6)km,the response of optimized frames to the static and the dynamic loads are comprehensively investigated.It is highlighted that the maximum residual stress of the optimized welded frame is reduced to 69 MPa from 477 MPa of previous existing one.Based on the measured stress and acceleration from the railways,the fatigue life of modified frame under various loading modes could fulfil the requirements of the lifecycle man-agement.Moreover,our recent developed intelligent quality control strategy of welding process mediated by machine learning is also introduced,envisioning its application in the intelligent weld-ing.
基金The National Natural Science Foundation of China under contract Nos 41372173,41476074 and 41806109the China Geological Survey Project under contract Nos DD20189506 and DD20211301.
文摘Using 110 newly revised Holocene sea level indicators categorized into three types,sediments(67),shelly cheniers(27)and oyster reefs(16),this paper firstly provides a Holocene relative sea level curve,based on multiple approaches of litho-and biostratigraphies and sedimentary faces analysis,for the west coast of Bohai Bay,China.Following considerations,including indicative meaning,the paleo tidal pattern and range and conversion from mean tidal level to mean sea level,an apparent relative mean sea level(RMSL)curve was further reconstructed.After systematical calibration using CALIB,those of the 48 reworked samples were further corrected for the residence-time effect.Similarly,the younger ages for another 35 samples were chosen at the subsample level.These result in a younger-oriented shift for about 0.5 ka.Three local spatial factors,including neotectonic subsidence(average rate about 0.1 mm/a),self-compaction of unconsolidated sediments(between a few decimeters to about 6 m)and subsidence due to groundwater withdrawal(between a few centimeters to about 2.5 m),were quantitatively corrected.Finally,the amended RMSL curve after eliminating all these local temporo-spatial factors is very likely to show non-existence of mid-Holocene highstand and imply potential influences of both ice-volume equivalent sea level and regional glacial isostatic adjustment.Although it is still unable to divide both global and regional factors,the slowdown of sea level rise,in 7.5–6.8 ka with a maximum height less than+1 m,may constrain the model effort in the near future.
基金Youth Scientific Research Foundation of General Logistics Department of Chinese PLA,No.01Q033
文摘BACKGROUND: Several studies have demonstrated that sustained cognitive tasks can induce cognitive fatigue and that the mean cerebral blood flow velocity changes in some cerebral regions during cerebral fatigue. OBJECTIVE: To dynamically monitor the changes in mean cerebral blood flow velocity in different brain regions of high performance fighter pilots during mental arithmetic tasks and consecutive performance tasks. DESIGN, TIME AND SETTING: The present neurophysiological trial, based on controlled observation, was performed at the Laboratory of Neurophysiology, Institute of Aviation Medicine, Air Force of China between January 2003 and December 2005. PARTICIPANTS: Forty-five males, high performance fighter pilots, averaging (27.6±2.5) years, were recruited for this study. METHODS: The mean cerebral blood flow velocity in the anterior cerebral artery, middle cerebral artery, and posterior cerebral artery of subjects was dynamically tested using transcranial Doppler during 5- hour mental arithmetic tasks and during 5- hour consecutive performance tasks. The neurobehavioral ability index was analyzed throughout each trial according to the number of correct responses, false responses, and lost responses. Simultaneously, cerebral cognitive fatigue-induced lethargy was assessed by the Stanford Sleepiness Scale. MAIN OUTCOME MEASURES: Changes in mean cerebral blood flow velocity in the anterior cerebral artery, middle cerebral artery, and posterior cerebral artery; neurobehavioral ability index of mental arithmetic and consecutive performance tasks; Stanford Sleepiness Scale scores. RESULTS: During mental arithmetic tasks, the mean cerebral blood flow velocity in the anterior cerebral artery increased during hour 2 and decreased after hour 4. There was no significant change in mean cerebral blood flow velocity in the middle cerebral artery and posterior cerebral artery. During hour 4, cerebral cognitive fatigue was observed and, simultaneously, Stanford Sleepiness Scale scores demonstrated the presence of fatigue. During such a stage, the neurobehavioral ability index decreased, indicating a decline in performance ability. During consecutive performance tasks, the mean cerebral blood flow velocity declined earlier in the posterior cerebral artery compared to the middle cerebral artery. CONCLUSION: Five- hour mental arithmetic tasks have few effects on cerebral functions and do not lead to a significant change in mean cerebral blood flow velocity. Five-hour consecutive performance tasks can induce cerebral cognitive fatigue, and a marked decline in mean cerebral blood flow velocity.
基金the National Natural Science Foundation of China(No.31670216,No.31900194)the Foundation of the State Key Laboratory of Palaeobiology and Stratigraphy,Nanjing Institute of Geology and Palaeontology,Chinese Academy of Sciences(No.183112)。
文摘East Asia has long been recognized as a major center for temperate woody plants diversity.Although several theories have been proposed to explain how the diversity of these temperate elements accumulated in the region,the specific process remains unclear.Here we describe six species of Carpinus,a typical northern hemisphere temperate woody plant,from the early Miocene of the Maguan Basin,southwestern China,southern East Asia.This constitutes the southernmost,and the earliest occurrence that shows a high species diversity of the genus.Together with other Carpinus fossil records from East Asia,we show that the genus had achieved a high diversity in East Asia at least by the middle Miocene.Of the six species here described,three have become extinct,indicating that the genus has experienced apparent species loss during its evolutionary history in East Asia.In contrast,the remaining three species closely resemble extant species,raising the possibility that these species may have persisted in East Asia at least since the early Miocene.These findings indicate that the accumulation of species diversity of Carpinus in East Asia is a complex process involving extinction,persistence,and possible subsequent speciation.
文摘Tonle Sap Lake is the largest river-connected lake, buffer area and ecological zone of Mekong River, which plays a huge role in dispelling flood peak and compensating water, and the conservation of biological diversity. The river-lake relationship between Mekong River and Tonle Sap Lake is unique and has always been a major focus in the international community. The land terrain and under-water topography were used to analyze the morphological characteristics of Cambodia Mekong Delta and Tonle Sap Lake. Long series of hydrological data of river-lake controlling stations were used to analyze the water level variation characteristics and water volume exchange pattern between Mekong River and Tonle Sap Lake, and the response relationship to river-lake morphological characteristics were also researched. The results show that: Cambodia Mekong Delta and Tonle Sap Lake Area is low-lying and flat with gentle channel gradient and water surface gradient, making the relationship between water level and area (or volume) smooth. The channel storage capacity of Mekong River and Tonle Sap River is not enough compared to the inflow, so vast flooding plain is extremely prone to be inundated, making the flood relationships between the left and right banks become very complicated. Tonle Sap Lake is a seasonal freshwater lake with water flowing in and flowing out, and the timing and intensity of water exchange with Mekong River are closely related to the water flow resistance at the exit section of Tonle Sap Lake and the cross-sectional area of Tonle Sap River, which can be reflected by the river-lake water level difference and the water level of Tonle Sap River. Affected by the river-lake morphological characteristics, the water exchange intensity between Mekong River and Tonle Sap Lake is great. Tonle Sap Lake not only stores 14.4% of flood volume (39.7 billion m3) from the Mekong River every year, but also supplies 29.7% of dry water (69.4 billion m3) to the Mekong River. Influenced by the adjustment of the floodplain, the water level fluctuation of Mekong River and Tonle Sap Lake is slow, and the rising and droop rates of water level are positively correlated with the floodplain storage area. The research results will help to understand the relationship mechanism between Mekong River and Tonle Sap Lake and provide a scientific basis for the comprehensive governance of Cambodia Mekong Delta and Tonle Sap Lake Area.
基金supported by NSFC(21376261,21173270,21177160)Beijing Natural Science Foundation(2142027)+1 种基金863 Program of China(2013AA065302)the Doctor Select Foundation(20130007110007)
文摘SBA-15 supported Mo catalysts (Moy/SBA-15) were prepared by an ultrasonic assisted incipient-wetness impregnation method. The physical and chemical properties of the catalysts were characterized by means of N2-adsorption-desorption, XRD, TEM, UV-Vis, Raman, XANES and H2-TPR. The results showed that a trace amount of MoO3 was produced on high Mo content samples. Tum-over frequency (TOF) and product selectivity are dependent on the molybdenum content. Both Mo0.75/SBA-15 and Mo1.75/SBA-15 catalysts give the higher catalytic activity and the selectivity to the total aldehydes for the selective oxidation of C2H6. At the reaction temperature of 625℃, the maximum yield of aldehydes reached 4.2% over Mo0.75/SBA-15 catalyst. The improvement of the activity and selectivity was related with the state of MoOx species.
基金Supported by Special Public Welfare Industry Project of Ministry of Agriculture(nyhyzx07-019)Special Project for the Construction of Modern Agricultural Industrial Technology System of Ministry of AgricultureGuangdong Science and Technology Research Project(2011B020415007)
文摘Six sugarcane plant lines were selected from seedlings owing to good performance in agronomic characters under drought conditions.A special test with drought stress to death under groove was carried out to select the best drought tolerant clones among them. The proportion of bound water to free water content in leaves,cell cytoplasm membrane permeability in leaves,yield components,etc.,which were regarded as reasonable indexes to identify drought resistance of sugarcane,were measured. The results showed that both YT06-868 and YT05-339 were winners. The two were high-class drought-resistant clones. On some measured indexes,both of them had higher values than ROC22( the main check variety) and on the other ones,they both had the same values as ROC22. The drought resistance of YT05-291 was moderate and between ROC22 and ROC16( the secondary check variety),while the others had poor drought-resistant according to these indexes.
基金This study was partly supported by Natural Scientific Research Project(H2018048)of Heilongjiang province Science and Technology Department,and it was partly supported by the China Scholarship Council.
文摘The present study reports a rare primitive neuroectodermal tumor (PNET) of prostate.A 27-year-old male was admitted to Harbin Medical University Cancer Hospital (Harbin,China) for dysuria and dyschezia. Magnetic resonance imaging (MRI) revealed a large mass thatmay involve the bladder and rectum next to the prostate. Histopathological analysis of biopsyof prostate indicated mesenchymal origin tumor, and immunohistochemistric stainingconfirmed diagnosis of PNET of prostate. En bloc total pelvic exenteration and double barrelsigmoidostomy were performed. Double stomas in the skin incision were used for fecal andurinary diversion, respectively. Short-term outcome is satisfactory, while long-term efficacyremains to be poor. Clinical features of PNET of prostate should be paid much more attentionand radical surgery and adjuvant chemotherapy should be recommended.
基金Supported by Graduate Science and Technology Innovation Project of Inner Mongolia Autonomous Region(S2016013604)National Natural Science Foundation of China(31260336)
文摘HKT transport protein is an ion transporter thai exists on plasmalemma and a ubiquitous transmembrane protein responsible for Na + transport and K+ - Na + symport. HKT transport protein is regulated by the expression of ItKT family genes. The overexpression of HKT family genes can improve activity of Na+ transport and K+ - Na+ s.vmport proteins in plants, lead to Na + recycle, reduce Na + concentration in vivo, maintain K +/Na+ ratio, and ensure normal physiological functions of eells, thereby improving salt toleranee of plants. This paper introduced the discovery and claning of HKT family genes, revealed interactions between HKT family genes and SOS, NHX genes, and summarized the relationship between the structure, function of HKT protein and salt tolerance of plants to clarify the function and mechanism of action of HKT transport protein, aiming at laying the foundation for genetic engineering of plants for salt tolerauee and providing basis for breeding haloduric transgenie plant.
文摘Background: Most of the reports on tumor relapse are recurrence of the same type of tumor after months to few years of a successful initial cancer treatment. It is generally unusual and unexpected that a different type of the second tumor occurs after several decades of the curative treatment of the original tumor. Case Presentation: We report a case of 74-year-old man with intrahepatic cholangiocarcinoma (ICC) diagnosed 38 years after curative resection of hepatocellular carcinoma (HCC). In addition to the uniqueness of longer survival and developed a new type of tumor, both the original HCC and the later occurred ICC were detected through a cancer surveillance program by screening alpha-fetoprotein (AFP) and ultrasonography of the liver for the general population and/or high risk group of people who were asymptomatic. Conclusion: This report provides evidence demonstrating occurrence of new type of tumor following initial curative therapy of the original tumor. In addition, this case report also highlights the importance of cancer surveillance program for earlier detection of the tumors to achieve a remarkably improved prognosis of the cancer patients for a prolonged cancer free survival time.
基金This work is supported by National Key R&D Program of China(Grant No.2020YFA0711500)the National Natural Science Fund of China(51973095&52011540401).
文摘With practical interest in the future applications of next-generation electronic devices,it is imperative to develop new conductive interconnecting materials appropriate for modern electronic devices to replace traditional rigid solder tin and silver paste of high melting temperature or corrosive solvent requirements.Herein,we design highly stretchable shape memory self-soldering conductive(SMSC)tape with reversible adhesion switched by temperature,which is composed of silver particles encapsulated by shape memory polymer.SMSC tape has perfect shape and conductivity memory property and anti-fatigue ability even under the strain of 90%.It also exhibits an initial conductivity of 2772 S cm^(−1) and a maximum tensile strain of~100%.The maximum conductivity could be increased to 5446 S cm^(−1) by decreasing the strain to 17%.Meanwhile,SMSC tape can easily realize a heating induced reversible strong-to-weak adhe-sion transition for self-soldering circuit.The combination of stable conductivity,excellent shape memory performance,and temperature-switching reversible adhesion enables SMSC tape to serve two functions of electrode and solder simultaneously.This provides a new way for conductive interconnecting materials to meet requirements of modern electronic devices in the future.
基金Supported by Modern Agricultural Industry Technology System (CARS-2004B)
文摘[Objective] This study aimed to establish an effective detection technology for rapidly identifying Bt transgenic sugarcane, promptly removing non-Bt transgenic plants and increasing breeding efficiency of Bt transgenic plants, thereby improving breeding efficiency of insect-resistant sugarcane cultivars in China. [ Method] Approximately 1 mg of root tips and other materials were crushed, placed in the bottom of PCR tubes, added successively with solution I and mineral oil, headed at 95 ℃ for 15 rain, added with solution Ⅱ, and finally added with solution III containing GBt primer for PCR. After separated by using electrophoresis on agarese gel, amplification products were observed and photographed under a gel imaging system. [ Result] Various materials treated with different concentrations of solution led to different amplification results. Specifically, the appropriate concentration of NaOH in solution I was 0.1 -0.2 mol/L; the appropriate pH value of solution II was 2. No bands were amplified from mature leaves, tender leaves and old roots of Bt transgenic sugarcane, while root tips successfully amplified 545 bp target bands. The established method was used to identify and analyze 63 hybrid seedlings of YT 91 -976 × SBR216, results showed that a total of 17 samples exhibited 545 bp bands, accounting for approximately 27% of the total number of hybrid seedlings, indicating that these 17 seedlings were Bt transgenic sugarcane plants. [ Conclusion] The rapid detection method established in this study is conducive to identifying Bt transgenic sugarcane and improving breeding efficiency of insect-resistant sugarcane lines, which provides basis for screening of other transgenic materials.
基金Supported by Science and Technology Planning Project of Guangdong Province(2008 B020200002)Modern Agricultural Industrial Technology System(CARS-20-1-4)
文摘[ Objective] A large number of high-quality Bt transgenic sugarcane lines were obtained using transgenic technologies. This study aimed to explore the genetic background, genetic diversity, important traits and relationship between the heredity and phenotype of these transgenic sugarcane lines, thereby providing basis for further effective utilization and preservation of insect-resistant germplasm resources and improving breeding efficiency of insect-resistant sugarcane in China. [Method] By using six AFLP primers with high polymorphism, the genetic diversity of 13 Bt transgenic sugarcane lines and their donor varieties was analyzed. Growth assay and insect-resistance identification were carried out in a quarantine greenhouse with conventional methods. Evaluation of important economic traits was conducted in the field with conventional methods. [ Result] The polymorphism rate was relatively low. Specifically, the polymorphism rate of the first group was 21.00%, the polymorphism rate of the second group was 31.80%, and the total polymorphism rate was 42.50%. Cluster analysis showed that 13 Bt transgenic sugarcane lines and their donor varieties were divided into two categories, the genetic similarity coefficient between two categories was 0.54. All the six materials in the first group were clustered into category Ⅰ, with genetic similarity of 0. 921 ; nine materials in the second group were clustered into category Ⅱ, with genetic similarity of 0. 898. Bt transgenic sugarcane lines showed abundant phenotypic types and significant trait variations, and the economic traits were generally worse than donor varieties. The insect resistance of 13 Bt transgenic sugarcane lines was divided into five grades. [ Conclusion] The first-generation Bt transgenic sugarcane lines have low genetic diversity, abundant trait variations, high insect resistance and generally poor economic traits, which can only be used as germplasm resources for hybridization. Introducing Bt gene into multiple donors will to some extent improve the genetic diversity of sugarcane germplasm resources, but the increasing rate is relatively low. It is preliminarily considered that the genetic diversity of insect-resistant sugarcane germplasm resources should be improved by continuous hybridization and backcrossing of Bt transgenic lines with high-quality parents, thus laying foundation for breeding high-quality insect-resistant sugarcane varieties.
基金“Double first-class”construction project of Mongolian medicine scientific research and innovation team fund(190301)International cooperative scientific and technological innovation project of Mongolian medicine standardization research(MDK2018009)+1 种基金2018 National Civil Affairs Commission-Ministry of Education Mongolian Medicine R&D Engineering Key Laboratory Open Project(MDK2018056)Mongolian Medicine R&D National and Local Joint Engineering Research Center Open Fund Project(MDK2019044).
文摘Functional dyspepsia(FD)is a regularly diagnosed clinical gastrointestinal ailment with a high incidence rate that can considerably impact patients’health and quality of life and impose a substantial financial burden.Modern research on the pathophysiology of functional dyspepsia has not thoroughly explained the underlying reasons.The condition does not manifest any significant organ abnormalities,which raises the disease’s difficulty coefficient.Major pathogenic exceptions in FD include gastrointestinal motor dysfunction,gastrointestinal hormone secretion problem,visceral hypersensitivity,and brain-gut axis.Several ion channels have reportedly been implicated in the pathophysiological process of FD.Therefore,it is crucial to comprehend the probable activities of various ion channels in FD.This study focuses on the current state of research on the possible role of several ion channels in the pathogenesis of FD.
基金supported by the National Natural Science Foundation of China(32125026,31988102)the National Key Research Development Program of China(2022YFF0802300)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB31000000)。
文摘The Convention on Biological Diversity seeks to conserve at least 30%of global land and water areas by 2030,which is a challenge but also an opportunity to better preserve biodiversity,including flowering plants(angiosperms).Herein,we compiled a large database on distributions of over 300,000 angiosperm species and the key functional traits of 67,024 species.Using this database,we constructed biodiversity-environment models to predict global patterns of taxonomic,phylogenetic,and functional diversity in terrestrial angiosperms and provide a comprehensive mapping of the three diversity facets.We further evaluated the current protection status of the biodiversity centers of these diversity facets.Our results showed that geographical patterns of the three facets of plant diversity exhibited substantial spatial mismatches and nonoverlapping conservation priorities.Idiosyncratic centers of functional diversity,particularly of herbaceous species,were primarily distributed in temperate regions and under weaker protection compared with other biodiversity centers of taxonomic and phylogenetic facets.Our global assessment of multifaceted biodiversity patterns and centers highlights the insufficiency and unbalanced conservation among the three diversity facets and the two growth forms(woody vs.herbaceous),thus providing directions for guiding the future conservation of global plant diversity.
基金supported by the National Natural Science Foundation of China(92256202,12261131500,22305129,22371131,52103218)the Fundamental Research Funds for the Central Universities,Nankai University(023-63223021)+3 种基金Tianjin Key Lab for Rare Earth Materials and Applications(ZB19500202)the Outstanding Youth Project of Tianjin Natural Science Foundation(20JCJQJC00130)China Postdoctoral Science Foundation(BX20220157,2022M721698)the 111 Project(B12015,B18030)。
文摘Chiral organic-inorganic hybrid metal halides(OIHMHs)have attracted broader scientific community recently in spin lightemitting diodes,and circularly polarized light-emitting diodes.However,the emission peaks of the reported chiral OIHMHs mainly locate in the visible region,and chiral OIHMH with ultraviolet(UV)circularly polarized luminescence(CPL)has been rarely reported.To fill this gap,cerium,a unique rare-earth(RE)element with tunable luminescence from UV to the visible region owing to the 4 f-related electronic transition,was introduced to construct the first RE-based chiral OIHMHs,R/S-MCC.The chirality is successfully transferred from the chiral organic cations to the inorganic cerium chloride framework in R/S-MCC,as confirmed by the single crystal structures,circular dichroism,and CPL.The emission spectra of R/S-MCC are in the UV region,originating from the characteristic d-f transition of Ce^(3+),which making the Ce-based metal halides are ideal candidates towards CPL light sources in the UV region.Notably,R-and S-MCC are the first RE-based OIHMHs,also the first chiral metalhalides with UV CPL.Our work opens a new avenue for the development of the chiral OIHMH family towards RE-based chiral OIHMH.The RE-based chiral metal halides couple the unique and superior optical,electrical,magnetic,and spintronic properties of RE elements with chirality could accelerate the development of chiral optoelectronics and spintronics toward real applications.
基金supported by the Ministry of Science and Technology of China (National Key R&D Program of China,2022YFB4200400, 2019YFA0705900)the National Natural Science Foundation of China (21935007, 52025033, 22204119),Tianjin City(22JCQNJC00530)Haihe Laboratory of Sustainable Chemical Transformations。
文摘Dimerized small-molecule acceptors(SMAs) built by the conventional connection of terminal groups of monomers have contributed to exciting long-term stabilities of organic solar cells(OSCs). However, device efficiencies, especially fill factors(FFs), still need to be improved. This probably originates from unsymmetrical molecular structure/conformation-determined less compact/ordered molecular stackings, such as ineffective stackings of constraint terminals. Herein, an exotic dimerized SMA of BC-Th is established by bridging the branched groups(BC-type, branch coupling) of two monomers rather than conventional terminal units(TC-type, terminal coupling). Benefiting from the three-dimensional conformation and more uncurbed terminals,BC-Th exhibits multiple molecular orientations along with a larger dielectric constant and electron mobility compared with TCTh. Finally, an efficiency of 17.43% is achieved by BC-Th-based OSCs, along with the highest FF of 79.13% among all dimerized SMAs-based OSCs to date. When introducing L8-BO as the third component, overall enhanced efficiency of 18.05%and FF of 80.11% are further afforded. Contrarily, TC-Th-based OSCs exhibit much inferior PCE of 16.29% and FF of 74.81%,demonstrating the great advantages of “branch coupling” over “terminal coupling” when building dimerized SMAs.
基金supported by the Ministry of Science and Technology of China (2022YFB4200400, 2019YFA0705900,2023YFE0210400)the National Natural Science Foundation of China(21935007, 52025033, 52303237, 22361132530)。
文摘Inspired by the success of CH-series acceptors, a small-molecular acceptor, CH-Tz was reported by adopting a new conjugationextended electron-deficient unit([1,2,5]thiadiazolo[3,4-b]pyrazine) on the central core. Owing to the enhanced inter-/intramolecular interactions, CH-Tz exhibited near-infrared absorption and an effective three-dimensional molecular packing network in its single crystal. When blended with polymer donor PM6, the binary device achieved a high power conversion efficiency(PCE) of 18.54%, with a notable short-circuit current density(J_(sc)) of 27.54 m A cm-2and an excellent fill factor(FF) over 80%,which can be partly ascribed to the balanced charge transport properties in the blend film. After employing D18-Cl as the third component, an enhanced PCE of 18.85% was achieved due to a more obvious fiber network. Impressively, the CH-Tz-based OSC devices show excellent thermal stability and thickness insensitivity. Record-breaking Jscof 28.92 m A cm-2was reached for PM6:D18-Cl:CH-Tz ternary device with a thickness of 560 nm. Besides, CH-Tz shows potential in fabricating multicomponent high-performance organic solar cells, where over 19% efficiency could be realized in the quaternary device. Our work advances the strong influence of electron-deficient central units on molecular photovoltaic properties and guides the design of acceptors for stable and large-thickness organic solar cells.