After discussing the principle of dual energy substraction,this paper dealswith the matching problem in dual energy substraction in detail.In order to obtain bettermatching feature of images,the probability enhancemen...After discussing the principle of dual energy substraction,this paper dealswith the matching problem in dual energy substraction in detail.In order to obtain bettermatching feature of images,the probability enhancement is used to process the originalimages.Several matching methods are presented,among these methods,the segment chos-en matching is specially useful for applications.Several experimental results are presented.展开更多
For the determination of molybdenum in molybdenum concentrate,lead molybdate gravimetric method was considered as standard method.In order to ensure the lead ions to be washed thoroughly from the entrained precipitate...For the determination of molybdenum in molybdenum concentrate,lead molybdate gravimetric method was considered as standard method.In order to ensure the lead ions to be washed thoroughly from the entrained precipitate,lead molybdate precipitate was washed,filtered repeatedly,then ashed and burned.This method cannot satisfy the rapid measurement demand of mineral processing and metallurgy scientific research due to its time consuming.In the present work,molybdenum was determined by atomic absorption spectrometry indirectly and a rapid analysis method for molybdenum in molybdenum concentrate was proposed.The sample was dissolved by nitric acid,potassium chlorate and sulfuric acid,pH was adjusted by acetic acid and ammonium acetate buffer solution to pH 5~7,then a certain amount and excess of lead standard was added.Based on lead molybdate was considered as undissolved electrolyte on room temperature,the solubility of lead molybdate was 1.16×10^(-5)g,far less than 0.01 g,was considered as the undissolved electrolyte,the electrolyte insoluble at a certain temperature can complete precipitation,usually compared with the solubility production product Q_(c)and_the relative size of constant X_(sp),when Q_(c)K_(sp),solution was supersaturated,precipitation was precipitate completely,the content of molybdenum in molybdenum concentrate was 40%~60%,the amount of lead was 0.1250~0.1500 g,took the minimum calculated solution lead molybdate ion product,Q_(c)=[Pb^(2+)][MoO_(4)^(2-)]=2.51×10^(-5),K_(sp)=1.0×10^(-13),Q_(c)K_(sp).Therefore lead molybdate precipitate can be precipitated completely,after dry filtered,the excess of lead ions were determined by atomic absorption spectrometry,the content of molybdenum was calculated by subtraction method.In this paper,the amount of acetic acid-ammonium acetate buffer solution,the amount of lead standard,time of lead molybdate precipitation,heating time and maximum amount of coexisting ions such as W^(6+),Sn^(4+),Cu^(2+),etc were investigated.Compared with lead molybdate gravimetric method,repeatedly washing,ashing and burning with lead molybdate were eliminated by proposed method,which was simple,easy to master and was able to cut the analysis time in half.The control experiments were conducted by lead molybdate gravimetric method and proposed method.After the results were implemented by mathematical statistics,it can be concluded that it had good accuracy and precision for the proposed method,which can be applied to rapid analysis of molybdenum in molybdenum concentrate for mineral processing and metallurgy.展开更多
Acute ischemic stroke has the characteristics of high disability,lethality and recurrence rate,which seriously threatens the health of middle-aged and elderly people.This article describes the acute ischemic stroke wi...Acute ischemic stroke has the characteristics of high disability,lethality and recurrence rate,which seriously threatens the health of middle-aged and elderly people.This article describes the acute ischemic stroke with internal carotid artery occlusion as the main clinical feature and discusses its treatment strategy.Treatment remedies:clinical diagnosis was carried out based on the present medical history,physical examination and craniocerebral CT(computed tomography).Neurological function was improved by intravenous thrombolysis,cerebrovascular angiography was used to clarify cerebrovascular occlusion,cerebral blood supply was identified by CT perfusion,and neurological function recovery was followed up.After intravenous thrombolysis,the patient’s consciousness turned clear and the right limb muscle strength recovery was not obvious,but the patient did not receive bridging therapy.Cerebral angiography showed about 90%stenosis at the beginning of the left internal carotid artery,and the blood flow terminated at the C7 segment.Cerebral CT perfusion imaging showed decreased perfusion in the left cerebral hemisphere,but the patient did not receive carotid endarterectomy and vascular bypass treatment.Post treatment evaluating:follow-up showed that NIHSS(National Institute of Health stroke scale)score was significantly decreased and limb function was significantly restored.Conclusion:early intravenous thrombolytic therapy can help reduce the area of ischemic penumbra and improve long-term prognosis.Severe vascular stenosis can stimulate vascular compensation,significantly reduce the range of ischemia when thrombus occurs,and effectively reduce the disability rate without bridging therapy.Whether vascular stenosis and occlusion are treated by vascular bypass,etc.,individualized plans should be made according to vascular compensation.展开更多
Moving object detection including background subtraction and morphological processing is a critical research topic for video surveillance because of its high computational loading and power consumption. This paper pro...Moving object detection including background subtraction and morphological processing is a critical research topic for video surveillance because of its high computational loading and power consumption. This paper proposes a hardware design to accelerate the computation of background subtraction with low power consumption. A real-time background subtraction method is designed with a frame-buffer scheme and function partition to improve throughput, and implemented using Verilog HDL on FPGA. The design parallelizes the computations of background update and subtraction with a seven-stage pipeline. A stripe-based morphological processing and accounting for the completion of detected objects is devised. Simulation results for videos of VGA resolutions on a low-end FPGA device show 368 fps throughput for only the real-time background subtraction module, and 51 fps for the whole system, including off-chip memory access. Real-time efficiency with low power consumption and low resource utilization is thus demonstrated.展开更多
Effects of bifunctional chain extender on the crystallinity and the thermal stability of PET were studied in this work. Results of Infrared substractive spectrum indicated that one oxazoline ring of 2,2’-bis(2-oxazol...Effects of bifunctional chain extender on the crystallinity and the thermal stability of PET were studied in this work. Results of Infrared substractive spectrum indicated that one oxazoline ring of 2,2’-bis(2-oxazoline) (BOZ) reacted with one carboxyl in PET to generate a blocked PET chain with an oxazoline ring, which then reacted with one carboxyl in second PET to form an extended chain. The intrinsic viscosity (IV) of extended PET would increase from 0.61 of initial PET to 0.80 when the addition of BOZ was 0.52 wt%. Furthermore, when BOZ was used with hydroxyl-addition-type chain extender 2,2’-(1,4-phenyl)bis(4H-3,1-benzoxazin-4-one) (BNZ) or chain end modifier phthalic anhydride (PA), IV of chain extended PET would be 0.83 and 0.97 respectively. DSC results showed that chain extending would result in a decrease in crystallinity of PET. Comparing with initial PET, the intrinsic viscosity loss of the chain extended products would be smaller after multi-melting processing.展开更多
文摘After discussing the principle of dual energy substraction,this paper dealswith the matching problem in dual energy substraction in detail.In order to obtain bettermatching feature of images,the probability enhancement is used to process the originalimages.Several matching methods are presented,among these methods,the segment chos-en matching is specially useful for applications.Several experimental results are presented.
基金the National Science and Technology Support Program(2012BAB10B08)
文摘For the determination of molybdenum in molybdenum concentrate,lead molybdate gravimetric method was considered as standard method.In order to ensure the lead ions to be washed thoroughly from the entrained precipitate,lead molybdate precipitate was washed,filtered repeatedly,then ashed and burned.This method cannot satisfy the rapid measurement demand of mineral processing and metallurgy scientific research due to its time consuming.In the present work,molybdenum was determined by atomic absorption spectrometry indirectly and a rapid analysis method for molybdenum in molybdenum concentrate was proposed.The sample was dissolved by nitric acid,potassium chlorate and sulfuric acid,pH was adjusted by acetic acid and ammonium acetate buffer solution to pH 5~7,then a certain amount and excess of lead standard was added.Based on lead molybdate was considered as undissolved electrolyte on room temperature,the solubility of lead molybdate was 1.16×10^(-5)g,far less than 0.01 g,was considered as the undissolved electrolyte,the electrolyte insoluble at a certain temperature can complete precipitation,usually compared with the solubility production product Q_(c)and_the relative size of constant X_(sp),when Q_(c)K_(sp),solution was supersaturated,precipitation was precipitate completely,the content of molybdenum in molybdenum concentrate was 40%~60%,the amount of lead was 0.1250~0.1500 g,took the minimum calculated solution lead molybdate ion product,Q_(c)=[Pb^(2+)][MoO_(4)^(2-)]=2.51×10^(-5),K_(sp)=1.0×10^(-13),Q_(c)K_(sp).Therefore lead molybdate precipitate can be precipitated completely,after dry filtered,the excess of lead ions were determined by atomic absorption spectrometry,the content of molybdenum was calculated by subtraction method.In this paper,the amount of acetic acid-ammonium acetate buffer solution,the amount of lead standard,time of lead molybdate precipitation,heating time and maximum amount of coexisting ions such as W^(6+),Sn^(4+),Cu^(2+),etc were investigated.Compared with lead molybdate gravimetric method,repeatedly washing,ashing and burning with lead molybdate were eliminated by proposed method,which was simple,easy to master and was able to cut the analysis time in half.The control experiments were conducted by lead molybdate gravimetric method and proposed method.After the results were implemented by mathematical statistics,it can be concluded that it had good accuracy and precision for the proposed method,which can be applied to rapid analysis of molybdenum in molybdenum concentrate for mineral processing and metallurgy.
文摘Acute ischemic stroke has the characteristics of high disability,lethality and recurrence rate,which seriously threatens the health of middle-aged and elderly people.This article describes the acute ischemic stroke with internal carotid artery occlusion as the main clinical feature and discusses its treatment strategy.Treatment remedies:clinical diagnosis was carried out based on the present medical history,physical examination and craniocerebral CT(computed tomography).Neurological function was improved by intravenous thrombolysis,cerebrovascular angiography was used to clarify cerebrovascular occlusion,cerebral blood supply was identified by CT perfusion,and neurological function recovery was followed up.After intravenous thrombolysis,the patient’s consciousness turned clear and the right limb muscle strength recovery was not obvious,but the patient did not receive bridging therapy.Cerebral angiography showed about 90%stenosis at the beginning of the left internal carotid artery,and the blood flow terminated at the C7 segment.Cerebral CT perfusion imaging showed decreased perfusion in the left cerebral hemisphere,but the patient did not receive carotid endarterectomy and vascular bypass treatment.Post treatment evaluating:follow-up showed that NIHSS(National Institute of Health stroke scale)score was significantly decreased and limb function was significantly restored.Conclusion:early intravenous thrombolytic therapy can help reduce the area of ischemic penumbra and improve long-term prognosis.Severe vascular stenosis can stimulate vascular compensation,significantly reduce the range of ischemia when thrombus occurs,and effectively reduce the disability rate without bridging therapy.Whether vascular stenosis and occlusion are treated by vascular bypass,etc.,individualized plans should be made according to vascular compensation.
文摘Moving object detection including background subtraction and morphological processing is a critical research topic for video surveillance because of its high computational loading and power consumption. This paper proposes a hardware design to accelerate the computation of background subtraction with low power consumption. A real-time background subtraction method is designed with a frame-buffer scheme and function partition to improve throughput, and implemented using Verilog HDL on FPGA. The design parallelizes the computations of background update and subtraction with a seven-stage pipeline. A stripe-based morphological processing and accounting for the completion of detected objects is devised. Simulation results for videos of VGA resolutions on a low-end FPGA device show 368 fps throughput for only the real-time background subtraction module, and 51 fps for the whole system, including off-chip memory access. Real-time efficiency with low power consumption and low resource utilization is thus demonstrated.
文摘Effects of bifunctional chain extender on the crystallinity and the thermal stability of PET were studied in this work. Results of Infrared substractive spectrum indicated that one oxazoline ring of 2,2’-bis(2-oxazoline) (BOZ) reacted with one carboxyl in PET to generate a blocked PET chain with an oxazoline ring, which then reacted with one carboxyl in second PET to form an extended chain. The intrinsic viscosity (IV) of extended PET would increase from 0.61 of initial PET to 0.80 when the addition of BOZ was 0.52 wt%. Furthermore, when BOZ was used with hydroxyl-addition-type chain extender 2,2’-(1,4-phenyl)bis(4H-3,1-benzoxazin-4-one) (BNZ) or chain end modifier phthalic anhydride (PA), IV of chain extended PET would be 0.83 and 0.97 respectively. DSC results showed that chain extending would result in a decrease in crystallinity of PET. Comparing with initial PET, the intrinsic viscosity loss of the chain extended products would be smaller after multi-melting processing.
