Simultaneous dimming controlling and data transmission are usually required in a white LED based indoor visible light communication system.However,the diming controlling of LED normally interferes the data transmissio...Simultaneous dimming controlling and data transmission are usually required in a white LED based indoor visible light communication system.However,the diming controlling of LED normally interferes the data transmission due to the modulation nonlinearity of LED.In order to solve this problem,a scheme by separating the LEDs for the functions of dimming control and data transmission respectively is proposed in this paper.In the scheme,the LEDs used for dimming control function are driven by a dc amplified circuit,and the LEDs for data transmission are driven by a digital modulation circuit respectively.In this way,the modulation distortion to the data signal caused by the modulation nonlinearity can be avoided even if the dimming is at high level dc driven current.The proof-of-concept experiment of a 2.5Mbit/s visible light communication system demonstrates that the dimming controlling and data transmission can be realized simultaneously in a simple way,and the data transmission is not affected by the dimming controlling function.Compared to previous methods,the scheme in this paper is simpler and cost effective,and makes sense when high rate data is transmitted in a visible light communication system.展开更多
There <span style="font-family:Verdana;">are</span><span style="font-family:Verdana;"> a limited number of soil-applied herbicides available for broad-spectrum</span><spa...There <span style="font-family:Verdana;">are</span><span style="font-family:Verdana;"> a limited number of soil-applied herbicides available for broad-spectrum</span><span style="font-family:;" "=""><span style="font-family:Verdana;"> weed control in dry bean production in Ontario, Canada. Four experiments were conducted from 2017 to 2019 in southwestern Ontario to compare the efficacy of six soil-applied grass herbicides [trifluralin (600 g ai ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">), ethalfluralin (810 g ai ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">), pendimethalin (1080 g ai ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">), S-metolachlor (1050 g ai ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">), dimethenamid-p (544 g ai ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">) and EPTC (3400 g ai ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">)] and halosulfuron (35 g ai ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">) applied alone and in combination, applied preplant incorporated (PPI), on white bean tolerance and yield, and weed control efficacy. There was no white bean injury from the herbicide treatments eva</span><span style="font-family:Verdana;">luated. Grass herbicides (trifluralin, ethalfluralin, pendimethalin, S-metolachlor</span><span style="font-family:Verdana;"> dimethenamid-P and EPTC) controlled velvetleaf 0% - 82%, pigweeds 87% - 99%, common ragweed 0% - 93%, common lambsquarters 81% - 99%, wild mustard 0% - 71%, barnyardgrass 98% - 100% and green foxtail 98% - 99%. Halosulfuron controlled velvetleaf 98%, pigweeds 94%, common ragweed 90% - 94%, common lambsquarters 97%, wild mustard 98% - 100%, barnyardgrass 19% - 24% and green foxtail 20% - 25%. Tankmixes of halosulfuron with soil-applied grass herbicides provided ≥93% control of the weed species evaluated. Reduction in density and biomass generally followed the same trend as visible control with herbicide treatments evaluated. Weed interference reduced white bean seed yield 70%. Seed yield was 53% - 66% of </span><span style="font-family:Verdana;">the weed-free control with trifluralin, ethalfluralin, pendimethalin, S-metolachlor</span><span style="font-family:Verdana;"> and dimethenamid-P, 81% of the weed-free control with EPTC, 58% of the weed-free control with halosulfuron, and 87% - 95% of the weed-free control with halosulfuron tankmixes with the grass herbicides evaluated. Based on these results, halosulfuron in combination with trifluralin, ethalfluralin, pendimethalin, S-metolachlor, dimethenamid-p and EPTC, applied PPI at rates evaluated, can be used to effectively control common annual grass and broadleaf weeds in white beans.</span></span>展开更多
基金financially supported by National Natural Science Foundation of China(No.61475094)National 973 Program of China(No.2013CB329202)
文摘Simultaneous dimming controlling and data transmission are usually required in a white LED based indoor visible light communication system.However,the diming controlling of LED normally interferes the data transmission due to the modulation nonlinearity of LED.In order to solve this problem,a scheme by separating the LEDs for the functions of dimming control and data transmission respectively is proposed in this paper.In the scheme,the LEDs used for dimming control function are driven by a dc amplified circuit,and the LEDs for data transmission are driven by a digital modulation circuit respectively.In this way,the modulation distortion to the data signal caused by the modulation nonlinearity can be avoided even if the dimming is at high level dc driven current.The proof-of-concept experiment of a 2.5Mbit/s visible light communication system demonstrates that the dimming controlling and data transmission can be realized simultaneously in a simple way,and the data transmission is not affected by the dimming controlling function.Compared to previous methods,the scheme in this paper is simpler and cost effective,and makes sense when high rate data is transmitted in a visible light communication system.
文摘There <span style="font-family:Verdana;">are</span><span style="font-family:Verdana;"> a limited number of soil-applied herbicides available for broad-spectrum</span><span style="font-family:;" "=""><span style="font-family:Verdana;"> weed control in dry bean production in Ontario, Canada. Four experiments were conducted from 2017 to 2019 in southwestern Ontario to compare the efficacy of six soil-applied grass herbicides [trifluralin (600 g ai ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">), ethalfluralin (810 g ai ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">), pendimethalin (1080 g ai ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">), S-metolachlor (1050 g ai ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">), dimethenamid-p (544 g ai ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">) and EPTC (3400 g ai ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">)] and halosulfuron (35 g ai ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">) applied alone and in combination, applied preplant incorporated (PPI), on white bean tolerance and yield, and weed control efficacy. There was no white bean injury from the herbicide treatments eva</span><span style="font-family:Verdana;">luated. Grass herbicides (trifluralin, ethalfluralin, pendimethalin, S-metolachlor</span><span style="font-family:Verdana;"> dimethenamid-P and EPTC) controlled velvetleaf 0% - 82%, pigweeds 87% - 99%, common ragweed 0% - 93%, common lambsquarters 81% - 99%, wild mustard 0% - 71%, barnyardgrass 98% - 100% and green foxtail 98% - 99%. Halosulfuron controlled velvetleaf 98%, pigweeds 94%, common ragweed 90% - 94%, common lambsquarters 97%, wild mustard 98% - 100%, barnyardgrass 19% - 24% and green foxtail 20% - 25%. Tankmixes of halosulfuron with soil-applied grass herbicides provided ≥93% control of the weed species evaluated. Reduction in density and biomass generally followed the same trend as visible control with herbicide treatments evaluated. Weed interference reduced white bean seed yield 70%. Seed yield was 53% - 66% of </span><span style="font-family:Verdana;">the weed-free control with trifluralin, ethalfluralin, pendimethalin, S-metolachlor</span><span style="font-family:Verdana;"> and dimethenamid-P, 81% of the weed-free control with EPTC, 58% of the weed-free control with halosulfuron, and 87% - 95% of the weed-free control with halosulfuron tankmixes with the grass herbicides evaluated. Based on these results, halosulfuron in combination with trifluralin, ethalfluralin, pendimethalin, S-metolachlor, dimethenamid-p and EPTC, applied PPI at rates evaluated, can be used to effectively control common annual grass and broadleaf weeds in white beans.</span></span>
