Transient electromagnetic method (TEM),as a non-seismic geophysical exploration mainstream electromagnetic method,is widely used in oil,gas,mineral and other underground resources exploration areas. The coil sensor is...Transient electromagnetic method (TEM),as a non-seismic geophysical exploration mainstream electromagnetic method,is widely used in oil,gas,mineral and other underground resources exploration areas. The coil sensor is generally used to collect data. In view of the problems of incomplete information of the abnormal body and the data loss in the existing TEM single-component coil sensor,a three-component TEM coil sensor is designed. By analyzing the relationship between sensor sensitivity and coil structure parameters,the coil structure and turns are designed. By analyzing the frequency response characteristics of the TEM magnetic field sensor,the signal distortion is reduced by using the under-damped matching mode. By analyzing the distribution of various noise sources of the magnetic sensor,the appropriate amplifier is selected to reduce the background noise. Finally,a three-component TEM induction magnetic field sensor is designed. The weight of the sensor is controlled at 3.2 kg and the working frequency is 10 mHz-10 kHz. The background noises of X and Y components probably keep in 1.5×10^-8 V/ Hz and sensitivities are 8.4 and 9.8 nT/s,respectively,the background noise of vertical component is 2.1× 10^-7 V/ Hz and sensitivity is 18.5 nT/s. Compared with the existing single-component TEM receiving magnetic field sensor,the designed sensor realizes the signal acquisition of three components. Without too much increase in volume and total weight,it improves the sensitivity of the sensor and reduces the background noise,thus the signal-to-noise ratio (SNR) of the signal is improved.展开更多
In order to resolve the problean of the unbalanced threephase and unstable voltage, intellectual economized technique on elec- tricity based on electromagnetic regulation and control is proposed in this paper. We choo...In order to resolve the problean of the unbalanced threephase and unstable voltage, intellectual economized technique on elec- tricity based on electromagnetic regulation and control is proposed in this paper. We choose the TMS320LF2407A as the control chip and stepper motor as the executing agency. The equipment controls the movable contact reaching to the assigned position on the magnetic coil quickly and accurately, and outputs the sine-wave voltage steadily along with the network voltage variation though the fuzzy Porportional Integral Derivative（PID） control algorithm of integral separation and incremental mode with setting dead area. The principle of work and the key technique on the electromagnetic regulation and control are introduced in detail in this paper. The experiment result gives a proof for all the algorithm mentioned in this paper.展开更多
Helical-coil is a common structure of heat exchanger unit in phase change heat accumulator and usually has the equal coil pitch between adjacent coils. Its thermal performances could be improved by improving the unifo...Helical-coil is a common structure of heat exchanger unit in phase change heat accumulator and usually has the equal coil pitch between adjacent coils. Its thermal performances could be improved by improving the uniformity of the phase change material （PCM） temperature distribution. Thus, a novel non-equidistant helical-coil structure was proposed in this study. Its coil pitch decreased along the flow direction of heat transfer fluid, which made the heat exchange area in unit volume increase to match the decreasing temperature difference between the heat transfer fluid and PCM. The structure was optimized using numerical simulation. An experimental system was developed and the experiment results indicated that the proposed non-equidistant helical-coil heat accumulator was more effective than equidistant helical-coil for latent heat storage. The uniformity of the temperaalre distribution was also confirmed by simulation results.展开更多
Jasmonate （JA） regulates various plant defense and developmental processes. The F-box protein CORONATINE INSENSITIVE 1 （COIl） perceives JA signals to mediate diverse plant responses including male fertility, root ...Jasmonate （JA） regulates various plant defense and developmental processes. The F-box protein CORONATINE INSENSITIVE 1 （COIl） perceives JA signals to mediate diverse plant responses including male fertility, root growth, antho- cyanin accumulation, and defense against abiotic and biotic stresses. In this study, we carried out genetic, physiological and biochemical analysis on a series of coil mutant alleles, and found that different amino acid mutations in COIl distinctively af- fect JA-regulated male fertility in Arabidopsis. All the JA responses are disrupted by the COIl mutations W467＂ in coil-l, Q343＂ （coil-6）, G369E （coil-4）, G98D （coil-5）, G155E （coil-7）, D452A （coil-9） and L490A （coil-10）, though the coil-5 mutant （COIlG98D） contains adequate COIl protein （~60% of wild-type）. Interestingly, the low basal level of COIlE543K in the coil-8 mutant （-10% of wild-type COIl level） is sufficient for maintaining male fertility （-50% of wild-type fertility）; the coil-2 mutant with low level of COIlLz45F （-10% of wild-type） is male sterile under normal growth condition （22℃） but male fertile （~80% of wild-type fertility） at low temperature （16℃）; however, both coil-2 and coil-8 are defective in the other JA responses （root growth, anthocyanin accumulation, and plant response to the pathogen Pst DC3000 infection）.展开更多
Checking whether a given formula is an invariant at a given program location(especially,inside a loop) can be quite nontrivial even for simple loop programs,given that it is in general an undecidable property.This is ...Checking whether a given formula is an invariant at a given program location(especially,inside a loop) can be quite nontrivial even for simple loop programs,given that it is in general an undecidable property.This is especially the case if the given formula is not an inductive loop invariant,as most automated techniques can only check or generate inductive loop invariants.In this paper,conditions are identified on simple loops and formulas when this check can be performed automatically.A general theorem is proved which gives a necessary and sufficient condition for a formula to be an invariant under certain restrictions on a loop.As a byproduct of this analysis,a new kind of loop invariant inside the loop body,called inside-loop invariant,is proposed.Such an invariant is more general than an inductive loop invariant typically used in the Floyd-Hoare axiomatic approach to program verification.The use of such invariants for program debugging is explored;it is shown that such invariants can be more useful than traditional inductive loop invariants especially when one is interested in checking extreme/side conditions such as underflow,accessing array/collection data structures outside the range,divide by zero,etc.展开更多
文摘Transient electromagnetic method (TEM),as a non-seismic geophysical exploration mainstream electromagnetic method,is widely used in oil,gas,mineral and other underground resources exploration areas. The coil sensor is generally used to collect data. In view of the problems of incomplete information of the abnormal body and the data loss in the existing TEM single-component coil sensor,a three-component TEM coil sensor is designed. By analyzing the relationship between sensor sensitivity and coil structure parameters,the coil structure and turns are designed. By analyzing the frequency response characteristics of the TEM magnetic field sensor,the signal distortion is reduced by using the under-damped matching mode. By analyzing the distribution of various noise sources of the magnetic sensor,the appropriate amplifier is selected to reduce the background noise. Finally,a three-component TEM induction magnetic field sensor is designed. The weight of the sensor is controlled at 3.2 kg and the working frequency is 10 mHz-10 kHz. The background noises of X and Y components probably keep in 1.5×10^-8 V/ Hz and sensitivities are 8.4 and 9.8 nT/s,respectively,the background noise of vertical component is 2.1× 10^-7 V/ Hz and sensitivity is 18.5 nT/s. Compared with the existing single-component TEM receiving magnetic field sensor,the designed sensor realizes the signal acquisition of three components. Without too much increase in volume and total weight,it improves the sensitivity of the sensor and reduces the background noise,thus the signal-to-noise ratio (SNR) of the signal is improved.
基金supported by Natural Science Foundation of Shandong Province(No.Z2007F08)
文摘In order to resolve the problean of the unbalanced threephase and unstable voltage, intellectual economized technique on elec- tricity based on electromagnetic regulation and control is proposed in this paper. We choose the TMS320LF2407A as the control chip and stepper motor as the executing agency. The equipment controls the movable contact reaching to the assigned position on the magnetic coil quickly and accurately, and outputs the sine-wave voltage steadily along with the network voltage variation though the fuzzy Porportional Integral Derivative（PID） control algorithm of integral separation and incremental mode with setting dead area. The principle of work and the key technique on the electromagnetic regulation and control are introduced in detail in this paper. The experiment result gives a proof for all the algorithm mentioned in this paper.
基金supported by the National Natural Science Foundation of China(Grant No.51576187)Fundamental Research Funds for the Central Universities(Grant No.WK2090130016)
文摘Helical-coil is a common structure of heat exchanger unit in phase change heat accumulator and usually has the equal coil pitch between adjacent coils. Its thermal performances could be improved by improving the uniformity of the phase change material （PCM） temperature distribution. Thus, a novel non-equidistant helical-coil structure was proposed in this study. Its coil pitch decreased along the flow direction of heat transfer fluid, which made the heat exchange area in unit volume increase to match the decreasing temperature difference between the heat transfer fluid and PCM. The structure was optimized using numerical simulation. An experimental system was developed and the experiment results indicated that the proposed non-equidistant helical-coil heat accumulator was more effective than equidistant helical-coil for latent heat storage. The uniformity of the temperaalre distribution was also confirmed by simulation results.
基金supported by the National Natural Science Foundation of China(31230008 and 91017012)Ministry of Agriculture of China(2013ZX08011-006)
文摘Jasmonate （JA） regulates various plant defense and developmental processes. The F-box protein CORONATINE INSENSITIVE 1 （COIl） perceives JA signals to mediate diverse plant responses including male fertility, root growth, antho- cyanin accumulation, and defense against abiotic and biotic stresses. In this study, we carried out genetic, physiological and biochemical analysis on a series of coil mutant alleles, and found that different amino acid mutations in COIl distinctively af- fect JA-regulated male fertility in Arabidopsis. All the JA responses are disrupted by the COIl mutations W467＂ in coil-l, Q343＂ （coil-6）, G369E （coil-4）, G98D （coil-5）, G155E （coil-7）, D452A （coil-9） and L490A （coil-10）, though the coil-5 mutant （COIlG98D） contains adequate COIl protein （~60% of wild-type）. Interestingly, the low basal level of COIlE543K in the coil-8 mutant （-10% of wild-type COIl level） is sufficient for maintaining male fertility （-50% of wild-type fertility）; the coil-2 mutant with low level of COIlLz45F （-10% of wild-type） is male sterile under normal growth condition （22℃） but male fertile （~80% of wild-type fertility） at low temperature （16℃）; however, both coil-2 and coil-8 are defective in the other JA responses （root growth, anthocyanin accumulation, and plant response to the pathogen Pst DC3000 infection）.
基金supported by NSFC-90718041NKBRPC-2005C B321902+1 种基金China Scholarship Council in Chinasupported by the National Science Foundation award CCF-0729097
文摘Checking whether a given formula is an invariant at a given program location(especially,inside a loop) can be quite nontrivial even for simple loop programs,given that it is in general an undecidable property.This is especially the case if the given formula is not an inductive loop invariant,as most automated techniques can only check or generate inductive loop invariants.In this paper,conditions are identified on simple loops and formulas when this check can be performed automatically.A general theorem is proved which gives a necessary and sufficient condition for a formula to be an invariant under certain restrictions on a loop.As a byproduct of this analysis,a new kind of loop invariant inside the loop body,called inside-loop invariant,is proposed.Such an invariant is more general than an inductive loop invariant typically used in the Floyd-Hoare axiomatic approach to program verification.The use of such invariants for program debugging is explored;it is shown that such invariants can be more useful than traditional inductive loop invariants especially when one is interested in checking extreme/side conditions such as underflow,accessing array/collection data structures outside the range,divide by zero,etc.
