Introduction Paris polyphylla var. chinensis (Franch.) Hara ( P. polyphylla ) is a perennial medicinal plant with a reputation for therapeutic properties. It is imperative to study the photochemical processes of P. polyphylla in order to determine the optimal levels of shading and moisture management for its cultivation in artificial environments. Methods In this study, six shading levels (no shading, 30%, 50%, 70%, 80% and 90% shading) and three soil water contents (20%, 40% and 60% of the soil water saturation capacity) were established to determine the appropriate shade intensity and soil moisture content for the growth of P. polyphylla . Results The results showed that only the low shade groups (no shade and 30% shade) showed irreversible damage to the daily photosynthetic dynamics of the plant over the course of a day. It is important to note that excessive light can damage not only the quantum yield for electron transport (φDo) and PSII light quantum yield (Fv/Fm), but also various physiological mechanisms that can lead to overall plant damage and a decline in organic matter. A comparison of Fv/Fm during the midday period showed that the optimum shade intensity is between 50% and 70%. Low shading can significantly increase light use efficiency (LUE), but also reduces net photosynthetic rate ( P n) and transpiration ( T r), indicating the negative effect on P. polyphylla growth. Considering the balance between growth rate and damage incidence, 50% shade should be the optimal treatment for P. polyphylla , followed by 30% and 70% shade. It was also observed that treatment with low soil water content (20%) significantly reduced P n and LUE, while increasing stomatal conductance (gs) and water use efficiency (WUE). This is associated with a decrease in the light response curve, indicating that low soil moisture inhibits the growth of P. polyphylla and increases the likelihood of irreversible light damage, so the optimum soil moisture content for P. polyphylla should be above 20%. Discussion Considering the economic benefits and the growth and health of P. polyphylla in artificial cultivation, it is recommended that shade be controlled at around 50% while maintaining soil moisture between 40% and 60% of water content.
In this study, the effects of organic silicon (Si) on the toxicity of imidacloprid to a new invasive mealybug, Phenacoccus solenopsis (Hemiptera: Pseudococcidae), infesting Portulaca grandiflora (Caryophyllales: Portulacaceae) plants were evaluated using spotting and dipping methods under laboratory and field conditions to improve management strategies for solenopsis mealybug. Results showed significant synergistic effects of 0.06% organic Si with imidacloprid solution against third-instar P. solenopsis nymphs and adult females. However, the percentage mortalities increased remarkably after P. solenopsis was exposed to 100, 50, and 25 mg a.i./L of imidacloprid combined with organic Si. For the third-instar nymphs, these values increased to 100%, 100%, and 92.5%, respectively; for the adult females, these values increased to 100%, 100%, and 82.4%, respectively. After 5 days, the percentage mortalities reached 84.7%, 56.1%, and 39.7% when the third-instar nymphs were exposed to 100, 50, and 25 mg a.i./L of imidacloprid solution, respectively. The percentage mortalities reached 57.5%, 38.9%, and 26.2% when adult females were exposed to the same imidacloprid solutions, respectively. Organic Si alone elicited toxicity to P. solenopsis. The percentage mortalities of the first-, second-, and third-instar nymphs and the adult females were 76.9%, 47.5%, 39.2%, and 18.9%, respectively. Field data showed that imidacloprid combined with organic Si caused sustainable control of P. solenopsis. The percentage mortalities of P. solenopsis reached maximum values (approximately 99.9%) after 21 days. Thus, the combined treatment with imidacloprid and organic Si is synergistically more effective than the individual use of these substances against third-instar P. solenopsis nymphs and adult females.
This paper depicts a new concept of MLVR conversion(Multi-Level Voltage Reinjection).and an HVDC link based on MLVR-VSC(voltage Source Converter) terminals is simulated.The simulation results demonstrate that the MLVR-VSC can provide high quality waveforms,achieve high power and high voltage with low power rating and simple extra components,control active and reactive power to benefit the DC link as well as the two AC systems linked by the HVDC link,unity power factor transmission can be achieved.High power AC/DC converters based on forced commutated power switches and capable to provide high quality waveforms and flexible controllability of active and reactive powers for HVDC(High Voltage Direct Current) and FACTS(Flexible AC Transmission System) applications.The forced commutated AC/DC converters for transmission application must be high power and high voltage to suit practical requirements.The multi-level conversion could provide the possibility to increase the power and voltage level,but the complexity of conventional multi-level topologies is increased with the square of the level number,and also the restricts of the active power controllability limit their application in HVDC and FACTS transmissions.
Abstract A series of [PdPyCl 2 ] 2 (di‐NHC) complexes were prepared (di‐NHC are two 1‐(2,6‐dimethylphenyl)imidazolidene molecules bridged by an aliphatic –(CH 2 ) n – linker ( n = 3, 4, 5, 6, and 10)). All complexes were fully characterized by NMR spectroscopy and elemental analyses. The crystal structures of four complexes ( n = 3, 4, 5 and 6) were determined by X‐ray diffraction. The influence of the distant methyl group on the structural features and catalytic activity with increasing of length of linker was investigated by comparing the results of these 2,6‐dimethylphenyl palladium complexes with those of their known mesityl analogues. X‐ray studies show the distant methyl substitution has big impact on the structure feature of the complexes with the shorter linker between two NHC (ethylene and propylene), but has a little or no effect on that of the complexes with longer linker (butylene and hexylene). Catalytic results of the arylation of styrene show that the remote substitute has big effect on the regioselectivity of the product in all complexes with shorter and longer linkers, but has a limited effect on the yield.
One cobalt complex with distorted trigonal antiprismatic geometry was obtained using 2,4,6-tris(di-2-pyridylamine)-1,3,5-triazine (dipyatriz) as the ligand. X-ray crystallography showed the complex possessing a pair of metal centers, had an antiferromagnetic coupling between two Co(ii) ions. Further studied showed a field-induced slow relaxation under Hdc = 0.8 kOe. The peak of out-of-phase was observed after 1000 Hz, which exhibited a moderate slow-relaxation behaviour comparing to the magnetic couple for single Co(ii) complex. This study may provide some strategies on designing new functional molecular magnetic materials with distinct magnetic properties and diverse the structures.
Wireless video surveillance command system is widely used in the public security, transportation, water conservancy, urban management, electrical repair, emergency response projects and other industries. Vehicle-mounted wireless video surveillance system can promptly return the scene to command center using wireless networks. So it is easy for remote visualization, command and control. And it will greatly shorten the reaction time of the accident processing and enhance emergency response capabilities. Mobile evidence obtaining front-end is the most important part of the wireless video surveillance command system. The performance of front-end equipment determines the efficiency of the whole system. So the mobile evidence obtaining front-end is a system design difficult. The following is about the design and implementation of the mobile evidence obtaining front-end of the wireless video surveillance system.
Utilizing already existing DNA-encoded libraries (DELs) for the generation of a distinct DEL represents an expedited strategy for expanding the chemical space. Herein, we leverage the unique photoreactivity of tetrazoles to synthesize diacylhydrazines on DNA. Widely available carboxylic acids serving as building blocks were employed under the mild photomediated reaction conditions, affording diverse DNA-conjugated diacylhydrazines. This methodology also demonstrates robustness in DEL-compatible synthesis and facilitates the preparation of oligonucleotide-based chemical probes.
The Automotive Bus Stop Announcing System was designed,which used infrared sensing technology.It can be directly embedded into the existing bus stop announcing systems,and infrared transmitters were set up in front of the station.The infrared receivers were loaded in each bus,and the announcer was controlled by the received signal,and the phonetics chip could be used to achieve the automatic station report without manual operation.
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)